* lib/getcwd.c (__getcwd): Undo previous change; it mishandled
[gnulib.git] / lib / javacomp.c
index e4d60a1..37d72c2 100644 (file)
@@ -1,5 +1,5 @@
 /* Compile a Java program.
-   Copyright (C) 2001-2003 Free Software Foundation, Inc.
+   Copyright (C) 2001-2003, 2006-2007 Free Software Foundation, Inc.
    Written by Bruno Haible <haible@clisp.cons.org>, 2001.
 
    This program is free software; you can redistribute it and/or modify
    along with this program; if not, write to the Free Software Foundation,
    Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.  */
 
-#ifdef HAVE_CONFIG_H
-# include <config.h>
-#endif
+#include <config.h>
 #include <alloca.h>
 
 /* Specification.  */
 #include "javacomp.h"
 
+#include <errno.h>
+#include <limits.h>
 #include <stdio.h>
 #include <stdlib.h>
 #include <string.h>
+#include <unistd.h>
+#include <sys/types.h>
+#include <sys/stat.h>
 
+#include "javaversion.h"
 #include "execute.h"
 #include "pipe.h"
 #include "wait-process.h"
 #include "classpath.h"
 #include "xsetenv.h"
 #include "sh-quote.h"
+#include "binary-io.h"
 #include "safe-read.h"
 #include "xalloc.h"
 #include "xallocsa.h"
+#include "getline.h"
+#include "pathname.h"
+#include "fwriteerror.h"
+#include "clean-temp.h"
 #include "error.h"
+#include "xvasprintf.h"
+#include "c-strstr.h"
 #include "gettext.h"
 
 #define _(str) gettext (str)
 
+/* The results of open() in this file are not used with fchdir,
+   therefore save some unnecessary work in fchdir.c.  */
+#undef open
+#undef close
+
 
 /* Survey of Java compilers.
 
