1//===-- CommandFlags.h - Command Line Flags Interface -----------*- C++ -*-===//
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 codegen-specific flags that are shared between different
11// command line tools. The tools "llc" and "opt" both use this file to prevent
12// flag duplication.
13//
14//===----------------------------------------------------------------------===//
15
16#include "llvm/ADT/StringExtras.h"
17#include "llvm/IR/Instructions.h"
18#include "llvm/IR/Intrinsics.h"
19#include "llvm/IR/Module.h"
20#include "llvm/MC/MCTargetOptionsCommandFlags.inc"
21#include "llvm/MC/SubtargetFeature.h"
22#include "llvm/Support/CodeGen.h"
23#include "llvm/Support/CommandLine.h"
24#include "llvm/Support/Host.h"
25#include "llvm/Target/TargetMachine.h"
26#include "llvm/Target/TargetOptions.h"
27#include <string>
28using namespace llvm;
29
30static cl::opt<std::string>
31    MArch("march",
32          cl::desc("Architecture to generate code for (see --version)"));
33
34static cl::opt<std::string>
35    MCPU("mcpu",
36         cl::desc("Target a specific cpu type (-mcpu=help for details)"),
37         cl::value_desc("cpu-name"), cl::init(""));
38
39static cl::list<std::string>
40    MAttrs("mattr", cl::CommaSeparated,
41           cl::desc("Target specific attributes (-mattr=help for details)"),
42           cl::value_desc("a1,+a2,-a3,..."));
43
44static cl::opt<Reloc::Model> RelocModel(
45    "relocation-model", cl::desc("Choose relocation model"),
46    cl::values(
47        clEnumValN(Reloc::Static, "static", "Non-relocatable code"),
48        clEnumValN(Reloc::PIC_, "pic",
49                   "Fully relocatable, position independent code"),
50        clEnumValN(Reloc::DynamicNoPIC, "dynamic-no-pic",
51                   "Relocatable external references, non-relocatable code"),
52        clEnumValN(Reloc::ROPI, "ropi",
53                   "Code and read-only data relocatable, accessed PC-relative"),
54        clEnumValN(
55            Reloc::RWPI, "rwpi",
56            "Read-write data relocatable, accessed relative to static base"),
57        clEnumValN(Reloc::ROPI_RWPI, "ropi-rwpi",
58                   "Combination of ropi and rwpi")));
59
60LLVM_ATTRIBUTE_UNUSED static Optional<Reloc::Model> getRelocModel() {
61  if (RelocModel.getNumOccurrences()) {
62    Reloc::Model R = RelocModel;
63    return R;
64  }
65  return None;
66}
67
68static cl::opt<ThreadModel::Model> TMModel(
69    "thread-model", cl::desc("Choose threading model"),
70    cl::init(ThreadModel::POSIX),
71    cl::values(clEnumValN(ThreadModel::POSIX, "posix", "POSIX thread model"),
72               clEnumValN(ThreadModel::Single, "single",
73                          "Single thread model")));
74
75static cl::opt<llvm::CodeModel::Model> CMModel(
76    "code-model", cl::desc("Choose code model"),
77    cl::values(clEnumValN(CodeModel::Small, "small", "Small code model"),
78               clEnumValN(CodeModel::Kernel, "kernel", "Kernel code model"),
79               clEnumValN(CodeModel::Medium, "medium", "Medium code model"),
80               clEnumValN(CodeModel::Large, "large", "Large code model")));
81
82LLVM_ATTRIBUTE_UNUSED static Optional<CodeModel::Model> getCodeModel() {
83  if (CMModel.getNumOccurrences()) {
84    CodeModel::Model M = CMModel;
85    return M;
86  }
87  return None;
88}
89
90static cl::opt<llvm::ExceptionHandling> ExceptionModel(
91    "exception-model", cl::desc("exception model"),
92    cl::init(ExceptionHandling::None),
93    cl::values(
94        clEnumValN(ExceptionHandling::None, "default",
95                   "default exception handling model"),
96        clEnumValN(ExceptionHandling::DwarfCFI, "dwarf",
97                   "DWARF-like CFI based exception handling"),
98        clEnumValN(ExceptionHandling::SjLj, "sjlj", "SjLj exception handling"),
99        clEnumValN(ExceptionHandling::ARM, "arm", "ARM EHABI exceptions"),
100        clEnumValN(ExceptionHandling::WinEH, "wineh",
