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 "PrimType.h" 17 #include "clang/AST/Decl.h" 18 #include "clang/AST/Stmt.h" 19 #include "llvm/Support/Endian.h" 20 21 namespace clang { 22 namespace interp { 23 class Function; 24 25 /// Pointer into the code segment. 26 class CodePtr final { 27 public: 28 CodePtr() : Ptr(nullptr) {} 29 30 CodePtr &operator+=(int32_t Offset) { 31 Ptr += Offset; 32 return *this; 33 } 34 35 int32_t operator-(const CodePtr &RHS) const { 36 assert(Ptr != nullptr && RHS.Ptr != nullptr && "Invalid code pointer"); 37 return Ptr - RHS.Ptr; 38 } 39 40 CodePtr operator-(size_t RHS) const { 41 assert(Ptr != nullptr && "Invalid code pointer"); 42 return CodePtr(Ptr - RHS); 43 } 44 45 bool operator!=(const CodePtr &RHS) const { return Ptr != RHS.Ptr; } 46 47 operator bool() const { return Ptr; } 48 49 /// Reads data and advances the pointer. 50 template <typename T> std::enable_if_t<!std::is_pointer<T>::value, T> read() { 51 assert(aligned(Ptr)); 52 using namespace llvm::support; 53 T Value = endian::read<T, endianness::native, 1>(Ptr); 54 Ptr += align(sizeof(T)); 55 return Value; 56 } 57 58 private: 59 friend class Function; 60 /// Constructor used by Function to generate pointers. 61 CodePtr(const std::byte *Ptr) : Ptr(Ptr) {} 62 /// Pointer into the code owned by a function. 63 const std::byte *Ptr; 64 }; 65 66 /// Describes the statement/declaration an opcode was generated from. 67 class SourceInfo final { 68 public: 69 SourceInfo() {} 70 SourceInfo(const Stmt *E) : Source(E) {} 71 SourceInfo(const Decl *D) : Source(D) {} 72 73 SourceLocation getLoc() const; 74 75 const Stmt *asStmt() const { return Source.dyn_cast<const Stmt *>(); } 76 const Decl *asDecl() const { return Source.dyn_cast<const Decl *>(); } 77 const Expr *asExpr() const; 78 79 operator bool() const { return !Source.isNull(); } 80 81 private: 82 llvm::PointerUnion<const Decl *, const Stmt *> Source; 83 }; 84 85 using SourceMap = std::vector<std::pair<unsigned, SourceInfo>>; 86 87 /// Interface for classes which map locations to sources. 88 class SourceMapper { 89 public: 90 virtual ~SourceMapper() {} 91 92 /// Returns source information for a given PC in a function. 93 virtual SourceInfo getSource(const Function *F, CodePtr PC) const = 0; 94 95 /// Returns the expression if an opcode belongs to one, null otherwise. 96 const Expr *getExpr(const Function *F, CodePtr PC) const; 97 /// Returns the location from which an opcode originates. 98 SourceLocation getLocation(const Function *F, CodePtr PC) const; 99 }; 100 101 } // namespace interp 102 } // namespace clang 103 104 #endif 105