From 261ea0c4de42f36fee8ab514346d135217cc8b42 Mon Sep 17 00:00:00 2001
From: Bill Currie <bill@taniwha.org>
Date: Mon, 2 Oct 2023 14:21:40 +0900
Subject: [PATCH] [qfcc] Be more const-correct with expressions

Diagnostics that return an expression now return const, and fixes error
not returning an error expression.
---
 tools/qfcc/include/diagnostic.h | 22 ++++++++++++----------
 tools/qfcc/include/expr.h       | 10 +++++-----
 tools/qfcc/source/diagnostic.c  | 14 +++++++-------
 tools/qfcc/source/expr.c        | 10 +++++-----
 tools/qfcc/source/method.c      |  2 +-
 tools/qfcc/source/stub.c        |  4 ++--
 6 files changed, 32 insertions(+), 30 deletions(-)

diff --git a/tools/qfcc/include/diagnostic.h b/tools/qfcc/include/diagnostic.h
index 4e72b6da0..529f7db99 100644
--- a/tools/qfcc/include/diagnostic.h
+++ b/tools/qfcc/include/diagnostic.h
@@ -31,6 +31,8 @@
 #ifndef __diagnostic_h
 #define __diagnostic_h
 
+typedef struct expr_s expr_t;
+
 /**	\defgroup qfcc_diagnostic Diagnostic Messages
 	\ingroup qfcc
 */
@@ -42,37 +44,37 @@ extern diagnostic_hook error_hook;
 extern diagnostic_hook warning_hook;
 extern diagnostic_hook notice_hook;
 
-struct expr_s *_error (const struct expr_s *e, const char *file,
-					   int line, const char *func, const char *fmt, ...)
+const expr_t *_error (const expr_t *e, const char *file,
+					  int line, const char *func, const char *fmt, ...)
 	__attribute__ ((format (PRINTF, 5, 6)));
 #define error(e, fmt...) _error(e, __FILE__, __LINE__, __FUNCTION__, fmt)
 
-void _internal_error (const struct expr_s *e, const char *file, int line,
+void _internal_error (const expr_t *e, const char *file, int line,
 					  const char *func, const char *fmt, ...)
 	__attribute__ ((format (PRINTF, 5, 6), noreturn));
 #define internal_error(e, fmt...) _internal_error(e, __FILE__, __LINE__, __FUNCTION__, fmt)
 
-struct expr_s *_warning (const struct expr_s *e, const char *file,
-						 int line, const char *func, const char *fmt, ...)
+const expr_t *_warning (const expr_t *e, const char *file,
+						int line, const char *func, const char *fmt, ...)
 	__attribute__ ((format (PRINTF, 5, 6)));
 #define warning(e, fmt...) _warning(e, __FILE__, __LINE__, __FUNCTION__, fmt)
 
-struct expr_s *_notice (const struct expr_s *e, const char *file,
-						int line, const char *func, const char *fmt, ...)
+const expr_t *_notice (const expr_t *e, const char *file,
+					   int line, const char *func, const char *fmt, ...)
 	__attribute__ ((format (PRINTF, 5, 6)));
 #define notice(e, fmt...) _notice(e, __FILE__, __LINE__, __FUNCTION__, fmt)
 
-void _debug (const struct expr_s *e, const char *file, int line,
+void _debug (const expr_t *e, const char *file, int line,
 			 const char *func, const char *fmt, ...)
 	__attribute__ ((format (PRINTF, 5, 6)));
 #define debug(e, fmt...) _debug(e, __FILE__, __LINE__, __FUNCTION__, fmt)
 
-void _bug (const struct expr_s *e, const char *file, int line,
+void _bug (const expr_t *e, const char *file, int line,
 		   const char * func, const char *fmt, ...)
 	__attribute__ ((format (PRINTF, 5, 6)));
 #define bug(e, fmt...) _bug(e, __FILE__, __LINE__, __FUNCTION__, fmt)
 
-void print_srcline (int rep, const struct expr_s *e);
+void print_srcline (int rep, const expr_t *e);
 
 ///@}
 
diff --git a/tools/qfcc/include/expr.h b/tools/qfcc/include/expr.h
index 8a5b042ba..4fb859faf 100644
--- a/tools/qfcc/include/expr.h
+++ b/tools/qfcc/include/expr.h
@@ -360,11 +360,11 @@ extern const char *expr_names[];
 	\param op		The opcode of the expression.
 	\return			\a e1 with its type set to ex_error.
 */
-expr_t *type_mismatch (const expr_t *e1, const expr_t *e2, int op);
+const expr_t *type_mismatch (const expr_t *e1, const expr_t *e2, int op);
 
-expr_t *param_mismatch (const expr_t *e, int param, const char *fn,
-						type_t *t1, type_t *t2);
-expr_t *test_error (const expr_t *e, type_t *t);
+const expr_t *param_mismatch (const expr_t *e, int param, const char *fn,
+							  struct type_s *t1, struct type_s *t2);
+const expr_t *test_error (const expr_t *e, struct type_s *t);
 
 extern expr_t *local_expr;
 
@@ -540,7 +540,7 @@ expr_t *new_unary_expr (int op, const expr_t *e1);
 */
 expr_t *new_horizontal_expr (int op, const expr_t *vec, type_t *type);
 
-expr_t *new_swizzle_expr (const expr_t *src, const char *swizzle);
+const expr_t *new_swizzle_expr (const expr_t *src, const char *swizzle);
 
 expr_t *new_extend_expr (const expr_t *src, type_t *type, int ext, bool rev);
 
diff --git a/tools/qfcc/source/diagnostic.c b/tools/qfcc/source/diagnostic.c
index c6b447467..a6ba01d5e 100644
--- a/tools/qfcc/source/diagnostic.c
+++ b/tools/qfcc/source/diagnostic.c
@@ -208,14 +208,14 @@ _bug (const expr_t *e, const char *file, int line, const char *func,
 	va_end (args);
 }
 
