1 //===-- CommandFlags.cpp - Command Line Flags Interface ---------*- 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 codegen-specific flags that are shared between different
10 // command line tools. The tools "llc" and "opt" both use this file to prevent
11 // flag duplication.
12 //
13 //===----------------------------------------------------------------------===//
14 
15 #include "llvm/CodeGen/CommandFlags.h"
16 #include "llvm/IR/Module.h"
17 #include "llvm/MC/SubtargetFeature.h"
18 #include "llvm/Support/CommandLine.h"
19 #include "llvm/Support/Host.h"
20 
21 using namespace llvm;
22 
23 #define CGOPT(TY, NAME)                                                        \
24   static cl::opt<TY> *NAME##View;                                              \
25   TY codegen::get##NAME() {                                                    \
26     assert(NAME##View && "RegisterCodeGenFlags not created.");                 \
27     return *NAME##View;                                                        \
28   }
29 
30 #define CGLIST(TY, NAME)                                                       \
31   static cl::list<TY> *NAME##View;                                             \
32   std::vector<TY> codegen::get##NAME() {                                       \
33     assert(NAME##View && "RegisterCodeGenFlags not created.");                 \
34     return *NAME##View;                                                        \
35   }
36 
37 #define CGOPT_EXP(TY, NAME)                                                    \
38   CGOPT(TY, NAME)                                                              \
39   Optional<TY> codegen::getExplicit##NAME() {                                  \
40     if (NAME##View->getNumOccurrences()) {                                     \
41       TY res = *NAME##View;                                                    \
42       return res;                                                              \
43     }                                                                          \
44     return None;                                                               \
45   }
46 
47 CGOPT(std::string, MArch)
48 CGOPT(std::string, MCPU)
49 CGLIST(std::string, MAttrs)
50 CGOPT_EXP(Reloc::Model, RelocModel)
51 CGOPT(ThreadModel::Model, ThreadModel)
52 CGOPT_EXP(CodeModel::Model, CodeModel)
53 CGOPT(ExceptionHandling, ExceptionModel)
54 CGOPT_EXP(CodeGenFileType, FileType)
55 CGOPT(FramePointer::FP, FramePointerUsage)
56 CGOPT(bool, EnableUnsafeFPMath)
57 CGOPT(bool, EnableNoInfsFPMath)
58 CGOPT(bool, EnableNoNaNsFPMath)
59 CGOPT(bool, EnableNoSignedZerosFPMath)
60 CGOPT(bool, EnableNoTrappingFPMath)
61 CGOPT(bool, EnableAIXExtendedAltivecABI)
62 CGOPT(DenormalMode::DenormalModeKind, DenormalFPMath)
63 CGOPT(DenormalMode::DenormalModeKind, DenormalFP32Math)
64 CGOPT(bool, EnableHonorSignDependentRoundingFPMath)
65 CGOPT(FloatABI::ABIType, FloatABIForCalls)
66 CGOPT(FPOpFusion::FPOpFusionMode, FuseFPOps)
67 CGOPT(bool, DontPlaceZerosInBSS)
68 CGOPT(bool, EnableGuaranteedTailCallOpt)
69 CGOPT(bool, DisableTailCalls)
70 CGOPT(bool, StackSymbolOrdering)
71 CGOPT(unsigned, OverrideStackAlignment)
72 CGOPT(bool, StackRealign)
73 CGOPT(std::string, TrapFuncName)
74 CGOPT(bool, UseCtors)
75 CGOPT(bool, RelaxELFRelocations)
76 CGOPT_EXP(bool, DataSections)
77 CGOPT_EXP(bool, FunctionSections)
78 CGOPT(bool, IgnoreXCOFFVisibility)
79 CGOPT(std::string, BBSections)
80 CGOPT(std::string, StackProtectorGuard)
81 CGOPT(unsigned, StackProtectorGuardOffset)
82 CGOPT(std::string, StackProtectorGuardReg)
83 CGOPT(unsigned, TLSSize)
