m4: reinstate CC_CHECK_FLAG_APPEND summary

Earlier commit was reducing the license boilerplate to SPDX license
identifiers and erroneously dropped the function summary section.

Cc: Lucas De Marchi <lucas.de.marchi@gmail.com>
Fixes: b5a2cd0 ("Use SPDX header for license")
Signed-off-by: Emil Velikov <emil.l.velikov@gmail.com>
Signed-off-by: Lucas De Marchi <lucas.de.marchi@gmail.com>

diff --git a/m4/attributes.m4 b/m4/attributes.m4
index 69865eea6d2ec7d4a27f82e067b0999396a8a88c..a22bb58670fc27bf1e341f2c4fd53d2ca3dfb4b9 100644 (file)
--- a/m4/attributes.m4
+++ b/m4/attributes.m4
@@ -4,6 +4,11 @@
 # Copyright (c) 2006-2008 xine project
 # Copyright (c) 2012 Lucas De Marchi <lucas.de.marchi@gmail.com>
 
+# Check if FLAG in ENV-VAR is supported by compiler and append it
+# to WHERE-TO-APPEND variable. Note that we invert -Wno-* checks to
+# -W* as gcc cannot test for negated warnings.
+# CC_CHECK_FLAG_APPEND([WHERE-TO-APPEND], [ENV-VAR], [FLAG])
+
 AC_DEFUN([CC_CHECK_FLAG_APPEND], [
   AC_CACHE_CHECK([if $CC supports flag $3 in envvar $2],
                  AS_TR_SH([cc_cv_$2_$3]),