X-Git-Url: http://info.iut-bm.univ-fcomte.fr/pub/gitweb/simgrid.git/blobdiff_plain/5414074587ae221c7c677a3158ccebb617349e1a..57d96d2cf3a593395ef6657f07c06b57dcdac400:/src/mc/mc_dwarf.c

diff --git a/src/mc/mc_dwarf.c b/src/mc/mc_dwarf.c
index 1a69987860..5839708020 100644
--- a/src/mc/mc_dwarf.c
+++ b/src/mc/mc_dwarf.c
@@ -20,27 +20,81 @@ XBT_LOG_NEW_DEFAULT_SUBCATEGORY(mc_dwarf, mc, "DWARF processing");
 /** \brief The default DW_TAG_lower_bound for a given DW_AT_language.
  *
  *  The default for a given language is defined in the DWARF spec.
+ *
+ *  \param language consant as defined by the DWARf spec
  */
 static uint64_t MC_dwarf_default_lower_bound(int lang);
 
+/** \brief Computes the the element_count of a DW_TAG_enumeration_type DIE
+ *
+ * This is the number of elements in a given array dimension.
+ *
+ * A reference of the compilation unit (DW_TAG_compile_unit) is
+ * needed because the default lower bound (when there is no DW_AT_lower_bound)
+ * depends of the language of the compilation unit (DW_AT_language).
+ *
+ * \param die  DIE for the DW_TAG_enumeration_type or DW_TAG_subrange_type
+ * \param unit DIE of the DW_TAG_compile_unit
+ */
 static uint64_t MC_dwarf_subrange_element_count(Dwarf_Die* die, Dwarf_Die* unit);
 
-/** \brief Computes the number of elements of a given DW_TAG_array_type
+/** \brief Computes the number of elements of a given DW_TAG_array_type.
  *
+ * \param die DIE for the DW_TAG_array_type
  */
 static uint64_t MC_dwarf_array_element_count(Dwarf_Die* die, Dwarf_Die* unit);
 
-/** \brief Checks if a given tag is a (known) type tag.
+/** \brief Process a DIE
+ *
+ *  \param info the resulting object fot the library/binary file (output)
+ *  \param die  the current DIE
+ *  \param unit the DIE of the compile unit of the current DIE
+ *  \param frame containg frame if any
  */
-static int MC_dwarf_tag_type(int tag);
 static void MC_dwarf_handle_die(mc_object_info_t info, Dwarf_Die* die, Dwarf_Die* unit, dw_frame_t frame);
+
+/** \brief Process a type DIE
+ */
 static void MC_dwarf_handle_type_die(mc_object_info_t info, Dwarf_Die* die, Dwarf_Die* unit);
+
+/** \brief Calls MC_dwarf_handle_die on all childrend of the given die
+ *
+ *  \param info the resulting object fot the library/binary file (output)
+ *  \param die  the current DIE
+ *  \param unit the DIE of the compile unit of the current DIE
+ *  \param frame containg frame if any
+ */
 static void MC_dwarf_handle_children(mc_object_info_t info, Dwarf_Die* die, Dwarf_Die* unit, dw_frame_t frame);
+
+/** \brief Handle a variable (DW_TAG_variable or other)
+ *
+ *  \param info the resulting object fot the library/binary file (output)
+ *  \param die  the current DIE
+ *  \param unit the DIE of the compile unit of the current DIE
+ *  \param frame containg frame if any
+ */
 static void MC_dwarf_handle_variable_die(mc_object_info_t info, Dwarf_Die* die, Dwarf_Die* unit, dw_frame_t frame);
+
+/** \brief Convert a libdw DWARF expression into a MC representation of the location
+ *
+ *  \param expr array of DWARf operations
+ *  \param len  number of elements
+ *  \return a new MC expression
+ */
 static dw_location_t MC_dwarf_get_expression(Dwarf_Op* expr,  size_t len);
-static Dwarf_Die* MC_dwarf_resolve_die(Dwarf_Die* die, int attribute);
+
+/** \brief Get the DW_TAG_type of the DIE
+ *
+ *  \param die DIE
+ *  \return DW_TAG_type attribute as a new string (NULL if none)
+ */
 static char* MC_dwarf_at_type(Dwarf_Die* die);
 
+/** \brief Get the name of an attribute (DW_AT_*) from its code
+ *
+ *  \param attr attribute code (see the DWARF specification)
+ *  \return name of the attribute
+ */
 const char* MC_dwarf_attrname(int attr) {
   switch (attr) {
 #include "mc_dwarf_attrnames.h"
@@ -49,6 +103,11 @@ const char* MC_dwarf_attrname(int attr) {
   }
 }
 
