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Diffstat (limited to 'toolkit/crashreporter/google-breakpad/src/common/dwarf/dwarf2diehandler.h')
| -rw-r--r-- | toolkit/crashreporter/google-breakpad/src/common/dwarf/dwarf2diehandler.h | 365 |
1 files changed, 0 insertions, 365 deletions
diff --git a/toolkit/crashreporter/google-breakpad/src/common/dwarf/dwarf2diehandler.h b/toolkit/crashreporter/google-breakpad/src/common/dwarf/dwarf2diehandler.h deleted file mode 100644 index a1e589a86..000000000 --- a/toolkit/crashreporter/google-breakpad/src/common/dwarf/dwarf2diehandler.h +++ /dev/null @@ -1,365 +0,0 @@ -// -*- mode: c++ -*- - -// 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> - -// dwarf2reader::CompilationUnit is a simple and direct parser for -// DWARF data, but its handler interface is not convenient to use. In -// particular: -// -// - CompilationUnit calls Dwarf2Handler's member functions to report -// every attribute's value, regardless of what sort of DIE it is. -// As a result, the ProcessAttributeX functions end up looking like -// this: -// -// switch (parent_die_tag) { -// case DW_TAG_x: -// switch (attribute_name) { -// case DW_AT_y: -// handle attribute y of DIE type x -// ... -// } break; -// ... -// } -// -// In C++ it's much nicer to use virtual function dispatch to find -// the right code for a given case than to switch on the DIE tag -// like this. -// -// - Processing different kinds of DIEs requires different sets of -// data: lexical block DIEs have start and end addresses, but struct -// type DIEs don't. It would be nice to be able to have separate -// handler classes for separate kinds of DIEs, each with the members -// appropriate to its role, instead of having one handler class that -// needs to hold data for every DIE type. -// -// - There should be a separate instance of the appropriate handler -// class for each DIE, instead of a single object with tables -// tracking all the dies in the compilation unit. -// -// - It's not convenient to take some action after all a DIE's -// attributes have been seen, but before visiting any of its -// children. The only indication you have that a DIE's attribute -// list is complete is that you get either a StartDIE or an EndDIE -// call. -// -// - It's not convenient to make use of the tree structure of the -// DIEs. Skipping all the children of a given die requires -// maintaining state and returning false from StartDIE until we get -// an EndDIE call with the appropriate offset. -// -// This interface tries to take care of all that. (You're shocked, I'm sure.) -// -// Using the classes here, you provide an initial handler for the root -// DIE of the compilation unit. Each handler receives its DIE's -// attributes, and provides fresh handler objects for children of -// interest, if any. The three classes are: -// -// - DIEHandler: the base class for your DIE-type-specific handler -// classes. -// -// - RootDIEHandler: derived from DIEHandler, the base class for your -// root DIE handler class. -// -// - DIEDispatcher: derived from Dwarf2Handler, an instance of this -// invokes your DIE-type-specific handler objects. -// -// In detail: -// -// - Define handler classes specialized for the DIE types you're -// interested in. These handler classes must inherit from -// DIEHandler. Thus: -// -// class My_DW_TAG_X_Handler: public DIEHandler { ... }; -// class My_DW_TAG_Y_Handler: public DIEHandler { ... }; -// -// DIEHandler subclasses needn't correspond exactly to single DIE -// types, as shown here; the point is that you can have several -// different classes appropriate to different kinds of DIEs. -// -// - In particular, define a handler class for the compilation -// unit's root DIE, that inherits from RootDIEHandler: -// -// class My_DW_TAG_compile_unit_Handler: public RootDIEHandler { ... }; -// -// RootDIEHandler inherits from DIEHandler, adding a few additional -// member functions for examining the compilation unit as a whole, -// and other quirks of rootness. -// -// - Then, create a DIEDispatcher instance, passing it an instance of -// your root DIE handler class, and use that DIEDispatcher as the -// dwarf2reader::CompilationUnit's handler: -// -// My_DW_TAG_compile_unit_Handler root_die_handler(...); -// DIEDispatcher die_dispatcher(&root_die_handler); -// CompilationUnit reader(sections, offset, bytereader, &die_dispatcher); -// -// Here, 'die_dispatcher' acts as a shim between 'reader' and the -// various DIE-specific handlers you have defined. -// -// - When you call reader.Start(), die_dispatcher behaves as follows, -// starting with your root