From: Gabriel Corona <gabriel.corona@loria.fr>
Date: Thu, 6 Mar 2014 12:07:19 +0000 (+0100)
Subject: [mc] Support DWARF4 DW_FORM_sec_offset (found in libpthread_nonshared.a)
X-Git-Tag: v3_11~199^2~2^2~19^2~1
X-Git-Url: http://info.iut-bm.univ-fcomte.fr/pub/gitweb/simgrid.git/commitdiff_plain/7ef55d47978f2f2ef20bd27c85881faa99147034?hp=6399b037de5d22e37584d156b87f293dbfa16df7

[mc] Support DWARF4 DW_FORM_sec_offset (found in libpthread_nonshared.a)

Add support to DWARF4 DW_FORM_sec_offset in order to handle DWARF4
libpthread_nonshared.a.

We do not yet handle DWARF3 and 4 but only DWARF2. It is not a big
problem as it is possible to ask GCC to generate DWARF2 with:
-gdwarf-2.

However, even with this option, some static/non-shared libraries might
be included such as libpthread_nonshared.a which might be compiled
with DWARF4 information. This happen in Debian testing (2014-03-06).

   Dwarf_Attribute attr;
   dwarf_attr_integrate(child, DW_AT_data_member_location, &attr);
-  int form  = dwarf_whatform(&attr);
+  int form = dwarf_whatform(&attr);
   int klass = MC_dwarf_form_get_class(form);
   switch (klass) {
   case MC_DW_CLASS_EXPRLOC:
@@ -850,7 +850,8 @@ static dw_variable_t MC_die_to_variable(mc_object_info_t info, Dwarf_Die* die, D
   variable->name = xbt_strdup(MC_dwarf_attr_string(die, DW_AT_name));
   variable->type_origin = MC_dwarf_at_type(die);

-  int klass = MC_dwarf_form_get_class(dwarf_whatform(&attr_location));
+  int form = dwarf_whatform(&attr_location);
+  int klass = form == DW_FORM_sec_offset ? MC_DW_CLASS_CONSTANT : MC_dwarf_form_get_class(form);
   switch (klass) {
   case MC_DW_CLASS_EXPRLOC:
   case MC_DW_CLASS_BLOCK:
@@ -882,8 +883,8 @@ static dw_variable_t MC_die_to_variable(mc_object_info_t info, Dwarf_Die* die, D
     variable->location = MC_dwarf_get_location_list(info, die, &attr_location);
     break;
   default:
-    xbt_die("Unexpected calss 0x%x (%i) list for location in <%p>%s",
-      klass, klass, (void*) variable->dwarf_offset, variable->name);
+    xbt_die("Unexpected form 0x%x (%i), class 0x%x (%i) list for location in <%p>%s",
+      form, form, klass, klass, (void*) variable->dwarf_offset, variable->name);
   }

   // The current code needs a variable name,
---

diff --git a/src/mc/mc_dwarf.c b/src/mc/mc_dwarf.c
index f13cc5063d..618ed29097 100644
--- a/src/mc/mc_dwarf.c
+++ b/src/mc/mc_dwarf.c
@@ -508,7 +508,7 @@ static void MC_dwarf_fill_member_location(dw_type_t type, dw_type_t member, Dwar
 
   Dwarf_Attribute attr;
   dwarf_attr_integrate(child, DW_AT_data_member_location, &attr);
-  int form  = dwarf_whatform(&attr);
+  int form = dwarf_whatform(&attr);
   int klass = MC_dwarf_form_get_class(form);
   switch (klass) {
   case MC_DW_CLASS_EXPRLOC:
@@ -850,7 +850,8 @@ static dw_variable_t MC_die_to_variable(mc_object_info_t info, Dwarf_Die* die, D
   variable->name = xbt_strdup(MC_dwarf_attr_string(die, DW_AT_name));
   variable->type_origin = MC_dwarf_at_type(die);
 
-  int klass = MC_dwarf_form_get_class(dwarf_whatform(&attr_location));
+  int form = dwarf_whatform(&attr_location);
+  int klass = form == DW_FORM_sec_offset ? MC_DW_CLASS_CONSTANT : MC_dwarf_form_get_class(form);
   switch (klass) {
   case MC_DW_CLASS_EXPRLOC:
   case MC_DW_CLASS_BLOCK:
@@ -882,8 +883,8 @@ static dw_variable_t MC_die_to_variable(mc_object_info_t info, Dwarf_Die* die, D
     variable->location = MC_dwarf_get_location_list(info, die, &attr_location);
     break;
   default:
-    xbt_die("Unexpected calss 0x%x (%i) list for location in <%p>%s",
-      klass, klass, (void*) variable->dwarf_offset, variable->name);
+    xbt_die("Unexpected form 0x%x (%i), class 0x%x (%i) list for location in <%p>%s",
+      form, form, klass, klass, (void*) variable->dwarf_offset, variable->name);
   }
 
   // The current code needs a variable name,