Scaffold for oss-fuzz, from Sergey Nizovtsev.

1 files changed, 44 insertions, 3 deletions

diff --git a/configure.ac b/configure.ac
index cf621835..97010df4 100644
--- a/configure.ac
+++ b/configure.ac
@@ -21,6 +21,26 @@ SAVED_CFLAGS="$CFLAGS"
 SAVED_CPPFLAGS="$CPPFLAGS"
 SAVED_LDFLAGS="$LDFLAGS"
 
+# Is this oss-fuzz build?
+AC_ARG_ENABLE(
+	fuzzing,
+	AC_HELP_STRING(--enable-fuzzing, build fuzzers)
+)
+AC_ARG_VAR(
+	FUZZING_LIBS,
+	AC_HELP_STRING(libraries to link fuzzing targets with)
+)
+
+# Set up convenient fuzzing defaults before initializing compiler.
+if test "x$enable_fuzzing" = xyes; then
+	AC_DEFINE(NEED_FUZZING)
+	test "x$CC" == x && CC=clang
+	test "x$FUZZING_LIBS" == x && \
+		FUZZING_LIBS="-fsanitize=fuzzer"
+	test "x$SAVED_CFLAGS" == x && \
+		AM_CFLAGS="-g -fsanitize=fuzzer-no-link,address"
+fi
+
 # Set up the compiler in two different ways and say yes we may want to install.
 AC_PROG_CC
 AM_PROG_CC_C_O
@@ -54,8 +74,11 @@ if test "x$enable_static" = xyes; then
 	LDFLAGS="$AM_LDFLAGS $SAVED_LDFLAGS"
 fi
 
+# Do we need fuzzers?
+AM_CONDITIONAL(NEED_FUZZING, test "x$enable_fuzzing" = xyes)
+
 # Is this gcc?
-AM_CONDITIONAL(IS_GCC, test "x$GCC" = xyes)
+AM_CONDITIONAL(IS_GCC, test "x$GCC" = xyes -a "x$enable_fuzzing" != xyes)
 
 # Is this Sun CC?
 AC_EGREP_CPP(
@@ -117,8 +140,6 @@ AC_REPLACE_FUNCS([ \
 	getline \
 	getprogname \
 	memmem \
-	recallocarray \
-	reallocarray \
 	setenv \
 	setproctitle \
 	strcasestr \
@@ -130,6 +151,26 @@ AC_REPLACE_FUNCS([ \
 ])
 AC_FUNC_STRNLEN
 
+# Clang sanitizers wrap reallocarray even if it isn't available on the target
+# system. When compiled it always returns NULL and crashes the program. To
+# detect this we need a more complicated test.
+AC_MSG_CHECKING([for working reallocarray])
+AC_RUN_IFELSE([AC_LANG_PROGRAM(
+		[#include <stdlib.h>],
+		[return (reallocarray(NULL, 1, 1) == NULL);]
+	)],
+	AC_MSG_RESULT(yes),
+	[AC_LIBOBJ(reallocarray) AC_MSG_RESULT([no])]
+)
+AC_MSG_CHECKING([for working recallocarray])
+AC_RUN_IFELSE([AC_LANG_PROGRAM(
+		[#include <stdlib.h>],
+		[return (recallocarray(NULL, 1, 1, 1) == NULL);]
+	)],
+	AC_MSG_RESULT(yes),
+	[AC_LIBOBJ(recallocarray) AC_MSG_RESULT([no])]
+)
+
 # Look for clock_gettime. Must come before event_init.
 AC_SEARCH_LIBS(clock_gettime, rt)