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author | iddqd <iddqd@yandex-team.com> | 2024-12-19 10:46:06 +0300 |
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committer | iddqd <iddqd@yandex-team.com> | 2024-12-19 10:59:56 +0300 |
commit | bb0840c0025a75dd3b85b746ebcec7deb7d9fe1c (patch) | |
tree | 85bc5522e873d9d5c37df278f0300c26fe9e729e /contrib/libs/breakpad/src/processor/postfix_evaluator.h | |
parent | 1353077f79bb3547792b2fc86c22a695f0bc76f9 (diff) | |
download | ydb-bb0840c0025a75dd3b85b746ebcec7deb7d9fe1c.tar.gz |
Add contib/libs/breakpad to export
commit_hash:9d85255f8d9249f14105e4626bf4484805b8aed4
Diffstat (limited to 'contrib/libs/breakpad/src/processor/postfix_evaluator.h')
-rw-r--r-- | contrib/libs/breakpad/src/processor/postfix_evaluator.h | 179 |
1 files changed, 179 insertions, 0 deletions
diff --git a/contrib/libs/breakpad/src/processor/postfix_evaluator.h b/contrib/libs/breakpad/src/processor/postfix_evaluator.h new file mode 100644 index 0000000000..d847a9b166 --- /dev/null +++ b/contrib/libs/breakpad/src/processor/postfix_evaluator.h @@ -0,0 +1,179 @@ +// -*- 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. + +// postfix_evaluator.h: Postfix (reverse Polish) notation expression evaluator. +// +// PostfixEvaluator evaluates an expression, using the expression itself +// in postfix (reverse Polish) notation and a dictionary mapping constants +// and variables to their values. The evaluator supports standard +// arithmetic operations, assignment into variables, and when an optional +// MemoryRange is provided, dereferencing. (Any unary key-to-value operation +// may be used with a MemoryRange implementation that returns the appropriate +// values, but PostfixEvaluator was written with dereferencing in mind.) +// +// The expression language is simple. Expressions are supplied as strings, +// with operands and operators delimited by whitespace. Operands may be +// either literal values suitable for ValueType, or constants or variables, +// which reference the dictionary. The supported binary operators are + +// (addition), - (subtraction), * (multiplication), / (quotient of division), +// % (modulus of division), and @ (data alignment). The alignment operator (@) +// accepts a value and an alignment size, and produces a result that is a +// multiple of the alignment size by truncating the input value. +// The unary ^ (dereference) operator is also provided. These operators +// allow any operand to be either a literal value, constant, or variable. +// Assignment (=) of any type of operand into a variable is also supported. +// +// The dictionary is provided as a map with string keys. Keys beginning +// with the '$' character are treated as variables. All other keys are +// treated as constants. Any results must be assigned into variables in the +// dictionary. These variables do not need to exist prior to calling +// Evaluate, unless used in an expression prior to being assigned to. The +// internal stack state is not made available after evaluation, and any +// values remaining on the stack are treated as evidence of incomplete +// execution and cause the evaluator to indicate failure. +// +// PostfixEvaluator is intended to support evaluation of "program strings" +// obtained from MSVC frame data debugging information in pdb files as +// returned by the DIA APIs. +// +// Author: Mark Mentovai + +#ifndef PROCESSOR_POSTFIX_EVALUATOR_H__ +#define PROCESSOR_POSTFIX_EVALUATOR_H__ + + +#include <map> +#include <string> +#include <vector> + +#include "common/using_std_string.h" + +namespace google_breakpad { + +using std::map; +using std::vector; + +class MemoryRegion; + +template<typename ValueType> +class PostfixEvaluator { + public: + typedef map<string, ValueType> DictionaryType; + typedef map<string, bool> DictionaryValidityType; + + // Create a PostfixEvaluator object that may be used (with Evaluate) on + // one or more expressions. PostfixEvaluator does not take ownership of + // either argument. |memory| may be NULL, in which case dereferencing + // (^) will not be supported. |dictionary| may be NULL, but evaluation + // will fail in that case unless set_dictionary is used before calling + // Evaluate. + PostfixEvaluator(DictionaryType* dictionary, const MemoryRegion* memory) + : dictionary_(dictionary), memory_(memory), stack_() {} + + // Evaluate the expression, starting with an empty stack. The results of + // execution will be stored in one (or more) variables in the dictionary. + // Returns false if any failures occur during execution, leaving + // variables in the dictionary in an indeterminate state. If assigned is + // non-NULL, any keys set in the dictionary as a result of evaluation + // will also be set to true in assigned, providing a way to determine if + // an expression modifies any of its input variables. + bool Evaluate(const string& expression, DictionaryValidityType* assigned); + + // Like Evaluate, but provides the value left on the stack to the + // caller. If evaluation succeeds and leaves exactly one value on + // the stack, pop that value, store it in *result, and return true. + // Otherwise, return false. + bool EvaluateForValue(const string& expression, ValueType* result); + + DictionaryType* dictionary() const { return dictionary_; } + + // Reset the dictionary. PostfixEvaluator does not take ownership. + void set_dictionary(DictionaryType* dictionary) {dictionary_ = dictionary; } + + private: + // Return values for PopValueOrIdentifier + enum PopResult { + POP_RESULT_FAIL = 0, + POP_RESULT_VALUE, + POP_RESULT_IDENTIFIER + }; + + // Retrieves the topmost literal value, constant, or variable from the + // stack. Returns POP_RESULT_VALUE if the topmost entry is a literal + // value, and sets |value| accordingly. Returns POP_RESULT_IDENTIFIER + // if the topmost entry is a constant or variable identifier, and sets + // |identifier| accordingly. Returns POP_RESULT_FAIL on failure, such + // as when the stack is empty. + PopResult PopValueOrIdentifier(ValueType* value, string* identifier); + + // Retrieves the topmost value on the stack. If the topmost entry is + // an identifier, the dictionary is queried for the identifier's value. + // Returns false on failure, such as when the stack is empty or when + // a nonexistent identifier is named. + bool PopValue(ValueType* value); + + // Retrieves the top two values on the stack, in the style of PopValue. + // value2 is popped before value1, so that value1 corresponds to the + // entry that was pushed prior to value2. Returns false on failure. + bool PopValues(ValueType* value1, ValueType* value2); + + // Pushes a new value onto the stack. + void PushValue(const ValueType& value); + + // Evaluate expression, updating *assigned if it is non-zero. Return + // true if evaluation completes successfully. Do not clear the stack + // upon successful evaluation. + bool EvaluateInternal(const string& expression, + DictionaryValidityType* assigned); + + bool EvaluateToken(const string& token, + const string& expression, + DictionaryValidityType* assigned); + + // The dictionary mapping constant and variable identifiers (strings) to + // values. Keys beginning with '$' are treated as variable names, and + // PostfixEvaluator is free to create and modify these keys. Weak pointer. + DictionaryType* dictionary_; + + // If non-NULL, the MemoryRegion used for dereference (^) operations. + // If NULL, dereferencing is unsupported and will fail. Weak pointer. + const MemoryRegion* memory_; + + // The stack contains state information as execution progresses. Values + // are pushed on to it as the expression string is read and as operations + // yield values; values are popped when used as operands to operators. + vector<string> stack_; +}; + +} // namespace google_breakpad + + +#endif // PROCESSOR_POSTFIX_EVALUATOR_H__ |