84 CGOPT(bool, EmulatedTLS)
85 CGOPT(bool, UniqueSectionNames)
86 CGOPT(bool, UniqueBasicBlockSectionNames)
87 CGOPT(EABI, EABIVersion)
88 CGOPT(DebuggerKind, DebuggerTuningOpt)
89 CGOPT(bool, EnableStackSizeSection)
90 CGOPT(bool, EnableAddrsig)
91 CGOPT(bool, EmitCallSiteInfo)
92 CGOPT(bool, EnableMachineFunctionSplitter)
93 CGOPT(bool, EnableDebugEntryValues)
94 CGOPT(bool, ValueTrackingVariableLocations)
95 CGOPT(bool, ForceDwarfFrameSection)
96 CGOPT(bool, XRayOmitFunctionIndex)
97 
98 codegen::RegisterCodeGenFlags::RegisterCodeGenFlags() {
99 #define CGBINDOPT(NAME)                                                        \
100   do {                                                                         \
101     NAME##View = std::addressof(NAME);                                         \
102   } while (0)
103 
104   static cl::opt<std::string> MArch(
105       "march", cl::desc("Architecture to generate code for (see --version)"));
106   CGBINDOPT(MArch);
107 
108   static cl::opt<std::string> MCPU(
109       "mcpu", cl::desc("Target a specific cpu type (-mcpu=help for details)"),
110       cl::value_desc("cpu-name"), cl::init(""));
111   CGBINDOPT(MCPU);
112 
113   static cl::list<std::string> MAttrs(
114       "mattr", cl::CommaSeparated,
115       cl::desc("Target specific attributes (-mattr=help for details)"),
116       cl::value_desc("a1,+a2,-a3,..."));
117   CGBINDOPT(MAttrs);
118 
119   static cl::opt<Reloc::Model> RelocModel(
120       "relocation-model", cl::desc("Choose relocation model"),
121       cl::values(
122           clEnumValN(Reloc::Static, "static", "Non-relocatable code"),
123           clEnumValN(Reloc::PIC_, "pic",
124                      "Fully relocatable, position independent code"),
125           clEnumValN(Reloc::DynamicNoPIC, "dynamic-no-pic",
126                      "Relocatable external references, non-relocatable code"),
127           clEnumValN(
128               Reloc::ROPI, "ropi",
129               "Code and read-only data relocatable, accessed PC-relative"),
130           clEnumValN(
131               Reloc::RWPI, "rwpi",
132               "Read-write data relocatable, accessed relative to static base"),
133           clEnumValN(Reloc::ROPI_RWPI, "ropi-rwpi",
134                      "Combination of ropi and rwpi")));
135   CGBINDOPT(RelocModel);
136 
137   static cl::opt<ThreadModel::Model> ThreadModel(
138       "thread-model", cl::desc("Choose threading model"),
139       cl::init(ThreadModel::POSIX),
140       cl::values(
141           clEnumValN(ThreadModel::POSIX, "posix", "POSIX thread model"),
142           clEnumValN(ThreadModel::Single, "single", "Single thread model")));
143   CGBINDOPT(ThreadModel);
144 
145   static cl::opt<CodeModel::Model> CodeModel(
146       "code-model", cl::desc("Choose code model"),
147       cl::values(clEnumValN(CodeModel::Tiny, "tiny", "Tiny code model"),
148                  clEnumValN(CodeModel::Small, "small", "Small code model"),
149                  clEnumValN(CodeModel::Kernel, "kernel", "Kernel code model"),
150                  clEnumValN(CodeModel::Medium, "medium", "Medium code model"),
151                  clEnumValN(CodeModel::Large, "large", "Large code model")));
152   CGBINDOPT(CodeModel);
153 
154   static cl::opt<ExceptionHandling> ExceptionModel(
155       "exception-model", cl::desc("exception model"),
156       cl::init(ExceptionHandling::None),
157       cl::values(
158           clEnumValN(ExceptionHandling::None, "default",
159                      "default exception handling model"),
160           clEnumValN(ExceptionHandling::DwarfCFI, "dwarf",