    this variable can confuse the JDK's javac.
  */
 
-bool
-compile_java_class (const char * const *java_sources,
-                   unsigned int java_sources_count,
-                   const char * const *classpaths,
-                   unsigned int classpaths_count,
-                   const char *directory,
-                   bool optimize, bool debug,
-                   bool use_minimal_classpath,
-                   bool verbose)
+/* Return the default target_version.  */
+static const char *
+default_target_version (void)
 {
-  bool err = false;
-  char *old_JAVA_HOME;
+  /* Use a cache.  Assumes that the PATH environment variable doesn't change
+     during the lifetime of the program.  */
+  static const char *java_version_cache;
+  if (java_version_cache == NULL)
+    {
+      /* Determine the version from the found JVM.  */
+      java_version_cache = javaexec_version ();
+      if (java_version_cache == NULL
+         || !(java_version_cache[0] == '1' && java_version_cache[1] == '.'
+              && (java_version_cache[2] >= '1' && java_version_cache[2] <= '6')
+              && java_version_cache[3] == '\0'))
+       java_version_cache = "1.1";
+    }
+  return java_version_cache;
+}
+
+/* ======================= Source version dependent ======================= */
+
+/* Convert a source version to an index.  */
+#define SOURCE_VERSION_BOUND 3 /* exclusive upper bound */
+static unsigned int
+source_version_index (const char *source_version)
+{
+  if (source_version[0] == '1' && source_version[1] == '.'
+      && (source_version[2] >= '3' && source_version[2] <= '5')
+      && source_version[3] == '\0')
+    return source_version[2] - '3';
+  error (EXIT_FAILURE, 0, _("invalid source_version argument to compile_java_class"));
+  return 0;
+}
+
+/* Return a snippet of code that should compile in the given source version.  */
+static const char *
+get_goodcode_snippet (const char *source_version)
+{
+  if (strcmp (source_version, "1.3") == 0)
+    return "class conftest {}\n";
+  if (strcmp (source_version, "1.4") == 0)
+    return "class conftest { static { assert(true); } }\n";
+  if (strcmp (source_version, "1.5") == 0)
+    return "class conftest<T> { T foo() { return null; } }\n";
+  error (EXIT_FAILURE, 0, _("invalid source_version argument to compile_java_class"));
+  return NULL;
+}
+
+/* Return a snippet of code that should fail to compile in the given source
+   version, or NULL (standing for a snippet that would fail to compile with
+   any compiler).  */
+static const char *
+get_failcode_snippet (const char *source_version)
+{
+  if (strcmp (source_version, "1.3") == 0)
+    return "class conftestfail { static { assert(true); } }\n";
+  if (strcmp (source_version, "1.4") == 0)
+    return "class conftestfail<T> { T foo() { return null; } }\n";
+  if (strcmp (source_version, "1.5") == 0)
+    return NULL;
+  error (EXIT_FAILURE, 0, _("invalid source_version argument to compile_java_class"));
+  return NULL;
+}
+
+/* ======================= Target version dependent ======================= */
+
+/* Convert a target version to an index.  */
+#define TARGET_VERSION_BOUND 6 /* exclusive upper bound */
+static unsigned int
+target_version_index (const char *target_version)
+{
+  if (target_version[0] == '1' && target_version[1] == '.'
+      && (target_version[2] >= '1' && target_version[2] <= '6')
+      && target_version[3] == '\0')
+    return target_version[2] - '1';
+  error (EXIT_FAILURE, 0, _("invalid target_version argument to compile_java_class"));
+  return 0;
+}
+
+/* Return the class file version number corresponding to a given target
+   version.  */
+static int
+corresponding_classfile_version (const char *target_version)
+{
+  if (strcmp (target_version, "1.1") == 0)
+    return 45;
+  if (strcmp (target_version, "1.2") == 0)
+    return 46;
+  if (strcmp (target_version, "1.3") == 0)
+    return 47;
+  if (strcmp (target_version, "1.4") == 0)
+    return 48;
+  if (strcmp (target_version, "1.5") == 0)
+    return 49;
+  if (strcmp (target_version, "1.6") == 0)
+    return 50;
+  error (EXIT_FAILURE, 0, _("invalid target_version argument to compile_java_class"));
+  return 0;
+}
+
+/* ======================== Compilation subroutines ======================== */
+
+/* Try to compile a set of Java sources with $JAVAC.
+   Return a failure indicator (true upon error).  */
+static bool
+compile_using_envjavac (const char *javac,
+                       const char * const *java_sources,
+                       unsigned int java_sources_count,
+                       const char *directory,
+                       bool optimize, bool debug,
+                       bool verbose, bool null_stderr)
+{
+  /* Because $JAVAC may consist of a command and options, we use the
+     shell.  Because $JAVAC has been set by the user, we leave all
+     environment variables in place, including JAVA_HOME, and we don't
+     erase the user's CLASSPATH.  */
+  bool err;
+  unsigned int command_length;
+  char *command;
+  char *argv[4];
+  int exitstatus;
+  unsigned int i;
+  char *p;
+
+  command_length = strlen (javac);
+  if (optimize)
+    command_length += 3;
+  if (debug)
+    command_length += 3;
+  if (directory != NULL)
+    command_length += 4 + shell_quote_length (directory);
+  for (i = 0; i < java_sources_count; i++)
+    command_length += 1 + shell_quote_length (java_sources[i]);
+  command_length += 1;
+
+  command = (char *) xallocsa (command_length);
+  p = command;
+  /* Don't shell_quote $JAVAC, because it may consist of a command
+     and options.  */
+  memcpy (p, javac, strlen (javac));
+  p += strlen (javac);
+  if (optimize)
+    {
+      memcpy (p, " -O", 3);
+      p += 3;
+    }
+  if (debug)
+    {
+      memcpy (p, " -g", 3);
+      p += 3;
+    }
+  if (directory != NULL)
+    {
+      memcpy (p, " -d ", 4);
+      p += 4;
+      p = shell_quote_copy (p, directory);
+    }
+  for (i = 0; i < java_sources_count; i++)
+    {
+      *p++ = ' ';
+      p = shell_quote_copy (p, java_sources[i]);
+    }
+  *p++ = '\0';
+  /* Ensure command_length was correctly calculated.  */
+  if (p - command > command_length)
+    abort ();
+
+  if (verbose)
+    printf ("%s\n", command);
+
+  argv[0] = "/bin/sh";
+  argv[1] = "-c";
+  argv[2] = command;
+  argv[3] = NULL;
+  exitstatus = execute (javac, "/bin/sh", argv, false, false, false,
+                       null_stderr, true, true);
+  err = (exitstatus != 0);
+
+  freesa (command);
+
+  return err;
+}
+
+/* Try to compile a set of Java sources with gcj.
+   Return a failure indicator (true upon error).  */
+static bool
+compile_using_gcj (const char * const *java_sources,
+                  unsigned int java_sources_count,
+                  bool no_assert_option,
+                  bool fsource_option, const char *source_version,
+                  bool ftarget_option, const char *target_version,
+                  const char *directory,
+                  bool optimize, bool debug,
+                  bool verbose, bool null_stderr)
+{
+  bool err;
+  unsigned int argc;
+  char **argv;
+  char **argp;
+  char *fsource_arg;
+  char *ftarget_arg;
+  int exitstatus;
+  unsigned int i;
+
+  argc =
+    2 + (no_assert_option ? 1 : 0) + (fsource_option ? 1 : 0)
+    + (ftarget_option ? 1 : 0) + (optimize ? 1 : 0) + (debug ? 1 : 0)
+    + (directory != NULL ? 2 : 0) + java_sources_count;
+  argv = (char **) xallocsa ((argc + 1) * sizeof (char *));
+
+  argp = argv;
+  *argp++ = "gcj";
+  *argp++ = "-C";
+  if (no_assert_option)
+    *argp++ = "-fno-assert";
+  if (fsource_option)
+    {
+      fsource_arg = (char *) xallocsa (9 + strlen (source_version) + 1);
+      memcpy (fsource_arg, "-fsource=", 9);
+      strcpy (fsource_arg + 9, source_version);
+      *argp++ = fsource_arg;
+    }
+  else
+    fsource_arg = NULL;
+  if (ftarget_option)
+    {
+      ftarget_arg = (char *) xallocsa (9 + strlen (target_version) + 1);
+      memcpy (ftarget_arg, "-ftarget=", 9);
+      strcpy (ftarget_arg + 9, target_version);
+      *argp++ = ftarget_arg;
+    }
+  else
+    ftarget_arg = NULL;
+  if (optimize)
+    *argp++ = "-O";
+  if (debug)
+    *argp++ = "-g";
+  if (directory != NULL)
+    {
+      *argp++ = "-d";
+      *argp++ = (char *) directory;
+    }
+  for (i = 0; i < java_sources_count; i++)
+    *argp++ = (char *) java_sources[i];
+  *argp = NULL;
+  /* Ensure argv length was correctly calculated.  */
+  if (argp - argv != argc)
+    abort ();
+
+  if (verbose)
+    {
+      char *command = shell_quote_argv (argv);
+      printf ("%s\n", command);
+      free (command);
+    }
+
+  exitstatus = execute ("gcj", "gcj", argv, false, false, false, null_stderr,
+                       true, true);
+  err = (exitstatus != 0);
+
+  if (ftarget_arg != NULL)
+    freesa (ftarget_arg);
+  if (fsource_arg != NULL)
+    freesa (fsource_arg);
+  freesa (argv);
+
+  return err;
+}
+
+/* Try to compile a set of Java sources with javac.
+   Return a failure indicator (true upon error).  */
+static bool
+compile_using_javac (const char * const *java_sources,
+                    unsigned int java_sources_count,
+                    bool source_option, const char *source_version,
+                    bool target_option, const char *target_version,
+                    const char *directory,
+                    bool optimize, bool debug,
+                    bool verbose, bool null_stderr)
+{
+  bool err;
+  unsigned int argc;
+  char **argv;
+  char **argp;
+  int exitstatus;
+  unsigned int i;
+
+  argc =
+    1 + (source_option ? 2 : 0) + (target_option ? 2 : 0) + (optimize ? 1 : 0)
+    + (debug ? 1 : 0) + (directory != NULL ? 2 : 0) + java_sources_count;
+  argv = (char **) xallocsa ((argc + 1) * sizeof (char *));
+
+  argp = argv;
+  *argp++ = "javac";
+  if (source_option)
+    {
+      *argp++ = "-source";
+      *argp++ = (char *) source_version;
+    }
+  if (target_option)
+    {
+      *argp++ = "-target";
+      *argp++ = (char *) target_version;
+    }
+  if (optimize)
+    *argp++ = "-O";
+  if (debug)
+    *argp++ = "-g";
+  if (directory != NULL)
+    {
+      *argp++ = "-d";
+      *argp++ = (char *) directory;
+    }
+  for (i = 0; i < java_sources_count; i++)
+    *argp++ = (char *) java_sources[i];
+  *argp = NULL;
+  /* Ensure argv length was correctly calculated.  */
+  if (argp - argv != argc)
+    abort ();
+
+  if (verbose)
+    {
+      char *command = shell_quote_argv (argv);
+      printf ("%s\n", command);
+      free (command);
+    }
+
+  exitstatus = execute ("javac", "javac", argv, false, false, false,
+                       null_stderr, true, true);
+  err = (exitstatus != 0);
+
+  freesa (argv);
+
+  return err;
+}
+
+/* Try to compile a set of Java sources with jikes.
+   Return a failure indicator (true upon error).  */
+static bool
+compile_using_jikes (const char * const *java_sources,
+                    unsigned int java_sources_count,
+                    const char *directory,
+                    bool optimize, bool debug,
+                    bool verbose, bool null_stderr)
+{
+  bool err;
+  unsigned int argc;
+  char **argv;
+  char **argp;
+  int exitstatus;
+  unsigned int i;
+
+  argc =
+    1 + (optimize ? 1 : 0) + (debug ? 1 : 0) + (directory != NULL ? 2 : 0)
+    + java_sources_count;
+  argv = (char **) xallocsa ((argc + 1) * sizeof (char *));
+
+  argp = argv;
+  *argp++ = "jikes";
+  if (optimize)
+    *argp++ = "-O";
+  if (debug)
+    *argp++ = "-g";
+  if (directory != NULL)
+    {
+      *argp++ = "-d";
+      *argp++ = (char *) directory;
+    }
+  for (i = 0; i < java_sources_count; i++)
+    *argp++ = (char *) java_sources[i];
+  *argp = NULL;
+  /* Ensure argv length was correctly calculated.  */
+  if (argp - argv != argc)
+    abort ();
+
+  if (verbose)
+    {
+      char *command = shell_quote_argv (argv);
+      printf ("%s\n", command);
+      free (command);
+    }
+
+  exitstatus = execute ("jikes", "jikes", argv, false, false, false,
+                       null_stderr, true, true);
+  err = (exitstatus != 0);
+
+  freesa (argv);
+
+  return err;
+}
+
+/* ====================== Usability test subroutines ====================== */
+
+/* Write a given contents to a temporary file.
+   FILE_NAME is the name of a file inside TMPDIR that is known not to exist
+   yet.
+   Return a failure indicator (true upon error).  */
+static bool
+write_temp_file (struct temp_dir *tmpdir, const char *file_name,
+                const char *contents)
+{
+  FILE *fp;
+
+  register_temp_file (tmpdir, file_name);
+  fp = fopen_temp (file_name, "w");
+  if (fp == NULL)
+    {
+      error (0, errno, _("failed to create \"%s\""), file_name);
+      unregister_temp_file (tmpdir, file_name);
+      return true;
+    }
+  fputs (contents, fp);
+  if (fwriteerror_temp (fp))
+    {
+      error (0, errno, _("error while writing \"%s\" file"), file_name);
+      return true;
+    }
+  return false;
+}
+
+/* Return the class file version number of a class file on disk.  */
+static int
+get_classfile_version (const char *compiled_file_name)
+{
+  unsigned char header[8];
+  int fd;
+
+  /* Open the class file.  */
+  fd = open (compiled_file_name, O_RDONLY | O_BINARY, 0);
+  if (fd >= 0)
+    {
+      /* Read its first 8 bytes.  */
+      if (safe_read (fd, header, 8) == 8)
+       {
+         /* Verify the class file signature.  */
+         if (header[0] == 0xCA && header[1] == 0xFE
+             && header[2] == 0xBA && header[3] == 0xBE)
+           return header[7];
+       }
+      close (fd);
+    }
+
+  /* Could not get the class file version.  Return a very large one.  */
+  return INT_MAX;
+}
+
+/* Return true if $JAVAC is a version of gcj.  */
+static bool
+is_envjavac_gcj (const char *javac)
+{
+  static bool envjavac_tested;
+  static bool envjavac_gcj;
+
+  if (!envjavac_tested)
+    {
+      /* Test whether $JAVAC is gcj:
+        "$JAVAC --version 2>/dev/null | sed -e 1q | grep gcj > /dev/null"  */
+      unsigned int command_length;
+      char *command;
+      char *argv[4];
+      pid_t child;
+      int fd[1];
+      FILE *fp;
+      char *line;
+      size_t linesize;
+      size_t linelen;
+      int exitstatus;
+      char *p;
+
+      /* Setup the command "$JAVAC --version".  */
+      command_length = strlen (javac) + 1 + 9 + 1;
+      command = (char *) xallocsa (command_length);
+      p = command;
+      /* Don't shell_quote $JAVAC, because it may consist of a command
+        and options.  */
+      memcpy (p, javac, strlen (javac));
+      p += strlen (javac);
+      memcpy (p, " --version", 1 + 9 + 1);
+      p += 1 + 9 + 1;
+      /* Ensure command_length was correctly calculated.  */
+      if (p - command > command_length)
+       abort ();
+
+      /* Call $JAVAC --version 2>/dev/null.  */
+      argv[0] = "/bin/sh";
+      argv[1] = "-c";
+      argv[2] = command;
+      argv[3] = NULL;
+      child = create_pipe_in (javac, "/bin/sh", argv, DEV_NULL, true, true,
+                             false, fd);
+      if (child == -1)
+       goto failed;
+
+      /* Retrieve its result.  */
+      fp = fdopen (fd[0], "r");
+      if (fp == NULL)
+       goto failed;
+
+      line = NULL; linesize = 0;
+      linelen = getline (&line, &linesize, fp);
+      if (linelen == (size_t)(-1))
+       {
+         fclose (fp);
+         goto failed;
+       }
+      /* It is safe to call c_strstr() instead of strstr() here; see the
+        comments in c-strstr.h.  */
+      envjavac_gcj = (c_strstr (line, "gcj") != NULL);
+
+      fclose (fp);
+
+      /* Remove zombie process from process list, and retrieve exit status.  */
+      exitstatus = wait_subprocess (child, javac, true, true, true, false);
+      if (exitstatus != 0)
+       envjavac_gcj = false;
+
+     failed:
+      freesa (command);
+
+      envjavac_tested = true;
+    }
+
+  return envjavac_gcj;
+}
+
+/* Return true if $JAVAC, known to be a version of gcj, is a version >= 4.3
+   of gcj.  */
+static bool
+is_envjavac_gcj43 (const char *javac)
+{
+  static bool envjavac_tested;
+  static bool envjavac_gcj43;
+
+  if (!envjavac_tested)
+    {
+      /* Test whether $JAVAC is gcj:
+        "$JAVAC --version 2>/dev/null | sed -e 's,^[^0-9]*,,' -e 1q \
+         | sed -e '/^4\.[012]/d' | grep '^[4-9]' >/dev/null"  */
+      unsigned int command_length;
+      char *command;
+      char *argv[4];
+      pid_t child;
+      int fd[1];
+      FILE *fp;
+      char *line;
+      size_t linesize;
+      size_t linelen;
+      int exitstatus;
+      char *p;
+
+      /* Setup the command "$JAVAC --version".  */
+      command_length = strlen (javac) + 1 + 9 + 1;
+      command = (char *) xallocsa (command_length);
+      p = command;
+      /* Don't shell_quote $JAVAC, because it may consist of a command
+        and options.  */
+      memcpy (p, javac, strlen (javac));
+      p += strlen (javac);
+      memcpy (p, " --version", 1 + 9 + 1);
+      p += 1 + 9 + 1;
+      /* Ensure command_length was correctly calculated.  */
+      if (p - command > command_length)
+       abort ();
+
+      /* Call $JAVAC --version 2>/dev/null.  */
+      argv[0] = "/bin/sh";
+      argv[1] = "-c";
+      argv[2] = command;
+      argv[3] = NULL;
+      child = create_pipe_in (javac, "/bin/sh", argv, DEV_NULL, true, true,
+                             false, fd);
+      if (child == -1)
+       goto failed;
+
+      /* Retrieve its result.  */
+      fp = fdopen (fd[0], "r");
+      if (fp == NULL)
+       goto failed;
+
+      line = NULL; linesize = 0;
+      linelen = getline (&line, &linesize, fp);
+      if (linelen == (size_t)(-1))
+       {
+         fclose (fp);
+         goto failed;
+       }
+      p = line;
+      while (*p != '\0' && !(*p >= '0' && *p <= '9'))
+       p++;
+      envjavac_gcj43 =
+        !(*p == '4' && p[1] == '.' && p[2] >= '0' && p[2] <= '2')
+       && (*p >= '4' && *p <= '9');
+
+      fclose (fp);
+
+      /* Remove zombie process from process list, and retrieve exit status.  */
+      exitstatus = wait_subprocess (child, javac, true, true, true, false);
+      if (exitstatus != 0)
+       envjavac_gcj43 = false;
+
+     failed:
+      freesa (command);
+
+      envjavac_tested = true;
+    }
+
+  return envjavac_gcj43;
+}
 
