Hello,
I prepared patch that give more precise control over __attribute__((warning)). Currently when you
use "warning" attribute with "-Werror" option warning become error and there is
no way to ignore this error.
With suggested changes it will be possible to use "-Werror
-Wno-error=warning-attribute" to compile code with warning attributes. This
particular case added as new testcase.
I tested suggested changes in two cases: with gcc-trunk compiled on GuixSD with
GCC 5.5 on amd64 machine and as patch to gcc 6.2.0 inside of Yocto 2.2
environment on Ubuntu 14.04 on amd64 machine.
Regards,
Nikolai
gcc/Changelog
2018-09-29 Nikolai Merinov <n.meri...@inango-systems.com>
* gcc/common.opt: Add -Wwarning-attribute.
* gcc/doc/invoke.texi: Add documentation for -Wno-warning-attribute.
* gcc/testsuite/gcc.dg/Wno-warning-attribute.c: New test.
* gcc/expr.c (expand_expr_real_1): Add new attribute to warning_at
call to allow user configure behavior of "warning" attribute
Index: gcc/common.opt
===================================================================
--- gcc/common.opt (revision 264725)
+++ gcc/common.opt (working copy)
@@ -571,6 +571,10 @@ Wcpp
Common Var(warn_cpp) Init(1) Warning
Warn when a #warning directive is encountered.
+Wwarning-attribute
+Common Var(warn_warning_attribute) Init(1) Warning
+Warn about uses of __attribute__((warning)) declarations.
+
Wdeprecated-declarations
Common Var(warn_deprecated_decl) Init(1) Warning
Warn about uses of __attribute__((deprecated)) declarations.
Index: gcc/doc/invoke.texi
===================================================================
--- gcc/doc/invoke.texi (revision 264725)
+++ gcc/doc/invoke.texi (working copy)
@@ -291,6 +291,7 @@ Objective-C and Objective-C++ Dialects}.
-Wclobbered -Wcomment -Wconditionally-supported @gol
-Wconversion -Wcoverage-mismatch -Wno-cpp -Wdangling-else -Wdate-time @gol
-Wdelete-incomplete @gol
+-Wno-warning-attribute @gol
-Wno-deprecated -Wno-deprecated-declarations -Wno-designated-init @gol
-Wdisabled-optimization @gol
-Wno-discarded-qualifiers -Wno-discarded-array-qualifiers @gol
@@ -6940,6 +6941,15 @@ confused with the digit 0, and so is not the defau
useful as a local coding convention if the programming environment
cannot be fixed to display these characters distinctly.
+@item -Wno-warning-attribute
+@opindex Wno-warning-attribute
+@opindex Wwarning-attribute
+Do not warn about usage of functions (@pxref{Function Attributes})
+declared with @code{warning} attribute. By default, this warning is
+enabled. @option{-Wno-warning-attribute} can be used to disable the
+warning or @option{-Wno-error=warning-attribute} can be used to
+disable the error when compiled with @option{-Werror} flag.
+
@item -Wno-deprecated
@opindex Wno-deprecated
@opindex Wdeprecated
Index: gcc/expr.c
===================================================================
--- gcc/expr.c (revision 264725)
+++ gcc/expr.c (working copy)
@@ -10930,7 +10930,8 @@ expand_expr_real_1 (tree exp, rtx target, machine_
DECL_ATTRIBUTES (fndecl))) != NULL)
{
const char *ident = lang_hooks.decl_printable_name (fndecl, 1);
- warning_at (tree_nonartificial_location (exp), 0,
+ warning_at (tree_nonartificial_location (exp),
+ OPT_Wwarning_attribute,
"%Kcall to %qs declared with attribute warning: %s",
exp, identifier_to_locale (ident),
TREE_STRING_POINTER (TREE_VALUE (TREE_VALUE (attr))));
Index: gcc/testsuite/gcc.dg/Wno-warning-attribute.c
===================================================================
--- gcc/testsuite/gcc.dg/Wno-warning-attribute.c (revision 0)
+++ gcc/testsuite/gcc.dg/Wno-warning-attribute.c (working copy)
@@ -0,0 +1,8 @@
+/* { dg-do compile } */
+/* { dg-options "-Werror -Wno-error=warning-attribute" } */
+
+int f1(void) __attribute__ ((warning("Please avoid f1")));
+int func1(void)
+{
+ return f1(); /* { dg-warning "'f1' declared with attribute warning: Please avoid f1" } */
+}
