Adapt the RGBASM parser to C++ (#1333)

This uses variants instead of a `%union`, and "complete symbols"
that can call complex constructors.

Makefile

@@ -174,7 +174,7 @@ clean:
 	$Qfind src/ -name "*.o" -exec rm {} \;
 	$Qfind . -type f \( -name "*.gcno" -o -name "*.gcda" -o -name "*.gcov" \) -exec rm {} \;
 	$Q${RM} rgbshim.sh
-	$Q${RM} src/asm/parser.cpp src/asm/parser.hpp
+	$Q${RM} src/asm/parser.cpp src/asm/parser.hpp src/asm/stack.hh
 	$Q${RM} src/link/script.cpp src/link/script.hpp src/link/stack.hh
 	$Q${RM} test/gfx/randtilegen test/gfx/rgbgfx_test
 

include/asm/lexer.hpp

@@ -9,6 +9,8 @@
 #include <variant>
 #include <vector>
 
+#include "asm/symbol.hpp" // MAXSYMLEN
+
 #include "platform.hpp" // SSIZE_MAX
 
 #define MAXSTRLEN 255
@@ -139,12 +141,19 @@ struct CaptureBody {
 	size_t size;
 };
 
+struct String {
+	char string[MAXSTRLEN + 1];
+};
+
+struct SymName {
+	char symName[MAXSYMLEN + 1];
+};
+
 void lexer_CheckRecursionDepth();
 char const *lexer_GetFileName();
 uint32_t lexer_GetLineNo();
 uint32_t lexer_GetColNo();
 void lexer_DumpStringExpansions();
-int yylex();
 bool lexer_CaptureRept(CaptureBody &capture);
 bool lexer_CaptureMacroBody(CaptureBody &capture);
 

src/asm/.gitignore

@@ -1,2 +1,3 @@
 /parser.cpp
 /parser.hpp
+/stack.hh

src/asm/main.cpp

@@ -399,8 +399,9 @@ int main(int argc, char *argv[]) {
 	// Init lexer and file stack, providing file info
 	fstk_Init(mainFileName, maxDepth);
 
-	// Perform parse (yyparse is auto-generated from `parser.y`)
-	if (yyparse() != 0 && nbErrors == 0)
+	// Perform parse
+	yy::parser parser;
+	if (parser.parse() != 0 && nbErrors == 0)
 		nbErrors = 1;
 
 	if (dependfile)