libdw: Handle DW_FORM_line_strp.

DW_FORM_line_strp strings come from a separate .debug_line_str section.
Make error messages more distinct (no .debug_str, no .debug_line_str or
not a string form).

Signed-off-by: Mark Wielaard <[email protected]>

1 files changed, 15 insertions, 3 deletions

diff --git a/libdw/dwarf_formstring.c b/libdw/dwarf_formstring.c
index 39766ad5..e7396a79 100644
--- a/libdw/dwarf_formstring.c
+++ b/libdw/dwarf_formstring.c
@@ -57,9 +57,14 @@ dwarf_formstring (Dwarf_Attribute *attrp)
       return NULL;
     }
 
-  if (dbg_ret->sectiondata[IDX_debug_str] == NULL)
+  Elf_Data *data = ((attrp->form == DW_FORM_line_strp)
+		    ? dbg_ret->sectiondata[IDX_debug_line_str]
+		    : dbg_ret->sectiondata[IDX_debug_str]);
+  if (data == NULL)
     {
-      __libdw_seterrno (DWARF_E_NO_STRING);
+      __libdw_seterrno ((attrp->form == DW_FORM_line_strp)
+			? DWARF_E_NO_DEBUG_LINE_STR
+			: DWARF_E_NO_DEBUG_STR);
       return NULL;
     }
 
@@ -72,6 +77,13 @@ dwarf_formstring (Dwarf_Attribute *attrp)
 			       IDX_debug_str, 1))
 	return NULL;
     }
+  else if (attrp->form == DW_FORM_line_strp)
+    {
+      if (__libdw_read_offset (dbg, dbg_ret, cu_sec_idx (cu),
+			       attrp->valp, cu->offset_size, &off,
+			       IDX_debug_line_str, 1))
+	return NULL;
+    }
   else
     {
       Dwarf_Word idx;
@@ -160,7 +172,7 @@ dwarf_formstring (Dwarf_Attribute *attrp)
 	goto invalid_offset;
     }
 
-  return (const char *) dbg_ret->sectiondata[IDX_debug_str]->d_buf + off;
+  return (const char *) data->d_buf + off;
 }
 INTDEF(dwarf_formstring)