+/* Test whether $JAVAC, known to be a version of gcj >= 4.3, can be used, and
+   whether it needs a -fsource and/or -ftarget option.
+   Return a failure indicator (true upon error).  */
+static bool
+is_envjavac_gcj43_usable (const char *javac,
+                         const char *source_version,
+                         const char *target_version,
+                         bool *usablep,
+                         bool *fsource_option_p, bool *ftarget_option_p)
+{
+  /* The cache depends on the source_version and target_version.  */
+  struct result_t
   {
-    const char *javac = getenv ("JAVAC");
-    if (javac != NULL && javac[0] != '\0')
-      {
-       /* Because $JAVAC may consist of a command and options, we use the
-          shell.  Because $JAVAC has been set by the user, we leave all
-          all environment variables in place, including JAVA_HOME, and
-          we don't erase the user's CLASSPATH.  */
-       char *old_classpath;
-       unsigned int command_length;
-       char *command;
-       char *argv[4];
-       int exitstatus;
-       unsigned int i;
-       char *p;
-
-       /* Set CLASSPATH.  */
-       old_classpath =
-         set_classpath (classpaths, classpaths_count, false,
-                        verbose);
-
-       command_length = strlen (javac);
-       if (optimize)
-         command_length += 3;
-       if (debug)
-         command_length += 3;
-       if (directory != NULL)
-         command_length += 4 + shell_quote_length (directory);
-       for (i = 0; i < java_sources_count; i++)
-         command_length += 1 + shell_quote_length (java_sources[i]);
-       command_length += 1;
-
-       command = (char *) xallocsa (command_length);
-       p = command;
-       /* Don't shell_quote $JAVAC, because it may consist of a command
-          and options.  */
-       memcpy (p, javac, strlen (javac));
-       p += strlen (javac);
-       if (optimize)
-         {
-           memcpy (p, " -O", 3);
-           p += 3;
-         }
-       if (debug)
-         {
-           memcpy (p, " -g", 3);
-           p += 3;
-         }
-       if (directory != NULL)
-         {
-           memcpy (p, " -d ", 4);
-           p += 4;
-           p = shell_quote_copy (p, directory);
-         }
-       for (i = 0; i < java_sources_count; i++)
-         {
-           *p++ = ' ';
-           p = shell_quote_copy (p, java_sources[i]);
-         }
-       *p++ = '\0';
-       /* Ensure command_length was correctly calculated.  */
-       if (p - command > command_length)
-         abort ();
+    bool tested;
+    bool usable;
+    bool fsource_option;
+    bool ftarget_option;
+  };
+  static struct result_t result_cache[SOURCE_VERSION_BOUND][TARGET_VERSION_BOUND];
+  struct result_t *resultp;
+
+  resultp = &result_cache[source_version_index (source_version)]
+                        [target_version_index (target_version)];
+  if (!resultp->tested)
+    {
+      /* Try $JAVAC.  */
+      struct temp_dir *tmpdir;
+      char *conftest_file_name;
+      char *compiled_file_name;
+      const char *java_sources[1];
+      struct stat statbuf;
+
+      tmpdir = create_temp_dir ("java", NULL, false);
+      if (tmpdir == NULL)
+       return true;
+
+      conftest_file_name =
+       concatenated_pathname (tmpdir->dir_name, "conftest.java", NULL);
+      if (write_temp_file (tmpdir, conftest_file_name,
+                          get_goodcode_snippet (source_version)))
+       {
+         free (conftest_file_name);
+         cleanup_temp_dir (tmpdir);
+         return true;
+       }
+
+      compiled_file_name =
+       concatenated_pathname (tmpdir->dir_name, "conftest.class", NULL);
+      register_temp_file (tmpdir, compiled_file_name);
+
+      java_sources[0] = conftest_file_name;
+      if (!compile_using_envjavac (javac,
+                                  java_sources, 1, tmpdir->dir_name,
+                                  false, false, false, true)
+         && stat (compiled_file_name, &statbuf) >= 0
+         && get_classfile_version (compiled_file_name)
+            <= corresponding_classfile_version (target_version))
+       {
+         /* $JAVAC compiled conftest.java successfully.  */
+         /* Try adding -fsource option if it is useful.  */
+         char *javac_source =
+           xasprintf ("%s -fsource=%s", javac, source_version);
+
+         unlink (compiled_file_name);
+
+         java_sources[0] = conftest_file_name;
+         if (!compile_using_envjavac (javac_source,
+                                      java_sources, 1, tmpdir->dir_name,
+                                      false, false, false, true)
+             && stat (compiled_file_name, &statbuf) >= 0
+             && get_classfile_version (compiled_file_name)
+                <= corresponding_classfile_version (target_version))
+           {
+             const char *failcode = get_failcode_snippet (source_version);
+
+             if (failcode != NULL)
+               {
+                 free (compiled_file_name);
+                 free (conftest_file_name);
+
+                 conftest_file_name =
+                   concatenated_pathname (tmpdir->dir_name,
+                                          "conftestfail.java",
+                                          NULL);
+                 if (write_temp_file (tmpdir, conftest_file_name, failcode))
+                   {
+                     free (conftest_file_name);
+                     free (javac_source);
+                     cleanup_temp_dir (tmpdir);
+                     return true;
+                   }
+
+                 compiled_file_name =
+                   concatenated_pathname (tmpdir->dir_name,
+                                          "conftestfail.class",
+                                          NULL);
+                 register_temp_file (tmpdir, compiled_file_name);
+
+                 java_sources[0] = conftest_file_name;
+                 if (!compile_using_envjavac (javac,
+                                              java_sources, 1,
+                                              tmpdir->dir_name,
+                                              false, false, false, true)
+                     && stat (compiled_file_name, &statbuf) >= 0)
+                   {
+                     unlink (compiled_file_name);
+
+                     java_sources[0] = conftest_file_name;
+                     if (compile_using_envjavac (javac_source,
+                                                 java_sources, 1,
+                                                 tmpdir->dir_name,
+                                                 false, false, false, true))
+                       /* $JAVAC compiled conftestfail.java successfully, and
+                          "$JAVAC -fsource=$source_version" rejects it.  So
+                          the -fsource option is useful.  */
+                       resultp->fsource_option = true;
+                   }
+               }
+           }
+
+         free (javac_source);
+
+         resultp->usable = true;
+       }
+      else
+       {
+         /* Try with -fsource and -ftarget options.  */
+         char *javac_target =
+           xasprintf ("%s -fsource=%s -ftarget=%s",
+                      javac, source_version, target_version);
+
+         unlink (compiled_file_name);
+
+         java_sources[0] = conftest_file_name;
+         if (!compile_using_envjavac (javac_target,
+                                      java_sources, 1, tmpdir->dir_name,
+                                      false, false, false, true)
+             && stat (compiled_file_name, &statbuf) >= 0
+             && get_classfile_version (compiled_file_name)
+                <= corresponding_classfile_version (target_version))
+           {
+             /* "$JAVAC -fsource $source_version -ftarget $target_version"
+                compiled conftest.java successfully.  */
+             resultp->fsource_option = true;
+             resultp->ftarget_option = true;
+             resultp->usable = true;
+           }
+
+         free (javac_target);
+       }
+
+      free (compiled_file_name);
+      free (conftest_file_name);
+
+      resultp->tested = true;
+    }
 
-       if (verbose)
-         printf ("%s\n", command);
+  *usablep = resultp->usable;
+  *fsource_option_p = resultp->fsource_option;
+  *ftarget_option_p = resultp->ftarget_option;
+  return false;
+}
 
-       argv[0] = "/bin/sh";
-       argv[1] = "-c";
-       argv[2] = command;
-       argv[3] = NULL;
-       exitstatus = execute (javac, "/bin/sh", argv, false, false, false,
-                             false, true, true);
-       err = (exitstatus != 0);
+/* Test whether $JAVAC, known to be a version of gcj < 4.3, can be used for
+   compiling with target_version = 1.4 and source_version = 1.4.
+   Return a failure indicator (true upon error).  */
+static bool
+is_envjavac_oldgcj_14_14_usable (const char *javac, bool *usablep)
+{
+  static bool envjavac_tested;
+  static bool envjavac_usable;
 
-       freesa (command);
+  if (!envjavac_tested)
+    {
+      /* Try $JAVAC.  */
+      struct temp_dir *tmpdir;
+      char *conftest_file_name;
+      char *compiled_file_name;
+      const char *java_sources[1];
+      struct stat statbuf;
+
+      tmpdir = create_temp_dir ("java", NULL, false);
+      if (tmpdir == NULL)
+       return true;
+
+      conftest_file_name =
+       concatenated_pathname (tmpdir->dir_name, "conftest.java", NULL);
+      if (write_temp_file (tmpdir, conftest_file_name,
+                          get_goodcode_snippet ("1.4")))
+       {
+         free (conftest_file_name);
+         cleanup_temp_dir (tmpdir);
+         return true;
+       }
+
+      compiled_file_name =
+       concatenated_pathname (tmpdir->dir_name, "conftest.class", NULL);
+      register_temp_file (tmpdir, compiled_file_name);
+
+      java_sources[0] = conftest_file_name;
+      if (!compile_using_envjavac (javac, java_sources, 1, tmpdir->dir_name,
+                                  false, false, false, true)
+         && stat (compiled_file_name, &statbuf) >= 0)
+       /* Compilation succeeded.  */
+       envjavac_usable = true;
+
+      free (compiled_file_name);
+      free (conftest_file_name);
+
+      cleanup_temp_dir (tmpdir);
+
+      envjavac_tested = true;
+    }
 
-       /* Reset CLASSPATH.  */
-       reset_classpath (old_classpath);
+  *usablep = envjavac_usable;
+  return false;
+}
 
-       goto done1;
-      }
-  }
+/* Test whether $JAVAC, known to be a version of gcj < 4.3, can be used for
+   compiling with target_version = 1.4 and source_version = 1.3.
+   Return a failure indicator (true upon error).  */
+static bool
+is_envjavac_oldgcj_14_13_usable (const char *javac,
+                             bool *usablep, bool *need_no_assert_option_p)
+{
+  static bool envjavac_tested;
+  static bool envjavac_usable;
+  static bool envjavac_need_no_assert_option;
 
