1 //===-- DwarfException.h - Dwarf Exception Framework -----------*- 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 dwarf exception info into asm files.
10 //
11 //===----------------------------------------------------------------------===//
12 
13 #ifndef LLVM_LIB_CODEGEN_ASMPRINTER_DWARFEXCEPTION_H
14 #define LLVM_LIB_CODEGEN_ASMPRINTER_DWARFEXCEPTION_H
15 
16 #include "EHStreamer.h"
17 #include "llvm/CodeGen/AsmPrinter.h"
18 #include "llvm/MC/MCDwarf.h"
19 
20 namespace llvm {
21 class MachineFunction;
22 class ARMTargetStreamer;
23 
24 class LLVM_LIBRARY_VISIBILITY DwarfCFIExceptionBase : public EHStreamer {
25 protected:
26   DwarfCFIExceptionBase(AsmPrinter *A);
27 
28   /// Per-function flag to indicate if frame CFI info should be emitted.
29   bool shouldEmitCFI;
30   /// Per-module flag to indicate if .cfi_section has beeen emitted.
31   bool hasEmittedCFISections;
32 
33   void markFunctionEnd() override;
34   void endFragment() override;
35 };
36 
37 class LLVM_LIBRARY_VISIBILITY DwarfCFIException : public DwarfCFIExceptionBase {
38   /// Per-function flag to indicate if .cfi_personality should be emitted.
39   bool shouldEmitPersonality;
40 
41   /// Per-function flag to indicate if .cfi_personality must be emitted.
42   bool forceEmitPersonality;
43 
44   /// Per-function flag to indicate if .cfi_lsda should be emitted.
45   bool shouldEmitLSDA;
46 
47 public:
48   //===--------------------------------------------------------------------===//
49   // Main entry points.
50   //
51   DwarfCFIException(AsmPrinter *A);
52   ~DwarfCFIException() override;
53 
54   /// Emit all exception information that should come after the content.
55   void endModule() override;
56 
57   /// Gather pre-function exception information.  Assumes being emitted
58   /// immediately after the function entry point.
59   void beginFunction(const MachineFunction *MF) override;
60 
61   /// Gather and emit post-function exception information.
62   void endFunction(const MachineFunction *) override;
63 
64   void beginFragment(const MachineBasicBlock *MBB,
65                      ExceptionSymbolProvider ESP) override;
66 
67   void beginBasicBlock(const MachineBasicBlock &MBB) override;
68   void endBasicBlock(const MachineBasicBlock &MBB) override;
69 };
70 
71 class LLVM_LIBRARY_VISIBILITY ARMException : public DwarfCFIExceptionBase {
72   void emitTypeInfos(unsigned TTypeEncoding, MCSymbol *TTBaseLabel) override;
73   ARMTargetStreamer &getTargetStreamer();
74 
75 public:
76   //===--------------------------------------------------------------------===//
77   // Main entry points.
78   //
79   ARMException(AsmPrinter *A);
80   ~ARMException() override;
81 
82   /// Emit all exception information that should come after the content.
83   void endModule() override {}
84 
85   /// Gather pre-function exception information.  Assumes being emitted
86   /// immediately after the function entry point.
87   void beginFunction(const MachineFunction *MF) override;
88 
89   /// Gather and emit post-function exception information.
90   void endFunction(const MachineFunction *) override;
91 };
92 
93 class LLVM_LIBRARY_VISIBILITY AIXException : public DwarfCFIExceptionBase {
94   /// This is AIX's compat unwind section, which unwinder would use
95   /// to find the location of LSDA area and personality rountine.
96   void emitExceptionInfoTable(const MCSymbol *LSDA, const MCSymbol *PerSym);
97 
98 public:
99   AIXException(AsmPrinter *A);
100 
101   void endModule() override {}
102   void beginFunction(const MachineFunction *MF) override {}
103 
104   void endFunction(const MachineFunction *MF) override;
105 };
106 } // End of namespace llvm
107 
108 #endif
109