From fb5f83c2e3f8f8a6a6444a33bec15e9477a487d1 Mon Sep 17 00:00:00 2001
From: Mikko Rasa <tdb@tdb.fi>
Date: Tue, 16 Mar 2021 20:05:24 +0200
Subject: [PATCH] Add idempotence test cases for GLSL compiler

Already compiled GLSL code should not change when passed through the
compiler again.
---
 tests/glsl/glslcompiler.cpp | 51 +++++++++++++++++++++++++++++++++++++
 1 file changed, 51 insertions(+)

diff --git a/tests/glsl/glslcompiler.cpp b/tests/glsl/glslcompiler.cpp
index 0fd08554..371df6cc 100644
--- a/tests/glsl/glslcompiler.cpp
+++ b/tests/glsl/glslcompiler.cpp
@@ -43,6 +43,18 @@ private:
 	virtual void fail(const std::string &m) { Test::fail(m); }
 };
 
+class GlslCompilerIdempotence: public Msp::Test::RegisteredTest<GlslCompilerIdempotence>, private GlslCompilerHelper
+{
+public:
+	GlslCompilerIdempotence();
+
+	static const char *get_name() { return "GLSL compiler idempotence"; }
+
+private:
+	void run_test_case(const TestCase *);
+	virtual void fail(const std::string &m) { Test::fail(m); }
+};
+
 using namespace std;
 using namespace Msp;
 
@@ -259,3 +271,42 @@ void GlslCompilerTest::run_test_case(const TestCase *test_case)
 		if(find(stages, s.first)==stages.end())
 			fail(format("Compiler didn't produce stage %s", GL::SL::Stage::get_stage_name(s.first)));
 }
+
+
+GlslCompilerIdempotence::GlslCompilerIdempotence()
+{
+	load_all_test_cases("glsl");
+	for(const auto &tc: test_cases)
+		if(tc.expected_error.empty())
+			add(&GlslCompilerIdempotence::run_test_case, &tc, tc.name);
+}
+
+void GlslCompilerIdempotence::run_test_case(const TestCase *test_case)
+{
+	GL::SL::Compiler compiler(GL::SL::Features::all());
+	compiler.set_source(test_case->source, "<test>");
+	if(test_case->compile_mode==GL::SL::Compiler::PROGRAM)
+		compiler.specialize(test_case->spec_values);
+	compiler.compile(test_case->compile_mode);
+
+	GL::SL::Compiler compiler2(GL::SL::Features::all());
+	compiler2.set_source(compiler.get_combined_glsl(), "<loopback>");
+	compiler2.compile(test_case->compile_mode);
+
+	auto stages = compiler.get_stages();
+	auto stages2 = compiler2.get_stages();
+	auto i = stages.begin();
+	auto j = stages2.begin();
+	for(; (i!=stages.end() && j!=stages2.end() && *i==*j); ++i, ++j)
+	{
+		string output = compiler.get_stage_glsl(*i);
+		string output2 = compiler2.get_stage_glsl(*j);
+
+		verify_output(output2, output);
+	}
+
+	if(i!=stages.end())
+		fail(format("Second pass didn't produce stage %s", GL::SL::Stage::get_stage_name(*i)));
+	if(j!=stages2.end())
+		fail(format("Second pass produced extra stage %s", GL::SL::Stage::get_stage_name(*j)));
+}
-- 
2.43.0