From: Gabriel Corona <gabriel.corona@loria.fr>
Date: Fri, 7 Mar 2014 13:07:36 +0000 (+0100)
Subject: [mc] Use new expression evaluation code frame_base
X-Git-Tag: v3_11~199^2~2^2~15
X-Git-Url: http://info.iut-bm.univ-fcomte.fr/pub/gitweb/simgrid.git/commitdiff_plain/f6e8576ae0221324ccba0eb542504e2d7bd9f766

[mc] Use new expression evaluation code frame_base
---

diff --git a/src/mc/mc_checkpoint.c b/src/mc/mc_checkpoint.c
index 6e86b8118d..eaf8566d9a 100644
--- a/src/mc/mc_checkpoint.c
+++ b/src/mc/mc_checkpoint.c
@@ -327,7 +327,7 @@ static xbt_dynar_t MC_unwind_stack_frames(void *stack_context) {
 
     if(frame) {
       stack_frame->frame_name = xbt_strdup(frame->name);
-      stack_frame->frame_base = (unw_word_t)mc_find_frame_base((void*)ip, frame, &c);
+      stack_frame->frame_base = (unw_word_t)mc_find_frame_base(frame, &c);
     } else {
       stack_frame->frame_base = 0;
     }
diff --git a/src/mc/mc_dwarf.c b/src/mc/mc_dwarf.c
index 9395335dd6..972d3e9607 100644
--- a/src/mc/mc_dwarf.c
+++ b/src/mc/mc_dwarf.c
@@ -309,31 +309,6 @@ static dw_location_t MC_dwarf_get_location_list(mc_object_info_t info, Dwarf_Die
   }
 }
 
-/** \brief Find the frame base of a given frame
- *
- *  \param ip         Instruction pointer
- *  \param frame
- *  \param unw_cursor
- */
-void* mc_find_frame_base(void* ip, dw_frame_t frame, unw_cursor_t* unw_cursor) {
-  switch(frame->frame_base->type) {
-  case e_dw_loclist:
-  {
-    int loclist_cursor;
-    for(loclist_cursor=0; loclist_cursor < xbt_dynar_length(frame->frame_base->location.loclist); loclist_cursor++){
-      dw_location_entry_t entry = xbt_dynar_get_as(frame->frame_base->location.loclist, loclist_cursor, dw_location_entry_t);
-      if((ip >= entry->lowpc) && (ip < entry->highpc)){
-        return (void*) MC_dwarf_resolve_location(unw_cursor, entry->location, NULL);
-      }
-    }
-    return NULL;
-  }
-  // Not handled:
-  default:
-    return NULL;
-  }
-}
-
 /** \brief Get the location expression or location list from an attribute
  *
  *  Processes direct expressions as well as location lists.
@@ -1008,6 +983,22 @@ static void MC_dwarf_handle_variable_die(mc_object_info_t info, Dwarf_Die* die,
 }
 
 static void MC_dwarf_handle_subprogram_die(mc_object_info_t info, Dwarf_Die* die, Dwarf_Die* unit, dw_frame_t parent_frame, const char* namespace) {
+
+  // (Template) Subprogram declaration:
+  if (MC_dwarf_attr_flag(die, DW_AT_declaration, false))
+    return;
+
+  // Abstract inline instance (DW_AT_inline != DW_INL_not_inlined):
+  if (dwarf_func_inline(die))
+    return;
+
+  // This is probably not a concrete instance:
+  // DWARF2/3 and DWARF4 do not agree on the meaning of DW_INL_not_inlined.
+  // For DWARF2/3, the subprogram is abstract.
+  // For DARF4, the subprogram is not abstract.
+  if(!dwarf_hasattr_integrate(die, DW_AT_low_pc))
+    return;
+
   dw_frame_t frame = xbt_new0(s_dw_frame_t, 1);
 
   frame->start = dwarf_dieoffset(die);
@@ -1024,7 +1015,15 @@ static void MC_dwarf_handle_subprogram_die(mc_object_info_t info, Dwarf_Die* die
   frame->variables = xbt_dynar_new(sizeof(dw_variable_t), dw_variable_free_voidp);
   frame->high_pc = ((char*) base) + MC_dwarf_attr_addr(die, DW_AT_high_pc);
   frame->low_pc = ((char*) base) + MC_dwarf_attr_addr(die, DW_AT_low_pc);
-  frame->frame_base = MC_dwarf_at_location(info, die, DW_AT_frame_base);
+
+  if(frame->high_pc==0 || frame->low_pc==0)
+    xbt_die("Could not resolve highpc/lowpc");
+
+  Dwarf_Attribute attr_frame_base;
+  if (!dwarf_attr_integrate(die, DW_AT_frame_base, &attr_frame_base))
+    xbt_die("Coult not find DW_AT_frame_base for subprogram %s %p", frame->name, frame->start);
+  mc_dwarf_location_list_init(&frame->frame_base, info, die, &attr_frame_base);
+
   frame->end = -1; // This one is now useless:
 
   // Register it:
diff --git a/src/mc/mc_dwarf_expression.c b/src/mc/mc_dwarf_expression.c
index 54183b4bb9..7aadf06578 100644
--- a/src/mc/mc_dwarf_expression.c
+++ b/src/mc/mc_dwarf_expression.c
@@ -279,6 +279,15 @@ Dwarf_Off mc_dwarf_resolve_locations(mc_location_list_t locations, unw_cursor_t*
   xbt_die("Could not resolve location");
 }
 
