Linux DWARF reader: Follow DW_AT_abstract_origin links to find function names.

Without this patch, debugging information like the following will produce
FUNC records with no names, because the dumper (correctly) ignores the
DW_TAG_subprogram DIEs that lack DW_AT_low_pc/DW_AT_high_pc attributes, but
won't follow the DW_AT_abstract_origin link from the DIE that does have
code addresses to find its name.

 <1><168>: Abbrev Number: 5 (DW_TAG_class_type)
    <169>   DW_AT_name        : Foo	
 <2><183>: Abbrev Number: 7 (DW_TAG_subprogram)
    <185>   DW_AT_name        : Foo	
    <18b>   DW_AT_declaration : 1	
 <1><1b7>: Abbrev Number: 12 (DW_TAG_subprogram)
    <1b8>   DW_AT_specification: <0x183>	
    <1bc>   DW_AT_inline      : 2	(declared as inline but ignored)
 <1><1dc>: Abbrev Number: 16 (DW_TAG_subprogram)
    <1dd>   DW_AT_abstract_origin: <0x1b7>	
    <1e1>   DW_AT_low_pc      : 0x8048578	
    <1e5>   DW_AT_high_pc     : 0x8048588	

a=dmuir, r=jimblandy


git-svn-id: http://google-breakpad.googlecode.com/svn/trunk@520 4c0a9323-5329-0410-9bdc-e9ce6186880e

3 files changed, 256 insertions, 3 deletions

diff --git a/src/common/linux/dwarf_cu_to_module.cc b/src/common/linux/dwarf_cu_to_module.cc
index 3c339870..88cea940 100644
--- a/src/common/linux/dwarf_cu_to_module.cc
+++ b/src/common/linux/dwarf_cu_to_module.cc
@@ -68,6 +68,16 @@ struct DwarfCUToModule::Specification {
   string unqualified_name;
 };
 
+// An abstract origin -- base definition of an inline function.
+struct AbstractOrigin {
+  AbstractOrigin() : name() {}
+  AbstractOrigin(const string& name) : name(name) {}
+
+  string name;
+};
+
+typedef map<uint64, AbstractOrigin> AbstractOriginByOffset;
+
 // Data global to the DWARF-bearing file that is private to the
 // DWARF-to-Module process.
 struct DwarfCUToModule::FilePrivate {
@@ -75,6 +85,8 @@ struct DwarfCUToModule::FilePrivate {
   // Specifications describing those DIEs. Specification references can
   // cross compilation unit boundaries.
   SpecificationByOffset specifications;
+
+  AbstractOriginByOffset origins;
 };
 
 DwarfCUToModule::FileContext::FileContext(const string &filename_arg,
@@ -230,7 +242,7 @@ void DwarfCUToModule::GenericDIEHandler::ProcessAttributeReference(
         // don't think any producers we care about ever emit such
         // things.
         cu_context_->reporter->UnknownSpecification(offset_, data);
-      }        
+      }
       break;
     }
     default: break;
@@ -287,10 +299,17 @@ class DwarfCUToModule::FuncHandler: public GenericDIEHandler {
   FuncHandler(CUContext *cu_context, DIEContext *parent_context,
               uint64 offset)
       : GenericDIEHandler(cu_context, parent_context, offset),
-        low_pc_(0), high_pc_(0) { }
+        low_pc_(0), high_pc_(0), abstract_origin_(NULL), inline_(false) { }
   void ProcessAttributeUnsigned(enum DwarfAttribute attr,
                                 enum DwarfForm form,
                                 uint64 data);
+  void ProcessAttributeSigned(enum DwarfAttribute attr,
+                              enum DwarfForm form,
+                              int64 data);
+  void ProcessAttributeReference(enum DwarfAttribute attr,
+                                 enum DwarfForm form,
+                                 uint64 data);
+
   bool EndAttributes();
   void Finish();
 
