diff options
Diffstat (limited to 'toolkit/crashreporter/google-breakpad/src/common/dwarf_cu_to_module.cc')
| -rw-r--r-- | toolkit/crashreporter/google-breakpad/src/common/dwarf_cu_to_module.cc | 1075 |
1 files changed, 0 insertions, 1075 deletions
diff --git a/toolkit/crashreporter/google-breakpad/src/common/dwarf_cu_to_module.cc b/toolkit/crashreporter/google-breakpad/src/common/dwarf_cu_to_module.cc deleted file mode 100644 index 479e39b22..000000000 --- a/toolkit/crashreporter/google-breakpad/src/common/dwarf_cu_to_module.cc +++ /dev/null @@ -1,1075 +0,0 @@ -// Copyright (c) 2010 Google Inc. -// All rights reserved. -// -// Redistribution and use in source and binary forms, with or without -// modification, are permitted provided that the following conditions are -// met: -// -// * Redistributions of source code must retain the above copyright -// notice, this list of conditions and the following disclaimer. -// * Redistributions in binary form must reproduce the above -// copyright notice, this list of conditions and the following disclaimer -// in the documentation and/or other materials provided with the -// distribution. -// * Neither the name of Google Inc. nor the names of its -// contributors may be used to endorse or promote products derived from -// this software without specific prior written permission. -// -// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS -// "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT -// LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR -// A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT -// OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, -// SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT -// LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, -// DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY -// THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT -// (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE -// OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. - -// Original author: Jim Blandy <jimb@mozilla.com> <jimb@red-bean.com> - -// Implement the DwarfCUToModule class; see dwarf_cu_to_module.h. - -// For <inttypes.h> PRI* macros, before anything else might #include it. -#ifndef __STDC_FORMAT_MACROS -#define __STDC_FORMAT_MACROS -#endif /* __STDC_FORMAT_MACROS */ - -#include "common/dwarf_cu_to_module.h" - -#include <assert.h> -#if !defined(__ANDROID__) -#include <cxxabi.h> -#endif -#include <inttypes.h> -#include <stdint.h> -#include <stdio.h> - -#include <algorithm> -#include <utility> - -#include "common/dwarf_line_to_module.h" -#include "common/unordered.h" - -namespace google_breakpad { - -using std::map; -using std::pair; -using std::sort; -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 -// example, it's common for a function's address range to appear only in -// its definition DIE, but its name to appear only in its declaration -// DIE. -// -// The dumper needs to be able to follow DW_AT_specification links to -// bring all this information together in a FUNC record. Conveniently, -// DIEs that are the target of such links have a DW_AT_declaration flag -// set, so we can identify them when we first see them, and record their -// contents for later reference. -// -// A Specification holds information gathered from a declaration DIE that -// we may need if we find a DW_AT_specification link pointing to it. -struct DwarfCUToModule::Specification { - // The qualified name that can be found by demangling DW_AT_MIPS_linkage_name. - string qualified_name; - - // The name of the enclosing scope, or the empty string if there is none. - string enclosing_name; - - // The name for the specification DIE itself, without any enclosing - // name components. - string unqualified_name; -}; - -// An abstract origin -- base definition of an inline function. -struct AbstractOrigin { - AbstractOrigin() : name() {} - explicit 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 { - // A set of strings used in this CU. Before storing a string in one of - // our data structures, insert it into this set, and then use the string - // from the set. - // - // In some STL implementations, strings are reference-counted internally, - // meaning that simply using strings from this set, even if passed by - // value, assigned, or held directly in structures and containers - // (map<string, ...