swung0x48/MobileGL
1
0
Fork 0
mirror of https://github.com/MobileGL-Dev/MobileGL synced 2026-09-10 05:08:31 +09:00
Code Issues Packages Projects Releases Wiki Activity

[Fix] (MG_Util/ShaderTranspiler): blank block comments lexically instead of erasing them - a '//*** banner ***' line opened a comment the old scanner never closed, so it deleted the rest of the shader, and a commented-out builtin definition renamed every genuine call to a name nothing defines

Browse Source
This commit is contained in:
swung0x48
2026-07-20 21:06:37 -04:00
parent 6eb5ff51c5
commit 05260d1262
2 changed files with 147 additions and 13 deletions
Download Patch File Download Diff File Expand all files Collapse all files
MobileGL/MG_Test/Program/ProgramUtilTest.cpp
+71
View File
@@ -455,6 +455,77 @@ void main() {
}
}
// A banner line like "//*** NOTE ***" contains "/*" at offset 1 and no "*/" anywhere after it. The
// old hand-rolled comment stripper searched for "/*" with no lexical state, found that, failed to
// find a terminator, and erased everything from there to the end of the file - deleting the entire
// shader. Banner comments in that exact shape are common in Iris and OptiFine packs.
TEST_F(ProgramUtilTest, PreprocessKeepsShaderBodyAfterAStarredLineComment) {
using namespace MG_Util::ShaderTranspiler;
String source = R"(#version 330 core
//*** lighting pass ***
out vec4 fragColor;
void main() {
fragColor = vec4(1.0);
}
)";
PreprocessShaderSource(ShaderStage::Fragment, source);
EXPECT_NE(source.find("void main()"), String::npos) << "shader body was truncated:\n" << source;
EXPECT_NE(source.find("fragColor = vec4(1.0);"), String::npos);
ShaderAttrib attrib{.shaderType = GL_FRAGMENT_SHADER, .sourceStr = source};
auto res = ShaderCompiler::CompileShader(attrib);
if (!res) {
FAIL() << "errc: " << res.error().errc << "\nlog: " << res.error().log << "\nsource:\n" << source;
}
}
// The builtin-shadowing rename only fires when the shader really defines its own round/tanh/etc.
// Deciding that from a commented-out definition renames every genuine call to the builtin to a
// mg_ name that nothing defines, which fails to link.
TEST_F(ProgramUtilTest, PreprocessIgnoresCommentedOutBuiltinShadowingDefinition) {
using namespace MG_Util::ShaderTranspiler;
String source = R"(#version 330 core
// float round(float x) { return floor(x + 0.5); }
out vec4 fragColor;
void main() {
fragColor = vec4(round(1.25));
}
)";
PreprocessShaderSource(ShaderStage::Fragment, source);
EXPECT_NE(source.find("round(1.25)"), String::npos) << "call was renamed from a comment:\n" << source;
EXPECT_EQ(source.find("mg_round"), String::npos);
}
// A block-commented extension directive must not be treated as a real one - the int64 filter turns
// unsupported directives into #error, so reading one out of a comment manufactures a compile
// failure for a shader that never asked for the extension.
TEST_F(ProgramUtilTest, PreprocessIgnoresBlockCommentedExtensionDirectives) {
using namespace MG_Util::ShaderTranspiler;
String source = R"(#version 330 core
/*
#extension GL_ARB_gpu_shader_int64 : require
*/
out vec4 fragColor;
void main() {
fragColor = vec4(1.0);
}
)";
PreprocessShaderSource(ShaderStage::Fragment, source);
EXPECT_EQ(source.find("#error"), String::npos) << "#error synthesized from a comment:\n" << source;
ShaderAttrib attrib{.shaderType = GL_FRAGMENT_SHADER, .sourceStr = source};
auto res = ShaderCompiler::CompileShader(attrib);
if (!res) {
FAIL() << "errc: " << res.error().errc << "\nlog: " << res.error().log << "\nsource:\n" << source;
}
}
TEST_F(ProgramUtilTest, PreprocessModernSampleQualifierStaysAtVersion460) {
using namespace MG_Util::ShaderTranspiler;
MobileGL/MG_Util/ShaderTranspiler/ShaderSourceProcessor.cpp
+76 -13
View File
@@ -96,6 +96,77 @@ namespace {
return masked;
}
// Blank out block comments in place, leaving line comments and every other byte where it is.