@@ -299,6 +318,8 @@ class DwarfCUToModule::FuncHandler: public GenericDIEHandler {
   // specification_, parent_context_.  Computed in EndAttributes.
   string name_;
   uint64 low_pc_, high_pc_; // DW_AT_low_pc, DW_AT_high_pc
+  const AbstractOrigin* abstract_origin_;
+  bool inline_;
 };
 
 void DwarfCUToModule::FuncHandler::ProcessAttributeUnsigned(
@@ -306,6 +327,16 @@ void DwarfCUToModule::FuncHandler::ProcessAttributeUnsigned(
     enum DwarfForm form,
     uint64 data) {
   switch (attr) {
+    case dwarf2reader::DW_AT_inline:
+      switch(data) {
+        case dwarf2reader::DW_INL_inlined:
+        case dwarf2reader::DW_INL_declared_not_inlined:
+        case dwarf2reader::DW_INL_declared_inlined:
+          inline_  = true; break;
+        default:
+          break;
+      }
+      break;
     case dwarf2reader::DW_AT_low_pc:      low_pc_  = data; break;
     case dwarf2reader::DW_AT_high_pc:     high_pc_ = data; break;
     default:
@@ -314,9 +345,54 @@ void DwarfCUToModule::FuncHandler::ProcessAttributeUnsigned(
   }
 }
 
+void DwarfCUToModule::FuncHandler::ProcessAttributeSigned(
+    enum DwarfAttribute attr,
+    enum DwarfForm form,
+    int64 data) {
+  switch (attr) {
+    case dwarf2reader::DW_AT_inline:
+      switch(data) {
+        case dwarf2reader::DW_INL_inlined:
+        case dwarf2reader::DW_INL_declared_not_inlined:
+        case dwarf2reader::DW_INL_declared_inlined:
+          inline_ = true; break;
+        default:
+          break;
+      }
+      break;
+    default:
+      break;
+  }
+}
+
+void DwarfCUToModule::FuncHandler::ProcessAttributeReference(
+    enum DwarfAttribute attr,
+    enum DwarfForm form,
+    uint64 data) {
+  switch(attr) {
+    case dwarf2reader::DW_AT_abstract_origin: {
+      const AbstractOriginByOffset& origins =
+          cu_context_->file_context->file_private->origins;
+      AbstractOriginByOffset::const_iterator origin = origins.find(data);
+      if (origin != origins.end()) {
+        abstract_origin_ = &(origin->second);
+      } else {
+        cu_context_->reporter->UnknownAbstractOrigin(offset_, data);
+      }
+      break;
+    }
+    default:
+      GenericDIEHandler::ProcessAttributeReference(attr, form, data);
+      break;
+  }
+}
+
 bool DwarfCUToModule::FuncHandler::EndAttributes() {
   // Compute our name, and record a specification, if appropriate.
   name_ = ComputeQualifiedName();
+  if (name_.empty() && abstract_origin_) {
+    name_ = abstract_origin_->name;
+  }
   return true;
 }
 
@@ -334,6 +410,9 @@ void DwarfCUToModule::FuncHandler::Finish() {
     func->size = high_pc_ - low_pc_;
     func->parameter_size = 0;
     cu_context_->functions.push_back(func);
+  } else if (inline_) {
+    AbstractOrigin origin(name_);
+    cu_context_->file_context->file_private->origins[offset_] = origin;
   }
 }
 
@@ -391,6 +470,15 @@ void DwarfCUToModule::WarningReporter::UnknownSpecification(uint64 offset,
           filename_.c_str(), offset, target);
 }
 