die handler and the compilation unit's -// root DIE: -// -// - It calls the handler's ProcessAttributeX member functions for -// each of the DIE's attributes. -// -// - It calls the handler's EndAttributes member function. This -// should return true if any of the DIE's children should be -// visited, in which case: -// -// - For each of the DIE's children, die_dispatcher calls the -// DIE's handler's FindChildHandler member function. If that -// returns a pointer to a DIEHandler instance, then -// die_dispatcher uses that handler to process the child, using -// this procedure recursively. Alternatively, if -// FindChildHandler returns NULL, die_dispatcher ignores that -// child and its descendants. -// -// - When die_dispatcher has finished processing all the DIE's -// children, it invokes the handler's Finish() member function, -// and destroys the handler. (As a special case, it doesn't -// destroy the root DIE handler.) -// -// This allows the code for handling a particular kind of DIE to be -// gathered together in a single class, makes it easy to skip all the -// children or individual children of a particular DIE, and provides -// appropriate parental context for each die. - -#ifndef COMMON_DWARF_DWARF2DIEHANDLER_H__ -#define COMMON_DWARF_DWARF2DIEHANDLER_H__ - -#include <stdint.h> - -#include <stack> -#include <string> - -#include "common/dwarf/types.h" -#include "common/dwarf/dwarf2enums.h" -#include "common/dwarf/dwarf2reader.h" -#include "common/using_std_string.h" - -namespace dwarf2reader { - -// A base class for handlers for specific DIE types. The series of -// calls made on a DIE handler is as follows: -// -// - for each attribute of the DIE: -// - ProcessAttributeX() -// - EndAttributes() -// - if that returned true, then for each child: -// - FindChildHandler() -// - if that returns a non-NULL pointer to a new handler: -// - recurse, with the new handler and the child die -// - Finish() -// - destruction -class DIEHandler { - public: - DIEHandler() { } - virtual ~DIEHandler() { } - - // When we visit a DIE, we first use these member functions to - // report the DIE's attributes and their values. These have the - // same restrictions as the corresponding member functions of - // dwarf2reader::Dwarf2Handler. - // - // Since DWARF does not specify in what order attributes must - // appear, avoid making decisions in these functions that would be - // affected by the presence of other attributes. The EndAttributes - // function is a more appropriate place for such work, as all the - // DIE's attributes have been seen at that point. - // - // The default definitions ignore the values they are passed. - virtual void ProcessAttributeUnsigned(enum DwarfAttribute attr, - enum DwarfForm form, - uint64 data) { } - virtual void ProcessAttributeSigned(enum DwarfAttribute attr, - enum DwarfForm form, - int64 data) { } - virtual void ProcessAttributeReference(enum DwarfAttribute attr, - enum DwarfForm form, - uint64 data) { } - virtual void ProcessAttributeBuffer(enum DwarfAttribute attr, - enum DwarfForm form, - const uint8_t *data, - uint64 len) { } - virtual void ProcessAttributeString(enum DwarfAttribute attr, - enum DwarfForm form, - const string& data) { } - virtual void ProcessAttributeSignature(enum DwarfAttribute attr, - enum DwarfForm form, - uint64 signture) { } - - // Once we have reported all the DIE's attributes' values, we call - // this member function. If it returns false, we skip all the DIE's - // children. If it returns true, we call FindChildHandler on each - // child. If that returns a handler object, we use that to visit - // the child; otherwise, we skip the child. - // - // This is a good place to make decisions that depend on more than - // one attribute. DWARF does not specify in what order attributes - // must appear, so only when the EndAttributes function is called - // does the handler have a complete picture of the DIE's attributes. - // - // The default definition elects to ignore the DIE's children. - // You'll need to override this if you override FindChildHandler, - // but at least the default behavior isn't to pass the children to - // FindChildHandler, which then ignores them all. - virtual bool EndAttributes() { return false; } - - // If EndAttributes returns true to indicate that some of the DIE's - // children might be of interest, then we apply this function to - // each of the DIE's children. If it returns a handler object, then - // we use that to visit the child DIE. If it returns NULL, we skip - // that child DIE (and all its descendants). - // - // OFFSET is the offset of the child; TAG