xref: /netbsd-src/external/apache2/llvm/dist/llvm/lib/CodeGen/AsmPrinter/WinException.h (revision 82d56013d7b633d116a93943de88e08335357a7c)
1 //===-- WinException.h - Windows Exception Handling ----------*- 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 // This file contains support for writing windows exception info into asm files.
10 //
11 //===----------------------------------------------------------------------===//
12 
13 #ifndef LLVM_LIB_CODEGEN_ASMPRINTER_WIN64EXCEPTION_H
14 #define LLVM_LIB_CODEGEN_ASMPRINTER_WIN64EXCEPTION_H
15 
16 #include "EHStreamer.h"
17 
18 namespace llvm {
19 class GlobalValue;
20 class MachineFunction;
21 class MCExpr;
22 class MCSection;
23 struct WinEHFuncInfo;
24 
25 class LLVM_LIBRARY_VISIBILITY WinException : public EHStreamer {
26   /// Per-function flag to indicate if personality info should be emitted.
27   bool shouldEmitPersonality = false;
28 
29   /// Per-function flag to indicate if the LSDA should be emitted.
30   bool shouldEmitLSDA = false;
31 
32   /// Per-function flag to indicate if frame moves info should be emitted.
33   bool shouldEmitMoves = false;
34 
35   /// True if this is a 64-bit target and we should use image relative offsets.
36   bool useImageRel32 = false;
37 
38   /// True if we are generating exception handling on Windows for ARM64.
39   bool isAArch64 = false;
40 
41   /// Pointer to the current funclet entry BB.
42   const MachineBasicBlock *CurrentFuncletEntry = nullptr;
43 
44   /// The section of the last funclet start.
45   MCSection *CurrentFuncletTextSection = nullptr;
46 
47   /// The list of symbols to add to the ehcont section
48   std::vector<const MCSymbol *> EHContTargets;
49 
50   void emitCSpecificHandlerTable(const MachineFunction *MF);
51 
52   void emitSEHActionsForRange(const WinEHFuncInfo &FuncInfo,
53                               const MCSymbol *BeginLabel,
54                               const MCSymbol *EndLabel, int State);
55 
56   /// Emit the EH table data for 32-bit and 64-bit functions using
57   /// the __CxxFrameHandler3 personality.
58   void emitCXXFrameHandler3Table(const MachineFunction *MF);
59 
60   /// Emit the EH table data for _except_handler3 and _except_handler4
61   /// personality functions. These are only used on 32-bit and do not use CFI
62   /// tables.
63   void emitExceptHandlerTable(const MachineFunction *MF);
64 
65   void emitCLRExceptionTable(const MachineFunction *MF);
66 
67   void computeIP2StateTable(
68       const MachineFunction *MF, const WinEHFuncInfo &FuncInfo,
69       SmallVectorImpl<std::pair<const MCExpr *, int>> &IPToStateTable);
70 
71   /// Emits the label used with llvm.eh.recoverfp, which is used by
72   /// outlined funclets.
73   void emitEHRegistrationOffsetLabel(const WinEHFuncInfo &FuncInfo,
74                                      StringRef FLinkageName);
75 
76   const MCExpr *create32bitRef(const MCSymbol *Value);
77   const MCExpr *create32bitRef(const GlobalValue *GV);
78   const MCExpr *getLabel(const MCSymbol *Label);
79   const MCExpr *getOffset(const MCSymbol *OffsetOf, const MCSymbol *OffsetFrom);
80   const MCExpr *getOffsetPlusOne(const MCSymbol *OffsetOf,
81                                  const MCSymbol *OffsetFrom);
82 
83   /// Gets the offset that we should use in a table for a stack object with the
84   /// given index. For targets using CFI (Win64, etc), this is relative to the
85   /// established SP at the end of the prologue. For targets without CFI (Win32
86   /// only), it is relative to the frame pointer.
87   int getFrameIndexOffset(int FrameIndex, const WinEHFuncInfo &FuncInfo);
88 
89   void endFuncletImpl();
90 public:
91   //===--------------------------------------------------------------------===//
92   // Main entry points.
93   //
94   WinException(AsmPrinter *A);
95   ~WinException() override;
96 
97   /// Emit all exception information that should come after the content.
98   void endModule() override;
99 
100   /// Gather pre-function exception information.  Assumes being emitted
101   /// immediately after the function entry point.
102   void beginFunction(const MachineFunction *MF) override;
103 
104   void markFunctionEnd() override;
105 
106   /// Gather and emit post-function exception information.
107   void endFunction(const MachineFunction *) override;
108 
109   /// Emit target-specific EH funclet machinery.
110   void beginFunclet(const MachineBasicBlock &MBB, MCSymbol *Sym) override;
111   void endFunclet() override;
112 };
113 }
114 
115 #endif
116 
117