1 //===-- AsmPrinterDwarf.cpp - AsmPrinter Dwarf Support --------------------===//
3 // The LLVM Compiler Infrastructure
5 // This file is distributed under the University of Illinois Open Source
6 // License. See LICENSE.TXT for details.
8 //===----------------------------------------------------------------------===//
10 // This file implements the Dwarf emissions parts of AsmPrinter.
12 //===----------------------------------------------------------------------===//
14 #define DEBUG_TYPE "asm-printer"
15 #include "llvm/CodeGen/AsmPrinter.h"
16 #include "llvm/MC/MCAsmInfo.h"
17 #include "llvm/MC/MCStreamer.h"
18 #include "llvm/ADT/Twine.h"
19 #include "llvm/Support/Dwarf.h"
22 /// EmitSLEB128 - emit the specified signed leb128 value.
23 void AsmPrinter::EmitSLEB128(int Value, const char *Desc) const {
24 if (isVerbose() && Desc)
25 OutStreamer.AddComment(Desc);
27 if (MAI->hasLEB128()) {
29 OutStreamer.EmitRawText("\t.sleb128\t" + Twine(Value));
33 // If we don't have .sleb128, emit as .bytes.
34 int Sign = Value >> (8 * sizeof(Value) - 1);
38 unsigned char Byte = static_cast<unsigned char>(Value & 0x7f);
40 IsMore = Value != Sign || ((Byte ^ Sign) & 0x40) != 0;
41 if (IsMore) Byte |= 0x80;
42 OutStreamer.EmitIntValue(Byte, 1, /*addrspace*/0);
46 /// EmitULEB128 - emit the specified signed leb128 value.
47 void AsmPrinter::EmitULEB128(unsigned Value, const char *Desc,
48 unsigned PadTo) const {
49 if (isVerbose() && Desc)
50 OutStreamer.AddComment(Desc);
52 if (MAI->hasLEB128() && PadTo == 0) {
54 OutStreamer.EmitRawText("\t.uleb128\t" + Twine(Value));
58 // If we don't have .uleb128 or we want to emit padding, emit as .bytes.
60 unsigned char Byte = static_cast<unsigned char>(Value & 0x7f);
62 if (Value || PadTo != 0) Byte |= 0x80;
63 OutStreamer.EmitIntValue(Byte, 1, /*addrspace*/0);
68 OutStreamer.EmitFill(PadTo - 1, 0x80/*fillval*/, 0/*addrspace*/);
69 OutStreamer.EmitFill(1, 0/*fillval*/, 0/*addrspace*/);
73 /// EmitCFAByte - Emit a .byte 42 directive for a DW_CFA_xxx value.
74 void AsmPrinter::EmitCFAByte(unsigned Val) const {
76 if (Val >= dwarf::DW_CFA_offset && Val < dwarf::DW_CFA_offset+64)
77 OutStreamer.AddComment("DW_CFA_offset + Reg (" +
78 Twine(Val-dwarf::DW_CFA_offset) + ")");
80 OutStreamer.AddComment(dwarf::CallFrameString(Val));
82 OutStreamer.EmitIntValue(Val, 1, 0/*addrspace*/);
85 static const char *DecodeDWARFEncoding(unsigned Encoding) {
87 case dwarf::DW_EH_PE_absptr: return "absptr";
88 case dwarf::DW_EH_PE_omit: return "omit";
89 case dwarf::DW_EH_PE_pcrel: return "pcrel";
90 case dwarf::DW_EH_PE_udata4: return "udata4";
91 case dwarf::DW_EH_PE_udata8: return "udata8";
92 case dwarf::DW_EH_PE_sdata4: return "sdata4";
93 case dwarf::DW_EH_PE_sdata8: return "sdata8";
94 case dwarf::DW_EH_PE_pcrel | dwarf::DW_EH_PE_udata4: return "pcrel udata4";
95 case dwarf::DW_EH_PE_pcrel | dwarf::DW_EH_PE_sdata4: return "pcrel sdata4";
96 case dwarf::DW_EH_PE_pcrel | dwarf::DW_EH_PE_udata8: return "pcrel udata8";
97 case dwarf::DW_EH_PE_pcrel | dwarf::DW_EH_PE_sdata8: return "pcrel sdata8";
98 case dwarf::DW_EH_PE_indirect | dwarf::DW_EH_PE_pcrel |dwarf::DW_EH_PE_udata4:
99 return "indirect pcrel udata4";
100 case dwarf::DW_EH_PE_indirect | dwarf::DW_EH_PE_pcrel |dwarf::DW_EH_PE_sdata4:
101 return "indirect pcrel sdata4";
102 case dwarf::DW_EH_PE_indirect | dwarf::DW_EH_PE_pcrel |dwarf::DW_EH_PE_udata8:
103 return "indirect pcrel udata8";
104 case dwarf::DW_EH_PE_indirect | dwarf::DW_EH_PE_pcrel |dwarf::DW_EH_PE_sdata8:
105 return "indirect pcrel sdata8";
108 return "<unknown encoding>";
112 /// EmitEncodingByte - Emit a .byte 42 directive that corresponds to an
113 /// encoding. If verbose assembly output is enabled, we output comments
114 /// describing the encoding. Desc is an optional string saying what the
115 /// encoding is specifying (e.g. "LSDA").
116 void AsmPrinter::EmitEncodingByte(unsigned Val, const char *Desc) {
119 OutStreamer.AddComment(Twine(Desc)+" Encoding = " +
120 Twine(DecodeDWARFEncoding(Val)));
122 OutStreamer.AddComment(Twine("Encoding = ") +
123 DecodeDWARFEncoding(Val));
126 OutStreamer.EmitIntValue(Val, 1, 0/*addrspace*/);