From: Mikko Rasa <tdb@tdb.fi>
Date: Sun, 21 Feb 2021 23:52:29 +0000 (+0200)
Subject: Slightly refactor layout qualifiers in the GLSL parser
X-Git-Url: http://git.tdb.fi/?p=libs%2Fgl.git;a=commitdiff_plain;h=ffdb126a55467245da08a9e6f5669f86e1899bb0

Slightly refactor layout qualifiers in the GLSL parser

Their values are now stored as integers, since no qualifier takes a
value of any other type.
---

diff --git a/source/glsl/compatibility.cpp b/source/glsl/compatibility.cpp
index 07698394..a65f6de7 100644
--- a/source/glsl/compatibility.cpp
+++ b/source/glsl/compatibility.cpp
@@ -264,20 +264,19 @@ void LegacyConverter::visit(VariableDeclaration &var)
 	if(var.layout && !supports_interface_layouts())
 	{
 		vector<Layout::Qualifier>::iterator i;
-		for(i=var.layout->qualifiers.begin(); (i!=var.layout->qualifiers.end() && i->identifier!="location"); ++i) ;
+		for(i=var.layout->qualifiers.begin(); (i!=var.layout->qualifiers.end() && i->name!="location"); ++i) ;
 		if(i!=var.layout->qualifiers.end())
 		{
-			unsigned location = lexical_cast<unsigned>(i->value);
 			if(stage->type==Stage::VERTEX && var.interface=="in")
 			{
-				stage->locations[var.name] = location;
+				stage->locations[var.name] = i->value;
 				var.layout->qualifiers.erase(i);
 			}
 			else if(stage->type==Stage::FRAGMENT && var.interface=="out")
 			{
-				if(location!=0 && !check_extension(&Features::ext_gpu_shader4))
+				if(i->value!=0 && !check_extension(&Features::ext_gpu_shader4))
 					throw unsupported_shader("EXT_gpu_shader4 is required");
-				stage->locations[var.name] = location;
+				stage->locations[var.name] = i->value;
 				var.layout->qualifiers.erase(i);
 			}
 
diff --git a/source/glsl/debug.cpp b/source/glsl/debug.cpp
index 0a5b6ef3..2bc3a893 100644
--- a/source/glsl/debug.cpp
+++ b/source/glsl/debug.cpp
@@ -196,9 +196,9 @@ void DumpTree::visit(Layout &layout)
 	for(vector<Layout::Qualifier>::const_iterator i=layout.qualifiers.begin(); i!=layout.qualifiers.end(); )
 	{
 		vector<Layout::Qualifier>::const_iterator j = increment(i, layout.qualifiers);
-		string qualifier = j->identifier;
-		if(!j->value.empty())
-			qualifier += format("=%s", j->value);
+		string qualifier = j->name;
+		if(j->has_value)
+			qualifier += format("=%d", j->value);
 		append(qualifier);
 	}
 	end_sub();
diff --git a/source/glsl/generate.cpp b/source/glsl/generate.cpp
index 064d217e..d435d29a 100644
--- a/source/glsl/generate.cpp
+++ b/source/glsl/generate.cpp
@@ -52,8 +52,9 @@ void DeclarationCombiner::visit(VariableDeclaration &var)
 				{
 					bool found = false;
 					for(vector<Layout::Qualifier>::iterator j=ptr->layout->qualifiers.begin(); (!found && j!=ptr->layout->qualifiers.end()); ++j)
-						if(j->identifier==i->identifier)
+						if(j->name==i->name)
 						{
+							j->has_value = i->value;
 							j->value = i->value;
 							found = true;
 						}
diff --git a/source/glsl/output.cpp b/source/glsl/output.cpp
index 3fc703c1..c1da9fec 100644
--- a/source/glsl/output.cpp
+++ b/source/glsl/output.cpp
@@ -186,9 +186,9 @@ void Formatter::visit(Layout &layout)
 	{
 		if(i!=layout.qualifiers.begin())
 			append(", ");
-		append(i->identifier);
-		if(!i->value.empty())
-			append(format("=%s", i->value));
+		append(i->name);
+		if(i->has_value)
+			append(format("=%d", i->value));
 	}
 	append(')');
 }
diff --git a/source/glsl/parser.cpp b/source/glsl/parser.cpp
index ec6ce6eb..4b6bd7ed 100644
--- a/source/glsl/parser.cpp
+++ b/source/glsl/parser.cpp
@@ -1,5 +1,6 @@
 #include <msp/strings/format.h>
 #include <msp/strings/regex.h>
+#include <msp/strings/utils.h>
 #include "glsl_error.h"
 #include "parser.h"
 
@@ -118,6 +119,14 @@ string Parser::expect_identifier()
 	return token;
 }
 
+int Parser::expect_integer()
+{
+	string token = tokenizer.parse_token();
+	if(!isnumrc(token))
+		throw parse_error(tokenizer.get_location(), token, "an integer literal");
+	return lexical_cast<int>(token);
+}
+
 bool Parser::check(const string &token)
 {
 	bool result = (tokenizer.peek_token()==token);
@@ -315,10 +324,10 @@ RefPtr<Layout> Parser::parse_layout()
 
 		layout->qualifiers.push_back(Layout::Qualifier());
 		Layout::Qualifier &qual = layout->qualifiers.back();
-		qual.identifier = token;
+		qual.name = token;
 
-		if(check("="))
-			qual.value = tokenizer.parse_token();
+		if((qual.has_value = check("=")))
+			qual.value = expect_integer();
 
 		if(tokenizer.peek_token()==")")
 			break;
diff --git a/source/glsl/parser.h b/source/glsl/parser.h
index cdb57ebc..1572128f 100644
--- a/source/glsl/parser.h
+++ b/source/glsl/parser.h
@@ -41,6 +41,7 @@ private:
 
 	std::string expect_type();
 	std::string expect_identifier();
+	int expect_integer();
 	bool check(const std::string &);
 
 	static bool is_interface_qualifier(const std::string &);
diff --git a/source/glsl/syntax.h b/source/glsl/syntax.h
index 3fb848d2..70b1bb39 100644
--- a/source/glsl/syntax.h
+++ b/source/glsl/syntax.h
@@ -242,9 +242,9 @@ struct Layout: Node
 {
 	struct Qualifier
 	{
-		// TODO the standard calls this name, not identifier
-		std::string identifier;
-		std::string value;
+		std::string name;
+		bool has_value;
+		int value;
 	};
 
 	std::vector<Qualifier> qualifiers;