+/** \brief Find the frame base of a given frame
+ *
+ *  \param frame
+ *  \param unw_cursor
+ */
+void* mc_find_frame_base(dw_frame_t frame, unw_cursor_t* unw_cursor) {
+  return (void*) mc_dwarf_resolve_locations(&frame->frame_base, unw_cursor, NULL);
+}
+
 static
 void mc_dwarf_expression_clear(mc_expression_t expression) {
   free(expression->ops);
@@ -344,8 +353,10 @@ void mc_dwarf_location_list_init(mc_location_list_t list, mc_object_info_t info,
 
     void* base = info->flags & MC_OBJECT_INFO_EXECUTABLE ? 0 : MC_object_base_address(info);
     mc_dwarf_expression_init(expression, len, ops);
-    expression->lowpc = (char*) base + start;
-    expression->highpc = (char*) base + end;
+
+    // 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;
   }
 
 }
diff --git a/src/mc/mc_hash.c b/src/mc/mc_hash.c
index 87e724a3ae..a6b9ae5147 100644
--- a/src/mc/mc_hash.c
+++ b/src/mc/mc_hash.c
@@ -240,7 +240,7 @@ static void mc_hash_stack_frame(
 
     XBT_DEBUG("Hash local variable %s", variable->name);
 
-    void* variable_address = (void*) mc_dwarf_resolve_location(&variable->locations, unw_cursor, frame_pointer);
+    void* variable_address = (void*) mc_dwarf_resolve_locations(&variable->locations, unw_cursor, frame_pointer);
 
     dw_type_t type = variable->type;
     if(type==NULL) {
diff --git a/src/mc/mc_private.h b/src/mc/mc_private.h
index 63a4b3851a..9672142970 100644
--- a/src/mc/mc_private.h
+++ b/src/mc/mc_private.h
@@ -479,7 +479,7 @@ struct s_dw_frame{
   char *name;
   void *low_pc;
   void *high_pc;
-  dw_location_t frame_base;
+  s_mc_location_list_t frame_base;
   xbt_dynar_t /* <dw_variable_t> */ variables; /* Cannot use dict, there may be several variables with the same name (in different lexical blocks)*/
   unsigned long int start; /* DWARF offset of the subprogram */
   unsigned long int end;   /* Dwarf offset of the next sibling */
@@ -503,7 +503,6 @@ void* MC_object_base_address(mc_object_info_t info);
 /********************************** DWARF **********************************/
 
 Dwarf_Off MC_dwarf_resolve_location(unw_cursor_t* c, dw_location_t location, void* frame_pointer_address);
-void* mc_find_frame_base(void* ip, dw_frame_t frame, unw_cursor_t* unw_cursor);
 
 #define MC_EXPRESSION_STACK_SIZE 64
 
@@ -524,6 +523,8 @@ typedef struct s_mc_expression_state {
 
 int mc_dwarf_execute_expression(size_t n, const Dwarf_Op* ops, mc_expression_state_t state);
 
+void* mc_find_frame_base(dw_frame_t frame, unw_cursor_t* unw_cursor);
+
 /********************************** Miscellaneous **********************************/
 
 typedef struct s_local_variable{
diff --git a/testsuite/mc/dwarf.c b/testsuite/mc/dwarf.c
index eecba82871..1d8ac45f82 100644
--- a/testsuite/mc/dwarf.c
+++ b/testsuite/mc/dwarf.c
@@ -37,6 +37,41 @@ static dw_variable_t find_global_variable_by_name(mc_object_info_t info, const c
   return NULL;
 }
 
+static dw_frame_t find_function_by_name(mc_object_info_t info, const char* name) {
+  unsigned int cursor = 0;
+  dw_frame_t subprogram;
+  xbt_dynar_foreach(info->subprograms, cursor, subprogram){
+    if(!strcmp(name, subprogram->name))
+      return subprogram;
+  }
+
+  return NULL;
+}
+
+static dw_variable_t find_local_variable(dw_frame_t frame, const char* argument_name) {
+  unsigned int cursor = 0;
+  dw_variable_t variable;
+  xbt_dynar_foreach(frame->variables, cursor, variable){
+    if(!strcmp(argument_name, variable->name))
+      return variable;
+  }
+
+  return NULL;
+}
+
+static void test_local_argument(mc_object_info_t info, const char* function, const char* variable, void* address, unw_cursor_t* cursor) {
+  dw_frame_t subprogram = find_function_by_name(info, function);
+  assert(subprogram);
+  // TODO, Lookup frame by IP and test against name instead
+
+  dw_variable_t var = find_local_variable(subprogram, variable);
+  assert(var);
+
+  void* frame_base = mc_find_frame_base(subprogram, cursor);
+  assert((void*)mc_dwarf_resolve_locations(&var->locations, cursor, frame_base) == address);
+
+}
+
 static dw_variable_t test_global_variable(mc_object_info_t info, const char* name, void* address, long byte_size) {
   dw_variable_t variable = find_global_variable_by_name(info, name);
   xbt_assert(variable, "Global variable %s was not found", name);
@@ -85,5 +120,12 @@ int main(int argc, char** argv) {
   assert(find_type(mc_binary_info, "second", type)->offset
       == ((const char*)&test_some_struct.second) - (const char*)&test_some_struct);
 
+  unw_context_t context;
+  unw_cursor_t cursor;
+  unw_getcontext(&context);
+  unw_init_local(&cursor, &context);
+
+  test_local_argument(mc_binary_info, "main", "argc", &argc, &cursor);
+
   _exit(0);
 }