build-sys: add check that our headers are ANSI compatible

diff --git a/Makefile.am b/Makefile.am
index 9cee98ec5ad0be6a77f7cb114389cf108157ef0d..0f1f79e62d489f7a7997290084444a499c403c12 100644 (file)
--- a/Makefile.am
+++ b/Makefile.am
@@ -6161,7 +6161,6 @@ DISTCHECK_CONFIGURE_FLAGS += \
 endif
 
 .PHONY: dist-check-help
-
 dist-check-help: $(rootbin_PROGRAMS) $(bin_PROGRAMS)
        for i in $(abspath $^); do                                             \
             if $$i  --help | grep -v 'default:' | grep -E -q '.{80}.' ; then   \
@@ -6170,6 +6169,18 @@ dist-check-help: $(rootbin_PROGRAMS) $(bin_PROGRAMS)
                exit 1;                                                        \
             fi; done
 
+include_compilers = "$(CC)" "$(CC) -ansi" "$(CC) -std=iso9899:1990"
+public_headers = $(filter-out src/systemd/_sd-common.h, $(pkginclude_HEADERS) $(include_HEADERS))
+.PHONY: dist-check-includes
+dist-check-includes: $(public_headers)
+       @res=0;                                                                 \
+       for i in $(abspath $^); do                                              \
+           for cc in $(include_compilers); do                                  \
+               echo "$$cc -o/dev/null -c -x c -include "$$i" - </dev/null";    \
+               $$cc -o/dev/null -c -x c -include "$$i" - </dev/null || res=1;  \
+           done;                                                               \
+       done; exit $$res
+
 .PHONY: hwdb-update
 hwdb-update:
        ( cd $(top_srcdir)/hwdb && \