[qfcc] Support generic scope blocks

That is, `@generic(...) { ... };`, which is handy for bulk declarations
(such as for glsl). This proved to be a lot harder than expected, I
suspect handling of specifiers needs a lot of work.

tools/qfcc/include/specifier.h

@@ -59,6 +59,7 @@ typedef struct specifier_s {
 		struct {
 			bool        multi_type:1;
 			bool        multi_store:1;
+			bool        multi_generic:1;
 			bool        is_signed:1;
 			bool        is_unsigned:1;
 			bool        is_short:1;
@@ -66,6 +67,7 @@ typedef struct specifier_s {
 			bool        is_typedef:1;
 			bool        is_overload:1;
 			bool        is_generic:1;
+			bool        is_generic_block:1;
 			bool        is_function:1;//FIXME do proper void(*)() -> ev_func
 			bool        nosave:1;
 			bool        no_va_list:1;

tools/qfcc/source/function.c

@@ -105,8 +105,8 @@ static void
 check_generic_param (genparam_t *param, genfunc_t *genfunc)
 {
 	if (param->gentype < 0 || param->gentype >= genfunc->num_types) {
-		internal_error (0, "invalid type index %s for %s",
+		internal_error (0, "invalid type index %d on %s for %s",
-						param->name, genfunc->name);
+						param->gentype, param->name, genfunc->name);
 	}
 }
 
@@ -295,7 +295,7 @@ parse_generic_function (const char *name, specifier_t spec)
 	for (auto p = &ret_param; p; p = p->next) {
 		num_params++;
 	}
-	auto generic_tab = current_symtab;
+	auto generic_tab = spec.symtab;
 	for (auto s = generic_tab->symbols; s; s = s->next) {
 		bool found = false;
 		for (auto q = &ret_param; q; q = q->next) {
@@ -309,7 +309,7 @@ parse_generic_function (const char *name, specifier_t spec)
 				break;
 			}
 		}
-		if (!found) {
+		if (!spec.is_generic_block && !found) {
 			warning (0, "generic parameter %s not used", s->name);
 		}
 	}

tools/qfcc/source/qc-parse.y

@@ -243,7 +243,25 @@ int yylex (YYSTYPE *yylval, YYLTYPE *yylloc);
 static switch_block_t *switch_block;
 static const expr_t *break_label;
 static const expr_t *continue_label;
-static bool generic_scope;
+static bool generic_scope, generic_block;
+static symtab_t *generic_symtab;
+
+static void
+end_generic_scope (void)
+{
+	generic_scope = false;
+	generic_symtab = nullptr;
+}
+
+static void
+restore_storage (specifier_t st)
+{
+	if (generic_block && !st.is_generic) {
+		end_generic_scope ();
+	}
+	generic_block = st.is_generic;
+	current_storage = st.storage;
+}
 
 static specifier_t
 type_spec (const type_t *type)
@@ -291,6 +309,7 @@ generic_spec (void)
 		.symtab = new_symtab (current_symtab, stab_local),
 		.is_generic = true,
 	};
+	generic_symtab = spec.symtab;
 	return spec;
 }
 
@@ -348,6 +367,12 @@ spec_merge (specifier_t spec, specifier_t new)
 		spec.storage = new.storage;
 		spec.is_typedef = new.is_typedef;
 	}
+	if (new.is_generic) {
+		if (spec.is_generic && !spec.multi_generic) {
+			error (0, "multiple @generic in declaration");
+			spec.multi_generic = true;
+		}
+	}
 	if ((new.is_unsigned && spec.is_signed)
 		|| (new.is_signed && spec.is_unsigned)) {
 		if (!spec.multi_type) {
@@ -398,6 +423,9 @@ function_spec (specifier_t spec, param_t *params)
 	spec.sym->params = params;
 	spec.sym->type = append_type (spec.sym->type, parse_params (0, params));
 	spec.is_function = true; //FIXME do proper void(*)() -> ev_func
+	spec.is_generic = generic_scope;
+	spec.is_generic_block = generic_block;
+	spec.symtab = generic_symtab;
 	return spec;
 }
 
@@ -581,13 +609,14 @@ program
 external_def_list
 	: /* empty */
 		{
+			if (!generic_block) {
 				current_symtab = pr.symtab;
 			}
+		}
 	| external_def_list external_def
 		{
-			if (generic_scope) {
+			if (generic_scope && !generic_block) {
-				generic_scope = false;
+				end_generic_scope ();
-				current_symtab = current_symtab->parent;
 			}
 		}
 	| external_def_list obj_def
@@ -599,10 +628,11 @@ external_def
 	| storage_class '{' save_storage
 		{
 			current_storage = $1.storage;
+			generic_block = generic_scope;
 		}
 	  external_def_list '}' ';'
 		{
-			current_storage = $3.storage;
+			restore_storage ($3);
 		}
 	;
 
@@ -773,7 +803,7 @@ qc_code_func
 			build_code_function ($1, $3, $6);
 			current_symtab = $<funcstate>5.symtab;
 			current_func = $<funcstate>5.function;
-			current_storage = $4.storage;
+			restore_storage ($4);
 		}
 	;
 
@@ -1054,6 +1084,7 @@ save_storage
 	: /* emtpy */
 		{
 			$$.storage = current_storage;
+			$$.is_generic = generic_block;
 		}
 	;
 
@@ -1080,7 +1111,7 @@ function_body
 			build_code_function ($<symbol>2, $1, $5);
 			current_symtab = $<funcstate>4.symtab;
 			current_func = $<funcstate>4.function;
-			current_storage = $3.storage;
+			restore_storage ($3);
 		}
 	| '=' '#' expr ';'
 		{
@@ -1100,13 +1131,14 @@ storage_class
 	| GENERIC '('				{ $<spec>$ = generic_spec (); }
 	  generic_param_list ')'
 		{
+			$$ = $<spec>3;
+
 			if (generic_scope) {
 				error (0, "multiple @generic in declaration");
+				$$.multi_generic = true;
 			} else {
 				generic_scope = true;
-				current_symtab = $<spec>3.symtab;
 			}
-			$$ = $<spec>3;
 		}
 	| ATTRIBUTE '(' attribute_list ')'
 		{
@@ -2438,7 +2470,7 @@ methoddef
 			build_code_function ($<symbol>4, $3, $7);
 			current_symtab = $<funcstate>6.symtab;
 			current_func = $<funcstate>6.function;
-			current_storage = $5.storage;
+			restore_storage ($5);
 		}
 	| ci methoddecl '=' '#' const ';'
 		{
@@ -2858,7 +2890,6 @@ qc_keyword_or_id (QC_YYSTYPE *lval, const char *token)
 	static hashtab_t *rua_keyword_tab;
 
 	keyword_t  *keyword = 0;
-	symbol_t   *sym;
 
 	if (!keyword_tab) {
 		size_t      i;
@@ -2908,9 +2939,17 @@ qc_keyword_or_id (QC_YYSTYPE *lval, const char *token)
 	if (token[0] == '@') {
 		return '@';
 	}
+
+	symbol_t   *sym = nullptr;
+	if (generic_symtab) {
+		sym = symtab_lookup (generic_symtab, token);
+	}
+	if (!sym) {
 		sym = symtab_lookup (current_symtab, token);
-	if (!sym)
+	}
+	if (!sym) {
 		sym = new_symbol (token);
+	}
 	lval->symbol = sym;
 	if (sym->sy_type == sy_type) {
 		lval->spec = (specifier_t) {