From 73067e5c9af6583bfc1b2da36e8162ac35035478 Mon Sep 17 00:00:00 2001
From: Janne Grunau <janne-vlc@jannau.net>
Date: Tue, 11 Dec 2018 21:27:37 +0100
Subject: [PATCH] allocation fail fuzzer: use a static library and objcopy

oss-fuzz can not handle shared libraries. Do not build it by default.
---
 tests/libfuzzer/alloc_fail.c |  6 ++----
 tests/meson.build            | 37 ++++++++++++++++++------------------
 2 files changed, 21 insertions(+), 22 deletions(-)

diff --git a/tests/libfuzzer/alloc_fail.c b/tests/libfuzzer/alloc_fail.c
index 515e8ee..50b2c4b 100644
--- a/tests/libfuzzer/alloc_fail.c
+++ b/tests/libfuzzer/alloc_fail.c
@@ -44,23 +44,21 @@ void dav1d_setup_alloc_fail(unsigned seed, unsigned probability) {
     fail_probability = probability;
 }
 
-void * __real_malloc(size_t);
 void * __wrap_malloc(size_t);
 
 void * __wrap_malloc(size_t sz) {
     if (rand() < fail_probability)
         return NULL;
-    return __real_malloc(sz);
+    return malloc(sz);
 }
 
 #if defined(HAVE_POSIX_MEMALIGN)
-int __real_posix_memalign(void **memptr, size_t alignment, size_t size);
 int __wrap_posix_memalign(void **memptr, size_t alignment, size_t size);
 
 int __wrap_posix_memalign(void **memptr, size_t alignment, size_t size) {
     if (rand() < fail_probability)
         return ENOMEM;
-    return __real_posix_memalign(memptr, alignment, size);
+    return posix_memalign(memptr, alignment, size);
 }
 #else
 #error "HAVE_POSIX_MEMALIGN required"
diff --git a/tests/meson.build b/tests/meson.build
index 9d8b304..16da420 100644
--- a/tests/meson.build
+++ b/tests/meson.build
@@ -124,28 +124,29 @@ dav1d_fuzzer_mt = executable('dav1d_fuzzer_mt',
     dependencies : [thread_dependency],
     )
 
-if (cc.has_function('posix_memalign', prefix : '#include <stdlib.h>', args : test_args) and
-    cc.has_link_argument('-Wl,-wrap,malloc') and not get_option('b_lto'))
-
-    alloc_fail = shared_library('alloc_fail',
-        files('libfuzzer/alloc_fail.c'),
-        libdav1d_nasm_objs_if_needed,
-        objects: [
-            libdav1d.extract_all_objects(recursive: true),
-            ],
-        include_directories: dav1d_inc_dirs,
-        c_args : [stackalign_flag],
-        link_args: ['-Wl,-wrap,malloc', '-Wl,-wrap,posix_memalign'],
-        dependencies : [thread_dependency],
-        )
+objcopy = find_program('objcopy',
+                       required: false)
+if (objcopy.found() and
+    not get_option('b_lto') and
+    get_option('default_library') == 'static' and
+    cc.has_function('posix_memalign', prefix : '#include <stdlib.h>', args : test_args))
+
+    libdav1d_af = custom_target('libdav1d_af',
+                                input: libdav1d,
+                                output: 'libdav1d_af.a',
+                                depends: libdav1d,
+                                command: [objcopy,
+                                          '--redefine-sym', 'malloc=__wrap_malloc',
+                                          '--redefine-sym', 'posix_memalign=__wrap_posix_memalign',
+                                          '@INPUT@', '@OUTPUT@'])
 
     dav1d_fuzzer_mem = executable('dav1d_fuzzer_mem',
-        dav1d_fuzzer_sources,
+        dav1d_fuzzer_sources + ['libfuzzer/alloc_fail.c'],
         include_directories: dav1d_inc_dirs,
         c_args: [stackalign_flag, stackrealign_flag, '-DDAV1D_ALLOC_FAIL'],
-        link_args: fuzzer_ldflags,
-        link_with : [alloc_fail],
-        build_by_default: true,
+        link_args: fuzzer_ldflags + [join_paths(libdav1d_af.full_path())],
+        link_depends: libdav1d_af,
+        build_by_default: false,
         dependencies : [thread_dependency],
         )
 endif
-- 
2.18.1