readelf: Handle .debug_info first if any other debug section needs it.

Some debug sections need information from the CU DIEs to properly
parse the data. Normally the .debug_info section is one of the first.
But some DWARF producers reorder the sections and put it after some
other debug sections. Make sure we first handle .debug_info if it
is needed by any other debug section.

Signed-off-by: Mark Wielaard <mark@klomp.org>

diff --git a/src/ChangeLog b/src/ChangeLog
index b1041a8..a6ee30b 100644 (file)
--- a/src/ChangeLog
+++ b/src/ChangeLog
@@ -1,3 +1,10 @@
+2018-04-28  Mark Wielaard  <mark@klomp.org>
+
+       * readelf.c (print_debug): If .debug_info is needed implicitly by
+       then handle it first before handling any other debug section.
+       (parse_opt): Set implicit_debug_sections to section_info when
+       showing all debug sections.
+
 2018-05-05  Mark Wielaard  <mark@klomp.org>
 
        * readelf.c (attr_callback): Handle DW_FORM_ref_sup4 and

diff --git a/src/readelf.c b/src/readelf.c
index c69910a..e44b2a3 100644 (file)
--- a/src/readelf.c
+++ b/src/readelf.c
@@ -420,7 +420,10 @@ parse_opt (int key, char *arg,
       break;
     case 'w':
       if (arg == NULL)
-       print_debug_sections = section_all;
+       {
+         print_debug_sections = section_all;
+         implicit_debug_sections = section_info;
+       }
       else if (strcmp (arg, "abbrev") == 0)
        print_debug_sections |= section_abbrev;
       else if (strcmp (arg, "aranges") == 0)
@@ -8730,6 +8733,40 @@ print_debug (Dwfl_Module *dwflmod, Ebl *ebl, GElf_Ehdr *ehdr)
     error (EXIT_FAILURE, 0,
           gettext ("cannot get section header string table index"));
 
+  /* If the .debug_info section is listed as implicitly required then
+     we must make sure to handle it before handling any other debug
+     section.  Various other sections depend on the CU DIEs being
+     scanned (silently) first.  */
+  if ((implicit_debug_sections & section_info) != 0)
+    {
+      Elf_Scn *scn = NULL;
+      while ((scn = elf_nextscn (ebl->elf, scn)) != NULL)
+       {
+         GElf_Shdr shdr_mem;
+         GElf_Shdr *shdr = gelf_getshdr (scn, &shdr_mem);
+
+         if (shdr != NULL && shdr->sh_type == SHT_PROGBITS)
+           {
+             const char *name = elf_strptr (ebl->elf, shstrndx,
+                                            shdr->sh_name);
+             if (name == NULL)
+               continue;
+
+             if (strcmp (name, ".debug_info") == 0
+                 || strcmp (name, ".debug_info.dwo") == 0
+                 || strcmp (name, ".zdebug_info") == 0
+                 || strcmp (name, ".zdebug_info.dwo") == 0)
+               {
+                 print_debug_info_section (dwflmod, ebl, ehdr,
+                                           scn, shdr, dbg);
+                 break;
+               }
+           }
+       }
+      print_debug_sections &= ~section_info;
+      implicit_debug_sections &= ~section_info;
+    }
+
   /* Look through all the sections for the debugging sections to print.  */
   Elf_Scn *scn = NULL;
   while ((scn = elf_nextscn (ebl->elf, scn)) != NULL)