xref: /freebsd/contrib/llvm-project/llvm/lib/CodeGen/AsmPrinter/WinException.h (revision 0b57cec536236d46e3dba9bd041533462f33dbb7)
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 Function;
20 class GlobalValue;
21 class MachineFunction;
22 class MCExpr;
23 class MCSection;
24 class Value;
25 struct WinEHFuncInfo;
26 
27 class LLVM_LIBRARY_VISIBILITY WinException : public EHStreamer {
28   /// Per-function flag to indicate if personality info should be emitted.
29   bool shouldEmitPersonality = false;
30 
31   /// Per-function flag to indicate if the LSDA should be emitted.
32   bool shouldEmitLSDA = false;
33 
34   /// Per-function flag to indicate if frame moves info should be emitted.
35   bool shouldEmitMoves = false;
36 
37   /// True if this is a 64-bit target and we should use image relative offsets.
38   bool useImageRel32 = false;
39 
40   /// True if we are generating exception handling on Windows for ARM64.
41   bool isAArch64 = false;
42 
43   /// Pointer to the current funclet entry BB.
44   const MachineBasicBlock *CurrentFuncletEntry = nullptr;
45 
46   /// The section of the last funclet start.
47   MCSection *CurrentFuncletTextSection = nullptr;
48 
49   void emitCSpecificHandlerTable(const MachineFunction *MF);
50 
51   void emitSEHActionsForRange(const WinEHFuncInfo &FuncInfo,
52                               const MCSymbol *BeginLabel,
53                               const MCSymbol *EndLabel, int State);
54 
55   /// Emit the EH table data for 32-bit and 64-bit functions using
56   /// the __CxxFrameHandler3 personality.
57   void emitCXXFrameHandler3Table(const MachineFunction *MF);
58 
59   /// Emit the EH table data for _except_handler3 and _except_handler4
60   /// personality functions. These are only used on 32-bit and do not use CFI
61   /// tables.
62   void emitExceptHandlerTable(const MachineFunction *MF);
63 
64   void emitCLRExceptionTable(const MachineFunction *MF);
65 
66   void computeIP2StateTable(
67       const MachineFunction *MF, const WinEHFuncInfo &FuncInfo,
68       SmallVectorImpl<std::pair<const MCExpr *, int>> &IPToStateTable);
69 
70   /// Emits the label used with llvm.eh.recoverfp, which is used by
71   /// outlined funclets.
72   void emitEHRegistrationOffsetLabel(const WinEHFuncInfo &FuncInfo,
73                                      StringRef FLinkageName);
74 
75   const MCExpr *create32bitRef(const MCSymbol *Value);
76   const MCExpr *create32bitRef(const GlobalValue *GV);
77   const MCExpr *getLabel(const MCSymbol *Label);
78   const MCExpr *getOffset(const MCSymbol *OffsetOf, const MCSymbol *OffsetFrom);
79   const MCExpr *getOffsetPlusOne(const MCSymbol *OffsetOf,
80                                  const MCSymbol *OffsetFrom);
81 
82   /// Gets the offset that we should use in a table for a stack object with the
83   /// given index. For targets using CFI (Win64, etc), this is relative to the
84   /// established SP at the end of the prologue. For targets without CFI (Win32
85   /// only), it is relative to the frame pointer.
86   int getFrameIndexOffset(int FrameIndex, const WinEHFuncInfo &FuncInfo);
87 
88   void endFuncletImpl();
89 public:
90   //===--------------------------------------------------------------------===//
91   // Main entry points.
92   //
93   WinException(AsmPrinter *A);
94   ~WinException() override;
95 
96   /// Emit all exception information that should come after the content.
97   void endModule() override;
98 
99   /// Gather pre-function exception information.  Assumes being emitted
100   /// immediately after the function entry point.
101   void beginFunction(const MachineFunction *MF) override;
102 
103   void markFunctionEnd() override;
104 
105   /// Gather and emit post-function exception information.
106   void endFunction(const MachineFunction *) override;
107 
108   /// Emit target-specific EH funclet machinery.
109   void beginFunclet(const MachineBasicBlock &MBB, MCSymbol *Sym) override;
110   void endFunclet() override;
111 };
112 }
113 
114 #endif
115 
116