X-Git-Url: http://erislabs.net/gitweb/?a=blobdiff_plain;f=lib%2Falloca.c;h=ee0f01886826ad9dcba250aad66fe7bc25c06213;hb=8e0f64e4cd12f7779113bc438afd106dad3e1f1a;hp=76b4ae00a8c5a5cc33035efffde44e9ed262c32f;hpb=b6fcba3d1ffb29311d82ed3ee2e32f132663465b;p=gnulib.git diff --git a/lib/alloca.c b/lib/alloca.c index 76b4ae00a..ee0f01886 100644 --- a/lib/alloca.c +++ b/lib/alloca.c @@ -21,12 +21,22 @@ allocating any. It is a good idea to use alloca(0) in your main control loop, etc. to force garbage collection. */ -#ifdef HAVE_CONFIG_H #include -#endif + +#include + +#include +#include #ifdef emacs -#include "blockinput.h" +# include "lisp.h" +# include "blockinput.h" +# ifdef EMACS_FREE +# undef free +# define free EMACS_FREE +# endif +#else +# define memory_full() abort () #endif /* If compiling with GCC 2, this file's not needed. */ @@ -34,54 +44,33 @@ /* If someone has defined alloca as a macro, there must be some other way alloca is supposed to work. */ -#ifndef alloca +# ifndef alloca -#ifdef emacs -#ifdef static +# ifdef emacs +# ifdef static /* actually, only want this if static is defined as "" -- this is for usg, in which emacs must undefine static in order to make unexec workable */ -#ifndef STACK_DIRECTION +# ifndef STACK_DIRECTION you lose -- must know STACK_DIRECTION at compile-time -#endif /* STACK_DIRECTION undefined */ -#endif /* static */ -#endif /* emacs */ +/* Using #error here is not wise since this file should work for + old and obscure compilers. */ +# endif /* STACK_DIRECTION undefined */ +# endif /* static */ +# endif /* emacs */ /* If your stack is a linked list of frames, you have to provide an "address metric" ADDRESS_FUNCTION macro. */ -#if defined (CRAY) && defined (CRAY_STACKSEG_END) +# if defined (CRAY) && defined (CRAY_STACKSEG_END) long i00afunc (); -#define ADDRESS_FUNCTION(arg) (char *) i00afunc (&(arg)) -#else -#define ADDRESS_FUNCTION(arg) &(arg) -#endif - -#if __STDC__ -typedef void *pointer; -#else -typedef char *pointer; -#endif - -#define NULL 0 - -/* Different portions of Emacs need to call different versions of - malloc. The Emacs executable needs alloca to call xmalloc, because - ordinary malloc isn't protected from input signals. On the other - hand, the utilities in lib-src need alloca to call malloc; some of - them are very simple, and don't have an xmalloc routine. - - Non-Emacs programs expect this to call xmalloc. - - Callers below should use malloc. */ - -#ifndef emacs -#define malloc xmalloc -#endif -extern pointer malloc (); +# define ADDRESS_FUNCTION(arg) (char *) i00afunc (&(arg)) +# else +# define ADDRESS_FUNCTION(arg) &(arg) +# endif /* Define STACK_DIRECTION if you know the direction of stack growth for your system; otherwise it will be automatically @@ -91,42 +80,31 @@ extern pointer malloc (); STACK_DIRECTION < 0 => grows toward lower addresses STACK_DIRECTION = 0 => direction of growth unknown */ -#ifndef STACK_DIRECTION -#define STACK_DIRECTION 0 /* Direction unknown. */ -#endif +# ifndef STACK_DIRECTION +# define STACK_DIRECTION 0 /* Direction unknown. */ +# endif -#if STACK_DIRECTION != 0 +# if STACK_DIRECTION != 0 -#define STACK_DIR STACK_DIRECTION /* Known at compile-time. */ +# define STACK_DIR STACK_DIRECTION /* Known at compile-time. */ -#else /* STACK_DIRECTION == 0; need run-time code. */ +# else /* STACK_DIRECTION == 0; need run-time code. */ -static int stack_dir; /* 1 or -1 once known. */ -#define STACK_DIR stack_dir +static int stack_dir; /* 1 or -1 once known. */ +# define STACK_DIR stack_dir -static void -find_stack_direction () +static int +find_stack_direction (int *addr, int depth) { - static char *addr = NULL; /* Address of first `dummy', once known. */ - auto char dummy; /* To get stack address. */ - - if (addr == NULL) - { /* Initial entry. */ - addr = ADDRESS_FUNCTION (dummy); - - find_stack_direction (); /* Recurse once. */ - } - else - { - /* Second entry. */ - if (ADDRESS_FUNCTION (dummy) > addr) - stack_dir = 1; /* Stack grew upward. */ - else - stack_dir = -1; /* Stack grew downward. */ - } + int dir, dummy = 0; + if (! addr) + addr = &dummy; + *addr = addr < &dummy ? 