Silence -Wclobbered in each file that needs it.

BUG=skia:
GOLD_TRYBOT_URL= https://gold.skia.org/search?issue=2184823009

Review-Url: https://codereview.chromium.org/2184823009

2 files changed, 18 insertions, 7 deletions

diff --git a/src/codec/SkJpegCodec.cpp b/src/codec/SkJpegCodec.cpp
index f4116e324f..6a1636c3cf 100644
--- a/src/codec/SkJpegCodec.cpp
+++ b/src/codec/SkJpegCodec.cpp
@@ -19,6 +19,12 @@
 #include <stdio.h>
 #include "SkJpegUtility.h"
 
+// Same as setjmp, but introduces a new empty scope.
+// This way we can avoid GCC's overactive warnings about clobbered locals.
+static int setjmp_no_locals(jmp_buf env) {
+    return setjmp(env);
+}
+
 extern "C" {
     #include "jerror.h"
     #include "jpeglib.h"
@@ -190,7 +196,7 @@ bool SkJpegCodec::ReadHeader(SkStream* stream, SkCodec** codecOut,
     SkAutoTDelete<JpegDecoderMgr> decoderMgr(new JpegDecoderMgr(stream));
 
     // libjpeg errors will be caught and reported here
-    if (setjmp(decoderMgr->getJmpBuf())) {
+    if (setjmp_no_locals(decoderMgr->getJmpBuf())) {
         return decoderMgr->returnFalse("setjmp");
     }
 
@@ -414,7 +420,7 @@ bool SkJpegCodec::setOutputColorSpace(const SkImageInfo& dst) {
  * dimensions if possible
  */
 bool SkJpegCodec::onDimensionsSupported(const SkISize& size) {
-    if (setjmp(fDecoderMgr->getJmpBuf())) {
+    if (setjmp_no_locals(fDecoderMgr->getJmpBuf())) {
         return fDecoderMgr->returnFalse("onDimensionsSupported/setjmp");
     }
 
@@ -466,7 +472,7 @@ SkCodec::Result SkJpegCodec::onGetPixels(const SkImageInfo& dstInfo,
     jpeg_decompress_struct* dinfo = fDecoderMgr->dinfo();
 
     // Set the jump location for libjpeg errors
-    if (setjmp(fDecoderMgr->getJmpBuf())) {
+    if (setjmp_no_locals(fDecoderMgr->getJmpBuf())) {
         return fDecoderMgr->returnFailure("setjmp", kInvalidInput);
     }
 
@@ -575,7 +581,7 @@ SkSampler* SkJpegCodec::getSampler(bool createIfNecessary) {
 SkCodec::Result SkJpegCodec::onStartScanlineDecode(const SkImageInfo& dstInfo,
         const Options& options, SkPMColor ctable[], int* ctableCount) {
     // Set the jump location for libjpeg errors
-    if (setjmp(fDecoderMgr->getJmpBuf())) {
+    if (setjmp_no_locals(fDecoderMgr->getJmpBuf())) {
         SkCodecPrintf("setjmp: Error from libjpeg\n");
         return kInvalidInput;
     }
@@ -651,7 +657,7 @@ SkCodec::Result SkJpegCodec::onStartScanlineDecode(const SkImageInfo& dstInfo,
 
 int SkJpegCodec::onGetScanlines(void* dst, int count, size_t dstRowBytes) {
     // Set the jump location for libjpeg errors
-    if (setjmp(fDecoderMgr->getJmpBuf())) {
+    if (setjmp_no_locals(fDecoderMgr->getJmpBuf())) {
         return fDecoderMgr->returnFailure("setjmp", kInvalidInput);
     }
     // Read rows one at a time
@@ -688,7 +694,7 @@ int SkJpegCodec::onGetScanlines(void* dst, int count, size_t dstRowBytes) {
 
 bool SkJpegCodec::onSkipScanlines(int count) {
     // Set the jump location for libjpeg errors
-    if (setjmp(fDecoderMgr->getJmpBuf())) {
+    if (setjmp_no_locals(fDecoderMgr->getJmpBuf())) {
         return fDecoderMgr->returnFalse("setjmp");
     }
 
@@ -803,7 +809,7 @@ SkCodec::Result SkJpegCodec::onGetYUV8Planes(const SkYUVSizeInfo& sizeInfo, void
     }
 
     // Set the jump location for libjpeg errors
-    if (setjmp(fDecoderMgr->getJmpBuf())) {
+    if (setjmp_no_locals(fDecoderMgr->getJmpBuf())) {
         return fDecoderMgr->returnFailure("setjmp", kInvalidInput);
     }
 
diff --git a/src/codec/SkPngCodec.cpp b/src/codec/SkPngCodec.cpp
index ee72af58ad..b8916f9de7 100644
--- a/src/codec/SkPngCodec.cpp
+++ b/src/codec/SkPngCodec.cpp
@@ -20,6 +20,11 @@
 #include "SkTemplates.h"
 #include "SkUtils.h"
 
+// This warning triggers false postives way too often in here.
+#if defined(__GNUC__) && !defined(__clang__)
+    #pragma GCC diagnostic ignored "-Wclobbered"
+#endif
+
 ///////////////////////////////////////////////////////////////////////////////
 // Callback functions
 ///////////////////////////////////////////////////////////////////////////////