Enable building a bounded version of the library for fuzzing

test/fuzzing/hb-fuzzer links against libharfbuzz-fuzzing.so now.

src/Makefile.am

@@ -15,6 +15,7 @@ DISTCHECK_CONFIGURE_FLAGS = --enable-introspection
 
 # Convenience targets:
 lib: $(BUILT_SOURCES) libharfbuzz.la
+fuzzing: $(BUILT_SOURCES) libharfbuzz-fuzzing.la
 
 lib_LTLIBRARIES = libharfbuzz.la
 
@@ -219,6 +220,21 @@ pkgconfigdir = $(libdir)/pkgconfig
 pkgconfig_DATA = harfbuzz.pc
 EXTRA_DIST += harfbuzz.pc.in
 
+FUZZING_CPPFLAGS= \
+	-DHB_MAX_NESTING_LEVEL=3 \
+	-DHB_SANITIZE_MAX_EDITS=3 \
+	-DHB_BUFFER_MAX_EXPANSION_FACTOR=3 \
+	-DHB_BUFFER_MAX_LEN_MIN=8 \
+	-DHB_BUFFER_MAX_LEN_DEFAULT=128 \
+	$(NULL)
+EXTRA_LTLIBRARIES = libharfbuzz-fuzzing.la
+libharfbuzz_fuzzing_la_LINK = $(libharfbuzz_la_LINK)
+libharfbuzz_fuzzing_la_SOURCES = $(libharfbuzz_la_SOURCES)
+libharfbuzz_fuzzing_la_CPPFLAGS = $(libharfbuzz_la_CPPFLAGS) $(FUZZING_CPPFLAGS)
+libharfbuzz_fuzzing_la_LDFLAGS = $(libharfbuzz_la_LDFLAGS)
+libharfbuzz_fuzzing_la_LIBADD = $(libharfbuzz_la_LIBADD)
+EXTRA_libharfbuzz_fuzzing_la_DEPENDENCIES = $(EXTRA_libharfbuzz_la_DEPENDENCIES)
+
 if HAVE_ICU
 lib_LTLIBRARIES += libharfbuzz-icu.la
 libharfbuzz_icu_la_SOURCES = hb-icu.cc

test/fuzzing/Makefile.am

@@ -8,7 +8,7 @@ MAINTAINERCLEANFILES =
 
 # Convenience targets:
 lib:
-	@$(MAKE) $(AM_MAKEFLAGS) -C $(top_builddir)/src lib
+	@$(MAKE) $(AM_MAKEFLAGS) -C $(top_builddir)/src fuzzing
 
 EXTRA_DIST += \
 	README \
@@ -25,7 +25,7 @@ AM_CPPFLAGS = \
 	-I$(top_builddir)/src/ \
 	$(NULL)
 LDADD = \
-	$(top_builddir)/src/libharfbuzz.la \
+	$(top_builddir)/src/libharfbuzz-fuzzing.la \
 	$(NULL)
 
 hb_fuzzer_SOURCES = \
@@ -37,11 +37,6 @@ hb_fuzzer_LDADD = \
 hb_fuzzer_CPPFLAGS = \
 	$(AM_CPPFLAGS) \
 	-DMAIN \
-	-DHB_MAX_NESTING_LEVEL=3 \
-	-DHB_SANITIZE_MAX_EDITS=3 \
-	-DHB_BUFFER_MAX_EXPANSION_FACTOR=3 \
-	-DHB_BUFFER_MAX_LEN_MIN=8 \
-	-DHB_BUFFER_MAX_LEN_DEFAULT=128 \
 	$(NULL)
 
 -include $(top_srcdir)/git.mk

test/fuzzing/README

@@ -3,10 +3,8 @@ harfbuzz/test/fuzzing/hb-fuzzer.cc with:
   - Using the most recent Clang
   - With -fsanitize=address (or =undefined, or a combination)
   - With -fsanitize-coverage=edge[,8bit-counters,trace-cmp]
-  - With various defines that limit worst case exponential behavior:
-    * -DHB_MAX_NESTING_LEVEL=3
-    * -DHB_SANITIZE_MAX_EDITS=3
-    * See Makefile.am for full list of flags
+  - With various defines that limit worst case exponential behavior.
+    See FUZZING_CPPFLAGS in harfbuzz/src/Makefile.am for the list.
   - link against libFuzzer
 
 To run the fuzzer one needs to first obtain a test corpus as a directory