indicates what kind of DIE - // it is. - // - // The default definition skips all children. - virtual DIEHandler *FindChildHandler(uint64 offset, enum DwarfTag tag) { - return NULL; - } - - // When we are done processing a DIE, we call this member function. - // This happens after the EndAttributes call, all FindChildHandler - // calls (if any), and all operations on the children themselves (if - // any). We call Finish on every handler --- even if EndAttributes - // returns false. - virtual void Finish() { }; -}; - -// A subclass of DIEHandler, with additional kludges for handling the -// compilation unit's root die. -class RootDIEHandler: public DIEHandler { - public: - RootDIEHandler() { } - virtual ~RootDIEHandler() { } - - // We pass the values reported via Dwarf2Handler::StartCompilationUnit - // to this member function, and skip the entire compilation unit if it - // returns false. So the root DIE handler is actually also - // responsible for handling the compilation unit metadata. - // The default definition always visits the compilation unit. - virtual bool StartCompilationUnit(uint64 offset, uint8 address_size, - uint8 offset_size, uint64 cu_length, - uint8 dwarf_version) { return true; } - - // For the root DIE handler only, we pass the offset, tag and - // attributes of the compilation unit's root DIE. This is the only - // way the root DIE handler can find the root DIE's tag. If this - // function returns true, we will visit the root DIE using the usual - // DIEHandler methods; otherwise, we skip the entire compilation - // unit. - // - // The default definition elects to visit the root DIE. - virtual bool StartRootDIE(uint64 offset, enum DwarfTag tag) { return true; } -}; - -class DIEDispatcher: public Dwarf2Handler { - public: - // Create a Dwarf2Handler which uses ROOT_HANDLER as the handler for - // the compilation unit's root die, as described for the DIEHandler - // class. - DIEDispatcher(RootDIEHandler *root_handler) : root_handler_(root_handler) { } - // Destroying a DIEDispatcher destroys all active handler objects - // except the root handler. - ~DIEDispatcher(); - bool StartCompilationUnit(uint64 offset, uint8 address_size, - uint8 offset_size, uint64 cu_length, - uint8 dwarf_version); - bool StartDIE(uint64 offset, enum DwarfTag tag); - void ProcessAttributeUnsigned(uint64 offset, - enum DwarfAttribute attr, - enum DwarfForm form, - uint64 data); - void ProcessAttributeSigned(uint64 offset, - enum DwarfAttribute attr, - enum DwarfForm form, - int64 data); - void ProcessAttributeReference(uint64 offset, - enum DwarfAttribute attr, - enum DwarfForm form, - uint64 data); - void ProcessAttributeBuffer(uint64 offset, - enum DwarfAttribute attr, - enum DwarfForm form, - const uint8_t *data, - uint64 len); - void ProcessAttributeString(uint64 offset, - enum DwarfAttribute attr, - enum DwarfForm form, - const string &data); - void ProcessAttributeSignature(uint64 offset, - enum DwarfAttribute attr, - enum DwarfForm form, - uint64 signature); - void EndDIE(uint64 offset); - - private: - - // The type of a handler stack entry. This includes some fields - // which don't really need to be on the stack --- they could just be - // single data members of DIEDispatcher --- but putting them here - // makes it easier to see that the code is correct. - struct HandlerStack { - // The offset of the DIE for this handler stack entry. - uint64 offset_; - - // The handler object interested in this DIE's attributes and - // children. If NULL, we're not interested in either. - DIEHandler *handler_; - - // Have we reported the end of this DIE's attributes to the handler? - bool reported_attributes_end_; - }; - - // Stack of DIE attribute handlers. At StartDIE(D), the top of the - // stack is the handler of D's parent, whom we may ask for a handler - // for D itself. At EndDIE(D), the top of the stack is D's handler. - // Special cases: - // - // - Before we've seen the compilation unit's root DIE, the stack is - // empty; we'll call root_handler_'s special member functions, and - // perhaps push root_handler_ on the stack to look at the root's - // immediate children. - // - // - When we decide to ignore a subtree, we only push an entry on - // the stack for the root of the tree being ignored, rather than - // pushing lots of stack entries with handler_ set to NULL. - std::stack<HandlerStack> die_handlers_; - - // The root handler. We don't push it on die_handlers_ until we - // actually get the StartDIE call for the root. - RootDIEHandler *root_handler_; -}; - -} // namespace dwarf2reader -#endif // COMMON_DWARF_DWARF2DIEHANDLER_H__ |