Re: [PATCH, testsuite] Fix PR37033, gcc.dg/pch/valid-1b.c failures

[Alexandre Oliva <aoliva at redhat dot com>]

On Dec 10, 2008, Ian Lance Taylor <iant@google.com> wrote:

> Alexandre Oliva <aoliva@redhat.com> writes:
>> On Dec  5, 2008, Ian Lance Taylor <iant@google.com> wrote:

>>> Please write this as two lines.
>>> saved_do_cfi_asm = true;
>>> return true;

>> Fixed, thanks.

>>> With that change this is OK when mainline returns to stage 1.

>> Err...  I thought it wasn't too late to fix regressions like this.  Is
>> it?

> Sorry, you're right, this is OK for mainline.

Thanks, here's the patch I'm checking in.  The only difference from
the one I posted before is the style fix Jakub and you suggested.

I've just re-tested it on i686-pc-linux-gnu, confirming it makes the
valid-1b.c regression go away.  Checking in... :-)

for  gcc/ChangeLog
from  Alexandre Oliva  <aoliva@redhat.com>

	PR target/37033
	* dwarf2out.c (saved_do_cfi_asm): New.
	(dwarf2out_do_frame): Take it into account.
	(dwarf2out_d_cfi_asm): Likewise.  Set it when appropriate.
	
for  libcpp/ChangeLog
from  Alexandre Oliva  <aoliva@redhat.com>

	PR target/37033
	* pch.c (cpp_valid_state): Improve message for poisoned symbols.
	Allow for differences in __GCC_HAVE_DWARF2_CFI_ASM.

Index: gcc/dwarf2out.c
===================================================================
--- gcc/dwarf2out.c.orig	2008-12-05 04:57:21.000000000 -0200
+++ gcc/dwarf2out.c	2008-12-10 15:21:31.000000000 -0200
@@ -110,6 +110,9 @@ static void dwarf2out_source_line (unsig
 #define DWARF2_FRAME_REG_OUT(REGNO, FOR_EH) (REGNO)
 #endif
 
+/* Save the result of dwarf2out_do_frame across PCH.  */
+static GTY(()) bool saved_do_cfi_asm = 0;
+
 /* Decide whether we want to emit frame unwind information for the current
    translation unit.  */
 
@@ -121,7 +124,7 @@ dwarf2out_do_frame (void)
      we're not going to output frame or unwind info.  */
   return (write_symbols == DWARF2_DEBUG
 	  || write_symbols == VMS_AND_DWARF2_DEBUG
-	  || DWARF2_FRAME_INFO
+	  || DWARF2_FRAME_INFO || saved_do_cfi_asm
 #ifdef DWARF2_UNWIND_INFO
 	  || (DWARF2_UNWIND_INFO
 	      && (flag_unwind_tables
@@ -142,7 +145,7 @@ dwarf2out_do_cfi_asm (void)
 #endif
   if (!flag_dwarf2_cfi_asm || !dwarf2out_do_frame ())
     return false;
-  if (!eh_personality_libfunc)
+  if (saved_do_cfi_asm || !eh_personality_libfunc)
     return true;
   if (!HAVE_GAS_CFI_PERSONALITY_DIRECTIVE)
     return false;
@@ -156,6 +159,7 @@ dwarf2out_do_cfi_asm (void)
   if ((enc & 0x70) != 0 && (enc & 0x70) != DW_EH_PE_pcrel)
     return false;
 
+  saved_do_cfi_asm = true;
   return true;
 }
 
Index: libcpp/pch.c
===================================================================
--- libcpp/pch.c.orig	2008-12-05 04:57:21.000000000 -0200
+++ libcpp/pch.c	2008-12-10 15:21:31.000000000 -0200
@@ -1,5 +1,5 @@
 /* Part of CPP library.  (Precompiled header reading/writing.)
-   Copyright (C) 2000, 2001, 2002, 2003, 2004, 2005
+   Copyright (C) 2000, 2001, 2002, 2003, 2004, 2005, 2008
    Free Software Foundation, Inc.
 
 This program is free software; you can redistribute it and/or modify it
@@ -477,11 +477,32 @@ cpp_valid_state (cpp_reader *r, const ch
 
       h = cpp_lookup (r, namebuf, m.name_length);
       if (m.flags & NODE_POISONED
-	  || h->type != NT_MACRO
 	  || h->flags & NODE_POISONED)
 	{
 	  if (CPP_OPTION (r, warn_invalid_pch))
 	    cpp_error (r, CPP_DL_WARNING_SYSHDR,
+		       "%s: not used because `%.*s' is poisoned",
+		       name, m.name_length, namebuf);
+	  goto fail;
+	}
+
+      if (h->type != NT_MACRO)
+	{
+	  /* It's ok if __GCC_HAVE_DWARF2_CFI_ASM becomes undefined,
+	     as in, when the PCH file is created with -g and we're
+	     attempting to use it without -g.  Restoring the PCH file
+	     is supposed to bring in this definition *and* enable the
+	     generation of call frame information, so that precompiled
+	     definitions that take this macro into accout, to decide
+	     what asm to emit, won't issue .cfi directives when the
+	     compiler doesn't.  */
+	  if (!(h->flags & NODE_USED)
+	      && m.name_length == sizeof ("__GCC_HAVE_DWARF2_CFI_ASM") - 1
+	      && !memcmp (namebuf, "__GCC_HAVE_DWARF2_CFI_ASM", m.name_length))
+	    continue;
+
+	  if (CPP_OPTION (r, warn_invalid_pch))
+	    cpp_error (r, CPP_DL_WARNING_SYSHDR,
 		       "%s: not used because `%.*s' not defined",
 		       name, m.name_length, namebuf);
 	  goto fail;

-- 
Alexandre Oliva           http://www.lsd.ic.unicamp.br/~oliva/
You must be the change you wish to see in the world. -- Gandhi
Be Free! -- http://FSFLA.org/   FSF Latin America board member
Free Software Evangelist      Red Hat Brazil Compiler Engineer