LLVM  3.7.0
X86MCAsmInfo.cpp
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1 //===-- X86MCAsmInfo.cpp - X86 asm properties -----------------------------===//
2 //
3 // The LLVM Compiler Infrastructure
4 //
5 // This file is distributed under the University of Illinois Open Source
6 // License. See LICENSE.TXT for details.
7 //
8 //===----------------------------------------------------------------------===//
9 //
10 // This file contains the declarations of the X86MCAsmInfo properties.
11 //
12 //===----------------------------------------------------------------------===//
13 
14 #include "X86MCAsmInfo.h"
15 #include "llvm/ADT/Triple.h"
16 #include "llvm/MC/MCContext.h"
17 #include "llvm/MC/MCExpr.h"
18 #include "llvm/MC/MCSectionELF.h"
19 #include "llvm/MC/MCStreamer.h"
21 #include "llvm/Support/ELF.h"
22 using namespace llvm;
23 
25  // Note: This numbering has to match the GCC assembler dialects for inline
26  // asm alternatives to work right.
27  ATT = 0, Intel = 1
28 };
29 
31 AsmWriterFlavor("x86-asm-syntax", cl::init(ATT),
32  cl::desc("Choose style of code to emit from X86 backend:"),
33  cl::values(clEnumValN(ATT, "att", "Emit AT&T-style assembly"),
34  clEnumValN(Intel, "intel", "Emit Intel-style assembly"),
35  clEnumValEnd));
36 
37 static cl::opt<bool>
38 MarkedJTDataRegions("mark-data-regions", cl::init(false),
39  cl::desc("Mark code section jump table data regions."),
40  cl::Hidden);
41 
42 void X86MCAsmInfoDarwin::anchor() { }
43 
45  bool is64Bit = T.getArch() == Triple::x86_64;
46  if (is64Bit)
48 
50 
51  TextAlignFillValue = 0x90;
52 
53  if (!is64Bit)
54  Data64bitsDirective = nullptr; // we can't emit a 64-bit unit
55 
56  // Use ## as a comment string so that .s files generated by llvm can go
57  // through the GCC preprocessor without causing an error. This is needed
58  // because "clang foo.s" runs the C preprocessor, which is usually reserved
59  // for .S files on other systems. Perhaps this is because the file system
60  // wasn't always case preserving or something.
61  CommentString = "##";
62 
65 
66  // Exceptions handling
68 
69  // old assembler lacks some directives
70  // FIXME: this should really be a check on the assembler characteristics
71  // rather than OS version
72  if (T.isMacOSX() && T.isMacOSXVersionLT(10, 6))
74 
75  // Assume ld64 is new enough that the abs-ified FDE relocs may be used
76  // (actually, must, since otherwise the non-extern relocations we produce
77  // overwhelm ld64's tiny little mind and it fails).
79 
81 }
82 
84  : X86MCAsmInfoDarwin(Triple) {
85 }
86 
87 void X86ELFMCAsmInfo::anchor() { }
88 
90  bool is64Bit = T.getArch() == Triple::x86_64;
91  bool isX32 = T.getEnvironment() == Triple::GNUX32;
92 
93  // For ELF, x86-64 pointer size depends on the ABI.
94  // For x86-64 without the x32 ABI, pointer size is 8. For x86 and for x86-64
95  // with the x32 ABI, pointer size remains the default 4.
96  PointerSize = (is64Bit && !isX32) ? 8 : 4;
97 
98  // OTOH, stack slot size is always 8 for x86-64, even with the x32 ABI.
99  CalleeSaveStackSlotSize = is64Bit ? 8 : 4;
100 
102 
103  TextAlignFillValue = 0x90;
104 
105  // Debug Information
107 
108  // Exceptions handling
110 
111  // Always enable the integrated assembler by default.
112  // Clang also enabled it when the OS is Solaris but that is redundant here.
113  UseIntegratedAssembler = true;
114 }
115 
116 const MCExpr *
118  unsigned Encoding,
119  MCStreamer &Streamer) const {
120  MCContext &Context = Streamer.getContext();
121  const MCExpr *Res =
123  const MCExpr *Four = MCConstantExpr::create(4, Context);
124  return MCBinaryExpr::createAdd(Res, Four, Context);
125 }
126 
127 void X86MCAsmInfoMicrosoft::anchor() { }
128 
130  if (Triple.getArch() == Triple::x86_64) {
131  PrivateGlobalPrefix = ".L";
132  PrivateLabelPrefix = ".L";
133  PointerSize = 8;
135  } else {
136  // 32-bit X86 doesn't use CFI, so this isn't a real encoding type. It's just
137  // a place holder that the Windows EHStreamer looks for to suppress CFI
138  // output. In particular, usesWindowsCFI() returns false.
140  }
141 
143 
145 
146  TextAlignFillValue = 0x90;
147 
148  AllowAtInName = true;
149 
150  UseIntegratedAssembler = true;
151 }
152 
153 void X86MCAsmInfoGNUCOFF::anchor() { }
154 
156  assert(Triple.isOSWindows() && "Windows is the only supported COFF target");
157  if (Triple.getArch() == Triple::x86_64) {
158  PrivateGlobalPrefix = ".L";
159  PrivateLabelPrefix = ".L";
160  PointerSize = 8;
163  } else {
165  }
166 
168 
169  TextAlignFillValue = 0x90;
170 
171  UseIntegratedAssembler = true;
172 }
ValuesClass< DataType > LLVM_END_WITH_NULL values(const char *Arg, DataType Val, const char *Desc,...)
