TPF: disable discriminators

TPF: disable discriminators

[DJ Delorie]

The TPF assembler supports dwarf4 discriminators, but the TPF
debuggers do not.  Ok to apply?

	* config/s390/tpf.h (SUPPORTS_DISCRIMINATOR): Define to 0 for TPF.

Index: gcc/config/s390/tpf.h
===================================================================
--- gcc/config/s390/tpf.h       (revision 189993)
+++ gcc/config/s390/tpf.h       (working copy)
@@ -116,3 +116,6 @@
 #define MATH_LIBRARY "CLBM"
 #define LIBSTDCXX "CPP2"
 #endif /* ! _TPF_H */
+
+/* GAS supports it, but the debuggers don't, so avoid it.  */
+#define SUPPORTS_DISCRIMINATOR 0

Re: TPF: disable discriminators

[Richard Henderson]

On 2012-07-30 21:07, DJ Delorie wrote:
> +
> +/* GAS supports it, but the debuggers don't, so avoid it.  */
> +#define SUPPORTS_DISCRIMINATOR 0

Then you shouldn't be fiddling this, but rather dwarf_strict.
See e.g. darwin and vxworks ports.


r~

Re: TPF: disable discriminators

[DJ Delorie]

Ah, the original complaint was for a gcc branch which doesn't have
your strict-dwarf/discriminator patch.

How's this?

Index: gcc/config/s390/s390.c
===================================================================
--- gcc/config/s390/s390.c      (revision 190017)
+++ gcc/config/s390/s390.c      (working copy)
@@ -1651,12 +1651,21 @@ s390_option_override (void)
     flag_prefetch_loop_arrays = 1;
 
   /* Use the alternative scheduling-pressure algorithm by default.  */
   maybe_set_param_value (PARAM_SCHED_PRESSURE_ALGORITHM, 2,
                          global_options.x_param_values,
                          global_options_set.x_param_values);
+
+#ifdef TARGET_TPF
+  /* Don't emit DWARF3/4 unless specifically selected.  The TPF
+     debuggers do not yet support DWARF 3/4.  */
+  if (!global_options_set.x_dwarf_strict) 
+    dwarf_strict = 1;
+  if (!global_options_set.x_dwarf_version)
+    dwarf_version = 2;
+#endif
 }
 
 /* Map for smallest class containing reg regno.  */
 
 const enum reg_class regclass_map[FIRST_PSEUDO_REGISTER] =
 { GENERAL_REGS, ADDR_REGS, ADDR_REGS, ADDR_REGS,

Re: TPF: disable discriminators

[Richard Henderson]

On 2012-07-31 14:09, DJ Delorie wrote:
> +#ifdef TARGET_TPF
> +  /* Don't emit DWARF3/4 unless specifically selected.  The TPF
> +     debuggers do not yet support DWARF 3/4.  */
> +  if (!global_options_set.x_dwarf_strict) 
> +    dwarf_strict = 1;
> +  if (!global_options_set.x_dwarf_version)
> +    dwarf_version = 2;
> +#endif

TARGET_TPF is always defined.  Just use a C if.
Otherwise ok.


r~

Re: TPF: disable discriminators

[DJ Delorie]

> TARGET_TPF is always defined.  Just use a C if.
> Otherwise ok.

Thanks, checked in as attached.

What about older branches?  4.7 needs this patch, 4.6 needs my
original patch.

2012-07-31  DJ Delorie  <dj@redhat.com>

	* config/s390/s390.c (s390_option_override): Disable DWARF 3/4
	extensions for TPF, unless specifically selected.

Index: gcc/config/s390/s390.c
===================================================================
--- gcc/config/s390/s390.c	(revision 190022)
+++ gcc/config/s390/s390.c	(working copy)
@@ -1651,12 +1651,22 @@ s390_option_override (void)
     flag_prefetch_loop_arrays = 1;
 
   /* Use the alternative scheduling-pressure algorithm by default.  */
   maybe_set_param_value (PARAM_SCHED_PRESSURE_ALGORITHM, 2,
                          global_options.x_param_values,
                          global_options_set.x_param_values);
+
+  if (TARGET_TPF)
+    {
+      /* Don't emit DWARF3/4 unless specifically selected.  The TPF
+	 debuggers do not yet support DWARF 3/4.  */
+      if (!global_options_set.x_dwarf_strict) 
+	dwarf_strict = 1;
+      if (!global_options_set.x_dwarf_version)
+	dwarf_version = 2;
+    }
 }
 
 /* Map for smallest class containing reg regno.  */
 
 const enum reg_class regclass_map[FIRST_PSEUDO_REGISTER] =
 { GENERAL_REGS, ADDR_REGS, ADDR_REGS, ADDR_REGS,

Re: TPF: disable discriminators

[Richard Henderson]

On 2012-07-31 15:21, DJ Delorie wrote:
> What about older branches?  4.7 needs this patch, 4.6 needs my
> original patch.

I don't see that 4.6 requires a different patch.
Otherwise ok to backport.


r~

Re: TPF: disable discriminators

[Richard Henderson]

On 2012-07-31 15:51, DJ Delorie wrote:
>> I don't see that 4.6 requires a different patch.
> 
> 4.6 is missing this:
> 
> 2011-04-01  Richard Henderson  <rth@redhat.com>
> 
> 	PR 48400
> 	* dwarf2out.c (dwarf2out_source_line): Disable discriminators
> 	in strict mode before dwarf4.  Re-order tests to early out
> 	before switching sections.
> 
> So either *that* patch needs to be back-ported, or the tpf-specific
> workaround does.
> 

In 4.6 we do not emit discriminators except with DWARF2_ASM_LINE_DEBUG_INFO,
and in that section we have

          if (SUPPORTS_DISCRIMINATOR && discriminator != 0
              && (dwarf_version >= 4 || !dwarf_strict))
            fprintf (asm_out_file, " discriminator %d", discriminator);

and sure enough dwarf_strict is honored.

That patch is only required if you have the other patches that introduce
discriminators to the non-dwarf2_asm_line path.


r~

Re: TPF: disable discriminators

[DJ Delorie]

> I don't see that 4.6 requires a different patch.

4.6 is missing this:

2011-04-01  Richard Henderson  <rth@redhat.com>

	PR 48400
	* dwarf2out.c (dwarf2out_source_line): Disable discriminators
	in strict mode before dwarf4.  Re-order tests to early out
	before switching sections.

So either *that* patch needs to be back-ported, or the tpf-specific
workaround does.