[mc] Avoid memsetting twice

[simgrid.git] / src / mc / mc_dwarf_expression.c

diff --git a/src/mc/mc_dwarf_expression.c b/src/mc/mc_dwarf_expression.c
index ec9d978..e06ad82 100644 (file)
--- a/src/mc/mc_dwarf_expression.c
+++ b/src/mc/mc_dwarf_expression.c
@@ -1,3 +1,8 @@
+/* Copyright (c) 2014. The SimGrid Team.
+ * All rights reserved.                                                     */
+
+/* This program is free software; you can redistribute it and/or modify it
+ * under the terms of the license (GNU LGPL) which comes with this package. */
 
 #include <stdint.h>
 #include <stdarg.h>
@@ -15,6 +20,45 @@ static int mc_dwarf_push_value(mc_expression_state_t state, Dwarf_Off value) {
   return 0;
 }
 
+static int mc_dwarf_register_to_libunwind(int dwarf_register) {
+  #if defined(UNW_TARGET_X86_64)
+  // It seems for this arch, DWARF and libunwind agree in the numbering:
+  return dwarf_register;
+  #elif defined(UNW_TARGET_X86)
+  // Could't find the authoritative source of information for this.
+  // This is inspired from http://source.winehq.org/source/dlls/dbghelp/cpu_i386.c#L517.
+  switch(dwarf_register) {
+  case 0:  return UNW_X86_EAX;
+  case 1:  return UNW_X86_ECX;
+  case 2:  return UNW_X86_EDX;
+  case 3:  return UNW_X86_EBX;
+  case 4:  return UNW_X86_ESP;
+  case 5:  return UNW_X86_EBP;
+  case 6:  return UNW_X86_ESI;
+  case 7:  return UNW_X86_EDI;
+  case 8:  return UNW_X86_EIP;
+  case 9:  return UNW_X86_EFLAGS;
+  case 10: return UNW_X86_CS;
+  case 11: return UNW_X86_SS;
+  case 12: return UNW_X86_DS;
+  case 13: return UNW_X86_ES;
+  case 14: return UNW_X86_FS;
+  case 15: return UNW_X86_GS;
+  case 16: return UNW_X86_ST0;
+  case 17: return UNW_X86_ST1;
+  case 18: return UNW_X86_ST2;
+  case 19: return UNW_X86_ST3;
+  case 20: return UNW_X86_ST4;
+  case 21: return UNW_X86_ST5;
+  case 22: return UNW_X86_ST6;
+  case 23: return UNW_X86_ST7;
+  default: xbt_die("Bad/unknown register number.");
+  }
+  #else
+  #error This architecture is not supported yet.
+  #endif
+}
+
 int mc_dwarf_execute_expression(
   size_t n, const Dwarf_Op* ops, mc_expression_state_t state) {
   for(int i=0; i!=n; ++i) {
@@ -34,7 +78,7 @@ int mc_dwarf_execute_expression(
     case DW_OP_breg20: case DW_OP_breg21: case DW_OP_breg22: case DW_OP_breg23:
     case DW_OP_breg24: case DW_OP_breg25: case DW_OP_breg26: case DW_OP_breg27:
     case DW_OP_breg28: case DW_OP_breg29: case DW_OP_breg30: case DW_OP_breg31:{
-        int register_id = op->atom - DW_OP_breg0;
+        int register_id = mc_dwarf_register_to_libunwind(op->atom - DW_OP_breg0);
         unw_word_t res;
         if(!state->cursor)
           return MC_EXPRESSION_E_MISSING_STACK_CONTEXT;
@@ -92,7 +136,8 @@ int mc_dwarf_execute_expression(
         return MC_EXPRESSION_E_NO_BASE_ADDRESS;
       if(state->stack_size==MC_EXPRESSION_STACK_SIZE)
         return MC_EXPRESSION_E_STACK_OVERFLOW;
-      error = mc_dwarf_push_value(state,  (Dwarf_Off)MC_object_base_address(state->object_info) + op->number);
+      error = mc_dwarf_push_value(state,
+        (Dwarf_Off)(uintptr_t)MC_object_base_address(state->object_info) + op->number);
       break;
 
     case DW_OP_const1u:
@@ -321,9 +366,6 @@ void mc_dwarf_location_list_clear(mc_location_list_t list) {
 }
 
 void mc_dwarf_expression_init(mc_expression_t expression, size_t len, Dwarf_Op* ops) {
-  if(expression->ops) {
-    free(expression->ops);
-  }
   expression->lowpc = NULL;
   expression->highpc = NULL;
   expression->size = len;
@@ -332,9 +374,6 @@ void mc_dwarf_expression_init(mc_expression_t expression, size_t len, Dwarf_Op*
 }
 
 void mc_dwarf_location_list_init_from_expression(mc_location_list_t target, size_t len, Dwarf_Op* ops) {
-  if(target->locations) {
-    mc_dwarf_location_list_clear(target);
-  }
   target->size = 1;
   target->locations = (mc_expression_t) xbt_malloc(sizeof(s_mc_expression_t));
   mc_dwarf_expression_init(target->locations, len, ops);
@@ -363,10 +402,10 @@ void mc_dwarf_location_list_init(mc_location_list_t list, mc_object_info_t info,
     list->size++;
     list->locations = (mc_expression_t) realloc(list->locations, list->size*sizeof(s_mc_expression_t));
     mc_expression_t expression = list->locations + i;
-
-    void* base = info->flags & MC_OBJECT_INFO_EXECUTABLE ? 0 : MC_object_base_address(info);
+    expression->ops = NULL;
     mc_dwarf_expression_init(expression, len, ops);
 
+    void* base = info->flags & MC_OBJECT_INFO_EXECUTABLE ? 0 : MC_object_base_address(info);
     // If start == 0, this is not a location list:
     expression->lowpc = start == 0 ? NULL : (char*) base + start;
     expression->highpc = start == 0 ? NULL : (char*) base + end;