Definition: CommandLine.h:536
unsigned TextAlignFillValue
If non-zero, this is used to fill the executable space created as the result of a alignment directive...
Definition: MCAsmInfo.h:225
bool UseIntegratedAssembler
Should we use the integrated assembler? The integrated assembler should be enabled by default (by the...
Definition: MCAsmInfo.h:353
static const MCSymbolRefExpr * create(const MCSymbol *Symbol, MCContext &Ctx)
Definition: MCExpr.h:315
MCSymbol - Instances of this class represent a symbol name in the MC file, and MCSymbols are created ...
Definition: MCSymbol.h:39
#define clEnumValEnd
Definition: CommandLine.h:498
const char * Data64bitsDirective
Definition: MCAsmInfo.h:191
static cl::opt< bool > MarkedJTDataRegions("mark-data-regions", cl::init(false), cl::desc("Mark code section jump table data regions."), cl::Hidden)
unsigned CalleeSaveStackSlotSize
Size of the stack slot reserved for callee-saved registers, in bytes.
Definition: MCAsmInfo.h:69
unsigned AssemblerDialect
Which dialect of an assembler variant to use. Defaults to 0.
Definition: MCAsmInfo.h:152
bool HasWeakDefCanBeHiddenDirective
True if we have a directive to declare a global as being a weak defined symbol that can be hidden (un...
Definition: MCAsmInfo.h:296
const MCExpr * getExprForPersonalitySymbol(const MCSymbol *Sym, unsigned Encoding, MCStreamer &Streamer) const override
const char * PrivateGlobalPrefix
This prefix is used for globals like constant pool entries that are completely private to the ...
Definition: MCAsmInfo.h:127
bool isOSWindows() const
Tests whether the OS is Windows.
Definition: Triple.h:464
X86_64MCAsmInfoDarwin(const Triple &Triple)
bool isMacOSX() const
isMacOSX - Is this a Mac OS X triple.
Definition: Triple.h:394
Base class for the full range of assembler expressions which are needed for parsing.
Definition: MCExpr.h:33
X86MCAsmInfoMicrosoft(const Triple &Triple)
MCContext & getContext() const
Definition: MCStreamer.h:210
Context object for machine code objects.
Definition: MCContext.h:48
unsigned isMacOSXVersionLT(unsigned Major, unsigned Minor=0, unsigned Micro=0) const
isMacOSXVersionLT - Comparison function for checking OS X version compatibility, which handles suppor...
Definition: Triple.h:379
const char * CommentString
This indicates the comment character used by the assembler.
Definition: MCAsmInfo.h:113
ArchType getArch() const
getArch - Get the parsed architecture type of this triple.
Definition: Triple.h:242
static const MCBinaryExpr * createAdd(const MCExpr *LHS, const MCExpr *RHS, MCContext &Ctx)
Definition: MCExpr.h:446
AsmWriterFlavorTy
initializer< Ty > init(const Ty &Val)
Definition: CommandLine.h:325
Streaming machine code generation interface.
Definition: MCStreamer.h:157
unsigned PointerSize
Pointer size in bytes. Default is 4.
Definition: MCAsmInfo.h:65
static bool is64Bit(const char *name)
bool AllowAtInName
This is true if the assembler allows @ characters in symbol names.
Definition: MCAsmInfo.h:156
bool SupportsDebugInformation
True if target supports emission of debugging information.
Definition: MCAsmInfo.h:318
X86ELFMCAsmInfo(const Triple &Triple)
WinEH::EncodingType WinEHEncodingType
Windows exception handling data (.pdata) encoding. Defaults to Invalid.
Definition: MCAsmInfo.h:324
Windows x64, Windows Itanium (IA-64)
Triple - Helper class for working with autoconf configuration names.
Definition: Triple.h:44
bool DwarfFDESymbolsUseAbsDiff
True if DWARF FDE symbol reference relocations should be replaced by an absolute difference.
Definition: MCAsmInfo.h:332
X86MCAsmInfoDarwin(const Triple &Triple)
#define clEnumValN(ENUMVAL, FLAGNAME, DESC)
Definition: CommandLine.h:497
ExceptionHandling ExceptionsType
Exception handling format for the target. Defaults to None.
Definition: MCAsmInfo.h:321
bool UseDataRegionDirectives
This is true if data region markers should be printed as ".data_region/.end_data_region" directives...
Definition: MCAsmInfo.h:165
X86MCAsmInfoGNUCOFF(const Triple &Triple)
EnvironmentType getEnvironment() const
getEnvironment - Get the parsed environment type of this triple.
Definition: Triple.h:260
Windows CE ARM, PowerPC, SH3, SH4.
No exception support.
const char * PrivateLabelPrefix
This prefix is used for labels for basic blocks.
Definition: MCAsmInfo.h:131
static cl::opt< AsmWriterFlavorTy > AsmWriterFlavor("x86-asm-syntax", cl::init(ATT), cl::desc("Choose style of code to emit from X86 backend:"), cl::values(clEnumValN(ATT,"att","Emit AT&T-style assembly"), clEnumValN(Intel,"intel","Emit Intel-style assembly"), clEnumValEnd))
static const MCConstantExpr * create(int64_t Value, MCContext &Ctx)
Definition: MCExpr.cpp:150