-  /* Unset the JAVA_HOME environment variable.  */
-  old_JAVA_HOME = getenv ("JAVA_HOME");
-  if (old_JAVA_HOME != NULL)
+  if (!envjavac_tested)
     {
-      old_JAVA_HOME = xstrdup (old_JAVA_HOME);
-      unsetenv ("JAVA_HOME");
+      /* Try $JAVAC and "$JAVAC -fno-assert".  But add -fno-assert only if
+        it makes a difference.  (It could already be part of $JAVAC.)  */
+      struct temp_dir *tmpdir;
+      char *conftest_file_name;
+      char *compiled_file_name;
+      const char *java_sources[1];
+      struct stat statbuf;
+      bool javac_works;
+      char *javac_noassert;
+      bool javac_noassert_works;
+
+      tmpdir = create_temp_dir ("java", NULL, false);
+      if (tmpdir == NULL)
+       return true;
+
+      conftest_file_name =
+       concatenated_pathname (tmpdir->dir_name, "conftest.java", NULL);
+      if (write_temp_file (tmpdir, conftest_file_name,
+                          get_goodcode_snippet ("1.3")))
+       {
+         free (conftest_file_name);
+         cleanup_temp_dir (tmpdir);
+         return true;
+       }
+
+      compiled_file_name =
+       concatenated_pathname (tmpdir->dir_name, "conftest.class", NULL);
+      register_temp_file (tmpdir, compiled_file_name);
+
+      java_sources[0] = conftest_file_name;
+      if (!compile_using_envjavac (javac,
+                                  java_sources, 1, tmpdir->dir_name,
+                                  false, false, false, true)
+         && stat (compiled_file_name, &statbuf) >= 0)
+       /* Compilation succeeded.  */
+       javac_works = true;
+      else
+       javac_works = false;
+
+      unlink (compiled_file_name);
+
+      javac_noassert = xasprintf ("%s -fno-assert", javac);
+
+      java_sources[0] = conftest_file_name;
+      if (!compile_using_envjavac (javac_noassert,
+                                  java_sources, 1, tmpdir->dir_name,
+                                  false, false, false, true)
+         && stat (compiled_file_name, &statbuf) >= 0)
+       /* Compilation succeeded.  */
+       javac_noassert_works = true;
+      else
+       javac_noassert_works = false;
+
+      free (compiled_file_name);
+      free (conftest_file_name);
+
+      if (javac_works && javac_noassert_works)
+       {
+         conftest_file_name =
+           concatenated_pathname (tmpdir->dir_name, "conftestfail.java",
+                                  NULL);
+         if (write_temp_file (tmpdir, conftest_file_name,
+                              get_failcode_snippet ("1.3")))
+           {
+             free (conftest_file_name);
+             free (javac_noassert);
+             cleanup_temp_dir (tmpdir);
+             return true;
+           }
+
+         compiled_file_name =
+           concatenated_pathname (tmpdir->dir_name, "conftestfail.class",
+                                  NULL);
+         register_temp_file (tmpdir, compiled_file_name);
+
+         java_sources[0] = conftest_file_name;
+         if (!compile_using_envjavac (javac,
+                                      java_sources, 1, tmpdir->dir_name,
+                                      false, false, false, true)
+             && stat (compiled_file_name, &statbuf) >= 0)
+           {
+             /* Compilation succeeded.  */
+             unlink (compiled_file_name);
+
+             java_sources[0] = conftest_file_name;
+             if (!(!compile_using_envjavac (javac_noassert,
+                                            java_sources, 1, tmpdir->dir_name,
+                                            false, false, false, true)
+                   && stat (compiled_file_name, &statbuf) >= 0))
+               /* Compilation failed.  */
+               /* "$JAVAC -fno-assert" works better than $JAVAC.  */
+               javac_works = true;
+           }
+
+         free (compiled_file_name);
+         free (conftest_file_name);
+       }
+
+      cleanup_temp_dir (tmpdir);
+
+      if (javac_works)
+       {
+         envjavac_usable = true;
+         envjavac_need_no_assert_option = false;
+       }
+      else if (javac_noassert_works)
+       {
+         envjavac_usable = true;
+         envjavac_need_no_assert_option = true;
+       }
+
+      envjavac_tested = true;
     }
 
+  *usablep = envjavac_usable;
+  *need_no_assert_option_p = envjavac_need_no_assert_option;
+  return false;
+}
+
+/* Test whether $JAVAC, known to be not a version of gcj, can be used, and
+   whether it needs a -source and/or -target option.
+   Return a failure indicator (true upon error).  */
+static bool
+is_envjavac_nongcj_usable (const char *javac,
+                          const char *source_version,
+                          const char *target_version,
+                          bool *usablep,
+                          bool *source_option_p, bool *target_option_p)
+{
+  /* The cache depends on the source_version and target_version.  */
+  struct result_t
   {
-    static bool gcj_tested;
-    static bool gcj_present;
+    bool tested;
+    bool usable;
+    bool source_option;
+    bool target_option;
+  };
+  static struct result_t result_cache[SOURCE_VERSION_BOUND][TARGET_VERSION_BOUND];
+  struct result_t *resultp;
+
+  resultp = &result_cache[source_version_index (source_version)]
+                        [target_version_index (target_version)];
+  if (!resultp->tested)
+    {
+      /* Try $JAVAC.  */
+      struct temp_dir *tmpdir;
+      char *conftest_file_name;
+      char *compiled_file_name;
+      const char *java_sources[1];
+      struct stat statbuf;
+
+      tmpdir = create_temp_dir ("java", NULL, false);
+      if (tmpdir == NULL)
+       return true;
+
+      conftest_file_name =
+       concatenated_pathname (tmpdir->dir_name, "conftest.java", NULL);
+      if (write_temp_file (tmpdir, conftest_file_name,
+                          get_goodcode_snippet (source_version)))
+       {
+         free (conftest_file_name);
+         cleanup_temp_dir (tmpdir);
+         return true;
+       }
+
+      compiled_file_name =
+       concatenated_pathname (tmpdir->dir_name, "conftest.class", NULL);
+      register_temp_file (tmpdir, compiled_file_name);
+
+      java_sources[0] = conftest_file_name;
+      if (!compile_using_envjavac (javac,
+                                  java_sources, 1, tmpdir->dir_name,
+                                  false, false, false, true)
+         && stat (compiled_file_name, &statbuf) >= 0
+         && get_classfile_version (compiled_file_name)
+            <= corresponding_classfile_version (target_version))
+       {
+         /* $JAVAC compiled conftest.java successfully.  */
+         /* Try adding -source option if it is useful.  */
+         char *javac_source =
+           xasprintf ("%s -source %s", javac, source_version);
+
+         unlink (compiled_file_name);
+
+         java_sources[0] = conftest_file_name;
+         if (!compile_using_envjavac (javac_source,
+                                      java_sources, 1, tmpdir->dir_name,
+                                      false, false, false, true)
+             && stat (compiled_file_name, &statbuf) >= 0
+             && get_classfile_version (compiled_file_name)
+                <= corresponding_classfile_version (target_version))
+           {
+             const char *failcode = get_failcode_snippet (source_version);
+
+             if (failcode != NULL)
+               {
+                 free (compiled_file_name);
+                 free (conftest_file_name);
+
+                 conftest_file_name =
+                   concatenated_pathname (tmpdir->dir_name,
+                                          "conftestfail.java",
+                                          NULL);
+                 if (write_temp_file (tmpdir, conftest_file_name, failcode))
+                   {
+                     free (conftest_file_name);
+                     free (javac_source);
+                     cleanup_temp_dir (tmpdir);
+                     return true;
+                   }
+
+                 compiled_file_name =
+                   concatenated_pathname (tmpdir->dir_name,
+                                          "conftestfail.class",
+                                          NULL);
+                 register_temp_file (tmpdir, compiled_file_name);
+
+                 java_sources[0] = conftest_file_name;
+                 if (!compile_using_envjavac (javac,
+                                              java_sources, 1,
+                                              tmpdir->dir_name,
+                                              false, false, false, true)
+                     && stat (compiled_file_name, &statbuf) >= 0)
+                   {
+                     unlink (compiled_file_name);
+
+                     java_sources[0] = conftest_file_name;
+                     if (compile_using_envjavac (javac_source,
+                                                 java_sources, 1,
+                                                 tmpdir->dir_name,
+                                                 false, false, false, true))
+                       /* $JAVAC compiled conftestfail.java successfully, and
+                          "$JAVAC -source $source_version" rejects it.  So the
+                          -source option is useful.  */
+                       resultp->source_option = true;
+                   }
+               }
+           }
+
+         free (javac_source);
+
+         resultp->usable = true;
+       }
+      else
+       {
+         /* Try with -target option alone. (Sun javac 1.3.1 has the -target
+            option but no -source option.)  */
+         char *javac_target =
+           xasprintf ("%s -target %s", javac, target_version);
+
+         unlink (compiled_file_name);
+
+         java_sources[0] = conftest_file_name;
+         if (!compile_using_envjavac (javac_target,
+                                      java_sources, 1, tmpdir->dir_name,
+                                      false, false, false, true)
+             && stat (compiled_file_name, &statbuf) >= 0
+             && get_classfile_version (compiled_file_name)
+                <= corresponding_classfile_version (target_version))
+           {
+             /* "$JAVAC -target $target_version" compiled conftest.java
+                successfully.  */
+             /* Try adding -source option if it is useful.  */
+             char *javac_target_source =
+               xasprintf ("%s -source %s", javac_target, source_version);
+
+             unlink (compiled_file_name);
+
+             java_sources[0] = conftest_file_name;
+             if (!compile_using_envjavac (javac_target_source,
+                                          java_sources, 1, tmpdir->dir_name,
+                                          false, false, false, true)
+                 && stat (compiled_file_name, &statbuf) >= 0
+                 && get_classfile_version (compiled_file_name)
+                    <= corresponding_classfile_version (target_version))
+               {
+                 const char *failcode = get_failcode_snippet (source_version);
+
+                 if (failcode != NULL)
+                   {
+                     free (compiled_file_name);
+                     free (conftest_file_name);
+
+                     conftest_file_name =
+                       concatenated_pathname (tmpdir->dir_name,
+                                              "conftestfail.java",
+                                              NULL);
+                     if (write_temp_file (tmpdir, conftest_file_name,
+                                          failcode))
+                       {
+                         free (conftest_file_name);
+                         free (javac_target_source);
+                         free (javac_target);
+                         cleanup_temp_dir (tmpdir);
+                         return true;
+                       }
+
+                     compiled_file_name =
+                       concatenated_pathname (tmpdir->dir_name,
+                                              "conftestfail.class",
+                                              NULL);
+                     register_temp_file (tmpdir, compiled_file_name);
+
+                     java_sources[0] = conftest_file_name;
+                     if (!compile_using_envjavac (javac_target,
+                                                  java_sources, 1,
+                                                  tmpdir->dir_name,
+                                                  false, false, false, true)
+                         && stat (compiled_file_name, &statbuf) >= 0)
+                       {
+                         unlink (compiled_file_name);
+
+                         java_sources[0] = conftest_file_name;
+                         if (compile_using_envjavac (javac_target_source,
+                                                     java_sources, 1,
+                                                     tmpdir->dir_name,
+                                                     false, false, false,
+                                                     true))
+                           /* "$JAVAC -target $target_version" compiled
+                              conftestfail.java successfully, and
+                              "$JAVAC -target $target_version -source $source_version"
+                              rejects it.  So the -source option is useful.  */
+                           resultp->source_option = true;
+                       }
+                   }
+               }
+
+             free (javac_target_source);
+
+             resultp->target_option = true;
+             resultp->usable = true;
+           }
+         else
+           {
+             /* Maybe this -target option requires a -source option? Try with
+                -target and -source options. (Supported by Sun javac 1.4 and
+                higher.)  */
+             char *javac_target_source =
+               xasprintf ("%s -source %s", javac_target, source_version);
+
+             unlink (compiled_file_name);
+
+             java_sources[0] = conftest_file_name;
+             if (!compile_using_envjavac (javac_target_source,
+                                          java_sources, 1, tmpdir->dir_name,
+                                          false, false, false, true)
+                 && stat (compiled_file_name, &statbuf) >= 0
+                 && get_classfile_version (compiled_file_name)
+                    <= corresponding_classfile_version (target_version))
+               {
+                 /* "$JAVAC -target $target_version -source $source_version"
+                    compiled conftest.java successfully.  */
+                 resultp->source_option = true;
+                 resultp->target_option = true;
+                 resultp->usable = true;
+               }
+
+             free (javac_target_source);
+           }
+
+         free (javac_target);
+       }
+
+      free (compiled_file_name);
+      free (conftest_file_name);
+
+      resultp->tested = true;
+    }
 
