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[RFA,2/4] Implement | (pipe) command.

Message ID 1555938944.22002.1.camel@skynet.be
State New
Headers show

Commit Message

Philippe Waroquiers April 22, 2019, 1:15 p.m. UTC
On Mon, 2019-04-22 at 14:08 +0300, Eli Zaretskii wrote:
> > From: Philippe Waroquiers <philippe.waroquiers@skynet.be>
> > Cc: gdb-patches@sourceware.org
> > Date: Mon, 22 Apr 2019 12:30:00 +0200
> > 
> > Currently, on MingW, the above macros (WIFEXITED, WIFSIGNALED, ...)
> > are not defined.
> 
> I think gdb_wait.h does define them for MinGW, it's just that those
> definitions are currently unused anywhere that is compiled into the
> MinGW build.
> 
> > So, the idea is to have gdb_wait.h defining them on MingW,
> > with something like:
> > 
> > #ifndef	WIFEXITED
> > #if defined (__MINGW32__)
> > #define WIFEXITED(stat_val)   (((stat_val) & 0xC0000000) == 0)
> > #else
> > #define WIFEXITED(w)	(((w)&0377) == 0)
> > #endif
> > #endif
> > 
> > Then in windows-nat.c, implement windows_status_to_termsig
> > that searches in xlate for stat_val & ~0xC0000000 to give
> > the equivalent signal.
> > 
> > Does the above look reasonable ?
> 
> Yes, thanks.
So, here is a trial patch, only compiled on Debian/amd64.
Does that compile/work on MingW ?
Thanks
Philippe

Comments

Eli Zaretskii April 22, 2019, 1:21 p.m. UTC | #1
> From: Philippe Waroquiers <philippe.waroquiers@skynet.be>
> Cc: gdb-patches@sourceware.org
> Date: Mon, 22 Apr 2019 15:15:44 +0200
> 
> So, here is a trial patch, only compiled on Debian/amd64.
> Does that compile/work on MingW ?

Thanks, it looks good when I read it.  I won't be able to actually
test it in compiling the MinGW build for a few days, perhaps someone
else will be able to do so sooner.
diff mbox

Patch

diff --git a/gdb/common/gdb_wait.h b/gdb/common/gdb_wait.h
index b3b752cf3a..ca95240009 100644
--- a/gdb/common/gdb_wait.h
+++ b/gdb/common/gdb_wait.h
@@ -40,13 +40,31 @@ 
    NOTE exception for GNU/Linux below).  We also fail to declare
    wait() and waitpid().  */
 
+/* For MINGW, the underlying idea is that when a Windows program is terminated
+   by a fatal exception, its exit code is the value of that exception, as
+   defined by the various STATUS_* symbols in the Windows API headers.
+
+   The below is not perfect, because a program could legitimately exit normally
+   with a status whose value happens to have the high bits set, but that's
+   extremely rare, to say the least, and it is deemed such a negligibly small
+   probability of false positives is justified by the utility of reporting the
+   terminating signal in the "normal" cases.  */
+
 #ifndef	WIFEXITED
+#if defined (__MINGW32__)
+#define WIFEXITED(stat_val)   (((stat_val) & 0xC0000000) == 0)
+#else
 #define WIFEXITED(w)	(((w)&0377) == 0)
 #endif
+#endif
 
 #ifndef	WIFSIGNALED
+#if defined (__MINGW32__)
+#define WIFSIGNALED(stat_val) (((stat_val) & 0xC0000000) == 0xC0000000)
+#else
 #define WIFSIGNALED(w)	(((w)&0377) != 0177 && ((w)&~0377) == 0)
 #endif
+#endif
 
 #ifndef	WIFSTOPPED
 #ifdef IBM6000
@@ -64,12 +82,21 @@ 
 #endif
 
 #ifndef	WEXITSTATUS
+#if defined (__MINGW32__)
+#define WEXITSTATUS(stat_val) ((stat_val) & 255)
+#else
 #define WEXITSTATUS(w)	(((w) >> 8) & 0377) /* same as WRETCODE */
 #endif
+#endif
 
 #ifndef	WTERMSIG
+#if defined (__MINGW32__)
+extern enum gdb_signal windows_status_to_termsig (int stat_val);
+#define WTERMSIG(stat_val)    windows_status_to_termsig (stat_val)
+#else
 #define WTERMSIG(w)	((w) & 0177)
 #endif
+#endif
 
 #ifndef	WSTOPSIG
 #define WSTOPSIG	WEXITSTATUS
diff --git a/gdb/windows-nat.c b/gdb/windows-nat.c
index 50094187bd..e12cf10416 100644
--- a/gdb/windows-nat.c
+++ b/gdb/windows-nat.c
@@ -281,9 +281,9 @@  static const int *mappings;
    a segment register or not.  */
 static segment_register_p_ftype *segment_register_p;
 
-/* See windows_nat_target::resume to understand why this is commented
-   out.  */
-#if 0
+/* See windows_nat_target::resume to understand why xlate is not used
+   to translate a signal into an exception.  */
+
 /* This vector maps the target's idea of an exception (extracted
    from the DEBUG_EVENT structure) to GDB's idea.  */
 
@@ -303,7 +303,17 @@  static const struct xlate_exception xlate[] =
   {STATUS_FLOAT_DIVIDE_BY_ZERO, GDB_SIGNAL_FPE}
 };
 
-#endif /* 0 */
+/* Translate a windows exception inside STAT_VAL into a gdb_signal.
+   This should only be called if WIFSIGNALED(stat_val).  */
+
+enum gdb_signal
+windows_status_to_termsig (int stat_val)
+{
+  for (const xlate_exception &x : xlate)
+    if (x.them == (stat_val & ~0xC0000000))
+      return x.us;
+  return GDB_SIGNAL_UNKNOWN;
+}
 
 struct windows_nat_target final : public x86_nat_target<inf_child_target>
 {