>, for example), causes those strings to share a - // single instance of each distinct piece of text. GNU's libstdc++ uses - // reference counts, and I believe MSVC did as well, at some point. - // However, C++ '11 implementations are moving away from reference - // counting. - // - // In other implementations, string assignments copy the string's text, - // so this set will actually hold yet another copy of the string (although - // everything will still work). To improve memory consumption portably, - // we will probably need to use pointers to strings held in this set. - unordered_set<string> common_strings; - - // A map from offsets of DIEs within the .debug_info section to - // Specifications describing those DIEs. Specification references can - // cross compilation unit boundaries. - SpecificationByOffset specifications; - - AbstractOriginByOffset origins; -}; - -DwarfCUToModule::FileContext::FileContext(const string &filename, - Module *module, - bool handle_inter_cu_refs) - : filename_(filename), - module_(module), - handle_inter_cu_refs_(handle_inter_cu_refs), - file_private_(new FilePrivate()) { -} - -DwarfCUToModule::FileContext::~FileContext() { -} - -void DwarfCUToModule::FileContext::AddSectionToSectionMap( - const string& name, const uint8_t *contents, uint64 length) { - section_map_[name] = std::make_pair(contents, length); -} - -void DwarfCUToModule::FileContext::ClearSectionMapForTest() { - section_map_.clear(); -} - -const dwarf2reader::SectionMap& -DwarfCUToModule::FileContext::section_map() const { - return section_map_; -} - -void DwarfCUToModule::FileContext::ClearSpecifications() { - if (!handle_inter_cu_refs_) - file_private_->specifications.clear(); -} - -bool DwarfCUToModule::FileContext::IsUnhandledInterCUReference( - uint64 offset, uint64 compilation_unit_start) const { - if (handle_inter_cu_refs_) - return false; - return offset < compilation_unit_start; -} - -// Information global to the particular compilation unit we're -// parsing. This is for data shared across the CU's entire DIE tree, -// and parameters from the code invoking the CU parser. -struct DwarfCUToModule::CUContext { - CUContext(FileContext *file_context_arg, WarningReporter *reporter_arg) - : file_context(file_context_arg), - reporter(reporter_arg), - language(Language::CPlusPlus) {} - - ~CUContext() { - for (vector<Module::Function *>::iterator it = functions.begin(); - it != functions.end(); ++it) { - delete *it; - } - }; - - // The DWARF-bearing file into which this CU was incorporated. - FileContext *file_context; - - // For printing error messages. - WarningReporter *reporter; - - // The source language of this compilation unit. - const Language *language; - - // The functions defined in this compilation unit. We accumulate - // them here during parsing. Then, in DwarfCUToModule::Finish, we - // assign them lines and add them to file_context->module. - // - // Destroying this destroys all the functions this vector points to. - vector<Module::Function *> functions; -}; - -// Information about the context of a particular DIE. This is for -// information that changes as we descend the tree towards the leaves: -// the containing classes/namespaces, etc. -struct DwarfCUToModule::DIEContext { - // The fully-qualified name of the context. For example, for a - // tree like: - // - // DW_TAG_namespace Foo - // DW_TAG_class Bar - // DW_TAG_subprogram Baz - // - // in a C++ compilation unit, the DIEContext's name for the - // DW_TAG_subprogram DIE would be "Foo::Bar". The DIEContext's - // name for the DW_TAG_namespace DIE would be "". - string name; -}; - -// An abstract base class for all the dumper's DIE handlers. -class DwarfCUToModule::GenericDIEHandler: public dwarf2reader::DIEHandler { - public: - // Create a handler for the DIE at OFFSET whose compilation unit is - // described by CU_CONTEXT, and whose immediate context is described - // by PARENT_CONTEXT. - GenericDIEHandler(CUContext *cu_context, DIEContext *parent_context, - uint64 offset) - : cu_context_(cu_context), - parent_context_(parent_context), - offset_(offset), - declaration_(false), - specification_(NULL) { } - - // Derived classes' ProcessAttributeUnsigned can defer to this to - // handle DW_AT_declaration, or simply not override it. - void ProcessAttributeUnsigned(enum