Use DW_AT_MIPS_linkage_name if it is available to get names of functions with arguments during symbol dumping.

A=Rafael Ávila de Espíndola <respindola@mozilla.com> R=ted at https://breakpad.appspot.com/457002/

git-svn-id: http://google-breakpad.googlecode.com/svn/trunk@1059 4c0a9323-5329-0410-9bdc-e9ce6186880e

2 files changed, 79 insertions, 34 deletions

diff --git a/src/common/dwarf_cu_to_module.cc b/src/common/dwarf_cu_to_module.cc
index ded5f83c..ef2489c8 100644
--- a/src/common/dwarf_cu_to_module.cc
+++ b/src/common/dwarf_cu_to_module.cc
@@ -39,6 +39,7 @@
 #include "common/dwarf_cu_to_module.h"
 
 #include <assert.h>
+#include <cxxabi.h>
 #include <inttypes.h>
 #include <stdio.h>
 
@@ -56,7 +57,7 @@ using std::set;
 using std::vector;
 
 // Data provided by a DWARF specification DIE.
-// 
+//
 // In DWARF, the DIE for a definition may contain a DW_AT_specification
 // attribute giving the offset of the corresponding declaration DIE, and
 // the definition DIE may omit information given in the declaration. For
@@ -218,6 +219,14 @@ class DwarfCUToModule::GenericDIEHandler: public dwarf2reader::DIEHandler {
   DIEContext *parent_context_;
   uint64 offset_;
 
+  // Place the name in the global set of strings. Even though this looks
+  // like a copy, all the major std::string implementations use reference
+  // counting internally, so the effect is to have all the data structures
+  // share copies of strings whenever possible.
+  // FIXME: Should this return something like a string_ref to avoid the
+  // assumption about how strings are implemented?
+  string AddStringToPool(const string &str);
+
   // If this DIE has a DW_AT_declaration attribute, this is its value.
   // It is false on DIEs with no DW_AT_declaration attribute.
   bool declaration_;
@@ -230,6 +239,11 @@ class DwarfCUToModule::GenericDIEHandler: public dwarf2reader::DIEHandler {
   // The value of the DW_AT_name attribute, or the empty string if the
   // DIE has no such attribute.
   string name_attribute_;
+
+  // The demangled value of the DW_AT_MIPS_linkage_name attribute, or the empty
+  // string if the DIE has no such attribute or its content could not be
+  // demangled.
+  string demangled_name_;
 };
 
 void DwarfCUToModule::GenericDIEHandler::ProcessAttributeUnsigned(
@@ -273,20 +287,26 @@ void DwarfCUToModule::GenericDIEHandler::ProcessAttributeReference(
   }
 }
 
+string DwarfCUToModule::GenericDIEHandler::AddStringToPool(const string &str) {
+  pair<set<string>::iterator, bool> result =
+    cu_context_->file_context->file_private->common_strings.insert(str);
+  return *result.first;
+}
+
 void DwarfCUToModule::GenericDIEHandler::ProcessAttributeString(
     enum DwarfAttribute attr,
     enum DwarfForm form,
     const string &data) {
   switch (attr) {
-    case dwarf2reader::DW_AT_name: {
-      // Place the name in our global set of strings, and then use the
-      // string from the set. Even though the assignment looks like a copy,
-      // all the major std::string implementations use reference counting
-      // internally, so the effect is to have all our data structures share
-      // copies of strings whenever possible.
-      pair<set<string>::iterator, bool> result =
-          cu_context_->file_context->file_private->common_strings.insert(data);
-      name_attribute_ = *result.first; 
+    case dwarf2reader::DW_AT_name:
+      name_attribute_ = AddStringToPool(data);
+      break;
+    case dwarf2reader::DW_AT_MIPS_linkage_name: {
+      char* demangled = abi::__cxa_demangle(data.c_str(), NULL, NULL, NULL);
+      if (demangled) {
+        demangled_name_ = AddStringToPool(demangled);
+        free(reinterpret_cast<void*>(demangled));
+      }
       break;
     }
     default: break;
@@ -294,6 +314,11 @@ void DwarfCUToModule::GenericDIEHandler::ProcessAttributeString(
 }
 
