[fuzz] Standardize, document, and backport fuzzing defines.

We had several defines around the code base that were not
very descriptive. Additionally, we had a patch of extra
runtime restrictions living in oss-fuzz that were applied
when fuzzing over there for some fuzzers.

This has all be consolidated and controlled via the defines
documented in site/dev/testing/fuzz.md

As such, we can remove one of the patches that is in oss-fuzz,
taking us closer to being able to fuzz in the CI/CQ.

PS 1 renames existing fuzz defines to the new schema.
PS 2-3 backports skia.diff from oss-fuzz and changes those
definitions to have the _GREATLY modifier.
PS 5+ further condenses the defines so that there is one
define for gating the runtime checks.

Change-Id: Ia4ad96f30c1e9620a2123b510e97c6f501a2e257
Docs-Preview: https://skia.org/?cl=316443
Bug: skia:10713
Reviewed-on: https://skia-review.googlesource.com/c/skia/+/316443
Commit-Queue: Kevin Lubick <kjlubick@google.com>
Reviewed-by: Mike Klein <mtklein@google.com>

fuzz/FuzzPathMeasure.cpp

@@ -22,6 +22,9 @@ DEF_FUZZ(PathMeasure, fuzz) {
     FuzzEvilPath(fuzz, &path, SkPath::Verb::kDone_Verb);
     SkRect bounds = path.getBounds();
     SkScalar maxDim = std::max(bounds.width(), bounds.height());
+    if (maxDim > 1000000) {
+        return;
+    }
     SkScalar resScale = maxDim / 1000;
     SkPathMeasure measure(path, bits & 1, resScale);
     SkPoint position;

fuzz/README.md

@@ -0,0 +1,13 @@
+We fuzz Skia using oss-fuzz, which in turn uses fuzzing engines such as libfuzzer, afl-fuzz,
+hong-fuzz and others.
+
+We define a `fuzzer` to be a targeted bit of code that takes a randomized input and executes code
+in a specific area. For example, we have a codec fuzzer which takes a mutated png/jpeg or similar
+file and attempts to turn it into an `SkImage`. We also have a canvas fuzzer which takes in a random
+set of bytes and turns them into calls on `SkCanvas`.
+
+See [../site/dev/testing/fuzz.md] for more information on building and running fuzzers.
+
+See also:
+  - [Creating a binary fuzzer](https://docs.google.com/document/d/1QDX0o8yDdmhbjoudNsXc66iuRXRF5XNNqGnzDzX7c2I/edit)
+  - [Creating an API fuzzer](https://docs.google.com/document/d/1e3ikXO7SwoBsbsi1MF06vydXRlXvYalVORaiUuOXk2Y/edit)

fuzz/oss_fuzz/FuzzAndroidCodec.cpp

@@ -50,7 +50,7 @@ bool FuzzAndroidCodec(sk_sp<SkData> bytes, uint8_t sampleSize) {
     return true;
 }
 
-#if defined(IS_FUZZING_WITH_LIBFUZZER)
+#if defined(SK_BUILD_FOR_LIBFUZZER)
 extern "C" int LLVMFuzzerTestOneInput(const uint8_t *data, size_t size) {
     if (size > 10240) {
         return 0;

fuzz/oss_fuzz/FuzzAnimatedImage.cpp

@@ -36,7 +36,7 @@ bool FuzzAnimatedImage(sk_sp<SkData> bytes) {
     return true;
 }
 
-#if defined(IS_FUZZING_WITH_LIBFUZZER)
+#if defined(SK_BUILD_FOR_LIBFUZZER)
 extern "C" int LLVMFuzzerTestOneInput(const uint8_t *data, size_t size) {
     if (size > 10240) {
         return 0;

fuzz/oss_fuzz/FuzzImage.cpp

@@ -28,7 +28,7 @@ bool FuzzImageDecode(sk_sp<SkData> bytes) {
     return true;
 }
 
-#if defined(IS_FUZZING_WITH_LIBFUZZER)
+#if defined(SK_BUILD_FOR_LIBFUZZER)
 extern "C" int LLVMFuzzerTestOneInput(const uint8_t *data, size_t size) {
     if (size > 10240) {
         return 0;

fuzz/oss_fuzz/FuzzImageFilterDeserialize.cpp

@@ -39,7 +39,7 @@ void FuzzImageFilterDeserialize(sk_sp<SkData> bytes) {
     }
 }
 
