clang 19.0.0git
EvalEmitter.h
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1//===--- EvalEmitter.h - Instruction emitter 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 the instruction emitters.
10//
11//===----------------------------------------------------------------------===//
12
13#ifndef LLVM_CLANG_AST_INTERP_EVALEMITTER_H
14#define LLVM_CLANG_AST_INTERP_EVALEMITTER_H
15
16#include "EvaluationResult.h"
17#include "InterpState.h"
18#include "PrimType.h"
19#include "Source.h"
20#include "llvm/Support/Error.h"
21
22namespace clang {
23namespace interp {
24class Context;
25class Function;
26class InterpStack;
27class Program;
28enum Opcode : uint32_t;
29
30/// An emitter which evaluates opcodes as they are emitted.
31class EvalEmitter : public SourceMapper {
32public:
33 using LabelTy = uint32_t;
36
38 bool ConvertResultToRValue = false);
39 EvaluationResult interpretDecl(const VarDecl *VD, bool CheckFullyInitialized);
40
41 InterpState &getState() { return S; }
42
43protected:
45
46 virtual ~EvalEmitter();
47
48 /// Define a label.
50 /// Create a label.
52
53 /// Methods implemented by the compiler.
54 virtual bool visitExpr(const Expr *E) = 0;
55 virtual bool visitDecl(const VarDecl *VD) = 0;
56
57 /// Emits jumps.
58 bool jumpTrue(const LabelTy &Label);
59 bool jumpFalse(const LabelTy &Label);
60 bool jump(const LabelTy &Label);
61 bool fallthrough(const LabelTy &Label);
62
63 /// Callback for registering a local.
65
66 /// Returns the source location of the current opcode.
67 SourceInfo getSource(const Function *F, CodePtr PC) const override {
68 return (F && F->hasBody()) ? F->getSource(PC) : CurrentSource;
69 }
70
71 /// Parameter indices.
72 llvm::DenseMap<const ParmVarDecl *, ParamOffset> Params;
73 /// Lambda captures.
74 llvm::DenseMap<const ValueDecl *, ParamOffset> LambdaCaptures;
75 /// Offset of the This parameter in a lambda record.
77 /// Local descriptors.
79
80private:
81 /// Current compilation context.
82 Context &Ctx;
83 /// Current program.
84 Program &P;
85 /// Callee evaluation state.
87 /// Location to write the result to.
88 EvaluationResult EvalResult;
89 /// Whether the result should be converted to an RValue.
90 bool ConvertResultToRValue = false;
91 /// Whether we should check if the result has been fully
92 /// initialized.
93 bool CheckFullyInitialized = false;
94
95 /// Temporaries which require storage.
96 llvm::DenseMap<unsigned, std::unique_ptr<char[]>> Locals;
97
98 Block *getLocal(unsigned Index) const {
99 auto It = Locals.find(Index);
100 assert(It != Locals.end() && "Missing local variable");
101 return reinterpret_cast<Block *>(It->second.get());
102 }
103
104 // The emitter always tracks the current instruction and sets OpPC to a token
105 // value which is mapped to the location of the opcode being evaluated.
106 CodePtr OpPC;
107 /// Location of the current instruction.
108 SourceInfo CurrentSource;
109
110 /// Next label ID to generate - first label is 1.
111 LabelTy NextLabel = 1;
112 /// Label being executed - 0 is the entry label.
113 LabelTy CurrentLabel = 0;
114 /// Active block which should be executed.
115 LabelTy ActiveLabel = 0;
116
117 /// Since expressions can only jump forward, predicated execution is
118 /// used to deal with if-else statements.
119 bool isActive() const { return CurrentLabel == ActiveLabel; }
120
121protected:
122#define GET_EVAL_PROTO
123#include "Opcodes.inc"
124#undef GET_EVAL_PROTO
125};
126
127} // namespace interp
128} // namespace clang
129
130#endif
NodeId Parent
Definition: ASTDiff.cpp:191
std::string Label
This represents one expression.
Definition: Expr.h:110
Represents a variable declaration or definition.
Definition: Decl.h:918
A memory block, either on the stack or in the heap.
Definition: InterpBlock.h:49
Pointer into the code segment.
Definition: Source.h:30
Holds all information required to evaluate constexpr code in a module.
Definition: Context.h:40
An emitter which evaluates opcodes as they are emitted.
Definition: EvalEmitter.h:31
bool jump(const LabelTy &Label)
EvaluationResult interpretExpr(const Expr *E, bool ConvertResultToRValue=false)
Definition: EvalEmitter.cpp:35
EvaluationResult interpretDecl(const VarDecl *VD, bool CheckFullyInitialized)
Definition: EvalEmitter.cpp:50
virtual bool visitExpr(const Expr *E)=0
Methods implemented by the compiler.
bool jumpFalse(const LabelTy &Label)
Local createLocal(Descriptor *D)
Callback for registering a local.
Definition: EvalEmitter.cpp:71
void emitLabel(LabelTy Label)
Define a label.
Definition: EvalEmitter.cpp:65
bool fallthrough(const LabelTy &Label)
LabelTy getLabel()
Create a label.
Definition: EvalEmitter.cpp:69
llvm::DenseMap< const ValueDecl *, ParamOffset > LambdaCaptures
Lambda captures.
Definition: EvalEmitter.h:74
llvm::DenseMap< const ParmVarDecl *, ParamOffset > Params
Parameter indices.
Definition: EvalEmitter.h:72
ParamOffset LambdaThisCapture
Offset of the This parameter in a lambda record.
Definition: EvalEmitter.h:76
SourceInfo getSource(const Function *F, CodePtr PC) const override
Returns the source location of the current opcode.
Definition: EvalEmitter.h:67
llvm::SmallVector< SmallVector< Local, 8 >, 2 > Descriptors
Local descriptors.
Definition: EvalEmitter.h:78
virtual bool visitDecl(const VarDecl *VD)=0
bool jumpTrue(const LabelTy &Label)
Emits jumps.
Definition: EvalEmitter.cpp:93
InterpState & getState()
Definition: EvalEmitter.h:41
Defines the result of an evaluation.
Bytecode function.
Definition: Function.h:77
bool hasBody() const
Checks if the function already has a body attached.
Definition: Function.h:174
SourceInfo getSource(CodePtr PC) const
Returns the source information at a given PC.
Definition: Function.cpp:36
Stack frame storing temporaries and parameters.
Definition: InterpStack.h:26
Interpreter context.
Definition: InterpState.h:35
The program contains and links the bytecode for all functions.
Definition: Program.h:39
Describes the statement/declaration an opcode was generated from.
Definition: Source.h:72
Interface for classes which map locations to sources.
Definition: Source.h:94
Interface for the VM to interact with the AST walker's context.
Definition: State.h:55
The JSON file list parser is used to communicate input to InstallAPI.
__UINTPTR_TYPE__ uintptr_t
An unsigned integer type with the property that any valid pointer to void can be converted to this ty...
Describes a memory block created by an allocation site.
Definition: Descriptor.h:91
Information about a local's storage.
Definition: Function.h:38