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
|
//===-- ARMSjLjLoweringPass.cpp - ARM SjLj Lowering Pass ------------------===//
//
// The LLVM Compiler Infrastructure
//
// This file is distributed under the University of Illinois Open Source
// License. See LICENSE.TXT for details.
//
//===----------------------------------------------------------------------===//
//
// This file contains a pass that lowers the SjLj exception handling into
// machine instructions.
//
//===----------------------------------------------------------------------===//
#define DEBUG_TYPE "arm-sjlj-lowering"
#include "ARM.h"
#include "llvm/Function.h"
#include "llvm/CodeGen/MachineFrameInfo.h"
#include "llvm/CodeGen/MachineFunction.h"
#include "llvm/CodeGen/MachineFunctionPass.h"
#include "llvm/Target/TargetData.h"
#include "llvm/Target/TargetLowering.h"
#include "llvm/Support/CommandLine.h"
using namespace llvm;
// Hidden options for the new EH stuff.
static cl::opt<bool>
EnableNewSjLjEHPrepare("enable-new-sjlj-eh", cl::Hidden,
cl::desc("Use the new SjLj EH preparation pass"));
namespace {
class ARMSjLjLowering : public MachineFunctionPass {
Type *FunctionCtxTy;
LLVMContext *Context;
MachineFunction *MF;
const Function *F;
const TargetLowering *TLI;
const TargetInstrInfo *TII;
const TargetRegisterInfo *TRI;
/// setupFunctionContext - Setup the function context on the stack. Some of
/// the fields were set by the SjLj EH prepare pass.
int setupFunctionContext();
public:
static char ID;
ARMSjLjLowering() : MachineFunctionPass(ID) {}
virtual bool runOnMachineFunction(MachineFunction &mf);
virtual const char *getPassName() const {
return "ARM setjmp/longjmp exception handling lowering pass";
}
};
char ARMSjLjLowering::ID = 0;
} // end anonymous namespace
FunctionPass *llvm::createARMSjLjLoweringPass() {
return new ARMSjLjLowering();
}
bool ARMSjLjLowering::runOnMachineFunction(MachineFunction &mf) {
if (!EnableNewSjLjEHPrepare) return false;
MF = &mf;
F = MF->getFunction();
Context = &F->getContext();
TLI = MF->getTarget().getTargetLowering();
TII = MF->getTarget().getInstrInfo();
TRI = MF->getTarget().getRegisterInfo();
// Perform the lowering only if there are invokes.
bool HasInvokes = false;
for (Function::const_iterator BB = F->begin(), E = F->end(); BB != E; ++BB)
if (isa<InvokeInst>(BB->getTerminator())) {
HasInvokes = true;
break;
}
if (!HasInvokes) return false;
int FrameIdx = setupFunctionContext(); (void)FrameIdx;
return true;
}
/// setupFunctionContext - Create the function context on the stack.
int ARMSjLjLowering::setupFunctionContext() {
// struct _Unwind_FunctionContext {
// // next function in stack of handlers.
// struct _Unwind_FunctionContext *prev;
//
// // set by calling function before registering to be the landing pad.
// uintptr_t resumeLocation;
//
// // set by personality handler to be parameters passed to landing pad
// // function.
// uintptr_t resumeParameters[4];
//
// // set by calling function before registering
// __personality_routine personality; // arm offset=24
//
// uintptr_t lsda // arm offset=28
//
// // variable length array, contains registers to restore
// // 0 = r7, 1 = pc, 2 = sp
// void *jbuf[]; // 5 for GCC compatibility.
// };
Type *VoidPtrTy = Type::getInt8PtrTy(*Context);
Type *Int32Ty = Type::getInt32Ty(*Context);
FunctionCtxTy =
StructType::get(VoidPtrTy, // prev
Int32Ty, // resumeLocation
ArrayType::get(Int32Ty, 4), // resumeParameters
VoidPtrTy, // personality
VoidPtrTy, // lsda
ArrayType::get(VoidPtrTy, 5), // jbuf
NULL);
uint64_t TySize = TLI->getTargetData()->getTypeAllocSize(FunctionCtxTy);
unsigned Align = TLI->getTargetData()->getPrefTypeAlignment(FunctionCtxTy);
return MF->getFrameInfo()->CreateStackObject(TySize, Align, false, false);
}
|