-    if (!gcj_tested)
-      {
-       /* Test for presence of gcj:
-          "gcj --version 2> /dev/null | \
-           sed -e 's,^[^0-9]*,,' -e 1q | \
-           sed -e '/^3\.[01]/d' | grep '^[3-9]' > /dev/null"  */
-       char *argv[3];
-       pid_t child;
-       int fd[1];
-       int exitstatus;
-
-       argv[0] = "gcj";
-       argv[1] = "--version";
-       argv[2] = NULL;
-       child = create_pipe_in ("gcj", "gcj", argv, DEV_NULL, true, true,
-                               false, fd);
-       gcj_present = false;
-       if (child != -1)
-         {
-           /* Read the subprocess output, drop all lines except the first,
-              drop all characters before the first digit, and test whether
-              the remaining string starts with a digit >= 3, but not with
-              "3.0" or "3.1".  */
-           char c[3];
-           size_t count = 0;
-
-           while (safe_read (fd[0], &c[count], 1) > 0)
-             {
-               if (c[count] == '\n')
+  *usablep = resultp->usable;
+  *source_option_p = resultp->source_option;
+  *target_option_p = resultp->target_option;
+  return false;
+}
+
+static bool
+is_gcj_present (void)
+{
+  static bool gcj_tested;
+  static bool gcj_present;
+
+  if (!gcj_tested)
+    {
+      /* Test for presence of gcj:
+        "gcj --version 2> /dev/null | \
+         sed -e 's,^[^0-9]*,,' -e 1q | \
+         sed -e '/^3\.[01]/d' | grep '^[3-9]' > /dev/null"  */
+      char *argv[3];
+      pid_t child;
+      int fd[1];
+      int exitstatus;
+
+      argv[0] = "gcj";
+      argv[1] = "--version";
+      argv[2] = NULL;
+      child = create_pipe_in ("gcj", "gcj", argv, DEV_NULL, true, true,
+                             false, fd);
+      gcj_present = false;
+      if (child != -1)
+       {
+         /* Read the subprocess output, drop all lines except the first,
+            drop all characters before the first digit, and test whether
+            the remaining string starts with a digit >= 3, but not with
+            "3.0" or "3.1".  */
+         char c[3];
+         size_t count = 0;
+
+         while (safe_read (fd[0], &c[count], 1) > 0)
+           {
+             if (c[count] == '\n')
+               break;
+             if (count == 0)
+               {
+                 if (!(c[0] >= '0' && c[0] <= '9'))
+                   continue;
+                 gcj_present = (c[0] >= '3');
+               }
+             count++;
+             if (count == 3)
+               {
+                 if (c[0] == '3' && c[1] == '.'
+                     && (c[2] == '0' || c[2] == '1'))
+                   gcj_present = false;
                  break;
-               if (count == 0)
-                 {
-                   if (!(c[0] >= '0' && c[0] <= '9'))
-                     continue;
-                   gcj_present = (c[0] >= '3');
-                 }
-               count++;
-               if (count == 3)
-                 {
-                   if (c[0] == '3' && c[1] == '.'
-                       && (c[2] == '0' || c[2] == '1'))
-                     gcj_present = false;
-                   break;
-                 }
-             }
-           while (safe_read (fd[0], &c[0], 1) > 0)
-             ;
+               }
+           }
+         while (safe_read (fd[0], &c[0], 1) > 0)
+           ;
+
+         close (fd[0]);
+
+         /* Remove zombie process from process list, and retrieve exit
+            status.  */
+         exitstatus =
+           wait_subprocess (child, "gcj", false, true, true, false);
+         if (exitstatus != 0)
+           gcj_present = false;
+       }
+
+      if (gcj_present)
+       {
+         /* See if libgcj.jar is well installed.  */
+         struct temp_dir *tmpdir;
+
+         tmpdir = create_temp_dir ("java", NULL, false);
+         if (tmpdir == NULL)
+           gcj_present = false;
+         else
+           {
+             char *conftest_file_name;
+
+             conftest_file_name =
+               concatenated_pathname (tmpdir->dir_name, "conftestlib.java",
+                                      NULL);
+             if (write_temp_file (tmpdir, conftest_file_name,
+"public class conftestlib {\n"
+"  public static void main (String[] args) {\n"
+"  }\n"
+"}\n"))
+               gcj_present = false;
+             else
+               {
+                 char *compiled_file_name;
+                 const char *java_sources[1];
+
+                 compiled_file_name =
+                   concatenated_pathname (tmpdir->dir_name,
+                                          "conftestlib.class",
+                                          NULL);
+                 register_temp_file (tmpdir, compiled_file_name);
+
+                 java_sources[0] = conftest_file_name;
+                 if (compile_using_gcj (java_sources, 1, false,
+                                        false, NULL, false, NULL,
+                                        tmpdir->dir_name,
+                                        false, false, false, true))
+                   gcj_present = false;
+
+                 free (compiled_file_name);
+               }
+             free (conftest_file_name);
+           }
+         cleanup_temp_dir (tmpdir);
+       }
+
+      gcj_tested = true;
+    }
 
-           close (fd[0]);
+  return gcj_present;
+}
 
-           /* Remove zombie process from process list, and retrieve exit
-              status.  */
-           exitstatus =
-             wait_subprocess (child, "gcj", NULL, false, true, true, false);
-           if (exitstatus != 0)
-             gcj_present = false;
-         }
-       gcj_tested = true;
-      }
+static bool
+is_gcj_43 (void)
+{
+  static bool gcj_tested;
+  static bool gcj_43;
 
-    if (gcj_present)
-      {
-       char *old_classpath;
-       unsigned int argc;
-       char **argv;
-       char **argp;
-       int exitstatus;
-       unsigned int i;
-
-       /* Set CLASSPATH.  We could also use the --CLASSPATH=... option
-          of gcj.  Note that --classpath=... option is different: its
-          argument should also contain gcj's libgcj.jar, but we don't
-          know its location.  */
-       old_classpath =
-         set_classpath (classpaths, classpaths_count, use_minimal_classpath,
-                        verbose);
-
-       argc =
-         2 + (optimize ? 1 : 0) + (debug ? 1 : 0) + (directory != NULL ? 2 : 0)
-         + java_sources_count;
-       argv = (char **) xallocsa ((argc + 1) * sizeof (char *));
-
-       argp = argv;
-       *argp++ = "gcj";
-       *argp++ = "-C";
-       if (optimize)
-         *argp++ = "-O";
-       if (debug)
-         *argp++ = "-g";
-       if (directory != NULL)
-         {
-           *argp++ = "-d";
-           *argp++ = (char *) directory;
-         }
-       for (i = 0; i < java_sources_count; i++)
-         *argp++ = (char *) java_sources[i];
-       *argp = NULL;
-       /* Ensure argv length was correctly calculated.  */
-       if (argp - argv != argc)
-         abort ();
-
-       if (verbose)
-         {
-           char *command = shell_quote_argv (argv);
-           printf ("%s\n", command);
-           free (command);
-         }
+  if (!gcj_tested)
+    {
+      /* Test for presence of gcj:
+        "gcj --version 2> /dev/null | \
+         sed -e 's,^[^0-9]*,,' -e 1q | \
+         sed -e '/^4\.[012]/d' | grep '^[4-9]'"  */
+      char *argv[3];
+      pid_t child;
+      int fd[1];
+      int exitstatus;
+
+      argv[0] = "gcj";
+      argv[1] = "--version";
+      argv[2] = NULL;
+      child = create_pipe_in ("gcj", "gcj", argv, DEV_NULL, true, true,
+                             false, fd);
+      gcj_43 = false;
+      if (child != -1)
+       {
+         /* Read the subprocess output, drop all lines except the first,
+            drop all characters before the first digit, and test whether
+            the remaining string starts with a digit >= 4, but not with
+            "4.0" or "4.1" or "4.2".  */
+         char c[3];
+         size_t count = 0;
+
+         while (safe_read (fd[0], &c[count], 1) > 0)
+           {
+             if (c[count] == '\n')
+               break;
+             if (count == 0)
+               {
+                 if (!(c[0] >= '0' && c[0] <= '9'))
+                   continue;
+                 gcj_43 = (c[0] >= '4');
+               }
+             count++;
+             if (count == 3)
+               {
+                 if (c[0] == '4' && c[1] == '.' && c[2] >= '0' && c[2] <= '2')
+                   gcj_43 = false;
+                 break;
+               }
+           }
+         while (safe_read (fd[0], &c[0], 1) > 0)
+           ;
+
+         close (fd[0]);
+
+         /* Remove zombie process from process list, and retrieve exit
+            status.  */
+         exitstatus =
+           wait_subprocess (child, "gcj", false, true, true, false);
+         if (exitstatus != 0)
+           gcj_43 = false;
+       }
+
+      gcj_tested = true;
+    }
 
