Patchwork [commit+7.9,patchv2+7.9] compile: Filter out -fpreprocessed

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Submitter Jan Kratochvil
Date Feb. 3, 2015, 5:24 p.m.
Message ID <20150203172452.GA20561@host1.jankratochvil.net>
Download mbox | patch
Permalink /patch/4900/
State New
Headers show

Comments

Jan Kratochvil - Feb. 3, 2015, 5:24 p.m.
On Tue, 03 Feb 2015 08:56:39 +0100, Joel Brobecker wrote:
> > gdb/ChangeLog
> > 2015-01-17  Jan Kratochvil  <jan.kratochvil@redhat.com>
> > 
> > 	Filter out inferior gcc option -fpreprocessed.
> > 	* compile/compile.c (filter_args): New function.
> > 	(get_args): Use it.
> 
> Looks good to me; and OK for both master and branch.

Checked in:
	a7606d8083c9e217294f6e47a8d2903716c6337c master
	c8b16901e05a15e018394ecefe7348c94b43a4f8 7.9
	https://sourceware.org/gdb/wiki/GDB_7.9_Release?action=diff&rev2=27&rev1=26

In the meantime ccache fix has been submitted (no reply) and gcc fix has been
posted+checked-in as referenced in the attached GDB commit.


Thanks,
Jan
With global system gcc-5.0 if one also installs ccache (needing a different
patch
	https://bugzilla.samba.org/show_bug.cgi?id=11060
for -fplugin=libcc1plugin) it breaks as GDB will read from inferior
DW_AT_producer containing -fpreprocessed (due to ccache used to compile the
inferior).
    <c>   DW_AT_producer    : (indirect string, offset: 0x52): GNU C11 5.0.0 20150114 (Red Hat 5.0.0-0.1) -fpreprocessed -mtune=generic -
march=x86-64 -g

It is wrong that gcc puts -fpreprocessed into DW_AT_producer - fixed it in
trunk GCCs:
	https://gcc.gnu.org/ml/gcc-patches/2015-01/msg01495.html
But even with that fix there are already built inferiors out there which GDB
could be compatible (for the 'compile' mode) with.

gdb/ChangeLog
2015-02-03  Jan Kratochvil  <jan.kratochvil@redhat.com>

	Filter out inferior gcc option -fpreprocessed.
	* compile/compile.c (filter_args): New function.
	(get_args): Use it.
---
 gdb/ChangeLog         |  6 ++++++
 gdb/compile/compile.c | 22 ++++++++++++++++++++++
 2 files changed, 28 insertions(+)

Patch

diff --git a/gdb/ChangeLog b/gdb/ChangeLog
index 44dc1ea..2266c11 100644
--- a/gdb/ChangeLog
+++ b/gdb/ChangeLog
@@ -1,3 +1,9 @@ 
+2015-02-03  Jan Kratochvil  <jan.kratochvil@redhat.com>
+
+	Filter out inferior gcc option -fpreprocessed.
+	* compile/compile.c (filter_args): New function.
+	(get_args): Use it.
+
 2015-02-03  Pedro Alves  <palves@redhat.com>
 
 	* event-loop.c: Don't declare nor define a queue type for
diff --git a/gdb/compile/compile.c b/gdb/compile/compile.c
index 70b6d44..c204a13 100644
--- a/gdb/compile/compile.c
+++ b/gdb/compile/compile.c
@@ -324,6 +324,27 @@  get_selected_pc_producer_options (void)
   return cs;
 }
 
+/* Filter out unwanted options from *ARGCP and ARGV.  */
+
+static void
+filter_args (int *argcp, char **argv)
+{
+  char **destv;
+
+  for (destv = argv; *argv != NULL; argv++)
+    {
+      /* -fpreprocessed may get in commonly from ccache.  */
+      if (strcmp (*argv, "-fpreprocessed") == 0)
+	{
+	  xfree (*argv);
+	  (*argcp)--;
+	  continue;
+	}
+      *destv++ = *argv;
+    }
+  *destv = NULL;
+}
+
 /* Produce final vector of GCC compilation options.  First element is target
    size ("-m64", "-m32" etc.), optionally followed by DW_AT_producer options
    and then compile-args string GDB variable.  */
@@ -346,6 +367,7 @@  get_args (const struct compile_instance *compiler, struct gdbarch *gdbarch,
       char **argv_producer;
 
       build_argc_argv (cs_producer_options, &argc_producer, &argv_producer);
+      filter_args (&argc_producer, argv_producer);
       append_args (argcp, argvp, argc_producer, argv_producer);
       freeargv (argv_producer);
     }