1 //===--- Source.h - Source location provider for the VM --------*- C++ -*-===// 2 // 3 // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions. 4 // See https://llvm.org/LICENSE.txt for license information. 5 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception 6 // 7 //===----------------------------------------------------------------------===// 8 // 9 // Defines a program which organises and links multiple bytecode functions. 10 // 11 //===----------------------------------------------------------------------===// 12 13 #ifndef LLVM_CLANG_AST_INTERP_SOURCE_H 14 #define LLVM_CLANG_AST_INTERP_SOURCE_H 15 16 #include "clang/AST/Decl.h" 17 #include "clang/AST/Stmt.h" 18 #include "llvm/Support/Endian.h" 19 20 namespace clang { 21 namespace interp { 22 class Function; 23 24 /// Pointer into the code segment. 25 class CodePtr { 26 public: 27 CodePtr() : Ptr(nullptr) {} 28 29 CodePtr &operator+=(int32_t Offset) { 30 Ptr += Offset; 31 return *this; 32 } 33 34 int32_t operator-(const CodePtr &RHS) const { 35 assert(Ptr != nullptr && RHS.Ptr != nullptr && "Invalid code pointer"); 36 return Ptr - RHS.Ptr; 37 } 38 39 CodePtr operator-(size_t RHS) const { 40 assert(Ptr != nullptr && "Invalid code pointer"); 41 return CodePtr(Ptr - RHS); 42 } 43 44 bool operator!=(const CodePtr &RHS) const { return Ptr != RHS.Ptr; } 45 46 /// Reads data and advances the pointer. 47 template <typename T> T read() { 48 T Value = ReadHelper<T>(Ptr); 49 Ptr += sizeof(T); 50 return Value; 51 } 52 53 private: 54 /// Constructor used by Function to generate pointers. 55 CodePtr(const char *Ptr) : Ptr(Ptr) {} 56 57 /// Helper to decode a value or a pointer. 58 template <typename T> 59 static std::enable_if_t<!std::is_pointer<T>::value, T> 60 ReadHelper(const char *Ptr) { 61 using namespace llvm::support; 62 return endian::read<T, endianness::native, 1>(Ptr); 63 } 64 65 template <typename T> 66 static std::enable_if_t<std::is_pointer<T>::value, T> 67 ReadHelper(const char *Ptr) { 68 using namespace llvm::support; 69 auto Punned = endian::read<uintptr_t, endianness::native, 1>(Ptr); 70 return reinterpret_cast<T>(Punned); 71 } 72 73 private: 74 friend class Function; 75 76 /// Pointer into the code owned by a function. 77 const char *Ptr; 78 }; 79 80 /// Describes the statement/declaration an opcode was generated from. 81 class SourceInfo { 82 public: 83 SourceInfo() {} 84 SourceInfo(const Stmt *E) : Source(E) {} 85 SourceInfo(const Decl *D) : Source(D) {} 86 87 SourceLocation getLoc() const; 88 89 const Stmt *asStmt() const { return Source.dyn_cast<const Stmt *>(); } 90 const Decl *asDecl() const { return Source.dyn_cast<const Decl *>(); } 91 const Expr *asExpr() const; 92 93 operator bool() const { return !Source.isNull(); } 94 95 private: 96 llvm::PointerUnion<const Decl *, const Stmt *> Source; 97 }; 98 99 using SourceMap = std::vector<std::pair<unsigned, SourceInfo>>; 100 101 /// Interface for classes which map locations to sources. 102 class SourceMapper { 103 public: 104 virtual ~SourceMapper() {} 105 106 /// Returns source information for a given PC in a function. 107 virtual SourceInfo getSource(Function *F, CodePtr PC) const = 0; 108 109 /// Returns the expression if an opcode belongs to one, null otherwise. 110 const Expr *getExpr(Function *F, CodePtr PC) const; 111 /// Returns the location from which an opcode originates. 112 SourceLocation getLocation(Function *F, CodePtr PC) const; 113 }; 114 115 } // namespace interp 116 } // namespace clang 117 118 #endif 119