halt='found useless parentheses in cpp directive' \
$(_sc_search_regexp)
+# List headers for which HAVE_HEADER_H is always true, assuming you are
+# using the appropriate gnulib module. CAUTION: for each "unnecessary"
+# #if HAVE_HEADER_H that you remove, be sure that your project explicitly
+# requires the gnulib module that guarantees the usability of that header.
+gl_assured_headers_ := \
+ $(shell cd $(gnulib_dir)/lib && ls -1 *.in.h|sed 's/\.in\.h$$/ \\/')
+
+# Convert the list of names to upper case, and replace each space with "|".
+az_ = abcdefghijklmnopqrstuvwxyz
+AZ_ = ABCDEFGHIJKLMNOPQRSTUVWXYZ
+gl_header_upper_case_or_ := \
+ $(shell echo $(gl_assured_headers_) \
+ | tr $(az_)/.- $(AZ_)___ \
+ | tr -s ' ' '|' \
+ )
+gl_have_header_regex_ = HAVE_($(gl_header_upper_case_or_))_H
+sc_prohibit_always_true_header_tests:
+ @prohibit='\<$(gl_have_header_regex_)\>' \
+ halt='do not test the above HAVE_<header>_H symbol(s);\n'\
+' with the corresponding gnulib module, they are always true' \
+ $(_sc_search_regexp)
+
# Prohibit checked in backup files.
sc_prohibit_backup_files:
@$(VC_LIST) | grep '~$$' && \