+/** \brief Get the name of a dwarf tag (DW_TAG_*) from its code
+ *
+ *  \param tag tag code (see the DWARF specification)
+ *  \return name of the tag
+ */
 const char* MC_dwarf_tagname(int tag) {
   switch (tag) {
 #include "mc_dwarf_tagnames.h"
@@ -59,12 +118,73 @@ const char* MC_dwarf_tagname(int tag) {
   }
 }
 
+#define MC_DW_CLASS_UNKNOWN 0
+#define MC_DW_CLASS_ADDRESS 1   // Location in the address space of the program
+#define MC_DW_CLASS_BLOCK 2     // Arbitrary block of bytes
+#define MC_DW_CLASS_CONSTANT 3
+#define MC_DW_CLASS_STRING 3    // String
+#define MC_DW_CLASS_FLAG 4      // Boolean
+#define MC_DW_CLASS_REFERENCE 5 // Reference to another DIE
+#define MC_DW_CLASS_EXPRLOC 6   // DWARF expression/location description
+#define MC_DW_CLASS_LINEPTR 7
+#define MC_DW_CLASS_LOCLISTPTR 8
+#define MC_DW_CLASS_MACPTR 9
+#define MC_DW_CLASS_RANGELISTPTR 10
+
+static int MC_dwarf_form_get_class(int form) {
+  switch(form) {
+  case DW_FORM_addr:
+    return MC_DW_CLASS_ADDRESS;
+  case DW_FORM_block2:
+  case DW_FORM_block4:
+  case DW_FORM_block:
+  case DW_FORM_block1:
+    return MC_DW_CLASS_BLOCK;
+  case DW_FORM_data2:
+  case DW_FORM_data4:
+  case DW_FORM_data8:
+  case DW_FORM_udata:
+  case DW_FORM_sdata:
+    return MC_DW_CLASS_CONSTANT;
+  case DW_FORM_string:
+  case DW_FORM_strp:
+    return MC_DW_CLASS_STRING;
+  case DW_FORM_ref_addr:
+  case DW_FORM_ref1:
+  case DW_FORM_ref2:
+  case DW_FORM_ref4:
+  case DW_FORM_ref8:
+  case DW_FORM_ref_udata:
+    return MC_DW_CLASS_REFERENCE;
+  case DW_FORM_flag:
+  case DW_FORM_flag_present:
+    return MC_DW_CLASS_FLAG;
+  case DW_FORM_exprloc:
+    return MC_DW_CLASS_EXPRLOC;
+  // TODO sec offset
+  // TODO indirect
+  default:
+    return MC_DW_CLASS_UNKNOWN;
+  }
+}
+
+/** \brief Get the name of the tag of a given DIE
+ *
+ *  \param die DIE
+ *  \return name of the tag of this DIE
+ */
 static inline const char* MC_dwarf_die_tagname(Dwarf_Die* die) {
   return MC_dwarf_tagname(dwarf_tag(die));
 }
 
 // ***** Attributes
 
+/** \brief Get an attribute of a given DIE as a string
+ *
+ *  \param the DIE
+ *  \param attribute attribute
+ *  \return value of the given attribute of the given DIE
+ */
 static const char* MC_dwarf_attr_string(Dwarf_Die* die, int attribute) {
   Dwarf_Attribute attr;
   if (!dwarf_attr_integrate(die, attribute, &attr)) {
@@ -74,8 +194,13 @@ static const char* MC_dwarf_attr_string(Dwarf_Die* die, int attribute) {
   }
 }
 
-/** \brief Get the linkage name (DW_AT_linkage_name or DW_AR_MIPS_linkage_name)
- *  of a DIE. */
+/** \brief Get the linkage name of a DIE.
+ *
+ *  Use either DW_AT_linkage_name or DW_AR_MIPS_linkage_name.
+ *
+ *  \param DIE
+ *  \return linkage name of the given DIE (or NULL)
+ * */
 static const char* MC_dwarf_at_linkage_name(Dwarf_Die* die) {
   const char* name = MC_dwarf_attr_string(die, DW_AT_linkage_name);
   if (!name)
@@ -83,20 +208,57 @@ static const char* MC_dwarf_at_linkage_name(Dwarf_Die* die) {
   return name;
 }
 