161                      "DWARF-like CFI based exception handling"),
162           clEnumValN(ExceptionHandling::SjLj, "sjlj",
163                      "SjLj exception handling"),
164           clEnumValN(ExceptionHandling::ARM, "arm", "ARM EHABI exceptions"),
165           clEnumValN(ExceptionHandling::WinEH, "wineh",
166                      "Windows exception model"),
167           clEnumValN(ExceptionHandling::Wasm, "wasm",
168                      "WebAssembly exception handling")));
169   CGBINDOPT(ExceptionModel);
170 
171   static cl::opt<CodeGenFileType> FileType(
172       "filetype", cl::init(CGFT_AssemblyFile),
173       cl::desc(
174           "Choose a file type (not all types are supported by all targets):"),
175       cl::values(
176           clEnumValN(CGFT_AssemblyFile, "asm", "Emit an assembly ('.s') file"),
177           clEnumValN(CGFT_ObjectFile, "obj",
178                      "Emit a native object ('.o') file"),
179           clEnumValN(CGFT_Null, "null",
180                      "Emit nothing, for performance testing")));
181   CGBINDOPT(FileType);
182 
183   static cl::opt<FramePointer::FP> FramePointerUsage(
184       "frame-pointer",
185       cl::desc("Specify frame pointer elimination optimization"),
186       cl::init(FramePointer::None),
187       cl::values(
188           clEnumValN(FramePointer::All, "all",
189                      "Disable frame pointer elimination"),
190           clEnumValN(FramePointer::NonLeaf, "non-leaf",
191                      "Disable frame pointer elimination for non-leaf frame"),
192           clEnumValN(FramePointer::None, "none",
193                      "Enable frame pointer elimination")));
194   CGBINDOPT(FramePointerUsage);
195 
196   static cl::opt<bool> EnableUnsafeFPMath(
197       "enable-unsafe-fp-math",
198       cl::desc("Enable optimizations that may decrease FP precision"),
199       cl::init(false));
200   CGBINDOPT(EnableUnsafeFPMath);
201 
202   static cl::opt<bool> EnableNoInfsFPMath(
203       "enable-no-infs-fp-math",
204       cl::desc("Enable FP math optimizations that assume no +-Infs"),
205       cl::init(false));
206   CGBINDOPT(EnableNoInfsFPMath);
207 
208   static cl::opt<bool> EnableNoNaNsFPMath(
209       "enable-no-nans-fp-math",
210       cl::desc("Enable FP math optimizations that assume no NaNs"),
211       cl::init(false));
212   CGBINDOPT(EnableNoNaNsFPMath);
213 
214   static cl::opt<bool> EnableNoSignedZerosFPMath(
215       "enable-no-signed-zeros-fp-math",
216       cl::desc("Enable FP math optimizations that assume "
217                "the sign of 0 is insignificant"),
218       cl::init(false));
219   CGBINDOPT(EnableNoSignedZerosFPMath);
220 
221   static cl::opt<bool> EnableNoTrappingFPMath(
222       "enable-no-trapping-fp-math",
223       cl::desc("Enable setting the FP exceptions build "
224                "attribute not to use exceptions"),
225       cl::init(false));
226   CGBINDOPT(EnableNoTrappingFPMath);
227 
228   static const auto DenormFlagEnumOptions =
229   cl::values(clEnumValN(DenormalMode::IEEE, "ieee",
230                         "IEEE 754 denormal numbers"),
231              clEnumValN(DenormalMode::PreserveSign, "preserve-sign",
232                         "the sign of a  flushed-to-zero number is preserved "
233                         "in the sign of 0"),
234              clEnumValN(DenormalMode::PositiveZero, "positive-zero",
235                         "denormals are flushed to positive zero"));
236 
237   // FIXME: Doesn't have way to specify separate input and output modes.
