xref: /freebsd-src/contrib/llvm-project/clang/lib/AST/Interp/ByteCodeEmitter.h (revision 0fca6ea1d4eea4c934cfff25ac9ee8ad6fe95583)
1*0fca6ea1SDimitry Andric //===--- ByteCodeEmitter.h - Instruction emitter for the VM -----*- C++ -*-===//
2a7dea167SDimitry Andric //
3a7dea167SDimitry Andric // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
4a7dea167SDimitry Andric // See https://llvm.org/LICENSE.txt for license information.
5a7dea167SDimitry Andric // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
6a7dea167SDimitry Andric //
7a7dea167SDimitry Andric //===----------------------------------------------------------------------===//
8a7dea167SDimitry Andric //
9a7dea167SDimitry Andric // Defines the instruction emitters.
10a7dea167SDimitry Andric //
11a7dea167SDimitry Andric //===----------------------------------------------------------------------===//
12a7dea167SDimitry Andric 
13a7dea167SDimitry Andric #ifndef LLVM_CLANG_AST_INTERP_LINKEMITTER_H
14a7dea167SDimitry Andric #define LLVM_CLANG_AST_INTERP_LINKEMITTER_H
15a7dea167SDimitry Andric 
16a7dea167SDimitry Andric #include "Context.h"
17a7dea167SDimitry Andric #include "PrimType.h"
18a7dea167SDimitry Andric #include "Program.h"
19a7dea167SDimitry Andric #include "Source.h"
20a7dea167SDimitry Andric 
21a7dea167SDimitry Andric namespace clang {
22a7dea167SDimitry Andric namespace interp {
23a7dea167SDimitry Andric enum Opcode : uint32_t;
24a7dea167SDimitry Andric 
25a7dea167SDimitry Andric /// An emitter which links the program to bytecode for later use.
26a7dea167SDimitry Andric class ByteCodeEmitter {
27a7dea167SDimitry Andric protected:
28a7dea167SDimitry Andric   using LabelTy = uint32_t;
29a7dea167SDimitry Andric   using AddrTy = uintptr_t;
30a7dea167SDimitry Andric   using Local = Scope::Local;
31a7dea167SDimitry Andric 
32a7dea167SDimitry Andric public:
33a7dea167SDimitry Andric   /// Compiles the function into the module.
347a6dacacSDimitry Andric   Function *compileFunc(const FunctionDecl *FuncDecl);
35a7dea167SDimitry Andric 
36a7dea167SDimitry Andric protected:
37a7dea167SDimitry Andric   ByteCodeEmitter(Context &Ctx, Program &P) : Ctx(Ctx), P(P) {}
38a7dea167SDimitry Andric 
39a7dea167SDimitry Andric   virtual ~ByteCodeEmitter() {}
40a7dea167SDimitry Andric 
41a7dea167SDimitry Andric   /// Define a label.
42a7dea167SDimitry Andric   void emitLabel(LabelTy Label);
43a7dea167SDimitry Andric   /// Create a label.
44a7dea167SDimitry Andric   LabelTy getLabel() { return ++NextLabel; }
45a7dea167SDimitry Andric 
46a7dea167SDimitry Andric   /// Methods implemented by the compiler.
47a7dea167SDimitry Andric   virtual bool visitFunc(const FunctionDecl *E) = 0;
48a7dea167SDimitry Andric   virtual bool visitExpr(const Expr *E) = 0;
49*0fca6ea1SDimitry Andric   virtual bool visitDeclAndReturn(const VarDecl *E, bool ConstantContext) = 0;
50a7dea167SDimitry Andric 
51a7dea167SDimitry Andric   /// Emits jumps.
52a7dea167SDimitry Andric   bool jumpTrue(const LabelTy &Label);
53a7dea167SDimitry Andric   bool jumpFalse(const LabelTy &Label);
54a7dea167SDimitry Andric   bool jump(const LabelTy &Label);
55a7dea167SDimitry Andric   bool fallthrough(const LabelTy &Label);
56a7dea167SDimitry Andric 
57*0fca6ea1SDimitry Andric   /// We're always emitting bytecode.
58*0fca6ea1SDimitry Andric   bool isActive() const { return true; }
59*0fca6ea1SDimitry Andric 
60a7dea167SDimitry Andric   /// Callback for local registration.
61a7dea167SDimitry Andric   Local createLocal(Descriptor *D);
62a7dea167SDimitry Andric 
63a7dea167SDimitry Andric   /// Parameter indices.
645f757f3fSDimitry Andric   llvm::DenseMap<const ParmVarDecl *, ParamOffset> Params;
6506c3fb27SDimitry Andric   /// Lambda captures.
665f757f3fSDimitry Andric   llvm::DenseMap<const ValueDecl *, ParamOffset> LambdaCaptures;
675f757f3fSDimitry Andric   /// Offset of the This parameter in a lambda record.
68*0fca6ea1SDimitry Andric   ParamOffset LambdaThisCapture{0, false};
69a7dea167SDimitry Andric   /// Local descriptors.
70a7dea167SDimitry Andric   llvm::SmallVector<SmallVector<Local, 8>, 2> Descriptors;
71a7dea167SDimitry Andric 
72a7dea167SDimitry Andric private:
73a7dea167SDimitry Andric   /// Current compilation context.
74a7dea167SDimitry Andric   Context &Ctx;
75a7dea167SDimitry Andric   /// Program to link to.
76a7dea167SDimitry Andric   Program &P;
77a7dea167SDimitry Andric   /// Index of the next available label.
78a7dea167SDimitry Andric   LabelTy NextLabel = 0;
79a7dea167SDimitry Andric   /// Offset of the next local variable.
80a7dea167SDimitry Andric   unsigned NextLocalOffset = 0;
81a7dea167SDimitry Andric   /// Label information for linker.
82a7dea167SDimitry Andric   llvm::DenseMap<LabelTy, unsigned> LabelOffsets;
83a7dea167SDimitry Andric   /// Location of label relocations.
84a7dea167SDimitry Andric   llvm::DenseMap<LabelTy, llvm::SmallVector<unsigned, 5>> LabelRelocs;
85a7dea167SDimitry Andric   /// Program code.
8606c3fb27SDimitry Andric   std::vector<std::byte> Code;
87a7dea167SDimitry Andric   /// Opcode to expression mapping.
88a7dea167SDimitry Andric   SourceMap SrcMap;
89a7dea167SDimitry Andric 
90a7dea167SDimitry Andric   /// Returns the offset for a jump or records a relocation.
91a7dea167SDimitry Andric   int32_t getOffset(LabelTy Label);
92a7dea167SDimitry Andric 
93a7dea167SDimitry Andric   /// Emits an opcode.
94a7dea167SDimitry Andric   template <typename... Tys>
95a7dea167SDimitry Andric   bool emitOp(Opcode Op, const Tys &... Args, const SourceInfo &L);
96a7dea167SDimitry Andric 
97a7dea167SDimitry Andric protected:
98a7dea167SDimitry Andric #define GET_LINK_PROTO
99a7dea167SDimitry Andric #include "Opcodes.inc"
100a7dea167SDimitry Andric #undef GET_LINK_PROTO
101a7dea167SDimitry Andric };
102a7dea167SDimitry Andric 
103a7dea167SDimitry Andric } // namespace interp
104a7dea167SDimitry Andric } // namespace clang
105a7dea167SDimitry Andric 
106a7dea167SDimitry Andric #endif
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