[Bug driver/81345] -Wall resets default option arguments to 1

["msebor at gcc dot gnu.org" <gcc-bugzilla at gcc dot gnu dot org>]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=81345

Martin Sebor <msebor at gcc dot gnu.org> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
            Summary|-Wall resets                |-Wall resets default option
                   |-Wstringop-overflow to 1    |arguments to 1
                   |from the default 2          |

--- Comment #1 from Martin Sebor <msebor at gcc dot gnu.org> ---
Applying the patch below makes it clear that -Wall resets the default option
argument to 1:

$ gcc -S -Wall -xc - </dev/null
cc1: note: warn_foobar=1


diff --git a/gcc/c-family/c.opt b/gcc/c-family/c.opt
index 3d96bf5..bfa1072 100644
--- a/gcc/c-family/c.opt
+++ b/gcc/c-family/c.opt
@@ -732,6 +732,9 @@ C ObjC C++ ObjC++ Joined RejectNegative UInteger
Var(warn_stringop_overflow) Ini
 Under the control of Object Size type, warn about buffer overflow in string
 manipulation functions like memcpy and strcpy.
 diff --git a/gcc/c-family/c.opt b/gcc/c-family/c.opt
index 3d96bf5..584ebc0 100644
--- a/gcc/c-family/c.opt
+++ b/gcc/c-family/c.opt
@@ -342,6 +342,9 @@ Wbool-operation
 C ObjC C++ ObjC++ Var(warn_bool_op) Warning LangEnabledBy(C ObjC C++
ObjC++,Wall)
 Warn about certain operations on boolean expressions.

+Wfoobar
+C ObjC C++ ObjC++ Joined RejectNegative UInteger Var(warn_foobar) Init(123)
Warning LangEnabledBy(C ObjC C++ ObjC++, Wall)
+
 Wframe-address
 C ObjC C++ ObjC++ Var(warn_frame_address) Warning LangEnabledBy(C ObjC C++
ObjC++,Wall)
 Warn when __builtin_frame_address or __builtin_return_address is used
unsafely.
diff --git a/gcc/toplev.c b/gcc/toplev.c
index e6c69a4..3697c48 100644
--- a/gcc/toplev.c
+++ b/gcc/toplev.c
@@ -2147,6 +2147,8 @@ toplev::main (int argc, char **argv)
   if (help_flag)
     print_plugins_help (stderr, "");

+  inform (UNKNOWN_LOCATION, "warn_foobar=%i", warn_foobar);
+
   /* Exit early if we can (e.g. -help).  */
   if (!exit_after_options)
     {