238   static cl::opt<DenormalMode::DenormalModeKind> DenormalFPMath(
239     "denormal-fp-math",
240     cl::desc("Select which denormal numbers the code is permitted to require"),
241     cl::init(DenormalMode::IEEE),
242     DenormFlagEnumOptions);
243   CGBINDOPT(DenormalFPMath);
244 
245   static cl::opt<DenormalMode::DenormalModeKind> DenormalFP32Math(
246     "denormal-fp-math-f32",
247     cl::desc("Select which denormal numbers the code is permitted to require for float"),
248     cl::init(DenormalMode::Invalid),
249     DenormFlagEnumOptions);
250   CGBINDOPT(DenormalFP32Math);
251 
252   static cl::opt<bool> EnableHonorSignDependentRoundingFPMath(
253       "enable-sign-dependent-rounding-fp-math", cl::Hidden,
254       cl::desc("Force codegen to assume rounding mode can change dynamically"),
255       cl::init(false));
256   CGBINDOPT(EnableHonorSignDependentRoundingFPMath);
257 
258   static cl::opt<FloatABI::ABIType> FloatABIForCalls(
259       "float-abi", cl::desc("Choose float ABI type"),
260       cl::init(FloatABI::Default),
261       cl::values(clEnumValN(FloatABI::Default, "default",
262                             "Target default float ABI type"),
263                  clEnumValN(FloatABI::Soft, "soft",
264                             "Soft float ABI (implied by -soft-float)"),
265                  clEnumValN(FloatABI::Hard, "hard",
266                             "Hard float ABI (uses FP registers)")));
267   CGBINDOPT(FloatABIForCalls);
268 
269   static cl::opt<FPOpFusion::FPOpFusionMode> FuseFPOps(
270       "fp-contract", cl::desc("Enable aggressive formation of fused FP ops"),
271       cl::init(FPOpFusion::Standard),
272       cl::values(
273           clEnumValN(FPOpFusion::Fast, "fast",
274                      "Fuse FP ops whenever profitable"),
275           clEnumValN(FPOpFusion::Standard, "on", "Only fuse 'blessed' FP ops."),
276           clEnumValN(FPOpFusion::Strict, "off",
277                      "Only fuse FP ops when the result won't be affected.")));
278   CGBINDOPT(FuseFPOps);
279 
280   static cl::opt<bool> DontPlaceZerosInBSS(
281       "nozero-initialized-in-bss",
282       cl::desc("Don't place zero-initialized symbols into bss section"),
283       cl::init(false));
284   CGBINDOPT(DontPlaceZerosInBSS);
285 
286   static cl::opt<bool> EnableAIXExtendedAltivecABI(
287       "vec-extabi", cl::desc("Enable the AIX Extended Altivec ABI."),
288       cl::init(false));
289   CGBINDOPT(EnableAIXExtendedAltivecABI);
290 
291   static cl::opt<bool> EnableGuaranteedTailCallOpt(
292       "tailcallopt",
293       cl::desc(
294           "Turn fastcc calls into tail calls by (potentially) changing ABI."),
295       cl::init(false));
296   CGBINDOPT(EnableGuaranteedTailCallOpt);
297 
298   static cl::opt<bool> DisableTailCalls(
299       "disable-tail-calls", cl::desc("Never emit tail calls"), cl::init(false));
300   CGBINDOPT(DisableTailCalls);
301 
302   static cl::opt<bool> StackSymbolOrdering(
303       "stack-symbol-ordering", cl::desc("Order local stack symbols."),
304       cl::init(true));
305   CGBINDOPT(StackSymbolOrdering);
306 
307   static cl::opt<unsigned> OverrideStackAlignment(
308       "stack-alignment", cl::desc("Override default stack alignment"),
309       cl::init(0));
310   CGBINDOPT(OverrideStackAlignment);
311 
312   static cl::opt<bool> StackRealign(
313       "stackrealign",
314       cl::desc("Force align the stack to the minimum alignment"),
315       cl::init(false));
316   CGBINDOPT(StackRealign);
317 
318   static cl::opt<std::string> TrapFuncName(
319       "trap-func", cl::Hidden,
320       cl::desc("Emit a call to trap function rather than a trap instruction"),
321       cl::init(""));
322   CGBINDOPT(TrapFuncName);
323 
324   static cl::opt<bool> UseCtors("use-ctors",
325                                 cl::desc("Use .ctors instead of .init_array."),
326                                 cl::init(false));
327   CGBINDOPT(UseCtors);
328 
329   static cl::opt<bool> RelaxELFRelocations(
330       "relax-elf-relocations",
331       cl::desc(
332           "Emit GOTPCRELX/REX_GOTPCRELX instead of GOTPCREL on x86-64 ELF"),