-#if defined(IS_FUZZING_WITH_LIBFUZZER)
+#if defined(SK_BUILD_FOR_LIBFUZZER)
 extern "C" int LLVMFuzzerTestOneInput(const uint8_t *data, size_t size) {
     if (size > 10024) {
         return 0;

fuzz/oss_fuzz/FuzzIncrementalImage.cpp

@@ -45,7 +45,7 @@ bool FuzzIncrementalImageDecode(sk_sp<SkData> bytes) {
     }
 }
 
-#if defined(IS_FUZZING_WITH_LIBFUZZER)
+#if defined(SK_BUILD_FOR_LIBFUZZER)
 extern "C" int LLVMFuzzerTestOneInput(const uint8_t *data, size_t size) {
     if (size > 10240) {
         return 0;

fuzz/oss_fuzz/FuzzJSON.cpp

@@ -15,7 +15,7 @@ void FuzzJSON(sk_sp<SkData> bytes) {
     dom.write(&wstream);
 }
 
-#if defined(IS_FUZZING_WITH_LIBFUZZER)
+#if defined(SK_BUILD_FOR_LIBFUZZER)
 extern "C" int LLVMFuzzerTestOneInput(const uint8_t *data, size_t size) {
     auto bytes = SkData::MakeWithoutCopy(data, size);
     FuzzJSON(bytes);

fuzz/oss_fuzz/FuzzPathDeserialize.cpp

@@ -26,7 +26,7 @@ void FuzzPathDeserialize(SkReadBuffer& buf) {
     s->getCanvas()->drawPath(path, SkPaint());
 }
 
-#if defined(IS_FUZZING_WITH_LIBFUZZER)
+#if defined(SK_BUILD_FOR_LIBFUZZER)
 extern "C" int LLVMFuzzerTestOneInput(const uint8_t *data, size_t size) {
     if (size < 4 || size > 2000) {
         return 0;

fuzz/oss_fuzz/FuzzRegionDeserialize.cpp

@@ -34,7 +34,7 @@ bool FuzzRegionDeserialize(sk_sp<SkData> bytes) {
     return true;
 }
 
-#if defined(IS_FUZZING_WITH_LIBFUZZER)
+#if defined(SK_BUILD_FOR_LIBFUZZER)
 extern "C" int LLVMFuzzerTestOneInput(const uint8_t *data, size_t size) {
     if (size > 512) {
         return 0;

fuzz/oss_fuzz/FuzzRegionSetPath.cpp

@@ -36,7 +36,7 @@ void FuzzRegionSetPath(Fuzz* fuzz) {
     }
 }
 
-#if defined(IS_FUZZING_WITH_LIBFUZZER)
+#if defined(SK_BUILD_FOR_LIBFUZZER)
 extern "C" int LLVMFuzzerTestOneInput(const uint8_t *data, size_t size) {
     if (size > 512) {
         return 0;

fuzz/oss_fuzz/FuzzSKP.cpp

@@ -27,7 +27,7 @@ void FuzzSKP(sk_sp<SkData> bytes) {
     return;
 }
 
-#if defined(IS_FUZZING_WITH_LIBFUZZER)
+#if defined(SK_BUILD_FOR_LIBFUZZER)
 extern "C" int LLVMFuzzerTestOneInput(const uint8_t *data, size_t size) {
     auto bytes = SkData::MakeWithoutCopy(data, size);
     FuzzSKP(bytes);

fuzz/oss_fuzz/FuzzSKSL2GLSL.cpp

@@ -27,7 +27,7 @@ bool FuzzSKSL2GLSL(sk_sp<SkData> bytes) {
     return true;
 }
 
-#if defined(IS_FUZZING_WITH_LIBFUZZER)
+#if defined(SK_BUILD_FOR_LIBFUZZER)
 extern "C" int LLVMFuzzerTestOneInput(const uint8_t *data, size_t size) {
     if (size > 3000) {
         return 0;

fuzz/oss_fuzz/FuzzSKSL2Metal.cpp

@@ -27,7 +27,7 @@ bool FuzzSKSL2Metal(sk_sp<SkData> bytes) {
     return true;
 }
 