-       exitstatus = execute ("gcj", "gcj", argv, false, false, false, false,
-                             true, true);
-       err = (exitstatus != 0);
+  return gcj_43;
+}
 
-       freesa (argv);
+/* Test whether gcj >= 4.3 can be used, and whether it needs a -fsource and/or
+   -ftarget option.
+   Return a failure indicator (true upon error).  */
+static bool
+is_gcj43_usable (const char *source_version,
+                const char *target_version,
+                bool *usablep,
+                bool *fsource_option_p, bool *ftarget_option_p)
+{
+  /* The cache depends on the source_version and target_version.  */
+  struct result_t
+  {
+    bool tested;
+    bool usable;
+    bool fsource_option;
+    bool ftarget_option;
+  };
+  static struct result_t result_cache[SOURCE_VERSION_BOUND][TARGET_VERSION_BOUND];
+  struct result_t *resultp;
+
+  resultp = &result_cache[source_version_index (source_version)]
+                        [target_version_index (target_version)];
+  if (!resultp->tested)
+    {
+      /* Try gcj.  */
+      struct temp_dir *tmpdir;
+      char *conftest_file_name;
+      char *compiled_file_name;
+      const char *java_sources[1];
+      struct stat statbuf;
+
+      tmpdir = create_temp_dir ("java", NULL, false);
+      if (tmpdir == NULL)
+       return true;
+
+      conftest_file_name =
+       concatenated_pathname (tmpdir->dir_name, "conftest.java", NULL);
+      if (write_temp_file (tmpdir, conftest_file_name,
+                          get_goodcode_snippet (source_version)))
+       {
+         free (conftest_file_name);
+         cleanup_temp_dir (tmpdir);
+         return true;
+       }
+
+      compiled_file_name =
+       concatenated_pathname (tmpdir->dir_name, "conftest.class", NULL);
+      register_temp_file (tmpdir, compiled_file_name);
+
+      java_sources[0] = conftest_file_name;
+      if (!compile_using_gcj (java_sources, 1, false, false, NULL, false, NULL,
+                             tmpdir->dir_name, false, false, false, true)
+         && stat (compiled_file_name, &statbuf) >= 0
+         && get_classfile_version (compiled_file_name)
+            <= corresponding_classfile_version (target_version))
+       {
+         /* gcj compiled conftest.java successfully.  */
+         /* Try adding -fsource option if it is useful.  */
+         unlink (compiled_file_name);
+
+         java_sources[0] = conftest_file_name;
+         if (!compile_using_gcj (java_sources, 1,
+                                 false, true, source_version, false, NULL,
+                                 tmpdir->dir_name, false, false, false, true)
+             && stat (compiled_file_name, &statbuf) >= 0
+             && get_classfile_version (compiled_file_name)
+                <= corresponding_classfile_version (target_version))
+           {
+             const char *failcode = get_failcode_snippet (source_version);
+
+             if (failcode != NULL)
+               {
+                 free (compiled_file_name);
+                 free (conftest_file_name);
+
+                 conftest_file_name =
+                   concatenated_pathname (tmpdir->dir_name,
+                                          "conftestfail.java",
+                                          NULL);
+                 if (write_temp_file (tmpdir, conftest_file_name, failcode))
+                   {
+                     free (conftest_file_name);
+                     cleanup_temp_dir (tmpdir);
+                     return true;
+                   }
+
+                 compiled_file_name =
+                   concatenated_pathname (tmpdir->dir_name,
+                                          "conftestfail.class",
+                                          NULL);
+                 register_temp_file (tmpdir, compiled_file_name);
+
+                 java_sources[0] = conftest_file_name;
+                 if (!compile_using_gcj (java_sources, 1,
+                                         false, false, NULL, false, NULL,
+                                         tmpdir->dir_name,
+                                         false, false, false, true)
+                     && stat (compiled_file_name, &statbuf) >= 0)
+                   {
+                     unlink (compiled_file_name);
+
+                     java_sources[0] = conftest_file_name;
+                     if (compile_using_gcj (java_sources, 1,
+                                            false, true, source_version,
+                                            false, NULL,
+                                            tmpdir->dir_name,
+                                            false, false, false, true))
+                       /* gcj compiled conftestfail.java successfully, and
+                          "gcj -fsource=$source_version" rejects it.  So
+                          the -fsource option is useful.  */
+                       resultp->fsource_option = true;
+                   }
+               }
+           }
+
+         resultp->usable = true;
+       }
+      else
+       {
+         /* Try with -fsource and -ftarget options.  */
+         unlink (compiled_file_name);
+
+         java_sources[0] = conftest_file_name;
+         if (!compile_using_gcj (java_sources, 1,
+                                 false, true, source_version,
+                                 true, target_version,
+                                 tmpdir->dir_name,
+                                 false, false, false, true)
+             && stat (compiled_file_name, &statbuf) >= 0
+             && get_classfile_version (compiled_file_name)
+                <= corresponding_classfile_version (target_version))
+           {
+             /* "gcj -fsource $source_version -ftarget $target_version"
+                compiled conftest.java successfully.  */
+             resultp->fsource_option = true;
+             resultp->ftarget_option = true;
+             resultp->usable = true;
+           }
+       }
+
+      free (compiled_file_name);
+      free (conftest_file_name);
+
+      resultp->tested = true;
+    }
 
-       /* Reset CLASSPATH.  */
-       reset_classpath (old_classpath);
+  *usablep = resultp->usable;
+  *fsource_option_p = resultp->fsource_option;
+  *ftarget_option_p = resultp->ftarget_option;
+  return false;
+}
 
-       goto done2;
-      }
-  }
+/* Test whether gcj < 4.3 can be used for compiling with target_version = 1.4
+   and source_version = 1.4.
+   Return a failure indicator (true upon error).  */
+static bool
+is_oldgcj_14_14_usable (bool *usablep)
+{
+  static bool gcj_tested;
+  static bool gcj_usable;
 
-  {
-    static bool javac_tested;
-    static bool javac_present;
+  if (!gcj_tested)
+    {
+      /* Try gcj.  */
+      struct temp_dir *tmpdir;
+      char *conftest_file_name;
+      char *compiled_file_name;
+      const char *java_sources[1];
+      struct stat statbuf;
+
+      tmpdir = create_temp_dir ("java", NULL, false);
+      if (tmpdir == NULL)
+       return true;
+
+      conftest_file_name =
+       concatenated_pathname (tmpdir->dir_name, "conftest.java", NULL);
+      if (write_temp_file (tmpdir, conftest_file_name,
+                          get_goodcode_snippet ("1.4")))
+       {
+         free (conftest_file_name);
+         cleanup_temp_dir (tmpdir);
+         return true;
+       }
+
+      compiled_file_name =
+       concatenated_pathname (tmpdir->dir_name, "conftest.class", NULL);
+      register_temp_file (tmpdir, compiled_file_name);
+
+      java_sources[0] = conftest_file_name;
+      if (!compile_using_gcj (java_sources, 1, false, false, NULL, false, NULL,
+                             tmpdir->dir_name, false, false, false, true)
+         && stat (compiled_file_name, &statbuf) >= 0)
+       /* Compilation succeeded.  */
+       gcj_usable = true;
+
+      free (compiled_file_name);
+      free (conftest_file_name);
+
+      cleanup_temp_dir (tmpdir);
+
+      gcj_tested = true;
+    }
 
-    if (!javac_tested)
-      {
-       /* Test for presence of javac: "javac 2> /dev/null ; test $? -le 2"  */
-       char *argv[2];
-       int exitstatus;
-
-       argv[0] = "javac";
-       argv[1] = NULL;
-       exitstatus = execute ("javac", "javac", argv, false, false, true, true,
-                             true, false);
-       javac_present = (exitstatus == 0 || exitstatus == 1 || exitstatus == 2);
-       javac_tested = true;
-      }
+  *usablep = gcj_usable;
+  return false;
+}
 
-    if (javac_present)
-      {
-       char *old_classpath;
-       unsigned int argc;
-       char **argv;
-       char **argp;
-       int exitstatus;
-       unsigned int i;
-
-       /* Set CLASSPATH.  We don't use the "-classpath ..." option because
-          in JDK 1.1.x its argument should also contain the JDK's classes.zip,
-          but we don't know its location.  (In JDK 1.3.0 it would work.)  */
-       old_classpath =
-         set_classpath (classpaths, classpaths_count, use_minimal_classpath,
-                        verbose);
-
-       argc =
-         1 + (optimize ? 1 : 0) + (debug ? 1 : 0) + (directory != NULL ? 2 : 0)
-         + java_sources_count;
-       argv = (char **) xallocsa ((argc + 1) * sizeof (char *));
-
-       argp = argv;
-       *argp++ = "javac";
-       if (optimize)
-         *argp++ = "-O";
-       if (debug)
-         *argp++ = "-g";
-       if (directory != NULL)
-         {
-           *argp++ = "-d";
-           *argp++ = (char *) directory;
-         }
-       for (i = 0; i < java_sources_count; i++)
-         *argp++ = (char *) java_sources[i];
-       *argp = NULL;
-       /* Ensure argv length was correctly calculated.  */
-       if (argp - argv != argc)
-         abort ();
-
-       if (verbose)
-         {
-           char *command = shell_quote_argv (argv);
-           printf ("%s\n", command);
-           free (command);
-         }
+/* Test whether gcj < 4.3 can be used for compiling with target_version = 1.4
+   and source_version = 1.3.
+   Return a failure indicator (true upon error).  */
+static bool
+is_oldgcj_14_13_usable (bool *usablep, bool *need_no_assert_option_p)
+{
+  static bool gcj_tested;
+  static bool gcj_usable;
+  static bool gcj_need_no_assert_option;
 