333       cl::init(false));
334   CGBINDOPT(RelaxELFRelocations);
335 
336   static cl::opt<bool> DataSections(
337       "data-sections", cl::desc("Emit data into separate sections"),
338       cl::init(false));
339   CGBINDOPT(DataSections);
340 
341   static cl::opt<bool> FunctionSections(
342       "function-sections", cl::desc("Emit functions into separate sections"),
343       cl::init(false));
344   CGBINDOPT(FunctionSections);
345 
346   static cl::opt<bool> IgnoreXCOFFVisibility(
347       "ignore-xcoff-visibility",
348       cl::desc("Not emit the visibility attribute for asm in AIX OS or give "
349                "all symbols 'unspecified' visibility in XCOFF object file"),
350       cl::init(false));
351   CGBINDOPT(IgnoreXCOFFVisibility);
352 
353   static cl::opt<std::string> BBSections(
354       "basic-block-sections",
355       cl::desc("Emit basic blocks into separate sections"),
356       cl::value_desc("all | <function list (file)> | labels | none"),
357       cl::init("none"));
358   CGBINDOPT(BBSections);
359 
360   static cl::opt<std::string> StackProtectorGuard(
361       "stack-protector-guard", cl::desc("Stack protector guard mode"),
362       cl::init("none"));
363   CGBINDOPT(StackProtectorGuard);
364 
365   static cl::opt<std::string> StackProtectorGuardReg(
366       "stack-protector-guard-reg", cl::desc("Stack protector guard register"),
367       cl::init("none"));
368   CGBINDOPT(StackProtectorGuardReg);
369 
370   static cl::opt<unsigned> StackProtectorGuardOffset(
371       "stack-protector-guard-offset", cl::desc("Stack protector guard offset"),
372       cl::init((unsigned)-1));
373   CGBINDOPT(StackProtectorGuardOffset);
374 
375   static cl::opt<unsigned> TLSSize(
376       "tls-size", cl::desc("Bit size of immediate TLS offsets"), cl::init(0));
377   CGBINDOPT(TLSSize);
378 
379   static cl::opt<bool> EmulatedTLS(
380       "emulated-tls", cl::desc("Use emulated TLS model"), cl::init(false));
381   CGBINDOPT(EmulatedTLS);
382 
383   static cl::opt<bool> UniqueSectionNames(
384       "unique-section-names", cl::desc("Give unique names to every section"),
385       cl::init(true));
386   CGBINDOPT(UniqueSectionNames);
387 
388   static cl::opt<bool> UniqueBasicBlockSectionNames(
389       "unique-basic-block-section-names",
390       cl::desc("Give unique names to every basic block section"),
391       cl::init(false));
392   CGBINDOPT(UniqueBasicBlockSectionNames);
393 
394   static cl::opt<EABI> EABIVersion(
395       "meabi", cl::desc("Set EABI type (default depends on triple):"),
396       cl::init(EABI::Default),
397       cl::values(
398           clEnumValN(EABI::Default, "default", "Triple default EABI version"),
399           clEnumValN(EABI::EABI4, "4", "EABI version 4"),
400           clEnumValN(EABI::EABI5, "5", "EABI version 5"),
401           clEnumValN(EABI::GNU, "gnu", "EABI GNU")));
402   CGBINDOPT(EABIVersion);
403 
404   static cl::opt<DebuggerKind> DebuggerTuningOpt(
405       "debugger-tune", cl::desc("Tune debug info for a particular debugger"),
406       cl::init(DebuggerKind::Default),
407       cl::values(
408           clEnumValN(DebuggerKind::GDB, "gdb", "gdb"),
409           clEnumValN(DebuggerKind::LLDB, "lldb", "lldb"),
410           clEnumValN(DebuggerKind::SCE, "sce", "SCE targets (e.g. PS4)")));
411   CGBINDOPT(DebuggerTuningOpt);
412 
413   static cl::opt<bool> EnableStackSizeSection(
414       "stack-size-section",
415       cl::desc("Emit a section containing stack size metadata"),
416       cl::init(false));
417   CGBINDOPT(EnableStackSizeSection);
418 
419   static cl::opt<bool> EnableAddrsig(
420       "addrsig", cl::desc("Emit an address-significance table"),
421       cl::init(false));
422   CGBINDOPT(EnableAddrsig);
423 
424   static cl::opt<bool> EmitCallSiteInfo(
425       "emit-call-site-info",
426       cl::desc(
427           "Emit call site debug information, if debug information is enabled."),
428       cl::init(false));
429   CGBINDOPT(EmitCallSiteInfo);
430 
431   static cl::opt<bool> EnableDebugEntryValues(
432       "debug-entry-values",