1 : addr == &dummy ? 0 : -1; + dir = depth ? find_stack_direction (addr, depth - 1) : 0; + return dir + dummy; } -#endif /* STACK_DIRECTION == 0 */ +# endif /* STACK_DIRECTION == 0 */ /* An "alloca header" is used to: (a) chain together all alloca'ed blocks; @@ -135,21 +113,21 @@ find_stack_direction () It is very important that sizeof(header) agree with malloc alignment chunk size. The following default should work okay. */ -#ifndef ALIGN_SIZE -#define ALIGN_SIZE sizeof(double) -#endif +# ifndef ALIGN_SIZE +# define ALIGN_SIZE sizeof(double) +# endif typedef union hdr { - char align[ALIGN_SIZE]; /* To force sizeof(header). */ + char align[ALIGN_SIZE]; /* To force sizeof(header). */ struct { - union hdr *next; /* For chaining headers. */ - char *deep; /* For stack depth measure. */ + union hdr *next; /* For chaining headers. */ + char *deep; /* For stack depth measure. */ } h; } header; -static header *last_alloca_header = NULL; /* -> last alloca header. */ +static header *last_alloca_header = NULL; /* -> last alloca header. */ /* Return a pointer to at least SIZE bytes of storage, which will be automatically reclaimed upon exit from @@ -158,84 +136,92 @@ static header *last_alloca_header = NULL; /* -> last alloca header. */ caller, but that method cannot be made to work for some implementations of C, for example under Gould's UTX/32. */ -pointer -alloca (size) - unsigned size; +void * +alloca (size_t size) { - auto char probe; /* Probes stack depth: */ + auto char probe; /* Probes stack depth: */ register char *depth = ADDRESS_FUNCTION (probe); -#if STACK_DIRECTION == 0 - if (STACK_DIR == 0) /* Unknown growth direction. */ - find_stack_direction (); -#endif +# if STACK_DIRECTION == 0 + if (STACK_DIR == 0) /* Unknown growth direction. */ + STACK_DIR = find_stack_direction (NULL, (size & 1) + 20); +# endif /* Reclaim garbage, defined as all alloca'd storage that - was allocated from deeper in the stack than currently. */ + was allocated from deeper in the stack than currently. */ { - register header *hp; /* Traverses linked list. */ + register header *hp; /* Traverses linked list. */ -#ifdef emacs +# ifdef emacs BLOCK_INPUT; -#endif +# endif for (hp = last_alloca_header; hp != NULL;) if ((STACK_DIR > 0 && hp->h.deep > depth) - || (STACK_DIR < 0 && hp->h.deep < depth)) - { - register header *np = hp->h.next; + || (STACK_DIR < 0 && hp->h.deep < depth)) + { + register header *np = hp->h.next; - free ((pointer) hp); /* Collect garbage. */ + free (hp); /* Collect garbage. */ - hp = np; /* -> next header. */ - } + hp = np; /* -> next header. */ + } else - break; /* Rest are not deeper. */ + break; /* Rest are not deeper. */ - last_alloca_header = hp; /* -> last valid storage. */ + last_alloca_header = hp; /* -> last valid storage. */ -#ifdef emacs +# ifdef emacs UNBLOCK_INPUT; -#endif +# endif } if (size == 0) - return NULL; /* No allocation required. */ + return NULL; /* No allocation required. */ /* Allocate combined header + user data storage. */ { - register pointer new = malloc (sizeof (header) + size); /* Address of header. */ + register header *new; + + size_t combined_size = sizeof (header) + size; + if (combined_size < sizeof (header)) + memory_full (); + + new = malloc (combined_size); - ((header *) new)->h.next = last_alloca_header; - ((header *) new)->h.deep = depth; + if (! new) + memory_full (); - last_alloca_header = (header *) new; + new->h.next = last_alloca_header; + new->h.deep = depth; + + last_alloca_header = new; /* User storage begins just after header. */ - return (pointer) ((char *) new + sizeof (header)); + return (void *) (new + 1); } } -#if defined (CRAY) && defined (CRAY_STACKSEG_END) +# if defined (CRAY) && defined (CRAY_STACKSEG_END) -#ifdef DEBUG_I00AFUNC -#include -#endif +# ifdef DEBUG_I00AFUNC +# include +# endif -#ifndef CRAY_STACK -#define CRAY_STACK -#ifndef CRAY2 +# ifndef CRAY_STACK +# define CRAY_STACK +# ifndef CRAY2 /* Stack structures for CRAY-1, CRAY X-MP, and CRAY Y-MP */ struct stack_control_header { - long shgrow:32; /* Number of times stack has grown. */ - long shaseg:32; /* Size of increments to stack. */ - long shhwm:32; /* High water mark of stack. */ - long shsize:32; /* Current size of stack (all segments). */ + long shgrow:32; /* Number of times stack has grown. */ + long shaseg:32; /* Size of increments to stack. */ + long shhwm:32; /* High water mark of stack. */ + long shsize:32; /* Current size of stack (all segments). */ }; /* The stack segment linkage control information occurs at @@ -247,21 +233,21 @@ struct stack_control_header struct stack_segment_linkage { - long ss[0200]; /* 0200 overflow words. */ - long sssize:32; /* Number of words in this segment. */ - long ssbase:32; /* Offset to stack base. */ + long ss[0200]; /* 0200 overflow words. */ + long sssize:32; /* Number of words in this segment. */ + long ssbase:32; /* Offset to stack base. */ long:32; - long sspseg:32; /* Offset to linkage control of previous - segment of stack. */ + long sspseg:32; /* Offset to linkage control of previous + segment of stack. */ long:32; - long sstcpt:32; /* Pointer to task common address block. */ - long sscsnm; /* Private control structure number for - microtasking. */ - long ssusr1; /* Reserved for user. */ - long ssusr2; /* Reserved for user. */ - long sstpid; /* Process ID for pid based multi-tasking. */ - long ssgvup; /* Pointer to multitasking thread giveup. */ - long sscray[7]; /* Reserved for Cray Research. */ + long sstcpt:32; /* Pointer to task common address block. */ + long sscsnm; /* Private control structure number for + microtasking. */ + long ssusr1; /* Reserved for user. */ + long ssusr2; /* Reserved for user. */ + long sstpid; /* Process ID for pid based multi-tasking. */ + long ssgvup; /* Pointer to multitasking thread giveup. */ + long sscray[7]; /* Reserved for Cray Research. */ long ssa0; long ssa1; long ssa2; @@ -280,32 +266,32 @@ struct stack_segment_linkage long sss7; }; -#else /* CRAY2 */ +# else /* CRAY2 */ /* The following structure defines the vector of words returned by the STKSTAT library routine. */ struct stk_stat { - long now; /* Current total stack size. */ - long maxc; /* Amount of contiguous space which would - be required to satisfy the maximum - stack demand to date. */ - long high_water; /* Stack high-water mark. */ - long overflows; /* Number of stack overflow ($STKOFEN) calls. */ - long hits; /* Number of internal buffer hits. */ - long extends; /* Number of block extensions. */ - long stko_mallocs; /* Block allocations by $STKOFEN. */ - long underflows; /* Number of stack underflow calls ($STKRETN). */ - long stko_free; /* Number of deallocations by $STKRETN. */ - long stkm_free; /* Number of deallocations by $STKMRET. */ - long segments; /* Current number of stack segments. */ - long maxs; /* Maximum number of stack segments so far. */ - long pad_size; /* Stack pad size. */ - long current_address; /* Current stack segment address. */ - long current_size; /* Current stack segment size. This - number is actually corrupted by STKSTAT to - include the fifteen word trailer area. */ - long initial_address; /* Address of initial segment. */ - long initial_size; /* Size of initial segment. */ + long now; /* Current total stack size. */ + long maxc; /* Amount of contiguous space which would + be required to satisfy the maximum + stack demand to date. */ + long high_water; /* Stack high-water mark. */ + long overflows; /* Number of stack overflow ($STKOFEN) calls. */ + long hits; /* Number of internal buffer hits. */ + long extends; /* Number of block extensions. */ + long stko_mallocs; /* Block allocations by $STKOFEN. */ + long underflows; /* Number of stack underflow calls ($STKRETN). */ + long stko_free; /* Number of deallocations by $STKRETN. */ + long stkm_free; /* Number of deallocations by $STKMRET. */ + long segments; /* Current number of stack segments. */ + long maxs; /* Maximum number of stack segments so far. */ + long pad_size; /* Stack pad size. */ + long current_address; /* Current stack segment address. */ + long current_size; /* Current stack segment size. This + number is actually corrupted by STKSTAT to + include the fifteen word trailer area. */ + long initial_address; /* Address of initial segment. */ + long initial_size; /* Size of initial segment. */ }; /* The following structure describes the data structure which trails @@ -314,13 +300,13 @@ struct stk_stat struct stk_trailer { - long this_address; /* Address of this block. */ - long this_size; /* Size of this block (does not include - this trailer). */ + long this_address; /* Address of this block. */ + long this_size; /* Size of this block (does not include + this trailer). */ long unknown2; long unknown3; - long link; /* Address of trailer block of previous - segment. */ + long link; /* Address of trailer block of previous + segment. */ long unknown5; long unknown6; long unknown7; @@ -333,12 +319,12 @@ struct stk_trailer long unknown14; }; -#endif /* CRAY2 */ -#endif /* not CRAY_STACK */ +# endif /* CRAY2 */ +# endif /* not CRAY_STACK */ -#ifdef CRAY2 +# ifdef CRAY2 /* Determine a "stack measure" for an arbitrary ADDRESS. - I doubt that "lint" will like this much. */ + I doubt that "lint" will like this much. */ static long i00afunc (long *address) @@ -358,8 +344,8 @@ i00afunc (long *address) /* Set up the iteration. */ trailer = (struct stk_trailer *) (status.current_address - + status.current_size - - 15); + + status.current_size + - 15); /* There must be at least one stack segment. Therefore it is a fatal error if "trailer" is null. */ @@ -374,10 +360,10 @@ i00afunc (long *address) block = (long *) trailer->this_address; size = trailer->this_size; if (block == 0 || size == 0) - abort (); + abort (); trailer = (struct stk_trailer *) trailer->link; if ((block <= address) && (address < (block + size))) - break; + break; } /* Set the result to the offset in this segment and add the sizes @@ -393,7 +379,7 @@ i00afunc (long *address) do { if (trailer->this_size <= 0) - abort (); + abort (); result += trailer->this_size; trailer = (struct stk_trailer *) trailer->link; } @@ -407,7 +393,7 @@ i00afunc (long *address) return (result); } -#else /* not CRAY2 */ +# else /* not CRAY2 */ /* Stack address function for a CRAY-1, CRAY X-MP, or CRAY Y-MP. Determine the number of the cell within the stack, given the address of the cell. The purpose of this @@ -452,11 +438,11 @@ i00afunc (long address) while (!(this_segment <= address && address <= stkl)) { -#ifdef DEBUG_I00AFUNC +# ifdef DEBUG_I00AFUNC fprintf (stderr, "%011o %011o %011o\n", this_segment, address, stkl); -#endif +# endif if (pseg == 0) - break; + break; stkl = stkl - pseg; ssptr = (struct stack_segment_linkage *) stkl; size = ssptr->sssize; @@ -473,9 +459,9 @@ i00afunc (long address) while (pseg != 0) { -#ifdef DEBUG_I00AFUNC +# ifdef DEBUG_I00AFUNC fprintf (stderr, "%011o %011o\n", pseg, size); -#endif +# endif stkl = stkl - pseg; ssptr = (struct stack_segment_linkage *) stkl; size = ssptr->sssize; @@ -485,8 +471,8 @@ i00afunc (long address) return (result); } -#endif /* not CRAY2 */ -#endif /* CRAY */ +# endif /* not CRAY2 */ +# endif /* CRAY */ -#endif /* no alloca */ -#endif /* not GCC version 2 */ +# endif /* no alloca */ +#endif /* not GCC 2 */