DwarfAttribute attr, - enum DwarfForm form, - uint64 data); - - // Derived classes' ProcessAttributeReference can defer to this to - // handle DW_AT_specification, or simply not override it. - void ProcessAttributeReference(enum DwarfAttribute attr, - enum DwarfForm form, - uint64 data); - - // Derived classes' ProcessAttributeReference can defer to this to - // handle DW_AT_specification, or simply not override it. - void ProcessAttributeString(enum DwarfAttribute attr, - enum DwarfForm form, - const string &data); - - protected: - // Compute and return the fully-qualified name of the DIE. If this - // DIE is a declaration DIE, to be cited by other DIEs' - // DW_AT_specification attributes, record its enclosing name and - // unqualified name in the specification table. - // - // Use this from EndAttributes member functions, not ProcessAttribute* - // functions; only the former can be sure that all the DIE's attributes - // have been seen. - string ComputeQualifiedName(); - - CUContext *cu_context_; - 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_; - - // If this DIE has a DW_AT_specification attribute, this is the - // Specification structure for the DIE the attribute refers to. - // Otherwise, this is NULL. - Specification *specification_; - - // 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( - enum DwarfAttribute attr, - enum DwarfForm form, - uint64 data) { - switch (attr) { - case dwarf2reader::DW_AT_declaration: declaration_ = (data != 0); break; - default: break; - } -} - -void DwarfCUToModule::GenericDIEHandler::ProcessAttributeReference( - enum DwarfAttribute attr, - enum DwarfForm form, - uint64 data) { - switch (attr) { - case dwarf2reader::DW_AT_specification: { - FileContext *file_context = cu_context_->file_context; - if (file_context->IsUnhandledInterCUReference( - data, cu_context_->reporter->cu_offset())) { - cu_context_->reporter->UnhandledInterCUReference(offset_, data); - break; - } - // Find the Specification to which this attribute refers, and - // set specification_ appropriately. We could do more processing - // here, but it's better to leave the real work to our - // EndAttribute member function, at which point we know we have - // seen all the DIE's attributes. - SpecificationByOffset *specifications = - &file_context->file_private_->specifications; - SpecificationByOffset::iterator spec = specifications->find(data); - if (spec != specifications->end()) { - specification_ = &spec->second; - } else { - // Technically, there's no reason a DW_AT_specification - // couldn't be a forward reference, but supporting that would - // be a lot of work (changing to a two-pass structure), and I - // don't think any producers we care about ever emit such - // things. - cu_context_->reporter->UnknownSpecification(offset_, data); - } - break; - } - default: break; - } -} - -string DwarfCUToModule::GenericDIEHandler::AddStringToPool(const string &str) { - pair<unordered_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: - name_attribute_ = AddStringToPool(data); - break; - case dwarf2reader::DW_AT_MIPS_linkage_name: { - char* demangled = NULL; - int status = -1; -#if !defined(__ANDROID__) // Android NDK doesn't provide abi::__cxa_demangle. - demangled = abi::__cxa_demangle(data.c_str(), NULL, NULL, &status); -#endif - if (status != 0) { - cu_context_->reporter->DemangleError(data, status); - demangled_name_ = ""; - break; - } - if (demangled) { - demangled_name_ = AddStringToPool(demangled); - free(reinterpret_cast<void*>(demangled)); - } - break; - } - default: break; - } -} - -string DwarfCUToModule::GenericDIEHandler::ComputeQualifiedName() { - // Use the demangled name, if one is available. Demangled names are - // preferable to those inferred from the DWARF structure because they - // include argument types. - const string *qualified_name = NULL; - if (!demangled_name_.empty()) { - // Found it is this DIE. - qualified_name = &demangled_name_; - } else if (specification_ && !specification_->qualified_name.empty()) { - // Found it on the specification. - qualified_name = &specification_->qualified_name; - } - - const string *unqualified_name = NULL; - const string *enclosing_name; - if (!qualified_name) { - // Find the unqualified name. If the DIE has its own DW_AT_name - // attribute, then use that; otherwise, check the