[binutils-gdb] Fix build breakage due to event loop simplification

[Pedro Alves <palves at sourceware dot org>]

https://sourceware.org/git/gitweb.cgi?p=binutils-gdb.git;h=80bd5fab6252d1cdff1ca95096ebe9b3053c8ec3

commit 80bd5fab6252d1cdff1ca95096ebe9b3053c8ec3
Author: Pedro Alves <palves@redhat.com>
Date:   Wed Feb 4 11:05:58 2015 +0100

    Fix build breakage due to event loop simplification
    
    commit 70b66289 (Simplify event-loop core, remove two-step event
    processing) causes a build failure when compiling GDB with gcc/-O2:
    
     gdb/event-loop.c: In function â??gdb_do_one_eventâ??:
     gdb/event-loop.c:296:10: error: â??resâ?? may be used uninitialized in this function
     [-Werror=maybe-uninitialized]
    	if (res > 0)
    	   ^
    
    GCC isn't realizing that event_source_head can never be > 2 and that
    therefore 'res' is always initialized in all possible paths.  Adding a
    default case that internal_error's makes GCC realize that.
    
    Tested on x86_64 Fedora 20.
    
    gdb/ChangeLog:
    2015-02-04  Pedro Alves  <palves@redhat.com>
    
    	Fix build breakage.
    	* event-loop.c (gdb_do_one_event): Add default switch case.

Diff:
---
 gdb/ChangeLog    | 5 +++++
 gdb/event-loop.c | 4 ++++
 2 files changed, 9 insertions(+)

diff --git a/gdb/ChangeLog b/gdb/ChangeLog
index 2266c11..1116853 100644
--- a/gdb/ChangeLog
+++ b/gdb/ChangeLog
@@ -1,3 +1,8 @@
+2015-02-04  Pedro Alves  <palves@redhat.com>
+
+	Fix build breakage.
+	* event-loop.c (gdb_do_one_event): Add default switch case.
+
 2015-02-03  Jan Kratochvil  <jan.kratochvil@redhat.com>
 
 	Filter out inferior gcc option -fpreprocessed.
diff --git a/gdb/event-loop.c b/gdb/event-loop.c
index 7425b3a..a2b41a7 100644
--- a/gdb/event-loop.c
+++ b/gdb/event-loop.c
@@ -287,6 +287,10 @@ gdb_do_one_event (void)
 	  /* Are there any asynchronous event handlers ready?  */
 	  res = check_async_event_handlers ();
 	  break;
+	default:
+	  internal_error (__FILE__, __LINE__,
+			  "unexpected event_source_head %d",
+			  event_source_head);
 	}
 
       event_source_head++;