[PATCH 2/4] dwarf2read.c: handle alternate dwarf2 debug sections name.

[Tristan Gingold <gingold at adacore dot com>]

Unfortunately, some object file format cannot accept the standard dwarf2
debug section names.  This is in particular the case of XCOFF (aix), which
has only 8 chars section names.  In order to support dwarf2 on aix, we need
to allow alternate section names.

The change is in fact simple as sections are localized by the dwarf2_has_info
function.  So I added a new parameter to this function to accept alternate
names.  In order to make this obvious, the value NULL means standard names.

The alternate names is a record of 2 entries: one for normal section and one
for uncompressed section.

gdb/
2011-05-23  Tristan Gingold  <gingold@adacore.com>

	* symfile.h (struct dwarf2_section_names): New type.
	(struct dwarf2_debug_sections): New type.
	(dwarf2_has_info): Add parameter.
	* dwarf2read.c (dwarf2_elf_names): New variable.
	(INFO_SECTION, ABBREV_SECTION, LINE_SECTION, LOC_SECTION)
	(MACINFO_SECTION, STR_SECTION, RANGES_SECTION, TYPES_SECTION)
	(FRAME_SECTION, EH_FRAME_SECTION, GDB_INDEX_SECTION): Remove.
	(dwarf2_has_info): Add names parameter.  Pass names
	to dwarf2_locate_sections.
	(section_is_p): Rewrite using the names parameter.
	(dwarf2_locate_sections): Use section names from the names parameter.
	* coffread.c (coff_symfile_read): Adjust call to dwarf2_has_info.
	* elfread.c (read_psyms): Ditto.
	* machoread.c (macho_symfile_read): Ditto.
---
 gdb/coffread.c   |    2 +-
 gdb/dwarf2read.c |   85 ++++++++++++++++++++++++++++++++---------------------
 gdb/elfread.c    |    4 +-
 gdb/machoread.c  |    4 +-
 gdb/symfile.h    |   24 ++++++++++++++-
 5 files changed, 79 insertions(+), 40 deletions(-)

diff --git a/gdb/coffread.c b/gdb/coffread.c
index b11dd73..16fd58f 100644
--- a/gdb/coffread.c
+++ b/gdb/coffread.c
@@ -637,7 +637,7 @@ coff_symfile_read (struct objfile *objfile, int symfile_flags)
 			       info->stabsects,
 			       info->stabstrsect->filepos, stabstrsize);
     }
-  if (dwarf2_has_info (objfile))
+  if (dwarf2_has_info (objfile, NULL))
     {
       /* DWARF2 sections.  */
       dwarf2_build_psymtabs (objfile);
diff --git a/gdb/dwarf2read.c b/gdb/dwarf2read.c
index 2003c46..7495d1f 100644
--- a/gdb/dwarf2read.c
+++ b/gdb/dwarf2read.c
@@ -243,22 +243,24 @@ struct dwarf2_per_objfile
 
 static struct dwarf2_per_objfile *dwarf2_per_objfile;
 
-/* names of the debugging sections */
+/* Default names of the debugging sections.  */
 
 /* Note that if the debugging section has been compressed, it might
    have a name like .zdebug_info.  */
 
-#define INFO_SECTION     "debug_info"
-#define ABBREV_SECTION   "debug_abbrev"
-#define LINE_SECTION     "debug_line"
-#define LOC_SECTION      "debug_loc"
-#define MACINFO_SECTION  "debug_macinfo"
-#define STR_SECTION      "debug_str"
-#define RANGES_SECTION   "debug_ranges"
-#define TYPES_SECTION    "debug_types"
-#define FRAME_SECTION    "debug_frame"
-#define EH_FRAME_SECTION "eh_frame"
-#define GDB_INDEX_SECTION "gdb_index"
+static const struct dwarf2_debug_sections dwarf2_elf_names = {
+  { ".debug_info", ".zdebug_info" },
+  { ".debug_abbrev", ".zdebug_abbrev" },
+  { ".debug_line", ".zdebug_line" },
+  { ".debug_loc", ".zdebug_loc" },
+  { ".debug_macinfo", ".zdebug_macinfo" },
+  { ".debug_str", ".zdebug_str" },
+  { ".debug_ranges", ".zdebug_ranges" },
+  { ".debug_types", ".zdebug_types" },
+  { ".debug_frame", ".zdebug_frame" },
+  { ".eh_frame", NULL },
+  { ".gdb_index", ".zgdb_index" }
+};
 
 /* local data types */
 
@@ -1338,10 +1340,13 @@ static const char *dwarf2_physname (char *name, struct die_info *die,
 				    struct dwarf2_cu *cu);
 