specification. - if (!name_attribute_.empty()) - unqualified_name = &name_attribute_; - else if (specification_) - unqualified_name = &specification_->unqualified_name; - - // Find the name of the enclosing context. If this DIE has a - // specification, it's the specification's enclosing context that - // counts; otherwise, use this DIE's context. - if (specification_) - enclosing_name = &specification_->enclosing_name; - else - enclosing_name = &parent_context_->name; - } - - // Prepare the return value before upcoming mutations possibly invalidate the - // existing pointers. - string return_value; - if (qualified_name) { - return_value = *qualified_name; - } else if (unqualified_name && enclosing_name) { - // Combine the enclosing name and unqualified name to produce our - // own fully-qualified name. - return_value = cu_context_->language->MakeQualifiedName(*enclosing_name, - *unqualified_name); - } - - // If this DIE was marked as a declaration, record its names in the - // specification table. - if ((declaration_ && qualified_name) || - (unqualified_name && enclosing_name)) { - Specification spec; - if (qualified_name) { - spec.qualified_name = *qualified_name; - } else { - spec.enclosing_name = *enclosing_name; - spec.unqualified_name = *unqualified_name; - } - cu_context_->file_context->file_private_->specifications[offset_] = spec; - } - - return return_value; -} - -// A handler class for DW_TAG_subprogram DIEs. -class DwarfCUToModule::FuncHandler: public GenericDIEHandler { - public: - FuncHandler(CUContext *cu_context, DIEContext *parent_context, - uint64 offset) - : GenericDIEHandler(cu_context, parent_context, offset), - low_pc_(0), high_pc_(0), high_pc_form_(dwarf2reader::DW_FORM_addr), - 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(); - - private: - // The fully-qualified name, as derived from name_attribute_, - // specification_, parent_context_. Computed in EndAttributes. - string name_; - uint64 low_pc_, high_pc_; // DW_AT_low_pc, DW_AT_high_pc - DwarfForm high_pc_form_; // DW_AT_high_pc can be length or address. - const AbstractOrigin* abstract_origin_; - bool inline_; -}; - -void DwarfCUToModule::FuncHandler::ProcessAttributeUnsigned( - enum DwarfAttribute attr, - enum DwarfForm form, - uint64 data) { - switch (attr) { - // If this attribute is present at all --- even if its value is - // DW_INL_not_inlined --- then GCC may cite it as someone else's - // DW_AT_abstract_origin attribute. - case dwarf2reader::DW_AT_inline: inline_ = true; break; - - case dwarf2reader::DW_AT_low_pc: low_pc_ = data; break; - case dwarf2reader::DW_AT_high_pc: - high_pc_form_ = form; - high_pc_ = data; - break; - - default: - GenericDIEHandler::ProcessAttributeUnsigned(attr, form, data); - break; - } -} - -void DwarfCUToModule::FuncHandler::ProcessAttributeSigned( - enum DwarfAttribute attr, - enum DwarfForm form, - int64 data) { - switch (attr) { - // If this attribute is present at all --- even if its value is - // DW_INL_not_inlined --- then GCC may cite it as someone else's - // DW_AT_abstract_origin attribute. - case dwarf2reader::DW_AT_inline: inline_ = true; 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; -} - -void DwarfCUToModule::FuncHandler::Finish() { - // Make high_pc_ an address, if it isn't already. - if (high_pc_form_ != dwarf2reader::DW_FORM_addr) { - high_pc_ += low_pc_; - } - - // Did we collect the information we need? Not all DWARF function - // entries have low and high addresses (for example, inlined - // functions that were never used), but all the ones we're - // interested in cover a non-empty range of bytes. - if (low_pc_ < high_pc_) { - // Malformed DWARF may omit the name, but all Module::Functions must - // have names. - string name; - if (!name_.empty()) { - name = name_; - } else { - cu_context_->reporter->UnnamedFunction(offset_); - name = "<name omitted>"; - } - - // Create a Module::Function based on the data we've gathered, and - // add it to the functions_ list. - scoped_ptr<Module::Function> func(new Module::Function(name, low_pc_)); - func->size = high_pc_ - low_pc_; - func->parameter_size = 0; - if (func->address) { - // If the function address is zero this is a sign that this function - // description is just empty debug data and should just be discarded. - cu_context_->functions.push_back(func.release()); - } - } else