 string DwarfCUToModule::GenericDIEHandler::ComputeQualifiedName() {
+  // Use DW_AT_MIPS_linkage_name if it is available. It is already qualified,
+  // so there is no need to add enclosing_name.
+  if (!demangled_name_.empty())
+    return demangled_name_;
+
   // Find our unqualified name. If the DIE has its own DW_AT_name
   // attribute, then use that; otherwise, check our specification.
   const string *unqualified_name;
diff --git a/src/common/dwarf_cu_to_module_unittest.cc b/src/common/dwarf_cu_to_module_unittest.cc
index 94259b61..93d27d98 100644
--- a/src/common/dwarf_cu_to_module_unittest.cc
+++ b/src/common/dwarf_cu_to_module_unittest.cc
@@ -202,7 +202,8 @@ class CUFixtureBase {
   // address, and size. Call EndAttributes and Finish; one cannot
   // define children of the defined function's DIE.
   void DefineFunction(DIEHandler *parent, const string &name,
-                      Module::Address address, Module::Address size);      
+                      Module::Address address, Module::Address size,
+                      const char* mangled_name);
 
   // Create a declaration DIE as a child of PARENT with the given
   // offset, tag and name. If NAME is the empty string, don't provide
@@ -452,7 +453,8 @@ DIEHandler *CUFixtureBase::StartSpecifiedDIE(DIEHandler *parent,
 
 void CUFixtureBase::DefineFunction(dwarf2reader::DIEHandler *parent,
                                    const string &name, Module::Address address,
-                                   Module::Address size) {
+                                   Module::Address size,
+                                   const char* mangled_name) {
   dwarf2reader::AttributeList func_attrs;
   func_attrs.push_back(make_pair(dwarf2reader::DW_AT_name,
                                  dwarf2reader::DW_FORM_strp));
@@ -475,6 +477,11 @@ void CUFixtureBase::DefineFunction(dwarf2reader::DIEHandler *parent,
   func->ProcessAttributeUnsigned(dwarf2reader::DW_AT_high_pc,
                                  dwarf2reader::DW_FORM_addr,
                                  address + size);
+  if (mangled_name)
+    func->ProcessAttributeString(dwarf2reader::DW_AT_MIPS_linkage_name,
+                                 dwarf2reader::DW_FORM_strp,
+                                 mangled_name);
+
   ProcessStrangeAttributes(func);
   EXPECT_TRUE(func->EndAttributes());
   func->Finish();
@@ -675,7 +682,7 @@ void CUFixtureBase::TestLine(int i, int j,
 #define PushLine(a,b,c,d)          TRACE(PushLine((a),(b),(c),(d)))
 #define SetLanguage(a)             TRACE(SetLanguage(a))
 #define StartCU()                  TRACE(StartCU())
-#define DefineFunction(a,b,c,d)    TRACE(DefineFunction((a),(b),(c),(d)))
+#define DefineFunction(a,b,c,d,e)  TRACE(DefineFunction((a),(b),(c),(d),(e)))
 #define DeclarationDIE(a,b,c,d)    TRACE(DeclarationDIE((a),(b),(c),(d)))
 #define DefinitionDIE(a,b,c,d,e,f) TRACE(DefinitionDIE((a),(b),(c),(d),(e),(f)))
 #define TestFunctionCount(a)       TRACE(TestFunctionCount(a))
@@ -691,7 +698,7 @@ TEST_F(SimpleCU, OneFunc) {
 
   StartCU();
   DefineFunction(&root_handler_, "function1",
-                 0x938cf8c07def4d34ULL, 0x55592d727f6cd01fLL);
+                 0x938cf8c07def4d34ULL, 0x55592d727f6cd01fLL, NULL);
   root_handler_.Finish();
 
   TestFunctionCount(1);
@@ -701,6 +708,18 @@ TEST_F(SimpleCU, OneFunc) {
            246571772);
 }
 