433       cl::desc("Enable debug info for the debug entry values."),
434       cl::init(false));
435   CGBINDOPT(EnableDebugEntryValues);
436 
437   static cl::opt<bool> ValueTrackingVariableLocations(
438       "experimental-debug-variable-locations",
439       cl::desc("Use experimental new value-tracking variable locations"),
440       cl::init(false));
441   CGBINDOPT(ValueTrackingVariableLocations);
442 
443   static cl::opt<bool> EnableMachineFunctionSplitter(
444       "split-machine-functions",
445       cl::desc("Split out cold basic blocks from machine functions based on "
446                "profile information"),
447       cl::init(false));
448   CGBINDOPT(EnableMachineFunctionSplitter);
449 
450   static cl::opt<bool> ForceDwarfFrameSection(
451       "force-dwarf-frame-section",
452       cl::desc("Always emit a debug frame section."), cl::init(false));
453   CGBINDOPT(ForceDwarfFrameSection);
454 
455   static cl::opt<bool> XRayOmitFunctionIndex(
456       "no-xray-index", cl::desc("Don't emit xray_fn_idx section"),
457       cl::init(false));
458   CGBINDOPT(XRayOmitFunctionIndex);
459 
460 #undef CGBINDOPT
461 
462   mc::RegisterMCTargetOptionsFlags();
463 }
464 
465 llvm::BasicBlockSection
466 codegen::getBBSectionsMode(llvm::TargetOptions &Options) {
467   if (getBBSections() == "all")
468     return BasicBlockSection::All;
469   else if (getBBSections() == "labels")
470     return BasicBlockSection::Labels;
471   else if (getBBSections() == "none")
472     return BasicBlockSection::None;
473   else {
474     ErrorOr<std::unique_ptr<MemoryBuffer>> MBOrErr =
475         MemoryBuffer::getFile(getBBSections());
476     if (!MBOrErr) {
477       errs() << "Error loading basic block sections function list file: "
478              << MBOrErr.getError().message() << "\n";
479     } else {
480       Options.BBSectionsFuncListBuf = std::move(*MBOrErr);
481     }
482     return BasicBlockSection::List;
483   }
484 }
485 
486 llvm::StackProtectorGuards
487 codegen::getStackProtectorGuardMode(llvm::TargetOptions &Options) {
488   if (getStackProtectorGuard() == "tls")
489     return StackProtectorGuards::TLS;
490   if (getStackProtectorGuard() == "global")
491     return StackProtectorGuards::Global;
492   if (getStackProtectorGuard() != "none") {
493     ErrorOr<std::unique_ptr<MemoryBuffer>> MBOrErr =
494         MemoryBuffer::getFile(getStackProtectorGuard());
495     if (!MBOrErr)
496       errs() << "error illegal stack protector guard mode: "
497              << MBOrErr.getError().message() << "\n";
498     else
499       Options.BBSectionsFuncListBuf = std::move(*MBOrErr);
500   }
501   return StackProtectorGuards::None;
502 }
503 
504 // Common utility function tightly tied to the options listed here. Initializes
505 // a TargetOptions object with CodeGen flags and returns it.
506 TargetOptions
507 codegen::InitTargetOptionsFromCodeGenFlags(const Triple &TheTriple) {
508   TargetOptions Options;
509   Options.AllowFPOpFusion = getFuseFPOps();
510   Options.UnsafeFPMath = getEnableUnsafeFPMath();
511   Options.NoInfsFPMath = getEnableNoInfsFPMath();
512   Options.NoNaNsFPMath = getEnableNoNaNsFPMath();
513   Options.NoSignedZerosFPMath = getEnableNoSignedZerosFPMath();
514   Options.NoTrappingFPMath = getEnableNoTrappingFPMath();
515 
516   DenormalMode::DenormalModeKind DenormKind = getDenormalFPMath();
517 
518   // FIXME: Should have separate input and output flags
519   Options.setFPDenormalMode(DenormalMode(DenormKind, DenormKind));
520 
521   Options.HonorSignDependentRoundingFPMathOption =
522       getEnableHonorSignDependentRoundingFPMath();
523   if (getFloatABIForCalls() != FloatABI::Default)
524     Options.FloatABIType = getFloatABIForCalls();
525   Options.EnableAIXExtendedAltivecABI = getEnableAIXExtendedAltivecABI();
526   Options.NoZerosInBSS = getDontPlaceZerosInBSS();
527   Options.GuaranteedTailCallOpt = getEnableGuaranteedTailCallOpt();
528   Options.StackAlignmentOverride = getOverrideStackAlignment();
529   Options.StackSymbolOrdering = getStackSymbolOrdering();
530   Options.UseInitArray = !getUseCtors();