if (inline_) { - AbstractOrigin origin(name_); - cu_context_->file_context->file_private_->origins[offset_] = origin; - } -} - -// A handler for DIEs that contain functions and contribute a -// component to their names: namespaces, classes, etc. -class DwarfCUToModule::NamedScopeHandler: public GenericDIEHandler { - public: - NamedScopeHandler(CUContext *cu_context, DIEContext *parent_context, - uint64 offset) - : GenericDIEHandler(cu_context, parent_context, offset) { } - bool EndAttributes(); - DIEHandler *FindChildHandler(uint64 offset, enum DwarfTag tag); - - private: - DIEContext child_context_; // A context for our children. -}; - -bool DwarfCUToModule::NamedScopeHandler::EndAttributes() { - child_context_.name = ComputeQualifiedName(); - return true; -} - -dwarf2reader::DIEHandler *DwarfCUToModule::NamedScopeHandler::FindChildHandler( - uint64 offset, - enum DwarfTag tag) { - switch (tag) { - case dwarf2reader::DW_TAG_subprogram: - return new FuncHandler(cu_context_, &child_context_, offset); - case dwarf2reader::DW_TAG_namespace: - case dwarf2reader::DW_TAG_class_type: - case dwarf2reader::DW_TAG_structure_type: - case dwarf2reader::DW_TAG_union_type: - return new NamedScopeHandler(cu_context_, &child_context_, offset); - default: - return NULL; - } -} - -void DwarfCUToModule::WarningReporter::CUHeading() { - if (printed_cu_header_) - return; - fprintf(stderr, "%s: in compilation unit '%s' (offset 0x%llx):\n", - filename_.c_str(), cu_name_.c_str(), cu_offset_); - printed_cu_header_ = true; -} - -void DwarfCUToModule::WarningReporter::UnknownSpecification(uint64 offset, - uint64 target) { - CUHeading(); - fprintf(stderr, "%s: the DIE at offset 0x%llx has a DW_AT_specification" - " attribute referring to the die at offset 0x%llx, which either" - " was not marked as a declaration, or comes later in the file\n", - 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\n", - filename_.c_str(), offset, target); -} - -void DwarfCUToModule::WarningReporter::MissingSection(const string &name) { - CUHeading(); - fprintf(stderr, "%s: warning: couldn't find DWARF '%s' section\n", - filename_.c_str(), name.c_str()); -} - -void DwarfCUToModule::WarningReporter::BadLineInfoOffset(uint64 offset) { - CUHeading(); - fprintf(stderr, "%s: warning: line number data offset beyond end" - " of '.debug_line' section\n", - filename_.c_str()); -} - -void DwarfCUToModule::WarningReporter::UncoveredHeading() { - if (printed_unpaired_header_) - return; - CUHeading(); - fprintf(stderr, "%s: warning: skipping unpaired lines/functions:\n", - filename_.c_str()); - printed_unpaired_header_ = true; -} - -void DwarfCUToModule::WarningReporter::UncoveredFunction( - const Module::Function &function) { - if (!uncovered_warnings_enabled_) - return; - UncoveredHeading(); - fprintf(stderr, " function%s: %s\n", - function.size == 0 ? " (zero-length)" : "", - function.name.c_str()); -} - -void DwarfCUToModule::WarningReporter::UncoveredLine(const Module::Line &line) { - if (!uncovered_warnings_enabled_) - return; - UncoveredHeading(); - fprintf(stderr, " line%s: %s:%d at 0x%" PRIx64 "\n", - (line.size == 0 ? " (zero-length)" : ""), - line.file->name.c_str(), line.number, line.address); -} - -void DwarfCUToModule::WarningReporter::UnnamedFunction(uint64 offset) { - CUHeading(); - fprintf(stderr, "%s: warning: function at offset 0x%llx has no name\n", - filename_.c_str(), offset); -} - -void DwarfCUToModule::WarningReporter::DemangleError( - const string &input, int error) { - CUHeading(); - fprintf(stderr, "%s: warning: failed to demangle %s with error %d\n", - filename_.c_str(), input.c_str(), error); -} - -void DwarfCUToModule::WarningReporter::UnhandledInterCUReference( - uint64 offset, uint64 target) { - CUHeading(); - fprintf(stderr, "%s: warning: the DIE at offset 0x%llx has a " - "DW_FORM_ref_addr attribute with an inter-CU reference to " - "0x%llx, but inter-CU reference handling is turned off.