+TEST_F(SimpleCU, MangledName) {
+  PushLine(0x938cf8c07def4d34ULL, 0x55592d727f6cd01fLL, "line-file", 246571772);
+
+  StartCU();
+  DefineFunction(&root_handler_, "function1",
+                 0x938cf8c07def4d34ULL, 0x55592d727f6cd01fLL, "_ZN1n1fEi");
+  root_handler_.Finish();
+
+  TestFunctionCount(1);
+  TestFunction(0, "n::f(int)", 0x938cf8c07def4d34ULL, 0x55592d727f6cd01fLL);
+}
+
 TEST_F(SimpleCU, IrrelevantRootChildren) {
   StartCU();
   dwarf2reader::AttributeList no_attrs;
@@ -805,7 +824,7 @@ TEST_F(SimpleCU, UnnamedFunction) {
 
   StartCU();
   DefineFunction(&root_handler_, "",
-                 0x72b80e41a0ac1d40ULL, 0x537174f231ee181cULL);
+                 0x72b80e41a0ac1d40ULL, 0x537174f231ee181cULL, NULL);
   root_handler_.Finish();
 
   TestFunctionCount(1);
@@ -882,10 +901,10 @@ TEST_P(FuncLinePairing, Pairing) {
   StartCU();
   DefineFunction(&root_handler_, "function1",
                  s.functions[0].start, 
-                 s.functions[0].end - s.functions[0].start);
+                 s.functions[0].end - s.functions[0].start, NULL);
   DefineFunction(&root_handler_, "function2",
                  s.functions[1].start, 
-                 s.functions[1].end - s.functions[1].start);
+                 s.functions[1].end - s.functions[1].start, NULL);
   root_handler_.Finish();
 
   TestFunctionCount(2);
@@ -929,7 +948,8 @@ TEST_F(FuncLinePairing, FuncsNoLines) {
   EXPECT_CALL(reporter_, UncoveredFunction(_)).WillOnce(Return());
 
   StartCU();
-  DefineFunction(&root_handler_, "function1", 0x127da12ffcf5c51fULL, 0x1000U);
+  DefineFunction(&root_handler_, "function1", 0x127da12ffcf5c51fULL, 0x1000U,
+		 NULL);
   root_handler_.Finish();
 
   TestFunctionCount(1);
@@ -941,8 +961,8 @@ TEST_F(FuncLinePairing, GapThenFunction) {
   PushLine(10, 2, "line-file-1", 263008005);
 
   StartCU();
-  DefineFunction(&root_handler_, "function1", 10, 2);
-  DefineFunction(&root_handler_, "function2", 20, 2);
+  DefineFunction(&root_handler_, "function1", 10, 2, NULL);
+  DefineFunction(&root_handler_, "function2", 20, 2, NULL);
   root_handler_.Finish();
 
   TestFunctionCount(2);
@@ -967,10 +987,10 @@ TEST_F(FuncLinePairing, GCCAlignmentStretch) {
   PushLine(20, 10, "line-file", 61661044);
 
   StartCU();
-  DefineFunction(&root_handler_, "function1", 10, 5);
+  DefineFunction(&root_handler_, "function1", 10, 5, NULL);
   // five-byte gap between functions, covered by line 63351048.
   // This should not elicit a warning.
-  DefineFunction(&root_handler_, "function2", 20, 10);
+  DefineFunction(&root_handler_, "function2", 20, 10, NULL);
   root_handler_.Finish();
 
   TestFunctionCount(2);
@@ -991,8 +1011,8 @@ TEST_F(FuncLinePairing, LineAtEndOfAddressSpace) {
   EXPECT_CALL(reporter_, UncoveredLine(_)).WillOnce(Return());
 
   StartCU();
-  DefineFunction(&root_handler_, "function1", 0xfffffffffffffff0ULL, 6);
-  DefineFunction(&root_handler_, "function2", 0xfffffffffffffffaULL, 5);
+  DefineFunction(&root_handler_, "function1", 0xfffffffffffffff0ULL, 6, NULL);
+  DefineFunction(&root_handler_, "function2", 0xfffffffffffffffaULL, 5, NULL);
   root_handler_.Finish();
 
   TestFunctionCount(2);
@@ -1012,7 +1032,7 @@ TEST_F(FuncLinePairing, WarnOnceFunc) {
   EXPECT_CALL(reporter_, UncoveredFunction(_)).WillOnce(Return());
 