+void DwarfCUToModule::WarningReporter::UnknownAbstractOrigin(uint64 offset,
+                                                             uint64 target) {
+  CUHeading();
+  fprintf(stderr, "%s: the DIE at offset 0x%llx has a DW_AT_abstract_origin"
+          " attribute referring to the die at offset 0x%llx, which either"
+          " was not marked as an inline, or comes later in the file",
+          filename_.c_str(), offset, target);
+}
+
 void DwarfCUToModule::WarningReporter::MissingSection(const string &name) {
   CUHeading();
   fprintf(stderr, "%s: warning: couldn't find DWARF '%s' section\n",
diff --git a/src/common/linux/dwarf_cu_to_module.h b/src/common/linux/dwarf_cu_to_module.h
index 9b33af9a..af330cff 100644
--- a/src/common/linux/dwarf_cu_to_module.h
+++ b/src/common/linux/dwarf_cu_to_module.h
@@ -130,7 +130,11 @@ class DwarfCUToModule: public dwarf2reader::RootDIEHandler {
     // haven't processed yet, or that wasn't marked as a declaration,
     // at TARGET.
     virtual void UnknownSpecification(uint64 offset, uint64 target);
-    
+
+    // A DW_AT_abstract_origin in the DIE at OFFSET refers to a DIE we
+    // haven't processed yet, or that wasn't marked as inline, at TARGET.
+    virtual void UnknownAbstractOrigin(uint64 offset, uint64 target);
+
     // We were unable to find the DWARF section named SECTION_NAME.
     virtual void MissingSection(const string &section_name);
 
diff --git a/src/common/linux/dwarf_cu_to_module_unittest.cc b/src/common/linux/dwarf_cu_to_module_unittest.cc
index d9e4ac0a..4e9062cf 100644
--- a/src/common/linux/dwarf_cu_to_module_unittest.cc
+++ b/src/common/linux/dwarf_cu_to_module_unittest.cc
@@ -43,6 +43,7 @@ using dwarf2reader::DIEHandler;
 using dwarf2reader::DwarfTag;
 using dwarf2reader::DwarfAttribute;
 using dwarf2reader::DwarfForm;
+using dwarf2reader::DwarfInline;
 using dwarf2reader::RootDIEHandler;
 using google_breakpad::DwarfCUToModule;
 using google_breakpad::Module;
@@ -74,6 +75,7 @@ class MockWarningReporter: public DwarfCUToModule::WarningReporter {
       : DwarfCUToModule::WarningReporter(filename, cu_offset) { }
   MOCK_METHOD1(SetCUName, void(const string &name));
   MOCK_METHOD2(UnknownSpecification, void(uint64 offset, uint64 target));
+  MOCK_METHOD2(UnknownAbstractOrigin, void(uint64 offset, uint64 target));
   MOCK_METHOD1(MissingSection, void(const string &section_name));
   MOCK_METHOD1(BadLineInfoOffset, void(uint64 offset));
   MOCK_METHOD1(UncoveredFunction, void(const Module::Function &function));
@@ -128,6 +130,7 @@ class CUFixtureBase {
     // these expectations.
     EXPECT_CALL(reporter_, SetCUName("compilation-unit-name")).Times(1);
     EXPECT_CALL(reporter_, UnknownSpecification(_, _)).Times(0);
+    EXPECT_CALL(reporter_, UnknownAbstractOrigin(_, _)).Times(0);
     EXPECT_CALL(reporter_, MissingSection(_)).Times(0);
     EXPECT_CALL(reporter_, BadLineInfoOffset(_)).Times(0);
     EXPECT_CALL(reporter_, UncoveredFunction(_)).Times(0);
@@ -210,6 +213,22 @@ class CUFixtureBase {
                      uint64 specification, const string &name,
                      Module::Address address = 0, Module::Address size = 0);
 
+  // Create an inline DW_TAG_subprogram DIE as a child of PARENT.  If
+  // SPECIFICATION is non-zero, then the DIE refers to the declaration DIE at
+  // offset SPECIFICATION as its specification.  If Name is non-empty, pass it
+  // as the DW_AT_name attribute.
+  void AbstractInstanceDIE(DIEHandler *parent, uint64 offset,
+                           DwarfInline type, uint64 specification,
+                           const string &name,
+                           DwarfForm form = dwarf2reader::DW_FORM_data1);
+
+  // Create a DW_TAG_subprogram DIE as a child of PARENT that refers to
+  // ORIGIN in its DW_AT_abstract_origin attribute.  If NAME is the empty
+  // string, don't provide a DW_AT_name attribute.
+  void DefineInlineInstanceDIE(DIEHandler *parent, const string &name,
+                               uint64 origin, Module::Address address,
+                               Module::Address size);
+
   // The following Test* functions should be called after calling
   // this.root_handler_.Finish. After that point, no further calls
   // should be made on the handler.
@@ -520,6 +539,83 @@ void CUFixtureBase::DefinitionDIE(DIEHandler *parent,
   delete die;
 }
 
