Front-end: Fix known crashes by early exit on error (issue #29, issue #34, issue #35).

Added -C option to request cascading errors.  By default, will exit early,
to avoid all error-recovery-based crashes.

This works by simulating end-of-file in input on first error, so no
need for exception handling, or stack unwinding, or any complex error
checking/handling to get out of the stack.

StandAlone/StandAlone.cpp

@@ -58,25 +58,26 @@ extern "C" {
 
 // Command-line options
 enum TOptions {
-    EOptionNone               = 0x0000,
+    EOptionNone               = 0,
-    EOptionIntermediate       = 0x0001,
+    EOptionIntermediate       = (1 <<  0),
-    EOptionSuppressInfolog    = 0x0002,
+    EOptionSuppressInfolog    = (1 <<  1),
-    EOptionMemoryLeakMode     = 0x0004,
+    EOptionMemoryLeakMode     = (1 <<  2),
-    EOptionRelaxedErrors      = 0x0008,
+    EOptionRelaxedErrors      = (1 <<  3),
-    EOptionGiveWarnings       = 0x0010,
+    EOptionGiveWarnings       = (1 <<  4),
-    EOptionLinkProgram        = 0x0020,
+    EOptionLinkProgram        = (1 <<  5),
-    EOptionMultiThreaded      = 0x0040,
+    EOptionMultiThreaded      = (1 <<  6),
-    EOptionDumpConfig         = 0x0080,
+    EOptionDumpConfig         = (1 <<  7),
-    EOptionDumpReflection     = 0x0100,
+    EOptionDumpReflection     = (1 <<  8),
-    EOptionSuppressWarnings   = 0x0200,
+    EOptionSuppressWarnings   = (1 <<  9),
-    EOptionDumpVersions       = 0x0400,
+    EOptionDumpVersions       = (1 << 10),
-    EOptionSpv                = 0x0800,
+    EOptionSpv                = (1 << 11),
-    EOptionHumanReadableSpv   = 0x1000,
+    EOptionHumanReadableSpv   = (1 << 12),
-    EOptionVulkanRules        = 0x2000,
+    EOptionVulkanRules        = (1 << 13),
-    EOptionDefaultDesktop     = 0x4000,
+    EOptionDefaultDesktop     = (1 << 14),
-    EOptionOutputPreprocessed = 0x8000,
+    EOptionOutputPreprocessed = (1 << 15),
-    EOptionOutputHexadecimal  = 0x10000,
+    EOptionOutputHexadecimal  = (1 << 16),
-    EOptionReadHlsl           = 0x20000,
+    EOptionReadHlsl           = (1 << 17),
+    EOptionCascadingErrors    = (1 << 18),
 };
 
 //
@@ -247,6 +248,9 @@ void ProcessArguments(int argc, char* argv[])
             case 'c':
                 Options |= EOptionDumpConfig;
                 break;
+            case 'C':
+                Options |= EOptionCascadingErrors;
+                break;
             case 'd':
                 Options |= EOptionDefaultDesktop;
                 break;
@@ -347,6 +351,8 @@ void SetMessageOptions(EShMessages& messages)
         messages = (EShMessages)(messages | EShMsgOnlyPreprocessor);
     if (Options & EOptionReadHlsl)
         messages = (EShMessages)(messages | EShMsgReadHlsl);
+    if (Options & EOptionCascadingErrors)
+        messages = (EShMessages)(messages | EShMsgCascadingErrors);
 }
 
 //
@@ -772,6 +778,7 @@ void usage()
            "              errors will appear on stderr.\n"
            "  -c          configuration dump;\n"
            "              creates the default configuration file (redirect to a .conf file)\n"
+           "  -C          cascading errors; risks crashes from accumulation of error recoveries\n"
            "  -d          default to desktop (#version 110) when there is no shader #version\n"
            "              (default is ES version 100)\n"
            "  -D          input is HLSL\n"

Test/runtests

@@ -22,15 +22,15 @@ rm -f comp.spv frag.spv geom.spv tesc.spv tese.spv vert.spv
 # reflection tests
 #
 echo Running reflection...
-$EXE -l -q reflection.vert > $TARGETDIR/reflection.vert.out
+$EXE -l -q -C reflection.vert > $TARGETDIR/reflection.vert.out
 diff -b $BASEDIR/reflection.vert.out $TARGETDIR/reflection.vert.out || HASERROR=1
 
 #
 # multi-threaded test
 #
 echo Comparing single thread to multithread for all tests in current directory...
-$EXE -i *.vert *.geom *.frag *.tes* *.comp > singleThread.out
+$EXE -i -C *.vert *.geom *.frag *.tes* *.comp > singleThread.out
-$EXE -i *.vert *.geom *.frag *.tes* *.comp -t > multiThread.out
+$EXE -i -C *.vert *.geom *.frag *.tes* *.comp -t > multiThread.out
 diff singleThread.out multiThread.out || HASERROR=1
 
 if [ $HASERROR -eq 0 ]

glslang/MachineIndependent/ParseHelper.cpp

@@ -377,6 +377,9 @@ void C_DECL TParseContext::error(const TSourceLoc& loc, const char* szReason, co
     va_start(args, szExtraInfoFormat);
     outputMessage(loc, szReason, szToken, szExtraInfoFormat, EPrefixError, args);
     va_end(args);
+
+    if ((messages & EShMsgCascadingErrors) == 0)
+        currentScanner->setEndOfInput();
 }
 