 /* Try to locate the sections we need for DWARF 2 debugging
-   information and return true if we have enough to do something.  */
+   information and return true if we have enough to do something.
+   NAMES points to the dwarf2 section names, or is NULL if the standard
+   ELF names are used.  */
 
 int
-dwarf2_has_info (struct objfile *objfile)
+dwarf2_has_info (struct objfile *objfile,
+                 const struct dwarf2_debug_sections *names)
 {
   dwarf2_per_objfile = objfile_data (objfile, dwarf2_objfile_data_key);
   if (!dwarf2_per_objfile)
@@ -1354,23 +1359,28 @@ dwarf2_has_info (struct objfile *objfile)
       set_objfile_data (objfile, dwarf2_objfile_data_key, data);
       dwarf2_per_objfile = data;
 
-      bfd_map_over_sections (objfile->obfd, dwarf2_locate_sections, NULL);
+      bfd_map_over_sections (objfile->obfd, dwarf2_locate_sections,
+                             (void *)names);
       dwarf2_per_objfile->objfile = objfile;
     }
   return (dwarf2_per_objfile->info.asection != NULL
 	  && dwarf2_per_objfile->abbrev.asection != NULL);
 }
 
-/* When loading sections, we can either look for ".<name>", or for
- * ".z<name>", which indicates a compressed section.  */
+/* When loading sections, we look either for uncompressed section or for
+   compressed section names.  */
 
 static int
-section_is_p (const char *section_name, const char *name)
+section_is_p (const char *section_name,
+              const struct dwarf2_section_names *names)
 {
-  return (section_name[0] == '.'
-	  && (strcmp (section_name + 1, name) == 0
-	      || (section_name[1] == 'z'
-		  && strcmp (section_name + 2, name) == 0)));
+  if (names->normal != NULL
+      && strcmp (section_name, names->normal) == 0)
+    return 1;
+  if (names->compressed != NULL
+      && strcmp (section_name, names->compressed) == 0)
+    return 1;
+  return 0;
 }
 
 /* This function is mapped across the sections and remembers the
@@ -1378,44 +1388,51 @@ section_is_p (const char *section_name, const char *name)
    in.  */
 
 static void
-dwarf2_locate_sections (bfd *abfd, asection *sectp, void *ignore_ptr)
+dwarf2_locate_sections (bfd *abfd, asection *sectp, void *vnames)
 {
-  if (section_is_p (sectp->name, INFO_SECTION))
+  const struct dwarf2_debug_sections *names;
+
+  if (vnames == NULL)
+    names = &dwarf2_elf_names;
+  else
+    names = (const struct dwarf2_debug_sections *)vnames;
+
+  if (section_is_p (sectp->name, &names->info))
     {
       dwarf2_per_objfile->info.asection = sectp;
       dwarf2_per_objfile->info.size = bfd_get_section_size (sectp);
     }
-  else if (section_is_p (sectp->name, ABBREV_SECTION))
+  else if (section_is_p (sectp->name, &names->abbrev))
     {
       dwarf2_per_objfile->abbrev.asection = sectp;
       dwarf2_per_objfile->abbrev.size = bfd_get_section_size (sectp);
     }
-  else if (section_is_p (sectp->name, LINE_SECTION))
+  else if (section_is_p (sectp->name, &names->line))
     {
       dwarf2_per_objfile->line.asection = sectp;
       dwarf2_per_objfile->line.size = bfd_get_section_size (sectp);
     }
-  else if (section_is_p (sectp->name, LOC_SECTION))
+  else if (section_is_p (sectp->name, &names->loc))
     {
       dwarf2_per_objfile->loc.asection = sectp;
       dwarf2_per_objfile->loc.size = bfd_get_section_size (sectp);
     }
-  else if (section_is_p (sectp->name, MACINFO_SECTION))
+  else if (section_is_p (sectp->name, &names->macinfo))
     {
       dwarf2_per_objfile->macinfo.asection = sectp;
       dwarf2_per_objfile->macinfo.size = bfd_get_section_size (sectp);
     }
-  else if (section_is_p (sectp->name, STR_SECTION))
+  else if (section_is_p (sectp->name, &names->str))
     {
       dwarf2_per_objfile->str.asection = sectp;
       dwarf2_per_objfile->str.size = bfd_get_section_size (sectp);
     }
-  else if (section_is_p (sectp->name, FRAME_SECTION))
+  else if (section_is_p (sectp->name, &names->frame))
     {
       dwarf2_per_objfile->frame.asection = sectp;
       dwarf2_per_objfile->frame.size = bfd_get_section_size (sectp);
     }
-  else if (section_is_p (sectp->name, EH_FRAME_SECTION))
+  else if (section_is_p (sectp->name, &names->eh_frame))
     {
       flagword aflag = bfd_get_section_flags (ignore_abfd, sectp);
 