-static dw_location_t MC_dwarf_resolve_location_list(mc_object_info_t info, Dwarf_Word offset) {
-  char *key = bprintf("%ld", (long) offset);
-  dw_location_t loc = xbt_new0(s_dw_location_t, 1);
-  loc->type = e_dw_loclist;
-  loc->location.loclist =  (xbt_dynar_t)xbt_dict_get_or_null(info->location_list, key);
-  if (!loc->location.loclist)
-    XBT_INFO("Key not found in loclist");
-  xbt_free(key);
-  return loc;
+/** \brief Create a location list from a given attribute
+ *
+ *  \param die the DIE
+ *  \param attr the attribute
+ *  \return MC specific representation of the location list represented by the given attribute
+ *  of the given die
+ */
+static dw_location_t MC_dwarf_get_location_list(Dwarf_Die* die, Dwarf_Attribute* attr) {
+
+  dw_location_t location = xbt_new0(s_dw_location_t, 1);
+  location->type = e_dw_loclist;
+  xbt_dynar_t loclist = xbt_dynar_new(sizeof(dw_location_entry_t), NULL);
+  location->location.loclist = loclist;
+
+  ptrdiff_t offset = 0;
+  Dwarf_Addr base, start, end;
+  Dwarf_Op *expr;
+  size_t len;
+
+  while (1) {
+
+    offset = dwarf_getlocations(attr, offset, &base, &start, &end, &expr, &len);
+    if (offset==0)
+      return location;
+    else if (offset==-1)
+      xbt_die("Error while loading location list");
+
+    dw_location_entry_t new_entry = xbt_new0(s_dw_location_entry_t, 1);
+    new_entry->lowpc = start;
+    new_entry->highpc = end;
+    new_entry->location = MC_dwarf_get_expression(expr, len);
+
+    xbt_dynar_push(loclist, &new_entry);
+
+  }
 }
 
-static dw_location_t MC_dwarf_get_location(Dwarf_Die* die, Dwarf_Attribute* attr, mc_object_info_t info) {
+/** \brief Get the location expression or location list from an attribute
+ *
+ *  Processes direct expressions as well as location lists.
+ *
+ *  \param die the DIE
+ *  \param attr the attribute
+ *  \return MC specific representation of the location represented by the given attribute
+ *  of the given die
+ */
+static dw_location_t MC_dwarf_get_location(Dwarf_Die* die, Dwarf_Attribute* attr) {
   int form = dwarf_whatform(attr);
   switch (form) {
+
+  // The attribute is an DWARF location expression:
   case DW_FORM_exprloc:
   case DW_FORM_block1: // not in the spec
   case DW_FORM_block2:
@@ -109,18 +271,17 @@ static dw_location_t MC_dwarf_get_location(Dwarf_Die* die, Dwarf_Attribute* attr
         xbt_die("Could not read location expression");
       return MC_dwarf_get_expression(expr, len);
     }
+
+  // The attribute is a reference to a location list entry:
   case DW_FORM_sec_offset:
   case DW_FORM_data2:
   case DW_FORM_data4:
   case DW_FORM_data8:
     {
-      Dwarf_Word offset;
-      if (!dwarf_formudata(attr, &offset))
-        return MC_dwarf_resolve_location_list(info, offset);
-      else
-        xbt_die("Location list not found");
+      return MC_dwarf_get_location_list(die, attr);
     }
     break;
+
   default:
     xbt_die("Unexpected form %i list for location in attribute %s of <%p>%s",
       form,
@@ -131,16 +292,24 @@ static dw_location_t MC_dwarf_get_location(Dwarf_Die* die, Dwarf_Attribute* attr
   }
 }
 
-static dw_location_t MC_dwarf_at_location(Dwarf_Die* die, int attribute, mc_object_info_t info) {
+/** \brief Get the location expression or location list from an attribute
+ *
+ *  Processes direct expressions as well as location lists.
+ *
+ *  \param die the DIE
+ *  \param attribute the attribute code
+ *  \return MC specific representation of the location represented by the given attribute
+ *  of the given die
+ */
+static dw_location_t MC_dwarf_at_location(Dwarf_Die* die, int attribute) {
   if(!dwarf_hasattr_integrate(die, attribute))
     return xbt_new0(s_dw_location_t, 1);
 
   Dwarf_Attribute attr;
   dwarf_attr_integrate(die, attribute, &attr);
-  return MC_dwarf_get_location(die, &attr, info);
+  return MC_dwarf_get_location(die, &attr);
 }
 
