[PATCH][gdbserver] Add missing include of gdbsupport/agent.h

[Tom de Vries <tdevries@suse.de>]

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[ was: Re: [committed][gdbserver] Fix Wlto-type-mismatch for debug_agent ]
On 6/17/20 6:38 PM, Tom de Vries wrote:
> On 6/12/20 8:19 PM, Christian Biesinger wrote:
>> On Fri, Jun 12, 2020 at 11:37 AM Tom de Vries <tdevries@suse.de> wrote:
>>>
>>> Hi,
>>>
>>> When building gdb including gdbserver with CFLAGS/CXXFLAGS -O2 -g -flto=auto,
>>> I run into:
>>> ...
>>> src/gdbserver/../gdbsupport/agent.h:47:13: error: type of 'debug_agent' \
>>>   does not match original declaration [-Werror=lto-type-mismatch]
>>>  extern bool debug_agent;
>>>              ^
>>> src/gdbserver/ax.cc:28:5: note: type 'int' should match type 'bool'
>>>  int debug_agent = 0;
>>>      ^
>>> src/gdbserver/ax.cc:28:5: note: 'debug_agent' was previously declared here
>>> src/gdbserver/ax.cc:28:5: note: code may be misoptimized unless \
>>>   -fno-strict-aliasing is used
>>
>> So it sounds like this didn't come up before because ax.cc doesn't
>> include gdbsupport/agent.h?
> 
> Yes.
> 
>> It probably should?
> 
> Um, good point, thanks.
> 
> Though ax.h does:
> ...
> #ifdef IN_PROCESS_AGENT
> #define debug_threads debug_agent
> #endif
> ...
> so I wonder if we should have the include there instead.  I'll try to
> test this.

Any comments?

Thanks,
- Tom


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[gdbserver] Add missing include of gdbsupport/agent.h

The file gdbserver/ax.h contains:
...
 #ifdef IN_PROCESS_AGENT
 #define debug_threads debug_agent
 #endif
...
but does not declare debug_agent.

Fix this by adding an include of gdbsupport/agent.h.

[ If this fix would have been in place before commit 8118159c69 "[gdbserver] Fix
Wlto-type-mismatch for debug_agent", we would have simply run into this build
breaker with a regular, non-lto build:
...
src/gdbserver/ax.cc:28:5: error: conflicting declaration 'int debug_agent'
 int debug_agent = 0;
     ^~~~~~~~~~~
In file included from src/gdbserver/ax.h:25:0,
                 from src/gdbserver/ax.cc:20:
src/gdbsupport/agent.h:47:13: note: previous declaration as 'bool debug_agent'
 extern bool debug_agent;
             ^~~~~~~~~~~
... ]

Tested on x86_64-linux.

gdbserver/ChangeLog:

2020-06-18  Tom de Vries  <tdevries@suse.de>

	* ax.h: Include gdbsupport/debug_agent.h.

---
 gdbserver/ax.h | 1 +
 1 file changed, 1 insertion(+)

diff --git a/gdbserver/ax.h b/gdbserver/ax.h
index 1fba69e7ad..b7ff7d8910 100644
--- a/gdbserver/ax.h
+++ b/gdbserver/ax.h
@@ -22,6 +22,7 @@
 #include "regcache.h"
 
 #ifdef IN_PROCESS_AGENT
+#include "gdbsupport/agent.h"
 #define debug_threads debug_agent
 #endif