1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
|
//===--- InterpFrame.h - Call Frame implementation for the VM ---*- C++ -*-===//
//
// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
// See https://llvm.org/LICENSE.txt for license information.
// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
//
//===----------------------------------------------------------------------===//
//
// Defines the class storing information about stack frames in the interpreter.
//
//===----------------------------------------------------------------------===//
#ifndef LLVM_CLANG_AST_INTERP_INTERPFRAME_H
#define LLVM_CLANG_AST_INTERP_INTERPFRAME_H
#include "Frame.h"
#include "Program.h"
namespace clang {
namespace interp {
class Function;
class InterpState;
class Pointer;
/// Frame storing local variables.
class InterpFrame final : public Frame {
public:
/// The frame of the previous function.
InterpFrame *Caller;
/// Bottom Frame.
InterpFrame(InterpState &S);
/// Creates a new frame for a method call.
InterpFrame(InterpState &S, const Function *Func, InterpFrame *Caller,
CodePtr RetPC, unsigned ArgSize);
/// Creates a new frame with the values that make sense.
/// I.e., the caller is the current frame of S,
/// the This() pointer is the current Pointer on the top of S's stack,
/// and the RVO pointer is before that.
InterpFrame(InterpState &S, const Function *Func, CodePtr RetPC,
unsigned VarArgSize = 0);
/// Destroys the frame, killing all live pointers to stack slots.
~InterpFrame();
static void free(InterpFrame *F) {
if (!F->isBottomFrame())
delete F;
}
/// Invokes the destructors for a scope.
void destroy(unsigned Idx);
void initScope(unsigned Idx);
void destroyScopes();
/// Describes the frame with arguments for diagnostic purposes.
void describe(llvm::raw_ostream &OS) const override;
/// Returns the parent frame object.
Frame *getCaller() const override;
/// Returns the location of the call to the frame.
SourceRange getCallRange() const override;
/// Returns the caller.
const FunctionDecl *getCallee() const override;
/// Returns the current function.
const Function *getFunction() const { return Func; }
/// Returns the offset on the stack at which the frame starts.
size_t getFrameOffset() const { return FrameOffset; }
/// Returns the value of a local variable.
template <typename T> const T &getLocal(unsigned Offset) const {
return localRef<T>(Offset);
}
/// Mutates a local variable.
template <typename T> void setLocal(unsigned Offset, const T &Value) {
localRef<T>(Offset) = Value;
localInlineDesc(Offset)->IsInitialized = true;
}
/// Returns a pointer to a local variables.
Pointer getLocalPointer(unsigned Offset) const;
/// Returns the value of an argument.
template <typename T> const T &getParam(unsigned Offset) const {
auto Pt = Params.find(Offset);
if (Pt == Params.end())
return stackRef<T>(Offset);
return Pointer(reinterpret_cast<Block *>(Pt->second.get())).deref<T>();
}
/// Mutates a local copy of a parameter.
template <typename T> void setParam(unsigned Offset, const T &Value) {
getParamPointer(Offset).deref<T>() = Value;
}
/// Returns a pointer to an argument - lazily creates a block.
Pointer getParamPointer(unsigned Offset);
/// Returns the 'this' pointer.
const Pointer &getThis() const { return This; }
/// Returns the RVO pointer, if the Function has one.
const Pointer &getRVOPtr() const { return RVOPtr; }
/// Checks if the frame is a root frame - return should quit the interpreter.
bool isRoot() const { return !Func; }
/// Returns the PC of the frame's code start.
CodePtr getPC() const { return Func->getCodeBegin(); }
/// Returns the return address of the frame.
CodePtr getRetPC() const { return RetPC; }
/// Map a location to a source.
SourceInfo getSource(CodePtr PC) const;
const Expr *getExpr(CodePtr PC) const;
SourceLocation getLocation(CodePtr PC) const;
SourceRange getRange(CodePtr PC) const;
unsigned getDepth() const { return Depth; }
bool isStdFunction() const;
bool isBottomFrame() const { return IsBottom; }
void dump() const { dump(llvm::errs(), 0); }
void dump(llvm::raw_ostream &OS, unsigned Indent = 0) const;
private:
/// Returns an original argument from the stack.
template <typename T> const T &stackRef(unsigned Offset) const {
assert(Args);
return *reinterpret_cast<const T *>(Args - ArgSize + Offset);
}
/// Returns an offset to a local.
template <typename T> T &localRef(unsigned Offset) const {
return getLocalPointer(Offset).deref<T>();
}
/// Returns a pointer to a local's block.
Block *localBlock(unsigned Offset) const {
return reinterpret_cast<Block *>(Locals.get() + Offset - sizeof(Block));
}
/// Returns the inline descriptor of the local.
InlineDescriptor *localInlineDesc(unsigned Offset) const {
return reinterpret_cast<InlineDescriptor *>(Locals.get() + Offset);
}
private:
/// Reference to the interpreter state.
InterpState &S;
/// Depth of this frame.
unsigned Depth;
/// Reference to the function being executed.
const Function *Func;
/// Current object pointer for methods.
Pointer This;
/// Pointer the non-primitive return value gets constructed in.
Pointer RVOPtr;
/// Return address.
CodePtr RetPC;
/// The size of all the arguments.
const unsigned ArgSize;
/// Pointer to the arguments in the callee's frame.
char *Args = nullptr;
/// Fixed, initial storage for known local variables.
std::unique_ptr<char[]> Locals;
/// Offset on the stack at entry.
const size_t FrameOffset;
/// Mapping from arg offsets to their argument blocks.
llvm::DenseMap<unsigned, std::unique_ptr<char[]>> Params;
bool IsBottom = false;
};
} // namespace interp
} // namespace clang
#endif
|