-       exitstatus = execute ("javac", "javac", argv, false, false, false,
-                             false, true, true);
-       err = (exitstatus != 0);
+  if (!gcj_tested)
+    {
+      /* Try gcj and "gcj -fno-assert".  But add -fno-assert only if
+        it works (not gcj < 3.3).  */
+      struct temp_dir *tmpdir;
+      char *conftest_file_name;
+      char *compiled_file_name;
+      const char *java_sources[1];
+      struct stat statbuf;
+
+      tmpdir = create_temp_dir ("java", NULL, false);
+      if (tmpdir == NULL)
+       return true;
+
+      conftest_file_name =
+       concatenated_pathname (tmpdir->dir_name, "conftest.java", NULL);
+      if (write_temp_file (tmpdir, conftest_file_name,
+                          get_goodcode_snippet ("1.3")))
+       {
+         free (conftest_file_name);
+         cleanup_temp_dir (tmpdir);
+         return true;
+       }
+
+      compiled_file_name =
+       concatenated_pathname (tmpdir->dir_name, "conftest.class", NULL);
+      register_temp_file (tmpdir, compiled_file_name);
+
+      java_sources[0] = conftest_file_name;
+      if (!compile_using_gcj (java_sources, 1, true, false, NULL, false, NULL,
+                             tmpdir->dir_name, false, false, false, true)
+         && stat (compiled_file_name, &statbuf) >= 0)
+       /* Compilation succeeded.  */
+       {
+         gcj_usable = true;
+         gcj_need_no_assert_option = true;
+       }
+      else
+       {
+         unlink (compiled_file_name);
+
+         java_sources[0] = conftest_file_name;
+         if (!compile_using_gcj (java_sources, 1, false,
+                                 false, NULL, false, NULL,
+                                 tmpdir->dir_name, false, false, false, true)
+             && stat (compiled_file_name, &statbuf) >= 0)
+           /* Compilation succeeded.  */
+           {
+             gcj_usable = true;
+             gcj_need_no_assert_option = false;
+           }
+       }
+
+      free (compiled_file_name);
+      free (conftest_file_name);
+
+      cleanup_temp_dir (tmpdir);
+
+      gcj_tested = true;
+    }
 
-       freesa (argv);
+  *usablep = gcj_usable;
+  *need_no_assert_option_p = gcj_need_no_assert_option;
+  return false;
+}
 
-       /* Reset CLASSPATH.  */
-       reset_classpath (old_classpath);
+static bool
+is_javac_present (void)
+{
+  static bool javac_tested;
+  static bool javac_present;
 
-       goto done2;
-      }
-  }
+  if (!javac_tested)
+    {
+      /* Test for presence of javac: "javac 2> /dev/null ; test $? -le 2"  */
+      char *argv[2];
+      int exitstatus;
+
+      argv[0] = "javac";
+      argv[1] = NULL;
+      exitstatus = execute ("javac", "javac", argv, false, false, true, true,
+                           true, false);
+      javac_present = (exitstatus == 0 || exitstatus == 1 || exitstatus == 2);
+      javac_tested = true;
+    }
 
+  return javac_present;
+}
+
+/* Test whether javac can be used and whether it needs a -source and/or
+   -target option.
+   Return a failure indicator (true upon error).  */
+static bool
+is_javac_usable (const char *source_version, const char *target_version,
+                bool *usablep, bool *source_option_p, bool *target_option_p)
+{
+  /* The cache depends on the source_version and target_version.  */
+  struct result_t
   {
-    static bool jikes_tested;
-    static bool jikes_present;
+    bool tested;
+    bool usable;
+    bool source_option;
+    bool target_option;
+  };
+  static struct result_t result_cache[SOURCE_VERSION_BOUND][TARGET_VERSION_BOUND];
+  struct result_t *resultp;
+
+  resultp = &result_cache[source_version_index (source_version)]
+                        [target_version_index (target_version)];
+  if (!resultp->tested)
+    {
+      /* Try javac.  */
+      struct temp_dir *tmpdir;
+      char *conftest_file_name;
+      char *compiled_file_name;
+      const char *java_sources[1];
+      struct stat statbuf;
+
+      tmpdir = create_temp_dir ("java", NULL, false);
+      if (tmpdir == NULL)
+       return true;
+
+      conftest_file_name =
+       concatenated_pathname (tmpdir->dir_name, "conftest.java", NULL);
+      if (write_temp_file (tmpdir, conftest_file_name,
+                          get_goodcode_snippet (source_version)))
+       {
+         free (conftest_file_name);
+         cleanup_temp_dir (tmpdir);
+         return true;
+       }
+
+      compiled_file_name =
+       concatenated_pathname (tmpdir->dir_name, "conftest.class", NULL);
+      register_temp_file (tmpdir, compiled_file_name);
+
+      java_sources[0] = conftest_file_name;
+      if (!compile_using_javac (java_sources, 1,
+                               false, source_version,
+                               false, target_version,
+                               tmpdir->dir_name, false, false, false, true)
+         && stat (compiled_file_name, &statbuf) >= 0
+         && get_classfile_version (compiled_file_name)
+            <= corresponding_classfile_version (target_version))
+       {
+         /* javac compiled conftest.java successfully.  */
+         /* Try adding -source option if it is useful.  */
+         unlink (compiled_file_name);
+
+         java_sources[0] = conftest_file_name;
+         if (!compile_using_javac (java_sources, 1,
+                                   true, source_version,
+                                   false, target_version,
+                                   tmpdir->dir_name, false, false, false, true)
+             && stat (compiled_file_name, &statbuf) >= 0
+             && get_classfile_version (compiled_file_name)
+                <= corresponding_classfile_version (target_version))
+           {
+             const char *failcode = get_failcode_snippet (source_version);
+
+             if (failcode != NULL)
+               {
+                 free (compiled_file_name);
+                 free (conftest_file_name);
+
+                 conftest_file_name =
+                   concatenated_pathname (tmpdir->dir_name,
+                                          "conftestfail.java",
+                                          NULL);
+                 if (write_temp_file (tmpdir, conftest_file_name, failcode))
+                   {
+                     free (conftest_file_name);
+                     cleanup_temp_dir (tmpdir);
+                     return true;
+                   }
+
+                 compiled_file_name =
+                   concatenated_pathname (tmpdir->dir_name,
+                                          "conftestfail.class",
+                                          NULL);
+                 register_temp_file (tmpdir, compiled_file_name);
+
+                 java_sources[0] = conftest_file_name;
+                 if (!compile_using_javac (java_sources, 1,
+                                           false, source_version,
+                                           false, target_version,
+                                           tmpdir->dir_name,
+                                           false, false, false, true)
+                     && stat (compiled_file_name, &statbuf) >= 0)
+                   {
+                     unlink (compiled_file_name);
+
+                     java_sources[0] = conftest_file_name;
+                     if (compile_using_javac (java_sources, 1,
+                                              true, source_version,
+                                              false, target_version,
+                                              tmpdir->dir_name,
+                                              false, false, false, true))
+                       /* javac compiled conftestfail.java successfully, and
+                          "javac -source $source_version" rejects it.  So the
+                          -source option is useful.  */
+                       resultp->source_option = true;
+                   }
+               }
+           }
+
+         resultp->usable = true;
+       }
+      else
+       {
+         /* Try with -target option alone. (Sun javac 1.3.1 has the -target
+            option but no -source option.)  */
+         unlink (compiled_file_name);
+
+         java_sources[0] = conftest_file_name;
+         if (!compile_using_javac (java_sources, 1,
+                                   false, source_version,
+                                   true, target_version,
+                                   tmpdir->dir_name,
+                                   false, false, false, true)
+             && stat (compiled_file_name, &statbuf) >= 0
+             && get_classfile_version (compiled_file_name)
+                <= corresponding_classfile_version (target_version))
+           {
+             /* "javac -target $target_version" compiled conftest.java
+                successfully.  */
+             /* Try adding -source option if it is useful.  */
+             unlink (compiled_file_name);
+
+             java_sources[0] = conftest_file_name;
+             if (!compile_using_javac (java_sources, 1,
+                                       true, source_version,
+                                       true, target_version,
+                                       tmpdir->dir_name,
+                                       false, false, false, true)
+                 && stat (compiled_file_name, &statbuf) >= 0
+                 && get_classfile_version (compiled_file_name)
+                    <= corresponding_classfile_version (target_version))
+               {
+                 const char *failcode = get_failcode_snippet (source_version);
+
+                 if (failcode != NULL)
+                   {
+                     free (compiled_file_name);
+                     free (conftest_file_name);
+
+                     conftest_file_name =
+                       concatenated_pathname (tmpdir->dir_name,
+                                              "conftestfail.java",
+                                              NULL);
+                     if (write_temp_file (tmpdir, conftest_file_name,
+                                          failcode))
+                       {
+                         free (conftest_file_name);
+                         cleanup_temp_dir (tmpdir);
+                         return true;
+                       }
+
+                     compiled_file_name =
+                       concatenated_pathname (tmpdir->dir_name,
+                                              "conftestfail.class",
+                                              NULL);
+                     register_temp_file (tmpdir, compiled_file_name);
+
+                     java_sources[0] = conftest_file_name;
+                     if (!compile_using_javac (java_sources, 1,
+                                               false, source_version,
+                                               true, target_version,
+                                               tmpdir->dir_name,
+                                               false, false, false, true)
+                         && stat (compiled_file_name, &statbuf) >= 0)
+                       {
+                         unlink (compiled_file_name);
+
+                         java_sources[0] = conftest_file_name;
+                         if (compile_using_javac (java_sources, 1,
+                                                  true, source_version,
+                                                  true, target_version,
+                                                  tmpdir->dir_name,
+                                                  false, false, false, true))
+                           /* "javac -target $target_version" compiled
+                              conftestfail.java successfully, and
+                              "javac -target $target_version -source $source_version"
+                              rejects it.  So the -source option is useful.  */
+                           resultp->source_option = true;
+                       }
+                   }
+               }
+
+             resultp->target_option = true;
+             resultp->usable = true;
+           }
+         else
+           {
+             /* Maybe this -target option requires a -source option? Try with
+                -target and -source options. (Supported by Sun javac 1.4 and
+                higher.)  */
+             unlink (compiled_file_name);
+
+             java_sources[0] = conftest_file_name;
+             if (!compile_using_javac (java_sources, 1,
+                                       true, source_version,
+                                       true, target_version,
+                                       tmpdir->dir_name,
+                                       false, false, false, true)
+                 && stat (compiled_file_name, &statbuf) >= 0
+                 && get_classfile_version (compiled_file_name)
+                    <= corresponding_classfile_version (target_version))
+               {
+                 /* "javac -target $target_version -source $source_version"
+                    compiled conftest.java successfully.  */
+                 resultp->source_option = true;
+                 resultp->target_option = true;
+                 resultp->usable = true;
+               }
+           }
+       }
+
+      free (compiled_file_name);
+      free (conftest_file_name);
+
+      resultp->tested = true;
+    }
 
