LCOV - code coverage report
Current view: top level - include/llvm/Transforms/Utils - SymbolRewriter.h (source / functions) Hit Total Coverage
Test: llvm-toolchain.info Lines: 3 5 60.0 %
Date: 2018-06-17 00:07:59 Functions: 0 1 0.0 %
Legend: Lines: hit not hit

          Line data    Source code
       1             : //===- SymbolRewriter.h - Symbol Rewriting Pass -----------------*- C++ -*-===//
       2             : //
       3             : //                     The LLVM Compiler Infrastructure
       4             : //
       5             : // This file is distributed under the University of Illinois Open Source
       6             : // License. See LICENSE.TXT for details.
       7             : //
       8             : //===----------------------------------------------------------------------===//
       9             : //
      10             : // This file provides the prototypes and definitions related to the Symbol
      11             : // Rewriter pass.
      12             : //
      13             : // The Symbol Rewriter pass takes a set of rewrite descriptors which define
      14             : // transformations for symbol names.  These can be either single name to name
      15             : // trnsformation or more broad regular expression based transformations.
      16             : //
      17             : // All the functions are re-written at the IR level.  The Symbol Rewriter itself
      18             : // is exposed as a module level pass.  All symbols at the module level are
      19             : // iterated.  For any matching symbol, the requested transformation is applied,
      20             : // updating references to it as well (a la RAUW).  The resulting binary will
      21             : // only contain the rewritten symbols.
      22             : //
      23             : // By performing this operation in the compiler, we are able to catch symbols
      24             : // that would otherwise not be possible to catch (e.g. inlined symbols).
      25             : //
      26             : // This makes it possible to cleanly transform symbols without resorting to
      27             : // overly-complex macro tricks and the pre-processor.  An example of where this
      28             : // is useful is the sanitizers where we would like to intercept a well-defined
      29             : // set of functions across the module.
      30             : //
      31             : //===----------------------------------------------------------------------===//
      32             : 
      33             : #ifndef LLVM_TRANSFORMS_UTILS_SYMBOLREWRITER_H
      34             : #define LLVM_TRANSFORMS_UTILS_SYMBOLREWRITER_H
      35             : 
      36             : #include "llvm/IR/PassManager.h"
      37             : #include <list>
      38             : #include <memory>
      39             : #include <string>
      40             : 
      41             : namespace llvm {
      42             : 
      43             : class MemoryBuffer;
      44             : class Module;
      45             : class ModulePass;
      46             : 
      47             : namespace yaml {
      48             : 
      49             : class KeyValueNode;
      50             : class MappingNode;
      51             : class ScalarNode;
      52             : class Stream;
      53             : 
      54             : } // end namespace yaml
      55             : 
      56             : namespace SymbolRewriter {
      57             : 
      58             : /// The basic entity representing a rewrite operation.  It serves as the base
      59             : /// class for any rewrite descriptor.  It has a certain set of specializations
      60             : /// which describe a particular rewrite.
      61             : ///
      62             : /// The RewriteMapParser can be used to parse a mapping file that provides the
      63             : /// mapping for rewriting the symbols.  The descriptors individually describe
      64             : /// whether to rewrite a function, global variable, or global alias.  Each of
      65             : /// these can be selected either by explicitly providing a name for the ones to
      66             : /// be rewritten or providing a (posix compatible) regular expression that will
      67             : /// select the symbols to rewrite.  This descriptor list is passed to the
      68             : /// SymbolRewriter pass.
      69             : class RewriteDescriptor {
      70             : public:
      71             :   enum class Type {
      72             :     Invalid,        /// invalid
      73             :     Function,       /// function - descriptor rewrites a function
      74             :     GlobalVariable, /// global variable - descriptor rewrites a global variable
      75             :     NamedAlias,     /// named alias - descriptor rewrites a global alias
      76             :   };
      77             : 
      78             :   RewriteDescriptor(const RewriteDescriptor &) = delete;
      79             :   RewriteDescriptor &operator=(const RewriteDescriptor &) = delete;
      80             :   virtual ~RewriteDescriptor() = default;
      81             : 
      82             :   Type getType() const { return Kind; }
      83             : 
      84             :   virtual bool performOnModule(Module &M) = 0;
      85             : 
      86             : protected:
      87          26 :   explicit RewriteDescriptor(Type T) : Kind(T) {}
      88             : 
      89             : private:
      90             :   const Type Kind;
      91             : };
      92             : 
      93             : using RewriteDescriptorList = std::list<std::unique_ptr<RewriteDescriptor>>;
      94             : 
      95             : class RewriteMapParser {
      96             : public:
      97             :   bool parse(const std::string &MapFile, RewriteDescriptorList *Descriptors);
      98             : 
      99             : private:
     100             :   bool parse(std::unique_ptr<MemoryBuffer> &MapFile, RewriteDescriptorList *DL);
     101             :   bool parseEntry(yaml::Stream &Stream, yaml::KeyValueNode &Entry,
     102             :                   RewriteDescriptorList *DL);
     103             :   bool parseRewriteFunctionDescriptor(yaml::Stream &Stream,
     104             :                                       yaml::ScalarNode *Key,
     105             :                                       yaml::MappingNode *Value,
     106             :                                       RewriteDescriptorList *DL);
     107             :   bool parseRewriteGlobalVariableDescriptor(yaml::Stream &Stream,
     108             :                                             yaml::ScalarNode *Key,
     109             :                                             yaml::MappingNode *Value,
     110             :                                             RewriteDescriptorList *DL);
     111             :   bool parseRewriteGlobalAliasDescriptor(yaml::Stream &YS, yaml::ScalarNode *K,
     112             :                                          yaml::MappingNode *V,
     113             :                                          RewriteDescriptorList *DL);
     114             : };
     115             : 
     116             : } // end namespace SymbolRewriter
     117             : 
     118             : ModulePass *createRewriteSymbolsPass();
     119             : ModulePass *createRewriteSymbolsPass(SymbolRewriter::RewriteDescriptorList &);
     120             : 
     121       22684 : class RewriteSymbolPass : public PassInfoMixin<RewriteSymbolPass> {
     122             : public:
     123       22793 :   RewriteSymbolPass() { loadAndParseMapFiles(); }
     124             : 
     125           0 :   RewriteSymbolPass(SymbolRewriter::RewriteDescriptorList &DL) {
     126             :     Descriptors.splice(Descriptors.begin(), DL);
     127           0 :   }
     128             : 
     129             :   PreservedAnalyses run(Module &M, ModuleAnalysisManager &AM);
     130             : 
     131             :   // Glue for old PM
     132             :   bool runImpl(Module &M);
     133             : 
     134             : private:
     135             :   void loadAndParseMapFiles();
     136             : 
     137             :   SymbolRewriter::RewriteDescriptorList Descriptors;  
     138             : };
     139             : 
     140             : } // end namespace llvm
     141             : 
     142             : #endif //LLVM_TRANSFORMS_UTILS_SYMBOLREWRITER_H

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