Extend the syntax of #line and __FILE__ to support filename strings.

According to the GLSL spec, the second parameter to #line should be
an integer source string number and __FILE__ will be substituted
with the integer source string number currently processed. This
patch extends the syntax of #line and __FILE__. Now #line accepts
as the second parameter a filename string quoted by double quotation
marks. And if such a #line is set, __FILE__ will be substituted with
the currently set filename string. The implementation is done via
introducing a new extension GL_GOOGLE_cpp_style_line_directive using
the extension framework.

The purpose is to support cpp-style #line directives, which is
required by #include.

Test/baseResults/preprocessor.cpp_style___FILE__.vert.out

@@ -0,0 +1,26 @@
+#extension GL_GOOGLE_cpp_style_line_directive : enable
+
+0
+#line 150 a.h
+ "a.h"
+#line 24
+ "a.h"
+#line 42
+ "a.h"
+#line 30 b.cc
+ "b.cc"
+#line 10 3
+ 3
+#line 48
+ 3
+#line 4
+ 3
+#line 55 100
+ 100
+#line 1000 c
+ "c"
+#line 42 1
+ 1
+#line 42 this-is-a-quite-long-name-maybe-i-should-shorten-it
+ "this-is-a-quite-long-name-maybe-i-should-shorten-it"
+

Test/baseResults/preprocessor.cpp_style_line_directive.vert.err

@@ -0,0 +1,15 @@
+ERROR: 0:3: '#error' : at 0:3
+ERROR: a.h:150: '#error' : at a.h:150
+ERROR: a.h:24: '#error' : at a.h:24
+ERROR: a.h:42: '#error' : at a.h:42
+ERROR: b.cc:30: '#error' : at b.cc:30
+ERROR: 3:10: '#error' : at 3:10
+ERROR: 3:48: '#error' : at 3:48
+ERROR: 3:4: '#error' : at 3:4
+ERROR: 100:55: '#error' : at 100:55
+ERROR: c:1000: '#error' : at c:1000
+ERROR: 1:42: '#error' : at 1:42
+ERROR: this-is-a-quite-long-name-maybe-i-should-shorten-it:42: '#error' : at this-is-a-quite-long-name-maybe-i-should-shorten-it:42
+ERROR: 12 compilation errors.  No code generated.
+
+

Test/preprocessor.cpp_style___FILE__.vert

@@ -0,0 +1,36 @@
+#extension GL_GOOGLE_cpp_style_line_directive : enable
+
+__FILE__
+
+#line 150 "a.h"
+__FILE__
+
+#line 24
+__FILE__
+
+#line 42
+__FILE__
+
+#line 30 "b.cc"
+__FILE__
+
+#line 10 3
+__FILE__
+
+#line 48
+__FILE__
+
+#line 4
+__FILE__
+
+#line 55 100
+__FILE__
+
+#line 1000 "c"
+__FILE__
+
+#line 42 1
+__FILE__
+
+#line 42 "this-is-a-quite-long-name-maybe-i-should-shorten-it"
+__FILE__

Test/preprocessor.cpp_style_line_directive.vert

@@ -0,0 +1,36 @@
+#extension GL_GOOGLE_cpp_style_line_directive : enable
+
+#error at "0:3"
+
+#line 150 "a.h"
+#error at "a.h:150"
+
+#line 24
+#error at "a.h:24"
+
+#line 42
+#error at "a.h:42"
+
+#line 30 "b.cc"
+#error at "b.cc:30"
+
+#line 10 3
+#error at "3:10"
+
+#line 48
+#error at "3:48"
+
+#line 4
+#error at "3:4"
+
+#line 55 100
+#error at "100:55"
+
+#line 1000 "c"
+#error at "c:1000"
+
+#line 42 1
+#error at "1:42"
+
+#line 42 "this-is-a-quite-long-name-maybe-i-should-shorten-it"
+#error at "this-is-a-quite-long-name-maybe-i-should-shorten-it:42"

Test/test-preprocessor-list

@@ -1,3 +1,4 @@
+preprocessor.cpp_style_line_directive.vert
 preprocessor.edge_cases.vert
 preprocessor.errors.vert
 preprocessor.extensions.vert

glslang/Include/Common.h

@@ -189,7 +189,8 @@ inline const TString String(const int i, const int base = 10)
 }
 
 struct TSourceLoc {
-    void init() { string = 0; line = 0; column = 0; }
+    void init() { name = nullptr; string = 0; line = 0; column = 0; }
+    const char* name; // descriptive name for this string
     int string;
     int line;
     int column;

glslang/Include/InfoSink.h

@@ -98,7 +98,12 @@ public:
     void location(TSourceLoc loc) {
         const int maxSize = 24;
         char locText[maxSize];
+        if (loc.name != nullptr) {
+            append(loc.name);
+            snprintf(locText, maxSize, ":%d", loc.line);
+        } else {
             snprintf(locText, maxSize, "%d:%d", loc.string, loc.line);
+        }
         append(locText);
         append(": ");
     }

glslang/MachineIndependent/ParseHelper.cpp

@@ -5346,10 +5346,10 @@ void TParseContext::notifyErrorDirective(int line, const char* error_message)
     }
 }
 
