Re: [PATCH] mingw32: Fix warning, update documentation

[Jonathan Yong via Gcc-patches]

On 9/8/22 11:02, Jan-Benedict Glaw wrote:

Hi!


The mingw32 port is the only port to have TARGET_OVERRIDES_FORMAT_ATTRIBUTES
defined. When this macro is defined, it will never evaluate to NULL, so this
check just leads to a warning:

/usr/lib/gcc-snapshot/bin/g++ -fcf-protection -fno-PIE -c  -DIN_GCC_FRONTEND 
-DIN_GCC_FRONTEND -DIN_GCC_FRONTEND -g -O2   -DIN_GCC  
-DCROSS_DIRECTORY_STRUCTURE   -fno-exceptions -fno-rtti 
-fasynchronous-unwind-tables -W -Wall -Wno-narrowing -Wwrite-strings 
-Wcast-qual -Wmissing-format-attribute -Woverloaded-virtual -pedantic 
-Wno-long-long -Wno-variadic-macros -Wno-overlength-strings -Werror -fno-common 
 -DHAVE_CONFIG_H -I. -Ic-family -I../../gcc/gcc -I../../gcc/gcc/c-family 
-I../../gcc/gcc/../include -I../../gcc/gcc/../libcpp/include 
-I../../gcc/gcc/../libcody  -I../../gcc/gcc/../libdecnumber 
-I../../gcc/gcc/../libdecnumber/bid -I../libdecnumber 
-I../../gcc/gcc/../libbacktrace   -o c-family/c-format.o -MT 
c-family/c-format.o -MMD -MP -MF c-family/.deps/c-format.TPo 
../../gcc/gcc/c-family/c-format.cc
../../gcc/gcc/c-family/c-format.cc: In function 'const char* 
convert_format_name_to_system_name(const char*)':
../../gcc/gcc/c-family/c-format.cc:5114:42: error: the address of 
'mingw_format_attribute_overrides' will never be NULL [-Werror=address]
  5114 |   if (TARGET_OVERRIDES_FORMAT_ATTRIBUTES != NULL
In file included from ./tm.h:26,
                  from ../../gcc/gcc/c-family/c-format.cc:23:
../../gcc/gcc/config/i386/mingw32.h:268:44: note: 
'mingw_format_attribute_overrides' declared here
   268 | #define TARGET_OVERRIDES_FORMAT_ATTRIBUTES 
mingw_format_attribute_overrides
       |                                            
^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
../../gcc/gcc/c-family/c-format.cc:5079:30: note: in expansion of macro 
'TARGET_OVERRIDES_FORMAT_ATTRIBUTES'
  5079 | extern const target_ovr_attr TARGET_OVERRIDES_FORMAT_ATTRIBUTES[];
       |                              ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
cc1plus: all warnings being treated as errors
make[1]: *** [Makefile:1146: c-family/c-format.o] Error 1
make[1]: Leaving directory 
'/var/lib/laminar/run/gcc-x86_64-w64-mingw32/1/toolchain-build/gcc'
make: *** [Makefile:4588: all-gcc] Error 2



   Also, when TARGET_OVERRIDES_FORMAT_ATTRIBUTES is defined,
TARGET_OVERRIDES_FORMAT_ATTRIBUTES_COUNT must be defined as well. Add
that requirement to the docs.


2022-09-07  Jan-Benedict Glaw  <jbg...@lug-owl.de>

gcc/ChangeLog:
        * c-family/c-format.cc (convert_format_name_to_system_name): Fix 
warning.
        * doc/tm.texi.in (TARGET_OVERRIDES_FORMAT_ATTRIBUTES): Document 
requirement
        of TARGET_OVERRIDES_FORMAT_ATTRIBUTES_COUNT being defined as well.
        * doc/tm.texi: Regenerate.

diff --git a/gcc/c-family/c-format.cc b/gcc/c-family/c-format.cc
index 68b94da40cc..a6c380bf1c8 100644
--- a/gcc/c-family/c-format.cc
+++ b/gcc/c-family/c-format.cc
@@ -5111,8 +5111,7 @@ convert_format_name_to_system_name (const char *attr_name)

    /* Check if format attribute is overridden by target.  */
-  if (TARGET_OVERRIDES_FORMAT_ATTRIBUTES != NULL
-      && TARGET_OVERRIDES_FORMAT_ATTRIBUTES_COUNT > 0)
+  if (TARGET_OVERRIDES_FORMAT_ATTRIBUTES_COUNT > 0)
      {
        for (i = 0; i < TARGET_OVERRIDES_FORMAT_ATTRIBUTES_COUNT; ++i)
          {
diff --git a/gcc/doc/tm.texi.in b/gcc/doc/tm.texi.in
index 5312059ea79..21b849ea32a 100644
--- a/gcc/doc/tm.texi.in
+++ b/gcc/doc/tm.texi.in
@@ -7836,7 +7836,8 @@ If defined, this macro is the number of entries in
  If defined, this macro is the name of a global variable containing
  target-specific format overrides for the @option{-Wformat} option. The
  default is to have no target-specific format overrides. If defined,
-@code{TARGET_FORMAT_TYPES} must be defined, too.
+@code{TARGET_FORMAT_TYPES} and @code{TARGET_OVERRIDES_FORMAT_ATTRIBUTES_COUNT}
+must be defined, too.
  @end defmac

diff --git a/gcc/doc/tm.texi b/gcc/doc/tm.texi
index e47bf28089a..858bfb80cec 100644
--- a/gcc/doc/tm.texi
+++ b/gcc/doc/tm.texi
@@ -12043,7 +12043,8 @@ If defined, this macro is the number of entries in
  If defined, this macro is the name of a global variable containing
  target-specific format overrides for the @option{-Wformat} option. The
  default is to have no target-specific format overrides. If defined,
-@code{TARGET_FORMAT_TYPES} must be defined, too.
+@code{TARGET_FORMAT_TYPES} and @code{TARGET_OVERRIDES_FORMAT_ATTRIBUTES_COUNT}
+must be defined, too.
  @end defmac



Okay for HEAD?

Thanks,
   Jan-Benedict

#ifdef TARGET_OVERRIDES_FORMAT_ATTRIBUTES @defmac TARGET_OVERRIDES_FORMAT_ATTRIBUTES_COUNT @defmac TARGET_OVERRIDES_FORMAT_ATTRIBUTES_COUNT

Looks good to me, thanks for working on it.

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