-// Return a new string for the type (NULL if none)
 static char* MC_dwarf_at_type(Dwarf_Die* die) {
   Dwarf_Attribute attr;
   if (dwarf_hasattr_integrate(die, DW_AT_type)) {
@@ -218,12 +387,15 @@ static uint64_t MC_dwarf_default_lower_bound(int lang) {
 }
 
 static uint64_t MC_dwarf_subrange_element_count(Dwarf_Die* die, Dwarf_Die* unit) {
+  xbt_assert(dwarf_tag(die)==DW_TAG_enumeration_type ||dwarf_tag(die)==DW_TAG_subrange_type,
+      "MC_dwarf_subrange_element_count called with DIE of type %s", MC_dwarf_die_tagname(die));
+
   // Use DW_TAG_count if present:
   if (dwarf_hasattr_integrate(die, DW_AT_count)) {
     return MC_dwarf_attr_uint(die, DW_AT_count, 0);
   }
 
-  // Otherwise compute DW_TAG_upper_bound-DW_TAG_lower_bound:
+  // Otherwise compute DW_TAG_upper_bound-DW_TAG_lower_bound + 1:
 
   if (!dwarf_hasattr_integrate(die, DW_AT_upper_bound)) {
 	// This is not really 0, but the code expects this (we do not know):
@@ -237,7 +409,7 @@ static uint64_t MC_dwarf_subrange_element_count(Dwarf_Die* die, Dwarf_Die* unit)
   } else {
 	lower_bound = MC_dwarf_default_lower_bound(dwarf_srclang(unit));
   }
-  return upper_bound - lower_bound;
+  return upper_bound - lower_bound + 1;
 }
 
 static uint64_t MC_dwarf_array_element_count(Dwarf_Die* die, Dwarf_Die* unit) {
@@ -307,9 +479,11 @@ 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);
-  switch (dwarf_whatform(&attr)) {
-
-  case DW_FORM_exprloc:
+  int klass = MC_dwarf_form_get_class(dwarf_whatform(&attr));
+  switch (klass) {
+  case MC_DW_CLASS_EXPRLOC:
+  case MC_DW_CLASS_BLOCK:
+    // Location expression:
     {
       Dwarf_Op* expr;
       size_t len;
@@ -322,28 +496,32 @@ static void MC_dwarf_fill_member_location(dw_type_t type, dw_type_t member, Dwar
       if (len==1 && expr[0].atom == DW_OP_plus_uconst) {
         member->offset =  expr[0].number;
       } else {
-        xbt_die("Can't groke this location expression yet. %i %i",
-          len==1 , expr[0].atom == DW_OP_plus_uconst);
+        xbt_die("Can't groke this location expression yet.");
       }
       break;
     }
-  case DW_FORM_data1:
-  case DW_FORM_data2:
-  case DW_FORM_data4:
-  case DW_FORM_data8:
-  case DW_FORM_sdata:
-  case DW_FORM_udata:
+  case MC_DW_CLASS_CONSTANT:
+    // Offset from the base address of the object:
     {
       Dwarf_Word offset;
       if (!dwarf_formudata(&attr, &offset))
         member->offset = offset;
       else
-        xbt_die("Cannot get DW_AT_data_member_%s location <%p>%s",
+        xbt_die("Cannot get %s location <%p>%s",
           MC_dwarf_attr_string(child, DW_AT_name),
           type->id, type->name);
       break;
     }
+  case MC_DW_CLASS_LOCLISTPTR:
+    // Reference to a location list:
+    // TODO
+  case MC_DW_CLASS_REFERENCE:
+    // It's supposed to be possible in DWARF2 but I couldn't find its semantic
+    // in the spec.
+  default:
+    xbt_die("Can't handle form class 0x%x (%i) as DW_AT_member_location", klass, klass);
   }
+
 }
 
 static void MC_dwarf_add_members(mc_object_info_t info, Dwarf_Die* die, Dwarf_Die* unit, dw_type_t type) {
@@ -386,6 +564,13 @@ static void MC_dwarf_add_members(mc_object_info_t info, Dwarf_Die* die, Dwarf_Di
   }
 }
 
+/** \brief Create a MC type object from a DIE
+ *
+ *  \param info current object info object
+ *  \param DIE (for a given type);
+ *  \param unit compilation unit of the current DIE
+ *  \return MC representation of the type
+ */
 static dw_type_t MC_dwarf_die_to_type(mc_object_info_t info, Dwarf_Die* die, Dwarf_Die* unit) {
 
   dw_type_t type = xbt_new0(s_dw_type_t, 1);
@@ -610,6 +795,8 @@ static dw_location_t MC_dwarf_get_expression(Dwarf_Op* expr,  size_t len) {
   return loc;
 }
 
