From: Mikko Rasa <tdb@tdb.fi>
Date: Sun, 21 Feb 2021 23:12:25 +0000 (+0200)
Subject: Add a standalone GLSL compiler frontend
X-Git-Url: http://git.tdb.fi/?p=libs%2Fgl.git;a=commitdiff_plain;h=b30777959d8e2ab2caf489e32f40390f60a75fcb

Add a standalone GLSL compiler frontend

This makes debugging the compiler easier and will eventually allow
shaders to be compiled into SPIR-V during build.
---

diff --git a/Build b/Build
index 19831c3e..fb571b0c 100644
--- a/Build
+++ b/Build
@@ -94,6 +94,12 @@ package "mspgl"
 		use "mspgl";
 	};
 
+	program "glslcompiler"
+	{
+		source "tools/glslcompiler.cpp";
+		use "mspgl";
+	};
+
 	source_tarball
 	{
 		source "License.txt";
diff --git a/source/glsl/compiler.cpp b/source/glsl/compiler.cpp
index 4a7a19e2..ca6c5805 100644
--- a/source/glsl/compiler.cpp
+++ b/source/glsl/compiler.cpp
@@ -3,6 +3,7 @@
 #include <msp/strings/format.h>
 #include "compatibility.h"
 #include "compiler.h"
+#include "debug.h"
 #include "error.h"
 #include "generate.h"
 #include "optimize.h"
@@ -132,6 +133,14 @@ const SourceMap &Compiler::get_source_map() const
 	return module->source_map;
 }
 
+string Compiler::get_stage_debug(Stage::Type stage_type) const
+{
+	for(list<Stage>::iterator i=module->stages.begin(); i!=module->stages.end(); ++i)
+		if(i->type==stage_type)
+			return DumpTree().apply(*i);
+	throw key_error(Stage::get_stage_name(stage_type));
+}
+
 void Compiler::append_module(Module &mod, DataFile::Collection *res)
 {
 	module->source_map.merge_from(mod.source_map);
diff --git a/source/glsl/compiler.h b/source/glsl/compiler.h
index 8340aa6d..4eaff213 100644
--- a/source/glsl/compiler.h
+++ b/source/glsl/compiler.h
@@ -44,8 +44,10 @@ public:
 	const std::map<std::string, unsigned> &get_vertex_attributes() const;
 	const std::map<std::string, unsigned> &get_fragment_outputs() const;
 	const SourceMap &get_source_map() const;
-private:
 
+	std::string get_stage_debug(Stage::Type) const;
+
+private:
 	void append_module(Module &, DataFile::Collection *);
 	void append_stage(Stage &);
 	void import(DataFile::Collection *, const std::string &);
diff --git a/source/glsl/features.cpp b/source/glsl/features.cpp
index d1c8101d..11b6c942 100644
--- a/source/glsl/features.cpp
+++ b/source/glsl/features.cpp
@@ -32,6 +32,19 @@ Features Features::from_context()
 	return features;
 }
 
+Features Features::all()
+{
+	Features features;
+	features.gl_api = OPENGL;
+	features.glsl_version = Version(4, 60);
+	features.arb_explicit_attrib_location = true;
+	features.arb_gpu_shader5 = true;
+	features.arb_uniform_buffer_object = true;
+	features.ext_gpu_shader4 = true;
+	features.ext_texture_array = true;
+	return features;
+}
+
 } // namespace SL
 } // namespace GL
 } // namespace Msp
diff --git a/source/glsl/features.h b/source/glsl/features.h
index 8f7a3e7c..8d32f8be 100644
--- a/source/glsl/features.h
+++ b/source/glsl/features.h
@@ -20,6 +20,7 @@ struct Features
 	Features();
 
 	static Features from_context();
+	static Features all();
 };
 
 } // namespace SL
diff --git a/tools/glslcompiler.cpp b/tools/glslcompiler.cpp
new file mode 100644
index 00000000..74b37ef6
--- /dev/null
+++ b/tools/glslcompiler.cpp
@@ -0,0 +1,71 @@
+#include <msp/core/application.h>
+#include <msp/core/getopt.h>
+#include <msp/gl/glsl/compiler.h>
+#include <msp/io/print.h>
+
+class GlslCompiler: public Msp::RegisteredApplication<GlslCompiler>
+{
+private:
+	std::string source_fn;
+	bool parse_only;
+	bool combined;
+	Msp::GL::SL::Stage::Type stage;
+	bool dump_ast;
+
+public:
+	GlslCompiler(int, char **);
+
+	virtual int main();
+};
+
+using namespace std;
+using namespace Msp;
+
+GlslCompiler::GlslCompiler(int argc, char **argv):
+	parse_only(false),
+	combined(false),
+	stage(GL::SL::Stage::SHARED),
+	dump_ast(false)
+{
+	string stage_str;
+
+	GetOpt getopt;
+	getopt.add_option('c', "combined", combined, GetOpt::NO_ARG).set_help("Output combined GLSL");
+	getopt.add_option('a', "dump-ast", dump_ast, GetOpt::NO_ARG).set_help("Dump AST for debugging");
+	getopt.add_option('p', "parse_only", parse_only, GetOpt::NO_ARG).set_help("Only parse the loaded source, don't compile");
+	getopt.add_option('s', "stage", stage_str, GetOpt::REQUIRED_ARG).set_help("Output GLSL for STAGE", "STAGE");
+	getopt.add_argument("source", source_fn, GetOpt::REQUIRED_ARG).set_help("GLSL file to compile");
+	getopt(argc, argv);
+
+	if(stage_str=="vertex")
+		stage = GL::SL::Stage::VERTEX;
+	else if(stage_str=="geometry")
+		stage = GL::SL::Stage::GEOMETRY;
+	else if(stage_str=="fragment")
+		stage = GL::SL::Stage::FRAGMENT;
+	else if(!dump_ast)
+		combined = true;
+}
+
+int GlslCompiler::main()
+{
+	GL::SL::Compiler compiler(GL::SL::Features::all());
+	IO::File file(source_fn);
+	compiler.load_source(file, source_fn);
+	if(!parse_only)
+		compiler.compile(GL::SL::Compiler::PROGRAM);
+
+	if(dump_ast)
+	{
+		vector<GL::SL::Stage::Type> stages = compiler.get_stages();
+		for(vector<GL::SL::Stage::Type>::const_iterator i=stages.begin(); i!=stages.end(); ++i)
+			IO::print("%s\n", compiler.get_stage_debug(*i));
+	}
+
+	if(combined)
+		IO::print("%s\n", compiler.get_combined_glsl());
+	else if(stage!=GL::SL::Stage::SHARED)
+		IO::print("%s\n", compiler.get_stage_glsl(stage));
+
+	return 0;
+}