\n", - filename_.c_str(), offset, target); -} - -DwarfCUToModule::DwarfCUToModule(FileContext *file_context, - LineToModuleHandler *line_reader, - WarningReporter *reporter) - : line_reader_(line_reader), - cu_context_(new CUContext(file_context, reporter)), - child_context_(new DIEContext()), - has_source_line_info_(false) { -} - -DwarfCUToModule::~DwarfCUToModule() { -} - -void DwarfCUToModule::ProcessAttributeSigned(enum DwarfAttribute attr, - enum DwarfForm form, - int64 data) { - switch (attr) { - case dwarf2reader::DW_AT_language: // source language of this CU - SetLanguage(static_cast<DwarfLanguage>(data)); - break; - default: - break; - } -} - -void DwarfCUToModule::ProcessAttributeUnsigned(enum DwarfAttribute attr, - enum DwarfForm form, - uint64 data) { - switch (attr) { - case dwarf2reader::DW_AT_stmt_list: // Line number information. - has_source_line_info_ = true; - source_line_offset_ = data; - break; - case dwarf2reader::DW_AT_language: // source language of this CU - SetLanguage(static_cast<DwarfLanguage>(data)); - break; - default: - break; - } -} - -void DwarfCUToModule::ProcessAttributeString(enum DwarfAttribute attr, - enum DwarfForm form, - const string &data) { - switch (attr) { - case dwarf2reader::DW_AT_name: - cu_context_->reporter->SetCUName(data); - break; - case dwarf2reader::DW_AT_comp_dir: - line_reader_->StartCompilationUnit(data); - break; - default: - break; - } -} - -bool DwarfCUToModule::EndAttributes() { - return true; -} - -dwarf2reader::DIEHandler *DwarfCUToModule::FindChildHandler( - uint64 offset, - enum DwarfTag tag) { - switch (tag) { - case dwarf2reader::DW_TAG_subprogram: - return new FuncHandler(cu_context_.get(), child_context_.get(), offset); - case dwarf2reader::DW_TAG_namespace: - case dwarf2reader::DW_TAG_class_type: - case dwarf2reader::DW_TAG_structure_type: - case dwarf2reader::DW_TAG_union_type: - return new NamedScopeHandler(cu_context_.get(), child_context_.get(), - offset); - default: - return NULL; - } -} - -void DwarfCUToModule::SetLanguage(DwarfLanguage language) { - switch (language) { - case dwarf2reader::DW_LANG_Java: - cu_context_->language = Language::Java; - break; - - // DWARF has no generic language code for assembly language; this is - // what the GNU toolchain uses. - case dwarf2reader::DW_LANG_Mips_Assembler: - cu_context_->language = Language::Assembler; - break; - - // C++ covers so many cases that it probably has some way to cope - // with whatever the other languages throw at us. So make it the - // default. - // - // Objective C and Objective C++ seem to create entries for - // methods whose DW_AT_name values are already fully-qualified: - // "-[Classname method:]". These appear at the top level. - // - // DWARF data for C should never include namespaces or functions - // nested in struct types, but if it ever does, then C++'s - // notation is probably not a bad choice for that. - default: - case dwarf2reader::DW_LANG_ObjC: - case dwarf2reader::DW_LANG_ObjC_plus_plus: - case dwarf2reader::DW_LANG_C: - case dwarf2reader::DW_LANG_C89: - case dwarf2reader::DW_LANG_C99: - case dwarf2reader::DW_LANG_C_plus_plus: - cu_context_->language = Language::CPlusPlus; - break; - } -} - -void DwarfCUToModule::ReadSourceLines(uint64 offset) { - const dwarf2reader::SectionMap §ion_map - = cu_context_->file_context->section_map(); - dwarf2reader::SectionMap::const_iterator map_entry - = section_map.find(".debug_line"); - // Mac OS X puts DWARF data in sections whose names begin with "__" - // instead of ".". - if (map_entry == section_map.end()) - map_entry = section_map.find("__debug_line"); - if (map_entry == section_map.end()) { - cu_context_->reporter->MissingSection(".debug_line"); - return; - } - const uint8_t *section_start = map_entry->second.first; - uint64 section_length = map_entry->second.second; - if (offset >= section_length) { - cu_context_->reporter->BadLineInfoOffset(offset); - return; - } - line_reader_->ReadProgram(section_start + offset, section_length - offset, - cu_context_->file_context->module_, &lines_); -} - -namespace { -// Return true if ADDRESS falls within the range of ITEM. -template <class T> -inline bool within(const T &item, Module::Address address) { - // Because Module::Address is unsigned, and unsigned arithmetic - // wraps around, this will be false if ADDRESS falls before the - // start of ITEM, or if it falls after ITEM's end. - return address - item.address < item.size; -} -} - -void DwarfCUToModule::AssignLinesToFunctions() { - vector<Module::Function *> *functions = &cu_context_->functions; - WarningReporter *reporter = cu_context_->reporter; - - // This would be simpler if we assumed that source line entries - // don't cross function