-void TParseContext::notifyLineDirective(int curLineNo, int newLineNo, bool hasSource, int sourceNum)
+void TParseContext::notifyLineDirective(int curLineNo, int newLineNo, bool hasSource, int sourceNum, const char* sourceName)
 {
     if (lineCallback) {
-        lineCallback(curLineNo, newLineNo, hasSource, sourceNum);
+        lineCallback(curLineNo, newLineNo, hasSource, sourceNum, sourceName);
     }
 }
 

glslang/MachineIndependent/ParseHelper.h

@@ -214,6 +214,7 @@ public:
     int getNumErrors() const { return numErrors; }
     const TSourceLoc& getCurrentLoc() const { return currentScanner->getSourceLoc(); }
     void setCurrentLine(int line) { currentScanner->setLine(line); }
+    void setCurrentSourceName(const char* name) { currentScanner->setFile(name); }
     void setCurrentString(int string) { currentScanner->setString(string); }
     void setScanner(TInputScanner* scanner) { currentScanner  = scanner; }
 
@@ -221,7 +222,7 @@ public:
 
     void notifyVersion(int line, int version, const char* type_string);
     void notifyErrorDirective(int line, const char* error_message);
-    void notifyLineDirective(int curLineNo, int newLineNo, bool hasSource, int sourceNum);
+    void notifyLineDirective(int curLineNo, int newLineNo, bool hasSource, int sourceNum, const char* sourceName);
     void notifyExtensionDirective(int line, const char* extension, const char* behavior);
 
     // The following are implemented in Versions.cpp to localize version/profile/stage/extensions control
@@ -243,7 +244,7 @@ public:
 
     void setVersionCallback(const std::function<void(int, int, const char*)>& func) { versionCallback = func; }
     void setPragmaCallback(const std::function<void(int, const TVector<TString>&)>& func) { pragmaCallback = func; }
-    void setLineCallback(const std::function<void(int, int, bool, int)>& func) { lineCallback = func; }
+    void setLineCallback(const std::function<void(int, int, bool, int, const char*)>& func) { lineCallback = func; }
     void setExtensionCallback(const std::function<void(int, const char*, const char*)>& func) { extensionCallback = func; }
     void setErrorCallback(const std::function<void(int, const char*)>& func) { errorCallback = func; }
 
@@ -357,7 +358,7 @@ protected:
 
     // These, if set, will be called when a line, pragma ... is preprocessed.
     // They will be called with any parameters to the original directive.
-    std::function<void(int, int, bool, int)> lineCallback;
+    std::function<void(int, int, bool, int, const char*)> lineCallback;
     std::function<void(int, const TVector<TString>&)> pragmaCallback;
     std::function<void(int, int, const char*)> versionCallback;
     std::function<void(int, const char*, const char*)> extensionCallback;

glslang/MachineIndependent/Scan.h

@@ -57,6 +57,9 @@ public:
         lengths(L), currentSource(0), currentChar(0), stringBias(b), finale(f)
     {
         loc = new TSourceLoc[numSources];
+        for (int i = 0; i < numSources; ++i) {
+            loc[i].init();
+        }
         loc[currentSource].string = -stringBias;
         loc[currentSource].line = 1;
         loc[currentSource].column = 0;
@@ -140,7 +143,12 @@ public:
 
     // for #line override
     void setLine(int newLine) { loc[getLastValidSourceIndex()].line = newLine; }
-    void setString(int newString) { loc[getLastValidSourceIndex()].string = newString; }
+    void setFile(const char* filename) { loc[getLastValidSourceIndex()].name = filename; }
+    void setString(int newString)
+    {
+        loc[getLastValidSourceIndex()].string = newString;
+        loc[getLastValidSourceIndex()].name = nullptr;
+    }
 
     const TSourceLoc& getSourceLoc() const { return loc[std::max(0, std::min(currentSource, numSources - finale - 1))]; }
     // Returns the index (starting from 0) of the most recent valid source string we are reading from.

glslang/MachineIndependent/ShaderLang.cpp

@@ -690,12 +690,17 @@ struct DoPreprocessing {
         });
 
         parseContext.setLineCallback([&lineSync, &outputStream, &parseContext](
-            int curLineNum, int newLineNum, bool hasSource, int sourceNum) {
+            int curLineNum, int newLineNum, bool hasSource, int sourceNum, const char* sourceName) {
             // SourceNum is the number of the source-string that is being parsed.
             lineSync.syncToLine(curLineNum);
             outputStream << "#line " << newLineNum;
             if (hasSource) {
-                outputStream << " " << sourceNum;
+                outputStream << " ";
+                if (sourceName != nullptr) {
+                    outputStream << "\"" << sourceName << "\"";
+                } else {
+                    outputStream << sourceNum;
+                }
             }
             if (parseContext.lineDirectiveShouldSetNextLine()) {
                 // newLineNum is the new line number for the line following the #line

glslang/MachineIndependent/Versions.cpp

@@ -190,6 +190,7 @@ void TParseContext::initializeExtensionBehavior()
     extensionBehavior[E_GL_EXT_tessellation_point_size]              = EBhDisable;
     extensionBehavior[E_GL_EXT_texture_buffer]                       = EBhDisablePartial;
     extensionBehavior[E_GL_EXT_texture_cube_map_array]               = EBhDisablePartial;
+    extensionBehavior[E_GL_GOOGLE_cpp_style_line_directive]          = EBhDisable;
 