@@ -1425,17 +1442,17 @@ dwarf2_locate_sections (bfd *abfd, asection *sectp, void *ignore_ptr)
           dwarf2_per_objfile->eh_frame.size = bfd_get_section_size (sectp);
         }
     }
-  else if (section_is_p (sectp->name, RANGES_SECTION))
+  else if (section_is_p (sectp->name, &names->ranges))
     {
       dwarf2_per_objfile->ranges.asection = sectp;
       dwarf2_per_objfile->ranges.size = bfd_get_section_size (sectp);
     }
-  else if (section_is_p (sectp->name, TYPES_SECTION))
+  else if (section_is_p (sectp->name, &names->types))
     {
       dwarf2_per_objfile->types.asection = sectp;
       dwarf2_per_objfile->types.size = bfd_get_section_size (sectp);
     }
-  else if (section_is_p (sectp->name, GDB_INDEX_SECTION))
+  else if (section_is_p (sectp->name, &names->gdb_index))
     {
       dwarf2_per_objfile->gdb_index.asection = sectp;
       dwarf2_per_objfile->gdb_index.size = bfd_get_section_size (sectp);
diff --git a/gdb/elfread.c b/gdb/elfread.c
index 6c6a7af..825df0f 100644
--- a/gdb/elfread.c
+++ b/gdb/elfread.c
@@ -1391,7 +1391,7 @@ elf_symfile_read (struct objfile *objfile, int symfile_flags)
 				bfd_section_size (abfd, str_sect));
     }
 
-  if (dwarf2_has_info (objfile))
+  if (dwarf2_has_info (objfile, NULL))
     {
       /* elf_sym_fns_gdb_index cannot handle simultaneous non-DWARF debug
 	 information present in OBJFILE.  If there is such debug info present
@@ -1437,7 +1437,7 @@ elf_symfile_read (struct objfile *objfile, int symfile_flags)
 static void
 read_psyms (struct objfile *objfile)
 {
-  if (dwarf2_has_info (objfile))
+  if (dwarf2_has_info (objfile, NULL))
     dwarf2_build_psymtabs (objfile);
 }
 
diff --git a/gdb/machoread.c b/gdb/machoread.c
index 28cb958..1cfa21e 100644
--- a/gdb/machoread.c
+++ b/gdb/machoread.c
@@ -660,7 +660,7 @@ macho_symfile_read (struct objfile *objfile, int symfile_flags)
       /* Try to read .eh_frame / .debug_frame.  */
       /* First, locate these sections.  We ignore the result status
 	 as it only checks for debug info.  */
-      dwarf2_has_info (objfile);
+      dwarf2_has_info (objfile, NULL);
       dwarf2_build_frame_info (objfile);
       
       /* Check for DSYM file.  */
@@ -702,7 +702,7 @@ macho_symfile_read (struct objfile *objfile, int symfile_flags)
 	}
     }
 
-  if (dwarf2_has_info (objfile))
+  if (dwarf2_has_info (objfile, NULL))
     {
       /* DWARF 2 sections */
       dwarf2_build_psymtabs (objfile);
diff --git a/gdb/symfile.h b/gdb/symfile.h
index 83e807c..e6c4613 100644
--- a/gdb/symfile.h
+++ b/gdb/symfile.h
@@ -553,7 +553,29 @@ extern struct cleanup *increment_reading_symtab (void);
 
 /* From dwarf2read.c */
 
-extern int dwarf2_has_info (struct objfile *);
+/* Name of the dwarf2 sections.  */
+
+struct dwarf2_section_names {
+  const char *normal;
+  const char *compressed;
+};
+
+struct dwarf2_debug_sections {
+  struct dwarf2_section_names info;
+  struct dwarf2_section_names abbrev;
+  struct dwarf2_section_names line;
+  struct dwarf2_section_names loc;
+  struct dwarf2_section_names macinfo;
+  struct dwarf2_section_names str;
+  struct dwarf2_section_names ranges;
+  struct dwarf2_section_names types;
+  struct dwarf2_section_names frame;
+  struct dwarf2_section_names eh_frame;
+  struct dwarf2_section_names gdb_index;
+};
+
+extern int dwarf2_has_info (struct objfile *,
+                            const struct dwarf2_debug_sections *);
 
 /* Dwarf2 sections that can be accessed by dwarf2_get_section_info.  */
 enum dwarf2_section_enum {
-- 
1.7.3.GIT