boundaries. However, there's no real reason - // to assume that (say) a series of function definitions on the same - // line wouldn't get coalesced into one line number entry. The - // DWARF spec certainly makes no such promises. - // - // So treat the functions and lines as peers, and take the trouble - // to compute their ranges' intersections precisely. In any case, - // the hair here is a constant factor for performance; the - // complexity from here on out is linear. - - // Put both our functions and lines in order by address. - std::sort(functions->begin(), functions->end(), - Module::Function::CompareByAddress); - std::sort(lines_.begin(), lines_.end(), Module::Line::CompareByAddress); - - // The last line that we used any piece of. We use this only for - // generating warnings. - const Module::Line *last_line_used = NULL; - - // The last function and line we warned about --- so we can avoid - // doing so more than once. - const Module::Function *last_function_cited = NULL; - const Module::Line *last_line_cited = NULL; - - // Make a single pass through both vectors from lower to higher - // addresses, populating each Function's lines vector with lines - // from our lines_ vector that fall within the function's address - // range. - vector<Module::Function *>::iterator func_it = functions->begin(); - vector<Module::Line>::const_iterator line_it = lines_.begin(); - - Module::Address current; - - // Pointers to the referents of func_it and line_it, or NULL if the - // iterator is at the end of the sequence. - Module::Function *func; - const Module::Line *line; - - // Start current at the beginning of the first line or function, - // whichever is earlier. - if (func_it != functions->end() && line_it != lines_.end()) { - func = *func_it; - line = &*line_it; - current = std::min(func->address, line->address); - } else if (line_it != lines_.end()) { - func = NULL; - line = &*line_it; - current = line->address; - } else if (func_it != functions->end()) { - func = *func_it; - line = NULL; - current = (*func_it)->address; - } else { - return; - } - - while (func || line) { - // This loop has two invariants that hold at the top. - // - // First, at least one of the iterators is not at the end of its - // sequence, and those that are not refer to the earliest - // function or line that contains or starts after CURRENT. - // - // Note that every byte is in one of four states: it is covered - // or not covered by a function, and, independently, it is - // covered or not covered by a line. - // - // The second invariant is that CURRENT refers to a byte whose - // state is different from its predecessor, or it refers to the - // first byte in the address space. In other words, CURRENT is - // always the address of a transition. - // - // Note that, although each iteration advances CURRENT from one - // transition address to the next in each iteration, it might - // not advance the iterators. Suppose we have a function that - // starts with a line, has a gap, and then a second line, and - // suppose that we enter an iteration with CURRENT at the end of - // the first line. The next transition address is the start of - // the second line, after the gap, so the iteration should - // advance CURRENT to that point. At the head of that iteration, - // the invariants require that the line iterator be pointing at - // the second line. But this is also true at the head of the - // next. And clearly, the iteration must not change the function - // iterator. So neither iterator moves. - - // Assert the first invariant (see above). - assert(!func || current < func->address || within(*func, current)); - assert(!line || current < line->address || within(*line, current)); - - // The next transition after CURRENT. - Module::Address next_transition; - - // Figure out which state we're in, add lines or warn, and compute - // the next transition address. - if (func && current >= func->address) { - if (line && current >= line->address) { - // Covered by both a line and a function. - Module::Address func_left = func->size - (current - func->address); - Module::Address line_left = line->size - (current - line->address); - // This may overflow, but things work out. - next_transition = current + std::min(func_left, line_left); - Module::Line l = *line; - l.address = current; - l.size = next_transition - current; - func->lines.push_back(l); - last_line_used = line; - } else { - // Covered by a function, but no line. - if (func != last_function_cited) { - reporter->UncoveredFunction(*func); - last_function_cited = func; - } - if (line && within(*func, line->address)) - next_transition = line->address; - else - // If this overflows, we'll catch it below. - next_transition = func->address + func->size; - } - } else { - if (line && current >= line->address) { - // Covered by a line, but no function. - // - // If GCC emits padding after one function to align the start - // of the next, then it will attribute the padding - // instructions to the last source line of function (to reduce - // the size of the line number info), but omit it from the - // DW_AT_{low,high}_pc range given in .debug_info (since it - // costs nothing to be precise there). If we did use at least - // some of the line we're about to skip, and it ends at the - // start of the next function, then assume this is what - // happened, and don't warn. - if (line != last_line_cited - && !(func - && line == last_line_used - && func->address - line->address == line->size)) { - reporter->UncoveredLine(*line); - last_line_cited = line; - } - if (func && within(*line, func->address)) - next_transition = func->address; - else - // If this overflows, we'll catch it below. - next_transition = line->address + line->size; - } else { - // Covered by neither a function nor a line. By the invariant, - // both func and line begin after CURRENT. The next transition - // is the start of the next function or next line, whichever - // is earliest. - assert(func || line); - if (func && line) - next_transition = std::min(func->address, line->address); - else if (func) - next_transition = func->address; - else - next_transition = line->address; - } - } - - // If a function or line abuts the end of the address space, then - // next_transition may end up being zero, in which case we've completed - // our pass. Handle that here, instead of trying to deal with it in - // each place we compute next_transition. - if (!next_transition) - break; - - // Advance iterators as needed. If lines overlap or functions overlap, - // then we could go around more than once. We don't worry too much - // about what result we produce in that case, just as long as we don't - // hang or crash. - while (func_it != functions->end() - && next_transition >= (*func_it)->address - && !within(**func_it, next_transition)) - func_it++; - func = (func_it != functions->end()) ? *func_it : NULL; - while (line_it != lines_.end() - && next_transition >= line_it->address - && !within(*line_it, next_transition)) - line_it++; - line = (line_it != lines_.end()) ? &*line_it : NULL; - - // We must make progress. - assert(next_transition > current); - current = next_transition; - } -} - -void DwarfCUToModule::Finish() { - // Assembly language files have no function data, and that gives us - // no place to store our line numbers (even though the GNU toolchain - // will happily produce source line info for assembly language - // files). To avoid spurious warnings about lines we can't assign - // to functions, skip CUs in languages that lack functions. - if (!cu_context_->language->HasFunctions()) - return; - - // Read source line info, if we have any. - if (has_source_line_info_) - ReadSourceLines(source_line_offset_); - - vector<Module::Function *> *functions = &cu_context_->functions; - - // Dole out lines to the appropriate functions. - AssignLinesToFunctions(); - - // Add our functions, which now have source lines assigned to them, - // to module_. - cu_context_->file_context->module_->AddFunctions(functions->begin(), - functions->end()); - - // Ownership of the function objects has shifted from cu_context to - // the Module. - functions->clear(); - - cu_context_->file_context->ClearSpecifications(); -} - -bool DwarfCUToModule::StartCompilationUnit(uint64 offset, - uint8 address_size, - uint8 offset_size, - uint64 cu_length, - uint8 dwarf_version) { - return dwarf_version >= 2; -} - -bool DwarfCUToModule::StartRootDIE(uint64 offset, enum DwarfTag tag) { - // We don't deal with partial compilation units (the only other tag - // likely to be used for root DIE). - return tag == dwarf2reader::DW_TAG_compile_unit; -} - -} // namespace google_breakpad |