   StartCU();
-  DefineFunction(&root_handler_, "function", 10, 11);
+  DefineFunction(&root_handler_, "function", 10, 11, NULL);
   root_handler_.Finish();
 
   TestFunctionCount(1);
@@ -1029,8 +1049,8 @@ TEST_F(FuncLinePairing, WarnOnceLine) {
   EXPECT_CALL(reporter_, UncoveredLine(_)).WillOnce(Return());
 
   StartCU();
-  DefineFunction(&root_handler_, "function1", 11, 1);
-  DefineFunction(&root_handler_, "function2", 13, 1);
+  DefineFunction(&root_handler_, "function1", 11, 1, NULL);
+  DefineFunction(&root_handler_, "function2", 13, 1, NULL);
   root_handler_.Finish();
 
   TestFunctionCount(2);
@@ -1062,8 +1082,8 @@ TEST_P(CXXQualifiedNames, TwoFunctions) {
   DIEHandler *enclosure_handler = StartNamedDIE(&root_handler_, tag,
                                                 "Enclosure");
   EXPECT_TRUE(enclosure_handler != NULL);
-  DefineFunction(enclosure_handler, "func_B", 10, 1);
-  DefineFunction(enclosure_handler, "func_C", 20, 1);
+  DefineFunction(enclosure_handler, "func_B", 10, 1, NULL);
+  DefineFunction(enclosure_handler, "func_C", 20, 1, NULL);
   enclosure_handler->Finish();
   delete enclosure_handler;
   root_handler_.Finish();
@@ -1087,7 +1107,7 @@ TEST_P(CXXQualifiedNames, FuncInEnclosureInNamespace) {
   DIEHandler *enclosure_handler = StartNamedDIE(namespace_handler, tag, 
                                                 "Enclosure");
   EXPECT_TRUE(enclosure_handler != NULL);
-  DefineFunction(enclosure_handler, "function", 10, 1);
+  DefineFunction(enclosure_handler, "function", 10, 1, NULL);
   enclosure_handler->Finish();
   delete enclosure_handler;
   namespace_handler->Finish();
@@ -1114,7 +1134,7 @@ TEST_F(CXXQualifiedNames, FunctionInClassInStructInNamespace) {
   DIEHandler *class_handler
       = StartNamedDIE(struct_handler, dwarf2reader::DW_TAG_class_type,
                       "class_C");
-  DefineFunction(class_handler, "function_D", 10, 1);
+  DefineFunction(class_handler, "function_D", 10, 1, NULL);
   class_handler->Finish();
   delete class_handler;
   struct_handler->Finish();
@@ -1160,7 +1180,7 @@ TEST_P(QualifiedForLanguage, MemberFunction) {
   DIEHandler *class_handler
       = StartNamedDIE(&root_handler_, dwarf2reader::DW_TAG_class_type,
                       "class_A");
-  DefineFunction(class_handler, "function_B", 10, 1);
+  DefineFunction(class_handler, "function_B", 10, 1, NULL);
   class_handler->Finish();
   delete class_handler;
   root_handler_.Finish();
@@ -1184,7 +1204,7 @@ TEST_P(QualifiedForLanguage, MemberFunctionSignedLanguage) {
   DIEHandler *class_handler
       = StartNamedDIE(&root_handler_, dwarf2reader::DW_TAG_class_type,
                       "class_A");
-  DefineFunction(class_handler, "function_B", 10, 1);
+  DefineFunction(class_handler, "function_B", 10, 1, NULL);
   class_handler->Finish();
   delete class_handler;
   root_handler_.Finish();
@@ -1286,7 +1306,7 @@ TEST_F(Specifications, NamedScopeDeclarationParent) {
                           0x419bb1d12f9a73a2ULL, "class-definition-name");
     ASSERT_TRUE(class_handler != NULL);
     DefineFunction(class_handler, "function", 
-                   0x5d13433d0df13d00ULL, 0x48ebebe5ade2cab4ULL);
+                   0x5d13433d0df13d00ULL, 0x48ebebe5ade2cab4ULL, NULL);
     class_handler->Finish();
     delete class_handler;
   }