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