[PATCH 14/16] warn on return <void expression>;

[Al Viro <viro@ftp.linux.org.uk>]

conditional on -Wreturn-void

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
---
 evaluate.c |    2 ++
 lib.c      |    2 ++
 lib.h      |    1 +
 3 files changed, 5 insertions(+), 0 deletions(-)

diff --git a/evaluate.c b/evaluate.c
index e3b4940..07ebf0c 100644
--- a/evaluate.c
+++ b/evaluate.c
@@ -2790,6 +2790,8 @@ static struct symbol *evaluate_return_expression(struct statement *stmt)
 	if (!fntype || fntype == &void_ctype) {
 		if (expr && expr->ctype != &void_ctype)
 			expression_error(expr, "return expression in %s function", fntype?"void":"typeless");
+		if (expr && Wreturn_void)
+			warning(stmt->pos, "returning void-valued expression");
 		return NULL;
 	}
 
diff --git a/lib.c b/lib.c
index 4856b65..7f6334c 100644
--- a/lib.c
+++ b/lib.c
@@ -207,6 +207,7 @@ int Wuninitialized = 1;
 int Wold_initializer = 1;
 int Wnon_pointer_null = 1;
 int Wparen_string = 0;
+int Wreturn_void = 0;
 
 int dbg_entry = 0;
 int dbg_dead = 0;
@@ -359,6 +360,7 @@ static const struct warning {
 	{ "old-initializer", &Wold_initializer },
 	{ "non-pointer-null", &Wnon_pointer_null },
 	{ "paren-string", &Wparen_string },
+	{ "return-void", &Wreturn_void },
 };
 
 enum {
diff --git a/lib.h b/lib.h
index 0fe4d2a..bc2a8c2 100644
--- a/lib.h
+++ b/lib.h
@@ -104,6 +104,7 @@ extern int Wuninitialized;
 extern int Wold_initializer;
 extern int Wnon_pointer_null;
 extern int Wparen_string;
+extern int Wreturn_void;
 
 extern int dbg_entry;
 extern int dbg_dead;
-- 
1.5.0-rc2.GIT