531   Options.RelaxELFRelocations = getRelaxELFRelocations();
532   Options.DataSections =
533       getExplicitDataSections().getValueOr(TheTriple.hasDefaultDataSections());
534   Options.FunctionSections = getFunctionSections();
535   Options.IgnoreXCOFFVisibility = getIgnoreXCOFFVisibility();
536   Options.BBSections = getBBSectionsMode(Options);
537   Options.UniqueSectionNames = getUniqueSectionNames();
538   Options.UniqueBasicBlockSectionNames = getUniqueBasicBlockSectionNames();
539   Options.StackProtectorGuard = getStackProtectorGuardMode(Options);
540   Options.StackProtectorGuardOffset = getStackProtectorGuardOffset();
541   Options.StackProtectorGuardReg = getStackProtectorGuardReg();
542   Options.TLSSize = getTLSSize();
543   Options.EmulatedTLS = getEmulatedTLS();
544   Options.ExplicitEmulatedTLS = EmulatedTLSView->getNumOccurrences() > 0;
545   Options.ExceptionModel = getExceptionModel();
546   Options.EmitStackSizeSection = getEnableStackSizeSection();
547   Options.EnableMachineFunctionSplitter = getEnableMachineFunctionSplitter();
548   Options.EmitAddrsig = getEnableAddrsig();
549   Options.EmitCallSiteInfo = getEmitCallSiteInfo();
550   Options.EnableDebugEntryValues = getEnableDebugEntryValues();
551   Options.ValueTrackingVariableLocations = getValueTrackingVariableLocations();
552   Options.ForceDwarfFrameSection = getForceDwarfFrameSection();
553   Options.XRayOmitFunctionIndex = getXRayOmitFunctionIndex();
554 
555   Options.MCOptions = mc::InitMCTargetOptionsFromFlags();
556 
557   Options.ThreadModel = getThreadModel();
558   Options.EABIVersion = getEABIVersion();
559   Options.DebuggerTuning = getDebuggerTuningOpt();
560 
561   return Options;
562 }
563 
564 std::string codegen::getCPUStr() {
565   // If user asked for the 'native' CPU, autodetect here. If autodection fails,
566   // this will set the CPU to an empty string which tells the target to
567   // pick a basic default.
568   if (getMCPU() == "native")
569     return std::string(sys::getHostCPUName());
570 
571   return getMCPU();
572 }
573 
574 std::string codegen::getFeaturesStr() {
575   SubtargetFeatures Features;
576 
577   // If user asked for the 'native' CPU, we need to autodetect features.
578   // This is necessary for x86 where the CPU might not support all the
579   // features the autodetected CPU name lists in the target. For example,
580   // not all Sandybridge processors support AVX.
581   if (getMCPU() == "native") {
582     StringMap<bool> HostFeatures;
583     if (sys::getHostCPUFeatures(HostFeatures))
584       for (auto &F : HostFeatures)
585         Features.AddFeature(F.first(), F.second);
586   }
587 
588   for (auto const &MAttr : getMAttrs())
589     Features.AddFeature(MAttr);
590 
591   return Features.getString();
592 }
593 
594 std::vector<std::string> codegen::getFeatureList() {
595   SubtargetFeatures Features;
596 
597   // If user asked for the 'native' CPU, we need to autodetect features.
598   // This is necessary for x86 where the CPU might not support all the
599   // features the autodetected CPU name lists in the target. For example,
600   // not all Sandybridge processors support AVX.
601   if (getMCPU() == "native") {
602     StringMap<bool> HostFeatures;
603     if (sys::getHostCPUFeatures(HostFeatures))
604       for (auto &F : HostFeatures)
605         Features.AddFeature(F.first(), F.second);
606   }
607 
608   for (auto const &MAttr : getMAttrs())
609     Features.AddFeature(MAttr);
610 
611   return Features.getFeatures();
612 }
613 
614 void codegen::renderBoolStringAttr(AttrBuilder &B, StringRef Name, bool Val) {
615   B.addAttribute(Name, Val ? "true" : "false");
616 }
617 
618 #define HANDLE_BOOL_ATTR(CL, AttrName)                                         \
619   do {                                                                         \
620     if (CL->getNumOccurrences() > 0 && !F.hasFnAttribute(AttrName))            \
621       renderBoolStringAttr(NewAttrs, AttrName, *CL);                           \
622   } while (0)
623 
624 /// Set function attributes of function \p F based on CPU, Features, and command
625 /// line flags.
