re PR target/37033 (Revision 138733 breaks -g vs -g0 for PCH)

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

From-SVN: r142652

4 files changed, 42 insertions, 4 deletions

diff --git a/gcc/ChangeLog b/gcc/ChangeLog
index a32639ef97d..2a1d73f6685 100644
--- a/gcc/ChangeLog
+++ b/gcc/ChangeLog
@@ -1,5 +1,12 @@
 2008-12-10  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.
+
+2008-12-10  Alexandre Oliva  <aoliva@redhat.com>
+
 	PR middle-end/38271
 	* tree-sra.c (sra_build_bf_assignment): Avoid warnings for
 	variables initialized from SRAed bit fields.
diff --git a/gcc/dwarf2out.c b/gcc/dwarf2out.c
index 68d0ee8da3b..669948bc7ce 100644
--- a/gcc/dwarf2out.c
+++ b/gcc/dwarf2out.c
@@ -110,6 +110,9 @@ static void dwarf2out_source_line (unsigned int, const char *);
 #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;
 }
 
diff --git a/libcpp/ChangeLog b/libcpp/ChangeLog
index 9f6148edc13..a6378bc339c 100644
--- a/libcpp/ChangeLog
+++ b/libcpp/ChangeLog
@@ -1,3 +1,9 @@
+2008-12-10  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.
+
 2008-11-29  Joseph Myers  <joseph@codesourcery.com>
 
 	* lex.c (cpp_token_len): Use 6 as default length.
diff --git a/libcpp/pch.c b/libcpp/pch.c
index bf7b9bea36d..f459d2cb906 100644
--- a/libcpp/pch.c
+++ b/libcpp/pch.c
@@ -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 char *name, int fd)
 
       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;