     // OES matching AEP
     extensionBehavior[E_GL_OES_geometry_shader]          = EBhDisable;
@@ -233,6 +234,7 @@ const char* TParseContext::getPreamble()
             "#define GL_EXT_tessellation_point_size 1\n"
             "#define GL_EXT_texture_buffer 1\n"
             "#define GL_EXT_texture_cube_map_array 1\n"
+            "#define GL_GOOGLE_cpp_style_line_directive 1\n"
 
             // OES matching AEP
             "#define GL_OES_geometry_shader 1\n"
@@ -264,6 +266,7 @@ const char* TParseContext::getPreamble()
             "#define GL_ARB_derivative_control 1\n"
             "#define GL_ARB_shader_texture_image_samples 1\n"
             "#define GL_ARB_viewport_array 1\n"
+            "#define GL_GOOGLE_cpp_style_line_directive 1\n"
 //            "#define GL_ARB_cull_distance 1\n"    // present for 4.5, but need extension control over block members
             ;
     }

glslang/MachineIndependent/Versions.h

@@ -129,6 +129,8 @@ const char* const E_GL_EXT_tessellation_point_size              = "GL_EXT_tessel
 const char* const E_GL_EXT_texture_buffer                       = "GL_EXT_texture_buffer";
 const char* const E_GL_EXT_texture_cube_map_array               = "GL_EXT_texture_cube_map_array";
 
+const char* const E_GL_GOOGLE_cpp_style_line_directive          = "GL_GOOGLE_cpp_style_line_directive";
+
 // OES matching AEP
 const char* const E_GL_OES_geometry_shader                      = "GL_OES_geometry_shader";
 const char* const E_GL_OES_geometry_point_size                  = "GL_OES_geometry_point_size";

glslang/MachineIndependent/preprocessor/Pp.cpp

@@ -612,8 +612,9 @@ int TPpContext::CPPline(TPpToken* ppToken)
 
     int lineRes = 0; // Line number after macro expansion.
     int lineToken = 0;
-    int fileRes = 0; // Source file number after macro expansion.
     bool hasFile = false;
+    int fileRes = 0; // Source file number after macro expansion.
+    const char* sourceName = nullptr; // Optional source file name.
     bool lineErr = false;
     bool fileErr = false;
     token = eval(token, MIN_PRECEDENCE, false, lineRes, lineErr, ppToken);
@@ -627,14 +628,25 @@ int TPpContext::CPPline(TPpToken* ppToken)
         parseContext.setCurrentLine(lineRes);
 
         if (token != '\n') {
+            if (parseContext.extensionTurnedOn(E_GL_GOOGLE_cpp_style_line_directive) && token == PpAtomConstString) {
+                // We need to save a copy of the string instead of pointing
+                // to the name field of the token since the name field
+                // will likely be overwritten by the next token scan.
+                sourceName = GetAtomString(LookUpAddString(ppToken->name));
+                parseContext.setCurrentSourceName(sourceName);
+                hasFile = true;
+                token = scanToken(ppToken);
+            } else {
                 token = eval(token, MIN_PRECEDENCE, false, fileRes, fileErr, ppToken);
-            if (! fileErr)
+                if (! fileErr) {
                     parseContext.setCurrentString(fileRes);
                     hasFile = true;
                 }
             }
+        }
+    }
     if (!fileErr && !lineErr) {
-        parseContext.notifyLineDirective(directiveLoc, lineToken, hasFile, fileRes);
+        parseContext.notifyLineDirective(directiveLoc, lineToken, hasFile, fileRes, sourceName);
     }
     token = extraTokenCheck(PpAtomLine, ppToken, token);
 
@@ -952,11 +964,17 @@ int TPpContext::MacroExpand(int atom, TPpToken* ppToken, bool expandUndef, bool
         UngetToken(PpAtomConstInt, ppToken);
         return 1;
 
-    case PpAtomFileMacro:
+    case PpAtomFileMacro: {
+        const char* current_file = parseContext.getCurrentLoc().name;
+        if (parseContext.extensionTurnedOn(E_GL_GOOGLE_cpp_style_line_directive) && current_file != nullptr) {
+            sprintf(ppToken->name, "\"%s\"", current_file);
+        } else {
             ppToken->ival = parseContext.getCurrentLoc().string;
             sprintf(ppToken->name, "%d", ppToken->ival);
+        }
         UngetToken(PpAtomConstInt, ppToken);
         return 1;
+    }
 
     case PpAtomVersionMacro:
         ppToken->ival = parseContext.version;