[Patch] PR55189 enable -Wreturn-type by default

[Manuel López-Ibáñez]

--- a/gcc/fortran/options.c
+++ b/gcc/fortran/options.c
@@ -693,6 +693,10 @@ gfc_handle_option (size_t scode, const char *arg,
int value,
       gfc_option.warn_line_truncation = value;
       break;

+    case OPT_Wmissing_return:
+      warn_missing_return = value;
+      break;
+
     case OPT_Wrealloc_lhs:
       gfc_option.warn_realloc_lhs = value;
       break;

The entry in c.opt says this is a C/C++ option, why you need this?

+Wmissing-return
+C ObjC C++ ObjC++ Var(warn_missing_return) LangEnabledBy(C ObjC C++
ObjC++,Wreturn-type)
+Warn whenever control may reach end of non-void function

This should prevent that using -Wreturn-type in Fortran tries to
enable -Wmissing-return, if not that is a bug.

In any case, the work-around should be adding Wmissing-return to
fortran/lang.opt with a ??? comment, not there.


--- a/gcc/c-family/c.opt
+++ b/gcc/c-family/c.opt
@@ -472,7 +472,7 @@ C ObjC Var(warn_implicit_function_declaration)
Init(-1) Warning LangEnabledBy(C
 Warn about implicit function declarations

 Wimplicit-int
-C ObjC Var(warn_implicit_int) Warning LangEnabledBy(C ObjC,Wimplicit)
+C ObjC Var(warn_implicit_int) Warning
 Warn when a declaration does not specify a type

 Wimport
diff --git a/gcc/doc/invoke.texi b/gcc/doc/invoke.texi
index 5ae910c..3f2019a 100644
--- a/gcc/doc/invoke.texi
+++ b/gcc/doc/invoke.texi
@@ -3615,7 +3615,7 @@ This warning is enabled by @option{-Wall} in C++.
 @opindex Wimplicit-int
 @opindex Wno-implicit-int
 Warn when a declaration does not specify a type.
-This warning is enabled by @option{-Wall}.
+This warning is enabled by default.

 @item -Wimplicit-function-declaration @r{(C and Objective-C only)}
 @opindex Wimplicit-function-declaration


Does this patch actually enables -Wimplicit-int by default? The
default without Init() should be zero!

And according to this: https://gcc.gnu.org/ml/gcc-patches/2014-06/msg01367.html

we still want -Wno-implicit to disable -Wimplicit-int (and
-Werror=implicit to set -Werror=implicit-int), so the LangEnabledBy()
should stay. The documentation could say: "This warning is enabled by
default and it is also controlled by -Wimplicit."

Cheers,

Manuel.