-expr_t *
+const expr_t *
 _notice (const expr_t *e, const char *file, int line, const char *func,
 		 const char *fmt, ...)
 {
 	va_list     args;
 
 	if (options.notices.silent)
-		return (expr_t *) e;
+		return e;
 
 	va_start (args, fmt);
 	if (options.notices.promote) {
@@ -237,10 +237,10 @@ _notice (const expr_t *e, const char *file, int line, const char *func,
 		dstring_delete (message);
 	}
 	va_end (args);
-	return (expr_t *) e;
+	return e;
 }
 
-expr_t *
+const expr_t *
 _warning (const expr_t *e, const char *file, int line, const char *func,
 		  const char *fmt, ...)
 {
@@ -249,7 +249,7 @@ _warning (const expr_t *e, const char *file, int line, const char *func,
 	va_start (args, fmt);
 	__warning (e, file, line, func, fmt, args);
 	va_end (args);
-	return (expr_t *) e;
+	return e;
 }
 
 void
@@ -263,7 +263,7 @@ _internal_error (const expr_t *e, const char *file, int line,
 	va_end (args);
 }
 
-expr_t *
+const expr_t *
 _error (const expr_t *e, const char *file, int line, const char *func,
 		const char *fmt, ...)
 {
@@ -292,5 +292,5 @@ _error (const expr_t *e, const char *file, int line, const char *func,
 
 	expr_t *err = new_expr ();
 	err->type = ex_error;
-	return (expr_t *) e;
+	return err;
 }
diff --git a/tools/qfcc/source/expr.c b/tools/qfcc/source/expr.c
index d24c65cbb..7a1e3ca80 100644
--- a/tools/qfcc/source/expr.c
+++ b/tools/qfcc/source/expr.c
@@ -214,7 +214,7 @@ extract_type (const expr_t *e)
 	return ev_type_count;
 }
 
-expr_t *
+const expr_t *
 type_mismatch (const expr_t *e1, const expr_t *e2, int op)
 {
 	if (options.verbosity >= 2) {
@@ -226,7 +226,7 @@ type_mismatch (const expr_t *e1, const expr_t *e2, int op)
 				  get_type_string (get_type (e2)));
 }
 
-expr_t *
+const expr_t *
 param_mismatch (const expr_t *e, int param, const char *fn, type_t *t1, type_t *t2)
 {
 	return error (e, "type mismatch for parameter %d of %s: "
@@ -234,7 +234,7 @@ param_mismatch (const expr_t *e, int param, const char *fn, type_t *t1, type_t *
 				  get_type_string (t2));
 }
 
-expr_t *
+const expr_t *
 test_error (const expr_t *e, type_t *t)
 {
 	dstring_t  *s = dstring_newstr ();
@@ -591,7 +591,7 @@ new_horizontal_expr (int op, const expr_t *vec, type_t *type)
 	return e;
 }
 
-expr_t *
+const expr_t *
 new_swizzle_expr (const expr_t *src, const char *swizzle)
 {
 	src = convert_name (src);
@@ -2076,7 +2076,7 @@ build_function_call (const expr_t *fexpr, const type_t *ftype, const expr_t *par
 {
 	int         param_count = 0;
 	expr_t     *call;
-	expr_t     *err = 0;
+	const expr_t *err = 0;
 
 	int arg_count = params ? list_count (&params->list) :0;
 	const expr_t *arguments[arg_count];
diff --git a/tools/qfcc/source/method.c b/tools/qfcc/source/method.c
index 7604e1f51..167ec1e30 100644
--- a/tools/qfcc/source/method.c
+++ b/tools/qfcc/source/method.c
@@ -704,7 +704,7 @@ const expr_t *
 method_check_params (method_t *method, const expr_t *args)
 {
 	int         i, param_count;
-	expr_t     *err = 0;
+	const expr_t *err = 0;
 	type_t     *mtype = method->type;
 
 	if (mtype->t.func.num_params == -1)
diff --git a/tools/qfcc/source/stub.c b/tools/qfcc/source/stub.c
index d944bc7b0..7dd5dcbff 100644
--- a/tools/qfcc/source/stub.c
+++ b/tools/qfcc/source/stub.c
@@ -55,8 +55,8 @@ void codespace_addcode (codespace_t *codespace, struct dstatement_s *code, int s
 __attribute__((const)) int function_parms (function_t *f, byte *parm_size) {return 0;}
 void def_to_ddef (def_t *def, ddef_t *ddef, int aux) {}
 __attribute__((noreturn)) void _internal_error (const expr_t *e, const char *file, int line, const char *func, const char *fmt, ...) {abort();}
-__attribute__((const)) expr_t *_warning (const expr_t *e, const char *file, int line, const char *func, const char *fmt, ...) {return 0;}
-__attribute__((const)) expr_t *_error (const expr_t *e, const char *file, int line, const char *func, const char *fmt, ...) {return 0;}
+__attribute__((const)) const expr_t *_warning (const expr_t *e, const char *file, int line, const char *func, const char *fmt, ...) {return 0;}
+__attribute__((const)) const expr_t *_error (const expr_t *e, const char *file, int line, const char *func, const char *fmt, ...) {return 0;}
 __attribute__((const)) symbol_t *make_structure (const char *name, int su, struct_def_t *defs, type_t *type) {return 0;}
 __attribute__((const)) symbol_t *symtab_addsymbol (symtab_t *symtab, symbol_t *symbol) {return 0;}
 __attribute__((const)) symbol_t *new_symbol_type (const char *name, type_t *type) {return 0;}