-#if defined(IS_FUZZING_WITH_LIBFUZZER)
+#if defined(SK_BUILD_FOR_LIBFUZZER)
 extern "C" int LLVMFuzzerTestOneInput(const uint8_t *data, size_t size) {
     if (size > 3000) {
         return 0;

fuzz/oss_fuzz/FuzzSKSL2Pipeline.cpp

@@ -27,7 +27,7 @@ bool FuzzSKSL2Pipeline(sk_sp<SkData> bytes) {
     return true;
 }
 
-#if defined(IS_FUZZING_WITH_LIBFUZZER)
+#if defined(SK_BUILD_FOR_LIBFUZZER)
 extern "C" int LLVMFuzzerTestOneInput(const uint8_t *data, size_t size) {
     if (size > 3000) {
         return 0;

fuzz/oss_fuzz/FuzzSKSL2SPIRV.cpp

@@ -27,7 +27,7 @@ bool FuzzSKSL2SPIRV(sk_sp<SkData> bytes) {
     return true;
 }
 
-#if defined(IS_FUZZING_WITH_LIBFUZZER)
+#if defined(SK_BUILD_FOR_LIBFUZZER)
 extern "C" int LLVMFuzzerTestOneInput(const uint8_t *data, size_t size) {
     if (size > 3000) {
         return 0;

fuzz/oss_fuzz/FuzzSVG.cpp

@@ -31,7 +31,7 @@ void FuzzSVG(sk_sp<SkData> bytes) {
 
 }
 
-#if defined(IS_FUZZING_WITH_LIBFUZZER)
+#if defined(SK_BUILD_FOR_LIBFUZZER)
 extern "C" int LLVMFuzzerTestOneInput(const uint8_t *data, size_t size) {
     if (size > 30000) {
         return 0;

fuzz/oss_fuzz/FuzzSkDescriptorDeserialize.cpp

@@ -27,7 +27,7 @@ void FuzzSkDescriptorDeserialize(sk_sp<SkData> bytes) {
     desc->findEntry(tagToFind, &ignore);
 }
 
-#if defined(IS_FUZZING_WITH_LIBFUZZER)
+#if defined(SK_BUILD_FOR_LIBFUZZER)
 extern "C" int LLVMFuzzerTestOneInput(const uint8_t *data, size_t size) {
     if (size > 1024) {
         return 0;

fuzz/oss_fuzz/FuzzSkRuntimeEffect.cpp

@@ -74,7 +74,7 @@ bool FuzzSkRuntimeEffect(sk_sp<SkData> bytes) {
     return result;
 }
 
-#if defined(IS_FUZZING_WITH_LIBFUZZER)
+#if defined(SK_BUILD_FOR_LIBFUZZER)
 extern "C" int LLVMFuzzerTestOneInput(const uint8_t *data, size_t size) {
     if (size > 3000) {
         return 0;

fuzz/oss_fuzz/FuzzTextBlobDeserialize.cpp

@@ -27,7 +27,7 @@ void FuzzTextBlobDeserialize(SkReadBuffer& buf) {
     s->getCanvas()->drawTextBlob(tb, 200, 200, SkPaint());
 }
 
-#if defined(IS_FUZZING_WITH_LIBFUZZER)
+#if defined(SK_BUILD_FOR_LIBFUZZER)
 extern "C" int LLVMFuzzerTestOneInput(const uint8_t *data, size_t size) {
     if (size > 1024) {
         return 0;

include/core/SkTypes.h

@@ -420,6 +420,14 @@
 #define SK_API_AVAILABLE(...)
 #endif
 
+#if defined(SK_BUILD_FOR_LIBFUZZER) || defined(SK_BUILD_FOR_AFL_FUZZ)
+    #define SK_BUILD_FOR_FUZZER
+#endif
+
+#if defined(SK_BUILD_FOR_LIBFUZZER)
+    SK_API void SkDebugf(const char format[], ...) {}
+#endif
+
 /** Called internally if we hit an unrecoverable error.
     The platform implementation must not return, but should either throw
     an exception or otherwise exit.