101                   "Windows exception model"),
102        clEnumValN(ExceptionHandling::Wasm, "wasm",
103                   "WebAssembly exception handling")));
104
105static cl::opt<TargetMachine::CodeGenFileType> FileType(
106    "filetype", cl::init(TargetMachine::CGFT_AssemblyFile),
107    cl::desc(
108        "Choose a file type (not all types are supported by all targets):"),
109    cl::values(clEnumValN(TargetMachine::CGFT_AssemblyFile, "asm",
110                          "Emit an assembly ('.s') file"),
111               clEnumValN(TargetMachine::CGFT_ObjectFile, "obj",
112                          "Emit a native object ('.o') file"),
113               clEnumValN(TargetMachine::CGFT_Null, "null",
114                          "Emit nothing, for performance testing")));
115
116static cl::opt<bool>
117    DisableFPElim("disable-fp-elim",
118                  cl::desc("Disable frame pointer elimination optimization"),
119                  cl::init(false));
120
121static cl::opt<bool> EnableUnsafeFPMath(
122    "enable-unsafe-fp-math",
123    cl::desc("Enable optimizations that may decrease FP precision"),
124    cl::init(false));
125
126static cl::opt<bool> EnableNoInfsFPMath(
127    "enable-no-infs-fp-math",
128    cl::desc("Enable FP math optimizations that assume no +-Infs"),
129    cl::init(false));
130
131static cl::opt<bool> EnableNoNaNsFPMath(
132    "enable-no-nans-fp-math",
133    cl::desc("Enable FP math optimizations that assume no NaNs"),
134    cl::init(false));
135
136static cl::opt<bool> EnableNoSignedZerosFPMath(
137    "enable-no-signed-zeros-fp-math",
138    cl::desc("Enable FP math optimizations that assume "
139             "the sign of 0 is insignificant"),
140    cl::init(false));
141
142static cl::opt<bool>
143    EnableNoTrappingFPMath("enable-no-trapping-fp-math",
144                           cl::desc("Enable setting the FP exceptions build "
145                                    "attribute not to use exceptions"),
146                           cl::init(false));
147
148static cl::opt<llvm::FPDenormal::DenormalMode> DenormalMode(
149    "denormal-fp-math",
150    cl::desc("Select which denormal numbers the code is permitted to require"),
151    cl::init(FPDenormal::IEEE),
152    cl::values(clEnumValN(FPDenormal::IEEE, "ieee",
153                          "IEEE 754 denormal numbers"),
154               clEnumValN(FPDenormal::PreserveSign, "preserve-sign",
155                          "the sign of a  flushed-to-zero number is preserved "
156                          "in the sign of 0"),
157               clEnumValN(FPDenormal::PositiveZero, "positive-zero",
158                          "denormals are flushed to positive zero")));
159
160static cl::opt<bool> EnableHonorSignDependentRoundingFPMath(
161    "enable-sign-dependent-rounding-fp-math", cl::Hidden,
162    cl::desc("Force codegen to assume rounding mode can change dynamically"),
163    cl::init(false));
164
165static cl::opt<llvm::FloatABI::ABIType> FloatABIForCalls(
166    "float-abi", cl::desc("Choose float ABI type"), cl::init(FloatABI::Default),
167    cl::values(clEnumValN(FloatABI::Default, "default",
168                          "Target default float ABI type"),
169               clEnumValN(FloatABI::Soft, "soft",
170                          "Soft float ABI (implied by -soft-float)"),
171               clEnumValN(FloatABI::Hard, "hard",
172                          "Hard float ABI (uses FP registers)")));
173
174static cl::opt<llvm::FPOpFusion::FPOpFusionMode> FuseFPOps(
175    "fp-contract", cl::desc("Enable aggressive formation of fused FP ops"),
176    cl::init(FPOpFusion::Standard),
177    cl::values(
178        clEnumValN(FPOpFusion::Fast, "fast", "Fuse FP ops whenever profitable"),
179        clEnumValN(FPOpFusion::Standard, "on", "Only fuse 'blessed' FP ops."),
180        clEnumValN(FPOpFusion::Strict, "off",
181                   "Only fuse FP ops when the result won't be affected.")));
182
183static cl::opt<bool> DontPlaceZerosInBSS(