-    if (!jikes_tested)
-      {
-       /* Test for presence of jikes: "jikes 2> /dev/null ; test $? = 1"  */
-       char *argv[2];
-       int exitstatus;
-
-       argv[0] = "jikes";
-       argv[1] = NULL;
-       exitstatus = execute ("jikes", "jikes", argv, false, false, true, true,
-                             true, false);
-       jikes_present = (exitstatus == 0 || exitstatus == 1);
-       jikes_tested = true;
-      }
+  *usablep = resultp->usable;
+  *source_option_p = resultp->source_option;
+  *target_option_p = resultp->target_option;
+  return false;
+}
+
+static bool
+is_jikes_present (void)
+{
+  static bool jikes_tested;
+  static bool jikes_present;
+
+  if (!jikes_tested)
+    {
+      /* Test for presence of jikes: "jikes 2> /dev/null ; test $? = 1"  */
+      char *argv[2];
+      int exitstatus;
+
+      argv[0] = "jikes";
+      argv[1] = NULL;
+      exitstatus = execute ("jikes", "jikes", argv, false, false, true, true,
+                           true, false);
+      jikes_present = (exitstatus == 0 || exitstatus == 1);
+      jikes_tested = true;
+    }
+
+  return jikes_present;
+}
 
-    if (jikes_present)
+/* ============================= Main function ============================= */
+
+bool
+compile_java_class (const char * const *java_sources,
+                   unsigned int java_sources_count,
+                   const char * const *classpaths,
+                   unsigned int classpaths_count,
+                   const char *source_version,
+                   const char *target_version,
+                   const char *directory,
+                   bool optimize, bool debug,
+                   bool use_minimal_classpath,
+                   bool verbose)
+{
+  bool err = false;
+  char *old_JAVA_HOME;
+
+  {
+    const char *javac = getenv ("JAVAC");
+    if (javac != NULL && javac[0] != '\0')
       {
-       char *old_classpath;
-       unsigned int argc;
-       char **argv;
-       char **argp;
-       int exitstatus;
-       unsigned int i;
-
-       /* Set CLASSPATH.  We could also use the "-classpath ..." option.
-          Since jikes doesn't come with its own standard library, it
-          needs a classes.zip or rt.jar or libgcj.jar in the CLASSPATH.
-          To increase the chance of success, we reuse the current CLASSPATH
-          if the user has set it.  */
-       old_classpath =
-         set_classpath (classpaths, classpaths_count, false,
-                        verbose);
-
-       argc =
-         1 + (optimize ? 1 : 0) + (debug ? 1 : 0) + (directory != NULL ? 2 : 0)
-         + java_sources_count;
-       argv = (char **) xallocsa ((argc + 1) * sizeof (char *));
-
-       argp = argv;
-       *argp++ = "jikes";
-       if (optimize)
-         *argp++ = "-O";
-       if (debug)
-         *argp++ = "-g";
-       if (directory != NULL)
+       bool usable = false;
+       bool no_assert_option = false;
+       bool source_option = false;
+       bool target_option = false;
+       bool fsource_option = false;
+       bool ftarget_option = false;
+
+       if (target_version == NULL)
+         target_version = default_target_version ();
+
+       if (is_envjavac_gcj (javac))
          {
-           *argp++ = "-d";
-           *argp++ = (char *) directory;
+           /* It's a version of gcj.  */
+           if (is_envjavac_gcj43 (javac))
+             {
+               /* It's a version of gcj >= 4.3.  Assume the classfile versions
+                  are correct.  */
+               if (is_envjavac_gcj43_usable (javac,
+                                             source_version, target_version,
+                                             &usable,
+                                             &fsource_option, &ftarget_option))
+                 {
+                   err = true;
+                   goto done1;
+                 }
+             }
+           else
+             {
+               /* It's a version of gcj < 4.3.  Ignore the version of the
+                  class files that it creates.  */
+               if (strcmp (target_version, "1.4") == 0
+                   && strcmp (source_version, "1.4") == 0)
+                 {
+                   if (is_envjavac_oldgcj_14_14_usable (javac, &usable))
+                     {
+                       err = true;
+                       goto done1;
+                     }
+                 }
+               else if (strcmp (target_version, "1.4") == 0
+                        && strcmp (source_version, "1.3") == 0)
+                 {
+                   if (is_envjavac_oldgcj_14_13_usable (javac,
+                                                        &usable,
+                                                        &no_assert_option))
+                     {
+                       err = true;
+                       goto done1;
+                     }
+                 }
+             }
+         }
+       else
+         {
+           /* It's not gcj.  Assume the classfile versions are correct.  */
+           if (is_envjavac_nongcj_usable (javac,
+                                          source_version, target_version,
+                                          &usable,
+                                          &source_option, &target_option))
+             {
+               err = true;
+               goto done1;
+             }
          }
-       for (i = 0; i < java_sources_count; i++)
-         *argp++ = (char *) java_sources[i];
-       *argp = NULL;
-       /* Ensure argv length was correctly calculated.  */
-       if (argp - argv != argc)
-         abort ();
-
-       if (verbose)
+
+       if (usable)
          {
-           char *command = shell_quote_argv (argv);
-           printf ("%s\n", command);
-           free (command);
+           char *old_classpath;
+           char *javac_with_options;
+
+           /* Set CLASSPATH.  */
+           old_classpath =
+             set_classpath (classpaths, classpaths_count, false, verbose);
+
+           javac_with_options =
+             (no_assert_option
+              ? xasprintf ("%s -fno-assert", javac)
+              : xasprintf ("%s%s%s%s%s%s%s%s%s",
+                           javac,
+                           source_option ? " -source " : "",
+                           source_option ? source_version : "",
+                           target_option ? " -target " : "",
+                           target_option ? target_version : "",
+                           fsource_option ? " -fsource=" : "",
+                           fsource_option ? source_version : "",
+                           ftarget_option ? " -ftarget=" : "",
+                           ftarget_option ? target_version : ""));
+
+           err = compile_using_envjavac (javac_with_options,
+                                         java_sources, java_sources_count,
+                                         directory, optimize, debug, verbose,
+                                         false);
+
+           free (javac_with_options);
+
+           /* Reset CLASSPATH.  */
+           reset_classpath (old_classpath);
+
+           goto done1;
          }
+      }
+  }
 
-       exitstatus = execute ("jikes", "jikes", argv, false, false, false,
-                             false, true, true);
-       err = (exitstatus != 0);
+  /* Unset the JAVA_HOME environment variable.  */
+  old_JAVA_HOME = getenv ("JAVA_HOME");
+  if (old_JAVA_HOME != NULL)
+    {
+      old_JAVA_HOME = xstrdup (old_JAVA_HOME);
+      unsetenv ("JAVA_HOME");
+    }
 
-       freesa (argv);
+  if (is_gcj_present ())
+    {
+      /* It's a version of gcj.  */
+      bool usable = false;
+      bool no_assert_option = false;
+      bool fsource_option = false;
+      bool ftarget_option = false;
+
+      if (target_version == NULL)
+       target_version = default_target_version ();
+
+      if (is_gcj_43 ())
+       {
+         /* It's a version of gcj >= 4.3.  Assume the classfile versions
+            are correct.  */
+         if (is_gcj43_usable (source_version, target_version,
+                              &usable, &fsource_option, &ftarget_option))
+           {
+             err = true;
+             goto done1;
+           }
+       }
+      else
+       {
+         /* It's a version of gcj < 4.3.  Ignore the version of the class
+            files that it creates.
+            Test whether it supports the desired target-version and
+            source-version.  */
+         if (strcmp (target_version, "1.4") == 0
+             && strcmp (source_version, "1.4") == 0)
+           {
+             if (is_oldgcj_14_14_usable (&usable))
+               {
+                 err = true;
+                 goto done1;
+               }
+           }
+         else if (strcmp (target_version, "1.4") == 0
+                  && strcmp (source_version, "1.3") == 0)
+           {
+             if (is_oldgcj_14_13_usable (&usable, &no_assert_option))
+               {
+                 err = true;
+                 goto done1;
+               }
+           }
+       }
+
+      if (usable)
+       {
+         char *old_classpath;
+
+         /* Set CLASSPATH.  We could also use the --CLASSPATH=... option
+            of gcj.  Note that --classpath=... option is different: its
+            argument should also contain gcj's libgcj.jar, but we don't
+            know its location.  */
+         old_classpath =
+           set_classpath (classpaths, classpaths_count, use_minimal_classpath,
+                          verbose);
+
+         err = compile_using_gcj (java_sources, java_sources_count,
+                                  no_assert_option,
+                                  fsource_option, source_version,
+                                  ftarget_option, target_version,
+                                  directory, optimize, debug, verbose, false);
+
+         /* Reset CLASSPATH.  */
+         reset_classpath (old_classpath);
+
+         goto done2;
+       }
+    }
 
-       /* Reset CLASSPATH.  */
-       reset_classpath (old_classpath);
+  if (is_javac_present ())
+    {
+      bool usable = false;
+      bool source_option = false;
+      bool target_option = false;
+
+      if (target_version == NULL)
+       target_version = default_target_version ();
+
+      if (is_javac_usable (source_version, target_version,
+                          &usable, &source_option, &target_option))
+       {
+         err = true;
+         goto done1;
+       }
+
+      if (usable)
+       {
+         char *old_classpath;
+
+         /* Set CLASSPATH.  We don't use the "-classpath ..." option because
+            in JDK 1.1.x its argument should also contain the JDK's
+            classes.zip, but we don't know its location.  (In JDK 1.3.0 it
+            would work.)  */
+         old_classpath =
+           set_classpath (classpaths, classpaths_count, use_minimal_classpath,
+                          verbose);
+
+         err = compile_using_javac (java_sources, java_sources_count,
+                                    source_option, source_version,
+                                    target_option, target_version,
+                                    directory, optimize, debug, verbose,
+                                    false);
+
+         /* Reset CLASSPATH.  */
+         reset_classpath (old_classpath);
+
+         goto done2;
+       }
+    }
 
-       goto done2;
-      }
-  }
+  if (is_jikes_present ())
+    {
+      /* Test whether it supports the desired target-version and
+        source-version.  */
+      bool usable = (strcmp (source_version, "1.3") == 0);
+
+      if (usable)
+       {
+         char *old_classpath;
+
+         /* Set CLASSPATH.  We could also use the "-classpath ..." option.
+            Since jikes doesn't come with its own standard library, it
+            needs a classes.zip or rt.jar or libgcj.jar in the CLASSPATH.
+            To increase the chance of success, we reuse the current CLASSPATH
+            if the user has set it.  */
+         old_classpath =
+           set_classpath (classpaths, classpaths_count, false, verbose);
+
+         err = compile_using_jikes (java_sources, java_sources_count,
+                                    directory, optimize, debug, verbose,
+                                    false);
+
+         /* Reset CLASSPATH.  */
+         reset_classpath (old_classpath);
+
+         goto done2;
+       }
+    }
 
   error (0, 0, _("Java compiler not found, try installing gcj or set $JAVAC"));
   err = true;