+static int mc_anonymous_variable_index = 0;
+
 static dw_variable_t MC_die_to_variable(mc_object_info_t info, Dwarf_Die* die, Dwarf_Die* unit, dw_frame_t frame) {
   // Drop declaration:
   if (MC_dwarf_attr_flag(die, DW_AT_declaration, false))
@@ -626,12 +813,12 @@ static dw_variable_t MC_die_to_variable(mc_object_info_t info, Dwarf_Die* die, D
   variable->global = frame == NULL; // Can be override base on DW_AT_location
   variable->name = xbt_strdup(MC_dwarf_attr_string(die, DW_AT_name));
   variable->type_origin = MC_dwarf_at_type(die);
-  variable->address.address = NULL;
 
-  int form;
-  switch (form = dwarf_whatform(&attr_location)) {
-  case DW_FORM_exprloc:
-  case DW_FORM_block1: // Not in the spec but found in the wild.
+  int klass = MC_dwarf_form_get_class(dwarf_whatform(&attr_location));
+  switch (klass) {
+  case MC_DW_CLASS_EXPRLOC:
+  case MC_DW_CLASS_BLOCK:
+    // Location expression:
     {
       Dwarf_Op* expr;
       size_t len;
@@ -645,21 +832,28 @@ static dw_variable_t MC_die_to_variable(mc_object_info_t info, Dwarf_Die* die, D
         variable->global = 1;
         Dwarf_Off offset = expr[0].number;
         // TODO, Why is this different base on the object?
-        Dwarf_Off base = strcmp(info->file_name, xbt_binary_name) !=0 ? (Dwarf_Off) info->start_text : 0;
-        variable->address.address = (void*) (base + offset);
+        Dwarf_Off base = strcmp(info->file_name, xbt_binary_name) !=0 ? (Dwarf_Off) info->start_exec : 0;
+        variable->address = (void*) (base + offset);
       } else {
-        variable->address.location = MC_dwarf_get_expression(expr, len);
+        variable->location = MC_dwarf_get_expression(expr, len);
       }
 
       break;
     }
-  case DW_FORM_sec_offset: // type loclistptr
-  case DW_FORM_data4:
-    xbt_die("Do not handle loclist locations yet");
+  case MC_DW_CLASS_LOCLISTPTR:
+  case MC_DW_CLASS_CONSTANT:
+    // Reference to location list:
+    variable->location = MC_dwarf_get_location_list(die, &attr_location);
     break;
   default:
-    xbt_die("Unexpected form %i list for location in <%p>%s",
-      form, (void*) variable->dwarf_offset, variable->name);
+    xbt_die("Unexpected calss 0x%x (%i) list for location in <%p>%s",
+      klass, klass, (void*) variable->dwarf_offset, variable->name);
+  }
+
+  // The current code needs a variable name,
+  // generate a fake one:
+  if(!variable->name) {
+    variable->name = bprintf("@anonymous#%i", mc_anonymous_variable_index++);
   }
 
   return variable;
@@ -686,7 +880,7 @@ 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 = (void*) MC_dwarf_attr_addr(die, DW_AT_high_pc);
   frame->low_pc = (void*) MC_dwarf_attr_addr(die, DW_AT_low_pc);
-  frame->frame_base = MC_dwarf_at_location(die, DW_AT_frame_base, info);
+  frame->frame_base = MC_dwarf_at_location(die, DW_AT_frame_base);
   frame->end = -1; // This one is now useless:
 
   // Handle children:
@@ -737,6 +931,7 @@ static void MC_dwarf_handle_die(mc_object_info_t info, Dwarf_Die* die, Dwarf_Die
       return;
     // case DW_TAG_formal_parameter:
     case DW_TAG_variable:
+    case DW_TAG_formal_parameter:
       MC_dwarf_handle_variable_die(info, die, unit, frame);
       break;
   }
@@ -745,7 +940,7 @@ static void MC_dwarf_handle_die(mc_object_info_t info, Dwarf_Die* die, Dwarf_Die
   MC_dwarf_handle_children(info, die, unit, frame);
 }
 
-void MC_dwarf_get_variables_libdw(mc_object_info_t info) {
+void MC_dwarf_get_variables(mc_object_info_t info) {
   int fd = open(info->file_name, O_RDONLY);
   if (fd<0) {
     xbt_die("Could not open file %s", info->file_name);
@@ -769,4 +964,3 @@ void MC_dwarf_get_variables_libdw(mc_object_info_t info) {
   dwarf_end(dwarf);
   close(fd);
 }
-