Merge branch 'fuzzer_updates' of https://github.com/randy408/stb into working

tests/Makefile

@@ -2,9 +2,11 @@ INCLUDES = -I..
 CFLAGS = -Wno-pointer-to-int-cast -Wno-int-to-pointer-cast -DSTB_DIVIDE_TEST
 CPPFLAGS = -Wno-write-strings -DSTB_DIVIDE_TEST
 
-#CFLAGS += -O -fsanitize=address
+# Uncomment this line for reproducing OSS-Fuzz bugs with image_fuzzer
+#CFLAGS += -O -fsanitize=address 
 
 all:
 	$(CC) $(INCLUDES) $(CFLAGS) ../stb_vorbis.c test_c_compilation.c test_c_lexer.c test_dxt.c test_easyfont.c test_image.c test_image_write.c test_perlin.c test_sprintf.c test_truetype.c test_voxel.c -lm
 	$(CC) $(INCLUDES) $(CPPFLAGS) -std=c++0x test_cpp_compilation.cpp -lm -lstdc++
 	$(CC) $(INCLUDES) $(CFLAGS) -DIWT_TEST image_write_test.c -lm -o image_write_test
+	$(CC) $(INCLUDES) $(CFLAGS) fuzz_main.c stbi_read_fuzzer.c -lm -o image_fuzzer

tests/fuzz_main.c

@@ -0,0 +1,54 @@
+#include <stdint.h>
+#include <stdio.h>
+#include <stdlib.h>
+
+/* fuzz target entry point, works without libFuzzer */
+
+int LLVMFuzzerTestOneInput(const uint8_t* data, size_t size);
+
+int main(int argc, char **argv)
+{
+    FILE *f;
+    char *buf = NULL;
+    long siz_buf;
+
+    if(argc < 2)
+    {
+        fprintf(stderr, "no input file\n");
+        goto err;
+    }
+
+    f = fopen(argv[1], "rb");
+    if(f == NULL)
+    {
+        fprintf(stderr, "error opening input file %s\n", argv[1]);
+        goto err;
+    }
+
+    fseek(f, 0, SEEK_END);
+
+    siz_buf = ftell(f);
+    rewind(f);
+
+    if(siz_buf < 1) goto err;
+
+    buf = (char*)malloc((size_t)siz_buf);
+    if(buf == NULL)
+    {
+        fprintf(stderr, "malloc() failed\n");
+        goto err;
+    }
+
+    if(fread(buf, (size_t)siz_buf, 1, f) != 1)
+    {
+        fprintf(stderr, "fread() failed\n");
+        goto err;
+    }
+
+    (void)LLVMFuzzerTestOneInput((uint8_t*)buf, (size_t)siz_buf);
+
+err:
+    free(buf);
+
+    return 0;
+}

tests/ossfuzz.sh

@@ -0,0 +1,25 @@
+#!/bin/bash -eu
+# This script is meant to be run by
+# https://github.com/google/oss-fuzz/blob/master/projects/stb/Dockerfile
+
+$CXX $CXXFLAGS -std=c++11 -I. -DSTBI_ONLY_PNG  \
+    $SRC/stb/tests/stbi_read_fuzzer.c \
+    -o $OUT/stb_png_read_fuzzer $LIB_FUZZING_ENGINE
+
+$CXX $CXXFLAGS -std=c++11 -I. \
+    $SRC/stb/tests/stbi_read_fuzzer.c \
+    -o $OUT/stbi_read_fuzzer $LIB_FUZZING_ENGINE
+
+find $SRC/stb/tests/pngsuite -name "*.png" | \
+     xargs zip $OUT/stb_png_read_fuzzer_seed_corpus.zip
+
+cp $SRC/stb/tests/stb_png.dict $OUT/stb_png_read_fuzzer.dict
+
+tar xvzf $SRC/stb/jpg.tar.gz --directory $SRC/stb/tests
+tar xvzf $SRC/stb/gif.tar.gz --directory $SRC/stb/tests
+
+find $SRC/stb/tests -name "*.png" -o -name "*.jpg" -o -name ".gif" | \
+     xargs zip $OUT/stbi_read_fuzzer_seed_corpus.zip
+
+echo "" >> $SRC/stb/tests/gif.dict
+cat $SRC/stb/tests/gif.dict $SRC/stb/tests/stb_png.dict > $OUT/stbi_read_fuzzer.dict

tests/stb_png_read_fuzzer.options

@@ -1,2 +0,0 @@
-[libfuzzer]
-dict = stb_png.dict

tests/stbi_read_fuzzer.c

@@ -1,8 +1,13 @@
+#ifdef __cplusplus
+extern "C" {
+#endif
+
 #define STB_IMAGE_IMPLEMENTATION
-#define STBI_ONLY_PNG
+
 #include "../stb_image.h"
 
-extern "C" int LLVMFuzzerTestOneInput(const uint8_t* data, size_t size)
+
+int LLVMFuzzerTestOneInput(const uint8_t* data, size_t size)
 {
     int x, y, channels;
 
@@ -17,3 +22,7 @@ extern "C" int LLVMFuzzerTestOneInput(const uint8_t* data, size_t size)
 
     return 0;
 }
+
+#ifdef __cplusplus
+}
+#endif