[binutils-gdb/gdb-7.12-branch] gdb: Fix C and C++03 builds

[Pedro Alves <palves at sourceware dot org>]

https://sourceware.org/git/gitweb.cgi?p=binutils-gdb.git;h=9bfe0298332782a9c082fb475bdf8eeeef8cf45e

commit 9bfe0298332782a9c082fb475bdf8eeeef8cf45e
Author: Pedro Alves <palves@redhat.com>
Date:   Tue Dec 20 19:18:15 2016 +0000

    gdb: Fix C and C++03 builds
    
    The readline/sjlj-exceptions fix added an unconditional use of
    noexcept, but that's only valid C++11, and 7.12 must build with C and
    C++03 too.  Fix this by adding a GDB_EXCEPT macro that compiles away
    to nothing in C, and to throw() in C++03, which I've confirmed fixes
    the original issue just the same as noexcept, with GCC 7 + -std=gnu+03
    + sjlj-exceptions.
    
    gdb/ChangeLog:
    2016-12-20  Pedro Alves  <palves@redhat.com>
    
    	PR gdb/20977
    	* event-top.c (GDB_NOEXCEPT): Define.
    	(gdb_rl_callback_read_char_wrapper_noexcept): Use GDB_NOEXCEPT
    	instead of noexcept and use (void) instead of ().
    	(gdb_rl_callback_handler): Use GDB_NOEXCEPT instead of noexcept.

Diff:
---
 gdb/ChangeLog   |  8 ++++++++
 gdb/event-top.c | 12 ++++++++++--
 2 files changed, 18 insertions(+), 2 deletions(-)

diff --git a/gdb/ChangeLog b/gdb/ChangeLog
index e99025e..0aaae46 100644
--- a/gdb/ChangeLog
+++ b/gdb/ChangeLog
@@ -1,4 +1,12 @@
 2016-12-20  Pedro Alves  <palves@redhat.com>
+
+	PR gdb/20977
+	* event-top.c (GDB_NOEXCEPT): Define.
+	(gdb_rl_callback_read_char_wrapper_noexcept): Use GDB_NOEXCEPT
+	instead of noexcept and use (void) instead of ().
+	(gdb_rl_callback_handler): Use GDB_NOEXCEPT instead of noexcept.
+
+2016-12-20  Pedro Alves  <palves@redhat.com>
 	    Yao Qi  <yao.qi@linaro.org>
 
 	PR gdb/20977
diff --git a/gdb/event-top.c b/gdb/event-top.c
index 3e218ff..7f590a9 100644
--- a/gdb/event-top.c
+++ b/gdb/event-top.c
@@ -73,6 +73,14 @@ static void async_stop_sig (gdb_client_data);
 #endif
 static void async_sigterm_handler (gdb_client_data arg);
 
+#ifndef __cplusplus
+# define GDB_NOEXCEPT
+#elif __cplusplus < 201103L
+# define GDB_NOEXCEPT throw ()
+#else
+# define GDB_NOEXCEPT noexcept
+#endif
+
 /* Instead of invoking (and waiting for) readline to read the command
    line and pass it back for processing, we use readline's alternate
    interface, via callback functions, so that the event loop can react
@@ -162,7 +170,7 @@ void (*after_char_processing_hook) (void);
    (sjlj-based) C++ exceptions.  */
 
 static struct gdb_exception
-gdb_rl_callback_read_char_wrapper_noexcept () noexcept
+gdb_rl_callback_read_char_wrapper_noexcept (void) GDB_NOEXCEPT
 {
   struct gdb_exception gdb_expt = exception_none;
 
@@ -203,7 +211,7 @@ gdb_rl_callback_read_char_wrapper (gdb_client_data client_data)
    (sjlj-based) C++ exceptions.  */
 
 static void
-gdb_rl_callback_handler (char *rl) noexcept
+gdb_rl_callback_handler (char *rl) GDB_NOEXCEPT
 {
   struct gdb_exception gdb_rl_expt = exception_none;
   struct ui *ui = current_ui;