[binutils-gdb] gdb: Silence -Wformat-nonliteral warning with clang

[binutils-gdb] gdb: Silence -Wformat-nonliteral warning with clang

[Simon Marchi]

https://sourceware.org/git/gitweb.cgi?p=binutils-gdb.git;h=284782de0750d6c0a24f2c8fd712b2954423e849

commit 284782de0750d6c0a24f2c8fd712b2954423e849
Author: Simon Marchi <simon.marchi@efficios.com>
Date:   Fri Oct 11 15:36:49 2019 -0400

    gdb: Silence -Wformat-nonliteral warning with clang
    
    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

Diff:
---
 gdb/ChangeLog | 5 +++++
 gdb/ui-out.c  | 9 +++++++++
 2 files changed, 14 insertions(+)

diff --git a/gdb/ChangeLog b/gdb/ChangeLog
index 5c3b45b..bcedf02 100644
--- a/gdb/ChangeLog
+++ b/gdb/ChangeLog
@@ -1,3 +1,8 @@
+2019-10-13  Simon Marchi  <simon.marchi@polymtl.ca>
+
+	* ui-out.c (ui_out::call_do_message): Silence
+	-Wformat-nonliteral warning.
+
 2019-10-12  Simon Marchi  <simon.marchi@polymtl.ca>
 
 	* breakpoint.c: Remove some includes: continuations.h, skip.h,
diff --git a/gdb/ui-out.c b/gdb/ui-out.c
index a64c794..6b0b5ac 100644
--- a/gdb/ui-out.c
+++ b/gdb/ui-out.c
@@ -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);
 }