include/private/SkMalloc.h

@@ -64,9 +64,8 @@ static inline void* sk_calloc_throw(size_t size) {
 }
 
 static inline void* sk_calloc_canfail(size_t size) {
-#if defined(IS_FUZZING_WITH_LIBFUZZER)
-    // The Libfuzzer environment is very susceptible to OOM, so to avoid those
-    // just pretend we can't allocate more than 200kb.
+#if defined(SK_BUILD_FOR_FUZZER)
+    // To reduce the chance of OOM, pretend we can't allocate more than 200kb.
     if (size > 200000) {
         return nullptr;
     }
@@ -83,9 +82,8 @@ SK_API extern void* sk_realloc_throw(void* buffer, size_t count, size_t elemSize
  *  These variants return nullptr on failure
  */
 static inline void* sk_malloc_canfail(size_t size) {
-#if defined(IS_FUZZING_WITH_LIBFUZZER)
-    // The Libfuzzer environment is very susceptible to OOM, so to avoid those
-    // just pretend we can't allocate more than 200kb.
+#if defined(SK_BUILD_FOR_FUZZER)
+    // To reduce the chance of OOM, pretend we can't allocate more than 200kb.
     if (size > 200000) {
         return nullptr;
     }

modules/skottie/fuzz/FuzzSkottieJSON.cpp

@@ -20,7 +20,7 @@ void FuzzSkottieJSON(sk_sp<SkData> bytes) {
     animation->seek(0.1337f); // A "nothing up my sleeve" number
 }
 
-#if defined(IS_FUZZING_WITH_LIBFUZZER)
+#if defined(SK_BUILD_FOR_LIBFUZZER)
 extern "C" int LLVMFuzzerTestOneInput(const uint8_t *data, size_t size) {
     gSkFontMgr_DefaultFactory = &ToolUtils::MakePortableFontMgr;
     auto bytes = SkData::MakeWithoutCopy(data, size);

site/dev/testing/fuzz.md

@@ -19,8 +19,8 @@ less machine- and platform- dependent:
     skia_enable_fontmgr_custom_embedded=false
     skia_enable_fontmgr_custom_empty=true
 
-All that is needed to reproduce a fuzz downloaded from ClusterFuzz, oss-fuzz or
-fuzzer.skia.org is to run something like:
+All that is needed to reproduce a fuzz downloaded from ClusterFuzz or oss-fuzz is to
+run something like:
 
     out/ASAN/fuzz -b /path/to/downloaded/testcase
 
@@ -69,3 +69,19 @@ Build Skia and your fuzzer entry point:
 Run your new fuzzer binary
 
     ./a.out
+
+
+Fuzzing Defines
+---------------
+There are some defines that can help guide a fuzzer to be more productive (e.g. avoid OOMs, avoid
+unnecessarily slow code).
+
+    // Required for fuzzing with afl-fuzz to prevent OOMs from adding noise.
+    SK_BUILD_FOR_AFL_FUZZ
+
+    // Required for fuzzing with libfuzzer
+    SK_BUILD_FOR_LIBFUZZER
+
+    // This define adds in guards to abort when we think some code path will take a long time or
+    // use a lot of RAM. It is set by default when either of the above defines are set.
+    SK_BUILD_FOR_FUZZER

src/codec/SkRawCodec.cpp

@@ -435,7 +435,7 @@ public:
      */
     static SkDngImage* NewFromStream(SkRawStream* stream) {
         std::unique_ptr<SkDngImage> dngImage(new SkDngImage(stream));
-#if defined(IS_FUZZING_WITH_LIBFUZZER)
+#if defined(SK_BUILD_FOR_LIBFUZZER)
         // Libfuzzer easily runs out of memory after here. To avoid that
         // We just pretend all streams are invalid. Our AFL-fuzzer
         // should still exercise this code; it's more resistant to OOM.

src/core/SkAAClip.cpp

@@ -1546,6 +1546,12 @@ static void operateY(SkAAClip::Builder& builder, const SkAAClip& A,
     int topB = iterB.top();
     int botB = iterB.bottom();
 
+#if defined(SK_BUILD_FOR_FUZZER)
+    if ((botA - topA) > 100000 || (botB - topB) > 100000) {
+        return;
+    }
+#endif
+
     do {
         const uint8_t* rowA = nullptr;
         const uint8_t* rowB = nullptr;

src/core/SkDraw.cpp

@@ -956,6 +956,12 @@ void SkDraw::drawPath(const SkPath& origSrcPath, const SkPaint& origPaint,
     // transform the path into device space
     pathPtr->transform(matrixProvider->localToDevice(), devPathPtr);
 