+void CUFixtureBase::AbstractInstanceDIE(DIEHandler *parent,
+                                        uint64 offset,
+                                        DwarfInline type,
+                                        uint64 specification,
+                                        const string &name,
+                                        DwarfForm form) {
+  dwarf2reader::AttributeList attrs;
+  if (specification != 0ULL)
+    attrs.push_back(make_pair(dwarf2reader::DW_AT_specification,
+                              dwarf2reader::DW_FORM_ref4));
+  attrs.push_back(make_pair(dwarf2reader::DW_AT_inline, form));
+  if (!name.empty())
+    attrs.push_back(make_pair(dwarf2reader::DW_AT_name,
+                              dwarf2reader::DW_FORM_strp));
+  dwarf2reader::DIEHandler *die
+    = parent->FindChildHandler(offset, dwarf2reader::DW_TAG_subprogram, attrs);
+  ASSERT_TRUE(die != NULL);
+  if (specification != 0ULL)
+    die->ProcessAttributeReference(dwarf2reader::DW_AT_specification,
+                                   dwarf2reader::DW_FORM_ref4,
+                                   specification);
+  if (form == dwarf2reader::DW_FORM_sdata) {
+    die->ProcessAttributeSigned(dwarf2reader::DW_AT_inline, form, type);
+  } else {
+    die->ProcessAttributeUnsigned(dwarf2reader::DW_AT_inline, form, type);
+  }
+  if (!name.empty())
+    die->ProcessAttributeString(dwarf2reader::DW_AT_name,
+                                dwarf2reader::DW_FORM_strp,
+                                name);
+
+  EXPECT_TRUE(die->EndAttributes());
+  die->Finish();
+  delete die;
+}
+
+void CUFixtureBase::DefineInlineInstanceDIE(DIEHandler *parent,
+                                            const string &name,
+                                            uint64 origin, 
+                                            Module::Address address,
+                                            Module::Address size) {
+  dwarf2reader::AttributeList func_attrs;
+  if (!name.empty())
+    func_attrs.push_back(make_pair(dwarf2reader::DW_AT_name,
+                                   dwarf2reader::DW_FORM_strp));
+  func_attrs.push_back(make_pair(dwarf2reader::DW_AT_low_pc,
+                                 dwarf2reader::DW_FORM_addr));
+  func_attrs.push_back(make_pair(dwarf2reader::DW_AT_high_pc,
+                                 dwarf2reader::DW_FORM_addr));
+  func_attrs.push_back(make_pair(dwarf2reader::DW_AT_abstract_origin,
+                                 dwarf2reader::DW_FORM_ref4));
+  PushBackStrangeAttributes(&func_attrs);
+  dwarf2reader::DIEHandler *func
+      = parent->FindChildHandler(0x11c70f94c6e87ccdLL,
+                                 dwarf2reader::DW_TAG_subprogram,
+                                 func_attrs);
+  ASSERT_TRUE(func != NULL);
+  if (!name.empty()) {
+    func->ProcessAttributeString(dwarf2reader::DW_AT_name,
+                                 dwarf2reader::DW_FORM_strp,
+                                 name);
+  }
+  func->ProcessAttributeUnsigned(dwarf2reader::DW_AT_low_pc,
+                                 dwarf2reader::DW_FORM_addr,
+                                 address);
+  func->ProcessAttributeUnsigned(dwarf2reader::DW_AT_high_pc,
+                                 dwarf2reader::DW_FORM_addr,
+                                 address + size);
+  func->ProcessAttributeReference(dwarf2reader::DW_AT_abstract_origin,
+                                 dwarf2reader::DW_FORM_ref4,
+                                 origin);
+  ProcessStrangeAttributes(func);
+  EXPECT_TRUE(func->EndAttributes());
+  func->Finish();
+  delete func;
+}
+
 void CUFixtureBase::FillFunctions() {
   if (functions_filled_)
     return;
@@ -629,6 +725,53 @@ TEST_F(Simple, UnusedFileContext) {
   reporter_.SetCUName("compilation-unit-name");
 }
 