626 void codegen::setFunctionAttributes(StringRef CPU, StringRef Features,
627                                     Function &F) {
628   auto &Ctx = F.getContext();
629   AttributeList Attrs = F.getAttributes();
630   AttrBuilder NewAttrs;
631 
632   if (!CPU.empty() && !F.hasFnAttribute("target-cpu"))
633     NewAttrs.addAttribute("target-cpu", CPU);
634   if (!Features.empty()) {
635     // Append the command line features to any that are already on the function.
636     StringRef OldFeatures =
637         F.getFnAttribute("target-features").getValueAsString();
638     if (OldFeatures.empty())
639       NewAttrs.addAttribute("target-features", Features);
640     else {
641       SmallString<256> Appended(OldFeatures);
642       Appended.push_back(',');
643       Appended.append(Features);
644       NewAttrs.addAttribute("target-features", Appended);
645     }
646   }
647   if (FramePointerUsageView->getNumOccurrences() > 0 &&
648       !F.hasFnAttribute("frame-pointer")) {
649     if (getFramePointerUsage() == FramePointer::All)
650       NewAttrs.addAttribute("frame-pointer", "all");
651     else if (getFramePointerUsage() == FramePointer::NonLeaf)
652       NewAttrs.addAttribute("frame-pointer", "non-leaf");
653     else if (getFramePointerUsage() == FramePointer::None)
654       NewAttrs.addAttribute("frame-pointer", "none");
655   }
656   if (DisableTailCallsView->getNumOccurrences() > 0)
657     NewAttrs.addAttribute("disable-tail-calls",
658                           toStringRef(getDisableTailCalls()));
659   if (getStackRealign())
660     NewAttrs.addAttribute("stackrealign");
661 
662   HANDLE_BOOL_ATTR(EnableUnsafeFPMathView, "unsafe-fp-math");
663   HANDLE_BOOL_ATTR(EnableNoInfsFPMathView, "no-infs-fp-math");
664   HANDLE_BOOL_ATTR(EnableNoNaNsFPMathView, "no-nans-fp-math");
665   HANDLE_BOOL_ATTR(EnableNoSignedZerosFPMathView, "no-signed-zeros-fp-math");
666 
667   if (DenormalFPMathView->getNumOccurrences() > 0 &&
668       !F.hasFnAttribute("denormal-fp-math")) {
669     DenormalMode::DenormalModeKind DenormKind = getDenormalFPMath();
670 
671     // FIXME: Command line flag should expose separate input/output modes.
672     NewAttrs.addAttribute("denormal-fp-math",
673                           DenormalMode(DenormKind, DenormKind).str());
674   }
675 
676   if (DenormalFP32MathView->getNumOccurrences() > 0 &&
677       !F.hasFnAttribute("denormal-fp-math-f32")) {
678     // FIXME: Command line flag should expose separate input/output modes.
679     DenormalMode::DenormalModeKind DenormKind = getDenormalFP32Math();
680 
681     NewAttrs.addAttribute(
682       "denormal-fp-math-f32",
683       DenormalMode(DenormKind, DenormKind).str());
684   }
685 
686   if (TrapFuncNameView->getNumOccurrences() > 0)
687     for (auto &B : F)
688       for (auto &I : B)
689         if (auto *Call = dyn_cast<CallInst>(&I))
690           if (const auto *F = Call->getCalledFunction())
691             if (F->getIntrinsicID() == Intrinsic::debugtrap ||
692                 F->getIntrinsicID() == Intrinsic::trap)
693               Call->addAttribute(
694                   AttributeList::FunctionIndex,
695                   Attribute::get(Ctx, "trap-func-name", getTrapFuncName()));
696 
697   // Let NewAttrs override Attrs.
698   F.setAttributes(
699       Attrs.addAttributes(Ctx, AttributeList::FunctionIndex, NewAttrs));
700 }
701 
702 /// Set function attributes of functions in Module M based on CPU,
703 /// Features, and command line flags.
704 void codegen::setFunctionAttributes(StringRef CPU, StringRef Features,
705                                     Module &M) {
706   for (Function &F : M)
707     setFunctionAttributes(CPU, Features, F);
708 }
709