check-headers.sh: Add a test for cairo_public decorators in public headers

Test fails currently because of bug 8313 and similar issues.

src/Makefile.am

@@ -281,7 +281,7 @@ install-data-local:
 	  false ;									\
         fi
 
-TESTS = check-def.sh check-plt.sh
+TESTS = check-def.sh check-plt.sh check-headers.sh
 EXTRA_DIST += $(TESTS)
 
 CLEANFILES = cairo.def cairo-features.h

src/check-headers.sh

@@ -0,0 +1,21 @@
+#!/bin/sh
+
+LANG=C
+
+test -z "$srcdir" && srcdir=.
+status=0
+
+echo Checking public headers for missing cairo_public decorators
+
+find "$srcdir" -name '*.h' -not -name '*-private.h' -not -name '*-test.h' -not -name 'cairoint.h' |
+xargs grep -B 1 '^cairo_.*[ 	]\+(' |
+awk '
+/^--$/ { context=""; public=0; next; }
+/:cairo_.*[ 	]+\(/ { if (!public) {print context; print; print "--";} next; }
+/-cairo_public\>/ {public=1;}
+{ context=$0; }
+' |
+sed 's/[.]h-/.h:/' |
+grep . && status=1
+
+exit $status