Check if DIE has_children and sibling, but doesn't have DW_AT_sibling

(And fix an embarrassing error where abbrev->used could have been run even
for NULL abbrev.  And make unnecessary padding wording clearer.)

diff --git a/src/ChangeLog b/src/ChangeLog
index c750aac1f816f95d13ebcdec1c9aaed3b89986b9..91053919d25975a08ea9816883a68dfcb88dac4c 100644 (file)
--- a/src/ChangeLog
+++ b/src/ChangeLog
@@ -1,3 +1,9 @@
+2009-01-07  Petr Machata  <pmachata@redhat.com>
+
+       * dwarflint.c: More checking DW_AT_sibling correctness.
+       - Rewrite abbrev_table_load logic for detecting sequences of
+       zeroes inside abbreviation section.
+
 2009-01-06  Petr Machata  <pmachata@redhat.com>
 
        * dwarflint.c: Checking DW_AT_sibling correctness.

diff --git a/src/dwarflint.c b/src/dwarflint.c
index eb791ef6a91a588376c9087bf7a8f3ca9f78dcac..4e5e275c8b27461f9e3579b4362f3b384ba279c5 100644 (file)
--- a/src/dwarflint.c
+++ b/src/dwarflint.c
@@ -662,7 +662,7 @@ abbrev_table_load (struct read_ctx *ctx)
        }
 
       if (zero_seq_off != (uint64_t)-1)
-       WARNING (PRI_ABBR": unnecessary zero padding.\n", zero_seq_off);
+       WARNING (PRI_ABBR": unnecessary padding with zero bytes.\n", zero_seq_off);
 
       if (SECTION_ENDS)
        break;
@@ -1114,12 +1114,13 @@ read_die_chain (struct read_ctx *ctx, uint64_t cu_off,
   bool got_die = false;
   const unsigned char *begin = ctx->ptr;
   uint64_t sibling_addr = 0;
-  uint64_t last_die_off = 0;
+  uint64_t die_off, prev_die_off = 0;
+  struct abbrev *abbrev, *prev_abbrev = NULL;
 
   while (ctx->ptr < ctx->end)
     {
-      uint64_t die_off = read_ctx_get_offset (ctx);
       uint64_t abbrev_code;
+      die_off = read_ctx_get_offset (ctx);
 
       if (sibling_addr != 0)
        {
@@ -1127,10 +1128,15 @@ read_die_chain (struct read_ctx *ctx, uint64_t cu_off,
            ERROR (PRI_CU_DIE
                   ": This DIE should have had its sibling at 0x%"
                   PRIx64 ", but it's at 0x%" PRIx64 " instead.\n",
-                  cu_off, last_die_off, sibling_addr, die_off);
+                  cu_off, prev_die_off, sibling_addr, die_off);
          sibling_addr = 0;
        }
-      last_die_off = die_off;
+      else if (prev_abbrev != NULL && prev_abbrev->has_children)
+       ERROR (PRI_CU_DIE
+              ": This DIE had children, but no DW_AT_sibling attribute.\n",
+              cu_off, prev_die_off);
+
+      prev_die_off = die_off;
 
       /* Abbrev code.  */
       if (!CHECKED_READ_ULEB128 (ctx, &abbrev_code,
@@ -1154,8 +1160,7 @@ read_die_chain (struct read_ctx *ctx, uint64_t cu_off,
 
       got_die = true;
 
-      struct abbrev *abbrev = abbrev_table_find_abbrev (abbrevs, abbrev_code);
-      abbrev->used = true;
+      abbrev = abbrev_table_find_abbrev (abbrevs, abbrev_code);
       if (abbrev == NULL)
        {
          ERROR (PRI_CU_DIE ": abbrev section at 0x%" PRIx64
@@ -1163,6 +1168,7 @@ read_die_chain (struct read_ctx *ctx, uint64_t cu_off,
                 cu_off, die_off, abbrevs->offset, abbrev_code);
          return -1;
        }
+      abbrev->used = true;
 
       if (die_addrs != NULL)
        addr_record_add (die_addrs, cu_off + die_off);
@@ -1444,7 +1450,7 @@ read_die_chain (struct read_ctx *ctx, uint64_t cu_off,
     ERROR (PRI_CU_DIE
           ": This DIE should have had its sibling at 0x%"
           PRIx64 ", but the DIE chain ended.\n",
-          cu_off, last_die_off, sibling_addr);
+          cu_off, prev_die_off, sibling_addr);
 
   /* DIEs with zero abbreviation code are excessive if: we check
      non-final section, or we check final section and these DIEs are