 void C_DECL TParseContext::warn(const TSourceLoc& loc, const char* szReason, const char* szToken,
@@ -397,6 +400,9 @@ void C_DECL TParseContext::ppError(const TSourceLoc& loc, const char* szReason,
     va_start(args, szExtraInfoFormat);
     outputMessage(loc, szReason, szToken, szExtraInfoFormat, EPrefixError, args);
     va_end(args);
+
+    if ((messages & EShMsgCascadingErrors) == 0)
+        currentScanner->setEndOfInput();
 }
 
 void C_DECL TParseContext::ppWarn(const TSourceLoc& loc, const char* szReason, const char* szToken,

glslang/MachineIndependent/Scan.h

@@ -40,7 +40,7 @@
 
 namespace glslang {
 
-// Use a global end-of-input character, so no tranlation is needed across
+// Use a global end-of-input character, so no translation is needed across
 // layers of encapsulation.  Characters are all 8 bit, and positive, so there is
 // no aliasing of character 255 onto -1, for example.
 const int EndOfInput = -1;
@@ -82,7 +82,8 @@ public:
     int get()
     {
         int ret = peek();
-        if (ret == EndOfInput)  return ret;
+        if (ret == EndOfInput)
+            return ret;
         ++loc[currentSource].column;
         ++logicalSourceLoc.column;
         if (ret == '\n') {
@@ -123,7 +124,8 @@ public:
     void unget()
     {
         // Do not roll back once we've reached the end of the file.
-        if (endOfFileReached) return;
+        if (endOfFileReached)
+            return;
 
         if (currentChar > 0) {
             --currentChar;
@@ -196,6 +198,12 @@ public:
         loc[getLastValidSourceIndex()].column = col;
     }
 
+    void setEndOfInput()
+    {
+        endOfFileReached = true;
+        currentSource = numSources;
+    }
+
     const TSourceLoc& getSourceLoc() const
     {
         if (singleLogical) {
@@ -255,7 +263,7 @@ protected:
     bool singleLogical; // treats the strings as a single logical string.
                         // locations will be reported from the first string.
 
-    // set to true once peak() returns EndOfFile, so that we won't roll back
+    // Set to true once peek() returns EndOfFile, so that we won't roll back
     // once we've reached EndOfFile.
     bool endOfFileReached;
 };

glslang/Public/ShaderLang.h

@@ -141,6 +141,7 @@ enum EShMessages {
     EShMsgVulkanRules      = (1 << 4),  // issue messages for Vulkan-requirements of GLSL for SPIR-V
     EShMsgOnlyPreprocessor = (1 << 5),  // only print out errors produced by the preprocessor
     EShMsgReadHlsl         = (1 << 6),  // use HLSL parsing rules and semantics
+    EShMsgCascadingErrors  = (1 << 7),  // get cascading errors; risks error-recovery issues, instead of an early exit
 };
 
 //

gtests/Config.FromFile.cpp

@@ -97,8 +97,8 @@ TEST_P(ConfigTest, FromFile)
 INSTANTIATE_TEST_CASE_P(
     Glsl, ConfigTest,
     ::testing::ValuesIn(std::vector<TestCaseSpec>({
-        {"specExamples.vert", "baseResults/test.conf", "specExamples.vert.out", EShMsgAST},
+        {"specExamples.vert", "baseResults/test.conf", "specExamples.vert.out", (EShMessages)(EShMsgAST | EShMsgCascadingErrors)},
-        {"100Limits.vert", "100.conf", "100LimitsConf.vert.out", EShMsgDefault},
+        {"100Limits.vert", "100.conf", "100LimitsConf.vert.out", EShMsgCascadingErrors},
     })),
 );
 // clang-format on

gtests/Initializer.h

@@ -51,7 +51,7 @@ namespace glslangtest {
 // gets fixed.
 class GlslangInitializer {
 public:
-    GlslangInitializer() : lastMessages(EShMsgDefault)
+    GlslangInitializer() : lastMessages(EShMsgCascadingErrors)
     {
         glslang::InitializeProcess();
     }

gtests/Link.FromFile.cpp

@@ -48,8 +48,7 @@ TEST_P(LinkTest, FromFile)
 {
     const auto& fileNames = GetParam();
     const size_t fileCount = fileNames.size();
-    const EShMessages controls = DeriveOptions(
+    const EShMessages controls = DeriveOptions(Source::GLSL, Semantics::OpenGL, Target::AST);
-            Source::GLSL, Semantics::OpenGL, Target::AST);
     GlslangResult result;
 
     // Compile each input shader file.

gtests/TestFixture.cpp

@@ -68,7 +68,7 @@ EShLanguage GetShaderStage(const std::string& stage)
 
 EShMessages DeriveOptions(Source source, Semantics semantics, Target target)
 {
-    EShMessages result = EShMsgDefault;
+    EShMessages result = EShMsgCascadingErrors;
 
     switch (source) {
         case Source::GLSL:

gtests/TestFixture.h

@@ -264,8 +264,7 @@ public:
         tryLoadFile(expectedOutputFname, "expected output", &expectedOutput);
 
         const EShMessages controls = DeriveOptions(source, semantics, target);
-        GlslangResult result =
+        GlslangResult result = compileAndLink(testName, input, entryPointName, controls);
-            compileAndLink(testName, input, entryPointName, controls);
 
         // Generate the hybrid output in the way of glslangValidator.
         std::ostringstream stream;
@@ -290,7 +289,7 @@ public:
         glslang::TShader::ForbidInclude includer;
         const bool success = shader.preprocess(
             &glslang::DefaultTBuiltInResource, defaultVersion, defaultProfile,
-            forceVersionProfile, isForwardCompatible, EShMsgOnlyPreprocessor,
+            forceVersionProfile, isForwardCompatible, (EShMessages)(EShMsgOnlyPreprocessor | EShMsgCascadingErrors),
             &ppShader, includer);
 
         std::string log = shader.getInfoLog();