+#if defined(SK_BUILD_FOR_FUZZER)
+    if (devPathPtr->countPoints() > 1000) {
+        return;
+    }
+#endif
+
     this->drawDevPath(*devPathPtr, *paint, drawCoverage, customBlitter, doFill);
 }
 

src/core/SkImageFilter.cpp

@@ -174,6 +174,12 @@ bool SkImageFilter_Base::Common::unflatten(SkReadBuffer& buffer, int expectedCou
         return false;
     }
 
+#if defined(SK_BUILD_FOR_FUZZER)
+    if (count > 4) {
+        return false;
+    }
+#endif
+
     SkASSERT(fInputs.empty());
     for (int i = 0; i < count; i++) {
         fInputs.push_back(buffer.readBool() ? buffer.readImageFilter() : nullptr);

src/core/SkMallocPixelRef.cpp

@@ -34,6 +34,11 @@ sk_sp<SkPixelRef> SkMallocPixelRef::MakeAllocate(const SkImageInfo& info, size_t
     if (SkImageInfo::ByteSizeOverflowed(size)) {
         return nullptr;
     }
+#if defined(SK_BUILD_FOR_FUZZER)
+    if (size > 100000) {
+        return nullptr;
+    }
+#endif
     void* addr = sk_calloc_canfail(size);
     if (nullptr == addr) {
         return nullptr;

src/core/SkMaskFilter.cpp

@@ -260,6 +260,11 @@ bool SkMaskFilterBase::filterPath(const SkPath& devPath, const SkMatrix& matrix,
 
     SkMask  srcM, dstM;
 
+#if defined(SK_BUILD_FOR_FUZZER)
+    if (devPath.countVerbs() > 1000 || devPath.countPoints() > 1000) {
+        return false;
+    }
+#endif
     if (!SkDraw::DrawToMask(devPath, &clip.getBounds(), this, &matrix, &srcM,
                             SkMask::kComputeBoundsAndRenderImage_CreateMode,
                             style)) {

src/core/SkPaint.cpp

@@ -333,6 +333,13 @@ bool SkPaint::getFillPath(const SkPath& src, SkPath* dst, const SkRect* cullRect
 
     SkStrokeRec rec(*this, resScale);
 
+#if defined(SK_BUILD_FOR_FUZZER)
+    // Prevent lines with small widths from timing out.
+    if (rec.getStyle() == SkStrokeRec::Style::kStroke_Style && rec.getWidth() < 0.001) {
+        return false;
+    }
+#endif
+
     const SkPath* srcPtr = &src;
     SkPath tmpPath;
 

src/core/SkPath.cpp

@@ -3162,7 +3162,11 @@ void SkPathPriv::CreateDrawArcPath(SkPath* path, const SkRect& oval, SkScalar st
                                    SkScalar sweepAngle, bool useCenter, bool isFillNoPathEffect) {
     SkASSERT(!oval.isEmpty());
     SkASSERT(sweepAngle);
-
+#if defined(SK_BUILD_FOR_FUZZER)
+    if (sweepAngle > 3600.0f || sweepAngle < -3600.0f) {
+        return;
+    }
+#endif
     path->reset();
     path->setIsVolatile(true);
     path->setFillType(SkPathFillType::kWinding);

src/core/SkScan_Hairline.cpp

@@ -122,7 +122,11 @@ void SkScan::HairLineRgn(const SkPoint array[], int arrayCount, const SkRegion*
             if (ix0 == ix1) {// too short to draw
                 continue;
             }
-
+#if defined(SK_BUILD_FOR_FUZZER)
+            if ((ix1 - ix0) > 100000 || (ix1 - ix0) < 0) {
+                continue; // too big to draw
+            }
+#endif
             SkFixed slope = SkFixedDiv(dy, dx);
             SkFixed startY = SkFDot6ToFixed(y0) + (slope * ((32 - x0) & 63) >> 6);
 
@@ -138,7 +142,11 @@ void SkScan::HairLineRgn(const SkPoint array[], int arrayCount, const SkRegion*
             if (iy0 == iy1) { // too short to draw
                 continue;
             }
-
+#if defined(SK_BUILD_FOR_FUZZER)
+            if ((iy1 - iy0) > 100000 || (iy1 - iy0) < 0) {
+                continue; // too big to draw
+            }
+#endif
             SkFixed slope = SkFixedDiv(dx, dy);
             SkFixed startX = SkFDot6ToFixed(x0) + (slope * ((32 - y0) & 63) >> 6);
 

src/effects/Sk1DPathEffect.cpp

@@ -175,7 +175,7 @@ void SkPath1DPathEffect::flatten(SkWriteBuffer& buffer) const {
 
