diff mbox series

[04/14] libdw: Handle other string forms in dwarf_macro_param2

Message ID a8f01e3a1f58a9b41f3af6409f97b15e0cc8e39e.1695837512.git.osandov@fb.com
State Committed
Headers
Series elfutils: DWARF package (.dwp) file support |

Commit Message

Omar Sandoval Sept. 27, 2023, 6:20 p.m. UTC 
  From: Omar Sandoval <osandov@fb.com>

dwarf_getmacros handles the additional macro string forms added by DWARF
5, but dwarf_macro_param2 doesn't.  Update it with the list of all
string forms allowed in .debug_macro.  In particular, GCC and Clang
generate DW_MACRO_define_strx and DW_MACRO_undef_strx, which
dwarf_macro_param2 couldn't handle.

Fixes: cdf865b890c2 ("readelf, libdw: Handle DWARF5 .debug_macro.")
Signed-off-by: Omar Sandoval <osandov@fb.com>
---
 libdw/ChangeLog            |  3 +++
 libdw/dwarf_macro_param2.c | 21 +++++++++++++++------
 2 files changed, 18 insertions(+), 6 deletions(-)

Comments

Mark Wielaard Oct. 3, 2023, 4:11 p.m. UTC | #1 
Hi Omar,

On Wed, 2023-09-27 at 11:20 -0700, Omar Sandoval wrote:
> From: Omar Sandoval <osandov@fb.com>
> 
> dwarf_getmacros handles the additional macro string forms added by DWARF
> 5, but dwarf_macro_param2 doesn't.  Update it with the list of all
> string forms allowed in .debug_macro.  In particular, GCC and Clang
> generate DW_MACRO_define_strx and DW_MACRO_undef_strx, which
> dwarf_macro_param2 couldn't handle.

So as far as I can see this is always only used for DWARF5 forms and
never uses the DW_FORM_GNU_strp_alt or DW_FORM_GNU_str_index because
the GNU DebugFission extension for DWARF4 kept the old macinfo format,
just moved it to the dwo.

Thanks for catching this. Applied.

Cheers,

Mark
diff mbox series

Patch

diff --git a/libdw/ChangeLog b/libdw/ChangeLog
index e84432f6..7528c093 100644
--- a/libdw/ChangeLog
+++ b/libdw/ChangeLog
@@ -4,6 +4,9 @@ 
 	* dwarf_entrypc.c (dwarf_entrypc): Call dwarf_lowpc.
 	* dwarf_ranges.c (dwarf_ranges): Use skeleton ranges section for
 	skeleton units.
+	* dwarf_macro_param2.c (dwarf_macro_param2): Change form condition to
+	switch statement and add DW_FORM_line_strp, DW_FORM_strp_sup,
+	DW_FORM_strx, and DW_FORM_strx[1-4].
 
 2023-02-22  Mark Wielaard  <mark@klomp.org>
 
diff --git a/libdw/dwarf_macro_param2.c b/libdw/dwarf_macro_param2.c
index cc902c99..f12e6f9a 100644
--- a/libdw/dwarf_macro_param2.c
+++ b/libdw/dwarf_macro_param2.c
@@ -44,12 +44,21 @@  dwarf_macro_param2 (Dwarf_Macro *macro, Dwarf_Word *paramp, const char **strp)
   if (dwarf_macro_param (macro, 1, &param) != 0)
     return -1;
 
-  if (param.form == DW_FORM_string
-      || param.form == DW_FORM_strp)
+  switch (param.form)
     {
-      *strp = dwarf_formstring (&param);
-      return 0;
+      /* String forms allowed by libdw_valid_user_form.  */
+      case DW_FORM_line_strp:
+      case DW_FORM_string:
+      case DW_FORM_strp:
+      case DW_FORM_strp_sup:
+      case DW_FORM_strx:
+      case DW_FORM_strx1:
+      case DW_FORM_strx2:
+      case DW_FORM_strx3:
+      case DW_FORM_strx4:
+	*strp = dwarf_formstring (&param);
+	return 0;
+      default:
+	return dwarf_formudata (&param, paramp);
     }
-  else
-    return dwarf_formudata (&param, paramp);
 }