//
// The passes that follow scan the source as raw text, so block comments have to stop being
// visible to them - but they must not be *deleted*: replacing the bytes with spaces keeps every
// later offset valid and keeps newlines, so glslang's diagnostics still point at the line the
// application wrote. It also has to be lexically aware. A banner line such as
//
// //*** lighting pass ***
//
// contains "/*" one byte in, and a naive search for that opener treats the rest of the file as
// an unterminated comment.
void BlankBlockComments(MobileGL::String& source) {
enum class Region { Code, SingleLineComment, MultiLineComment, QuotedText };
Region region = Region::Code;
char quote = '\0';
bool escaped = false;
for (SizeT pos = 0; pos < source.size(); pos++) {
const char ch = source[pos];
const char next = pos + 1 < source.size() ? source[pos + 1] : '\0';
if (region == Region::Code) {
if (ch == '/' && next == '/') {
pos++;
region = Region::SingleLineComment;
} else if (ch == '/' && next == '*') {
source[pos] = ' ';
source[pos + 1] = ' ';
pos++;
region = Region::MultiLineComment;
} else if (ch == '"' || ch == '\'') {
quote = ch;
escaped = false;
region = Region::QuotedText;
}
continue;
}
if (region == Region::SingleLineComment) {
if (ch == '\n' || ch == '\r') region = Region::Code;
continue;
}
if (region == Region::MultiLineComment) {
if (ch == '*' && next == '/') {
source[pos] = ' ';
source[pos + 1] = ' ';
pos++;
region = Region::Code;
} else if (ch != '\n' && ch != '\r') {
source[pos] = ' ';
}
continue;
}
// GLSL has no multi-line string literals, so a quote that reaches end of line was never
// a literal to begin with - most likely an apostrophe in a #error or #pragma message.
// Ending the region here keeps one stray apostrophe from swallowing the rest of the file.
if (ch == '\n' || ch == '\r') {
region = Region::Code;
} else if (escaped) {
escaped = false;
} else if (ch == '\\') {
escaped = true;
} else if (ch == quote) {
region = Region::Code;
}
}
}
struct CodeToken {
String text;
SizeT begin = 0;
@@ -686,7 +757,10 @@ namespace {
void RenameBuiltinShadowingFunction(MobileGL::String& source, const char* from, const char* to) {
const MobileGL::String fromName = from;
if (!HasSingleLineFunctionDefinition(source, fromName)) {
// Decide from a comment-free view. A commented-out definition is not a definition, and
// acting on one renames every genuine call to the builtin to a name nothing defines - which
// then fails to resolve. Line comments survive BlankBlockComments, so this matters.
if (!HasSingleLineFunctionDefinition(MaskCommentsAndQuotedText(source), fromName)) {
return;
}
@@ -1078,18 +1152,7 @@ namespace MobileGL {
const ShaderLanguageInfo originalLanguage = InspectShaderLanguage(source);
NormalizeVersionDirective(source, originalLanguage);
// remove multi-line comment
size_t commentStartPos = source.find("/*");
while (commentStartPos != String::npos) {
size_t commentEndPos = source.find("*/", commentStartPos);
if (commentEndPos == String::npos) {
source.erase(commentStartPos);
break;
}
// + length of "*/"
source = source.replace(commentStartPos, commentEndPos - commentStartPos + 2, "");
commentStartPos = source.find("/*", commentStartPos);
}
BlankBlockComments(source);
// remove #line directives
SizeT linedirPos = source.find("#line");