From: Mikko Rasa <tdb@tdb.fi>
Date: Thu, 11 Jul 2019 22:22:59 +0000 (+0300)
Subject: Recognize #version directive in GLSL
X-Git-Url: http://git.tdb.fi/?p=libs%2Fgl.git;a=commitdiff_plain;h=53dac3ba3cb3a1e4ed23d5fa459187acde7a4904

Recognize #version directive in GLSL

This allows shaders to explicitly specify the required version in
case there's a feature which is not detected by the program compiler
framework.
---

diff --git a/source/programcompiler.cpp b/source/programcompiler.cpp
index 989098d7..f30ccfa6 100644
--- a/source/programcompiler.cpp
+++ b/source/programcompiler.cpp
@@ -209,6 +209,8 @@ void ProgramCompiler::append_stage(Stage &stage)
 		target = &*i;
 	}
 
+	if(stage.required_version>target->required_version)
+		target->required_version = stage.required_version;
 	for(NodeList<Statement>::iterator i=stage.content.body.begin(); i!=stage.content.body.end(); ++i)
 		target->content.body.push_back(*i);
 	apply<DeclarationCombiner>(*target);
@@ -245,6 +247,8 @@ void ProgramCompiler::import(const string &name)
 
 void ProgramCompiler::generate(Stage &stage)
 {
+	if(module->shared.required_version>stage.required_version)
+		stage.required_version = module->shared.required_version;
 	inject_block(stage.content, module->shared.content);
 
 	apply<DeclarationReorderer>(stage);
diff --git a/source/programparser.cpp b/source/programparser.cpp
index ca554f42..7477f38b 100644
--- a/source/programparser.cpp
+++ b/source/programparser.cpp
@@ -369,8 +369,10 @@ void ProgramParser::preprocess()
 	string token = peek_token();
 	if(token=="pragma")
 		preprocess_pragma();
+	else if(token=="version")
+		preprocess_version();
 	else if(token=="define" || token=="undef" || token=="if" || token=="ifdef" || token=="ifndef" || token=="else" ||
-		token=="elif" || token=="endif" || token=="error" || token=="extension" || token=="version" || token=="line")
+		token=="elif" || token=="endif" || token=="error" || token=="extension" || token=="line")
 		throw runtime_error(format_error(format("Unsupported preprocessor directive '%s'", token)));
 	else if(!token.empty())
 		throw runtime_error(format_syntax_error("a preprocessor directive"));
@@ -378,6 +380,18 @@ void ProgramParser::preprocess()
 	iter = line_end;
 }
 
+void ProgramParser::preprocess_version()
+{
+	expect("version");
+	string token = parse_token();
+	unsigned version = lexical_cast<unsigned>(token);
+	cur_stage->required_version = Version(version/100, version%100);
+
+	token = parse_token();
+	if(!token.empty())
+		throw runtime_error(format_syntax_error("end of line"));
+}
+
 void ProgramParser::preprocess_pragma()
 {
 	expect("pragma");
diff --git a/source/programparser.h b/source/programparser.h
index dc94bd00..e3660473 100644
--- a/source/programparser.h
+++ b/source/programparser.h
@@ -87,6 +87,7 @@ private:
 	bool is_identifier(const std::string &);
 
 	void preprocess();
+	void preprocess_version();
 	void preprocess_pragma();
 	void preprocess_pragma_msp();
 	void preprocess_stage();