gdb: Silence -Wformat-nonliteral warning with clang
Commit Message
We get this warning when building with clang:
CXX ui-out.o
/home/smarchi/src/binutils-gdb/gdb/ui-out.c:590:22: error: format string is not a string literal [-Werror,-Wformat-nonliteral]
do_message (style, format, args);
^~~~~~
This can be considered a legitimate warning, as call_do_message's format
parameter is not marked as a format string. Therefore, we should
normally mark the call_do_message method with the `format` attribute.
However, doing so just moves (and multiplies) the problem, as all the
uses of call_do_message in the vmessage method now warn. If we wanted
to continue on that path, we should silence the warning for each of
them, as a way of telling the compiler "it's ok, we know what we are
doing".
But since call_do_message is really just vmessage's little helper, it's
simpler to just silence the warning at that single point.
gdb/ChangeLog:
* ui-out.c (ui_out::call_do_message): Silence
-Wformat-nonliteral warning.
Change-Id: I58ad41793448f38835c5d6ba7b9e5c4dd8df260f
---
gdb/ui-out.c | 9 +++++++++
1 file changed, 9 insertions(+)
Comments
On Fri, 11 Oct 2019 16:54:26 -0400
Simon Marchi <simon.marchi@efficios.com> wrote:
> We get this warning when building with clang:
>
> CXX ui-out.o
> /home/smarchi/src/binutils-gdb/gdb/ui-out.c:590:22: error: format string is not a string literal [-Werror,-Wformat-nonliteral]
> do_message (style, format, args);
> ^~~~~~
>
> This can be considered a legitimate warning, as call_do_message's format
> parameter is not marked as a format string. Therefore, we should
> normally mark the call_do_message method with the `format` attribute.
> However, doing so just moves (and multiplies) the problem, as all the
> uses of call_do_message in the vmessage method now warn. If we wanted
> to continue on that path, we should silence the warning for each of
> them, as a way of telling the compiler "it's ok, we know what we are
> doing".
>
> But since call_do_message is really just vmessage's little helper, it's
> simpler to just silence the warning at that single point.
>
> gdb/ChangeLog:
>
> * ui-out.c (ui_out::call_do_message): Silence
> -Wformat-nonliteral warning.
LGTM.
Kevin
On 2019-10-13 14:17, Kevin Buettner wrote:
> On Fri, 11 Oct 2019 16:54:26 -0400
> Simon Marchi <simon.marchi@efficios.com> wrote:
>
>> We get this warning when building with clang:
>>
>> CXX ui-out.o
>> /home/smarchi/src/binutils-gdb/gdb/ui-out.c:590:22: error: format
>> string is not a string literal [-Werror,-Wformat-nonliteral]
>> do_message (style, format, args);
>> ^~~~~~
>>
>> This can be considered a legitimate warning, as call_do_message's
>> format
>> parameter is not marked as a format string. Therefore, we should
>> normally mark the call_do_message method with the `format` attribute.
>> However, doing so just moves (and multiplies) the problem, as all the
>> uses of call_do_message in the vmessage method now warn. If we wanted
>> to continue on that path, we should silence the warning for each of
>> them, as a way of telling the compiler "it's ok, we know what we are
>> doing".
>>
>> But since call_do_message is really just vmessage's little helper,
>> it's
>> simpler to just silence the warning at that single point.
>>
>> gdb/ChangeLog:
>>
>> * ui-out.c (ui_out::call_do_message): Silence
>> -Wformat-nonliteral warning.
>
> LGTM.
>
> Kevin
Thanks, I pushed it.
Simon
@@ -26,6 +26,7 @@
#include "ui-out.h"
#include "gdbsupport/format.h"
#include "cli/cli-style.h"
+#include "diagnostics.h"
#include <vector>
#include <memory>
@@ -587,7 +588,15 @@ ui_out::call_do_message (const ui_file_style &style, const char *format,
va_list args;
va_start (args, format);
+
+ /* Since call_do_message is only used as a helper of vmessage, silence the
+ warning here once instead of at all call sites in vmessage, if we were
+ to put a "format" attribute on call_do_message. */
+ DIAGNOSTIC_PUSH
+ DIAGNOSTIC_IGNORE_FORMAT_NONLITERAL
do_message (style, format, args);
+ DIAGNOSTIC_POP
+
va_end (args);
}