 SkScalar SkPath1DPathEffect::next(SkPath* dst, SkScalar distance,
                                   SkPathMeasure& meas) const {
-#if defined(IS_FUZZING_WITH_LIBFUZZER)
+#if defined(SK_BUILD_FOR_FUZZER)
     if (dst->countPoints() > 100000) {
         return fAdvance;
     }

src/effects/Sk2DPathEffect.cpp

@@ -51,6 +51,11 @@ void Sk2DPathEffect::nextSpan(int x, int y, int count, SkPath* path) const {
     if (!fMatrixIsInvertible) {
         return;
     }
+#if defined(SK_BUILD_FOR_FUZZER)
+    if (count > 100) {
+        return;
+    }
+#endif
 
     const SkMatrix& mat = this->getMatrix();
     SkPoint src, dst;

src/effects/SkDiscretePathEffect.cpp

@@ -97,6 +97,11 @@ bool SkDiscretePathEffect::onFilterPath(SkPath* dst, const SkPath& src,
 
     do {
         SkScalar    length = meas.getLength();
+#if defined(SK_BUILD_FOR_FUZZER)
+        if (length > 1000) {
+            return false;
+        }
+#endif
 
         if (fSegLength * (2 + doFill) > length) {
             meas.getSegment(0, length, dst, true);  // to short for us to mangle

src/effects/SkLayerDrawLooper.cpp

@@ -213,6 +213,11 @@ void SkLayerDrawLooper::flatten(SkWriteBuffer& buffer) const {
 sk_sp<SkFlattenable> SkLayerDrawLooper::CreateProc(SkReadBuffer& buffer) {
     int count = buffer.readInt();
 
+#if defined(SK_BUILD_FOR_FUZZER)
+    if (count > 100) {
+        count = 100;
+    }
+#endif
     Builder builder;
     for (int i = 0; i < count; i++) {
         LayerInfo info;

src/pathops/SkOpCoincidence.cpp

@@ -811,11 +811,11 @@ bool SkOpCoincidence::addMissing(bool* added  DEBUG_COIN_DECLARE_PARAMS()) {
         SkOpSegment* outerCoinWritable = const_cast<SkOpSegment*>(outerCoin);
         SkOpSegment* outerOppWritable = const_cast<SkOpSegment*>(outerOpp);
         SkCoincidentSpans* inner = outer;
-#ifdef IS_FUZZING_WITH_LIBFUZZER
+#ifdef SK_BUILD_FOR_FUZZER
         int safetyNet = 1000;
 #endif
         while ((inner = inner->next())) {
-#ifdef IS_FUZZING_WITH_LIBFUZZER
+#ifdef SK_BUILD_FOR_FUZZER
             if (!--safetyNet) {
                 return false;
             }

src/pathops/SkPathOpsDebug.h

@@ -32,7 +32,7 @@ struct SkDCubic;
 class SkTSect;
 
 // define this when running fuzz
-// #define IS_FUZZING_WITH_LIBFUZZER
+// #define SK_BUILD_FOR_FUZZER
 
 // fake classes to fool msvs Visual Studio 2018 Immediate Window
 #define FakeClasses(a, b) \

src/ports/SkMemory_malloc.cpp

@@ -23,7 +23,7 @@
 static inline void sk_out_of_memory(size_t size) {
     SK_DEBUGFAILF("sk_out_of_memory (asked for %zu bytes)",
                   size);
-#if defined(IS_FUZZING_WITH_AFL)
+#if defined(SK_BUILD_FOR_AFL_FUZZ)
     exit(1);
 #else
     abort();
@@ -54,7 +54,7 @@ void sk_abort_no_print() {
 
 void sk_out_of_memory(void) {
     SkDEBUGFAIL("sk_out_of_memory");
-#if defined(IS_FUZZING_WITH_AFL)
+#if defined(SK_BUILD_FOR_AFL_FUZZ)
     exit(1);
 #else
     abort();