+TEST_F(Simple, InlineFunction) {
+  PushLine(0x1758a0f941b71efbULL, 0x1cf154f1f545e146ULL, "line-file", 75173118);
+
+  StartCU();
+  AbstractInstanceDIE(&root_handler_, 0x1e8dac5d507ed7abULL,
+                      dwarf2reader::DW_INL_inlined, 0, "inline-name");
+  DefineInlineInstanceDIE(&root_handler_, "", 0x1e8dac5d507ed7abULL,
+                       0x1758a0f941b71efbULL, 0x1cf154f1f545e146ULL);
+  root_handler_.Finish();
+
+  TestFunctionCount(1);
+  TestFunction(0, "inline-name",
+               0x1758a0f941b71efbULL, 0x1cf154f1f545e146ULL);
+}
+
+TEST_F(Simple, InlineFunctionSignedAttribute) {
+  PushLine(0x1758a0f941b71efbULL, 0x1cf154f1f545e146ULL, "line-file", 75173118);
+
+  StartCU();
+  AbstractInstanceDIE(&root_handler_, 0x1e8dac5d507ed7abULL,
+                      dwarf2reader::DW_INL_inlined, 0, "inline-name",
+                      dwarf2reader::DW_FORM_sdata);
+  DefineInlineInstanceDIE(&root_handler_, "", 0x1e8dac5d507ed7abULL,
+                       0x1758a0f941b71efbULL, 0x1cf154f1f545e146ULL);
+  root_handler_.Finish();
+
+  TestFunctionCount(1);
+  TestFunction(0, "inline-name",
+               0x1758a0f941b71efbULL, 0x1cf154f1f545e146ULL);
+}
+
+TEST_F(Simple, UnknownAbstractOrigin) {
+  EXPECT_CALL(reporter_, UnknownAbstractOrigin(_, 1ULL)).WillOnce(Return());
+  PushLine(0x1758a0f941b71efbULL, 0x1cf154f1f545e146ULL, "line-file", 75173118);
+
+  StartCU();
+  AbstractInstanceDIE(&root_handler_, 0x1e8dac5d507ed7abULL,
+                      dwarf2reader::DW_INL_inlined, 0, "inline-name");
+  DefineInlineInstanceDIE(&root_handler_, "", 1ULL,
+                       0x1758a0f941b71efbULL, 0x1cf154f1f545e146ULL);
+  root_handler_.Finish();
+
+  TestFunctionCount(1);
+  TestFunction(0, "",
+               0x1758a0f941b71efbULL, 0x1cf154f1f545e146ULL);
+}
+
 // An address range.
 struct Range {
   Module::Address start, end;
@@ -1114,6 +1257,24 @@ TEST_F(Specifications, NamedScopeDeclarationParent) {
                0x5d13433d0df13d00ULL, 0x48ebebe5ade2cab4ULL);
 }
 
+// This test recreates bug 364.
+TEST_F(Specifications, InlineFunction) {
+  PushLine(0x1758a0f941b71efbULL, 0x1cf154f1f545e146ULL, "line-file", 75173118);
+
+  StartCU();
+  DeclarationDIE(&root_handler_, 0xcd3c51b946fb1eeeLL,
+                 dwarf2reader::DW_TAG_subprogram, "inline-name");
+  AbstractInstanceDIE(&root_handler_, 0x1e8dac5d507ed7abULL,
+                      dwarf2reader::DW_INL_inlined, 0xcd3c51b946fb1eeeLL, "");
+  DefineInlineInstanceDIE(&root_handler_, "", 0x1e8dac5d507ed7abULL,
+                       0x1758a0f941b71efbULL, 0x1cf154f1f545e146ULL);
+  root_handler_.Finish();
+
+  TestFunctionCount(1);
+  TestFunction(0, "inline-name",
+               0x1758a0f941b71efbULL, 0x1cf154f1f545e146ULL);
+}
+
 // Check name construction for a long chain containing each combination of:
 // - struct, union, class, namespace
 // - direct and definition