184    "nozero-initialized-in-bss",
185    cl::desc("Don't place zero-initialized symbols into bss section"),
186    cl::init(false));
187
188static cl::opt<bool> EnableGuaranteedTailCallOpt(
189    "tailcallopt",
190    cl::desc(
191        "Turn fastcc calls into tail calls by (potentially) changing ABI."),
192    cl::init(false));
193
194static cl::opt<bool> DisableTailCalls("disable-tail-calls",
195                                      cl::desc("Never emit tail calls"),
196                                      cl::init(false));
197
198static cl::opt<bool> StackSymbolOrdering("stack-symbol-ordering",
199                                         cl::desc("Order local stack symbols."),
200                                         cl::init(true));
201
202static cl::opt<unsigned>
203    OverrideStackAlignment("stack-alignment",
204                           cl::desc("Override default stack alignment"),
205                           cl::init(0));
206
207static cl::opt<bool>
208    StackRealign("stackrealign",
209                 cl::desc("Force align the stack to the minimum alignment"),
210                 cl::init(false));
211
212static cl::opt<std::string> TrapFuncName(
213    "trap-func", cl::Hidden,
214    cl::desc("Emit a call to trap function rather than a trap instruction"),
215    cl::init(""));
216
217static cl::opt<bool> UseCtors("use-ctors",
218                              cl::desc("Use .ctors instead of .init_array."),
219                              cl::init(false));
220
221static cl::opt<bool> RelaxELFRelocations(
222    "relax-elf-relocations",
223    cl::desc("Emit GOTPCRELX/REX_GOTPCRELX instead of GOTPCREL on x86-64 ELF"),
224    cl::init(false));
225
226static cl::opt<bool> DataSections("data-sections",
227                                  cl::desc("Emit data into separate sections"),
228                                  cl::init(false));
229
230static cl::opt<bool>
231    FunctionSections("function-sections",
232                     cl::desc("Emit functions into separate sections"),
233                     cl::init(false));
234
235static cl::opt<bool> EmulatedTLS("emulated-tls",
236                                 cl::desc("Use emulated TLS model"),
237                                 cl::init(false));
238
239static cl::opt<bool>
240    UniqueSectionNames("unique-section-names",
241                       cl::desc("Give unique names to every section"),
242                       cl::init(true));
243
244static cl::opt<llvm::EABI>
245    EABIVersion("meabi", cl::desc("Set EABI type (default depends on triple):"),
246                cl::init(EABI::Default),
247                cl::values(clEnumValN(EABI::Default, "default",
248                                      "Triple default EABI version"),
249                           clEnumValN(EABI::EABI4, "4", "EABI version 4"),
250                           clEnumValN(EABI::EABI5, "5", "EABI version 5"),
251                           clEnumValN(EABI::GNU, "gnu", "EABI GNU")));
252
253static cl::opt<DebuggerKind> DebuggerTuningOpt(
254    "debugger-tune", cl::desc("Tune debug info for a particular debugger"),
255    cl::init(DebuggerKind::Default),
256    cl::values(clEnumValN(DebuggerKind::GDB, "gdb", "gdb"),
257               clEnumValN(DebuggerKind::LLDB, "lldb", "lldb"),
258               clEnumValN(DebuggerKind::SCE, "sce", "SCE targets (e.g. PS4)")));
259
260static cl::opt<bool> EnableStackSizeSection(
261    "stack-size-section",
262    cl::desc("Emit a section containing stack size metadata"), cl::init(false));
263
264static cl::opt<bool>
265    EnableAddrsig("addrsig", cl::desc("Emit an address-significance table"),
266                  cl::init(false));
267
268// Common utility function tightly tied to the options listed here. Initializes
269// a TargetOptions object with CodeGen flags and returns it.
270static TargetOptions InitTargetOptionsFromCodeGenFlags() {
271  TargetOptions Options;
272  Options.AllowFPOpFusion = FuseFPOps;
273  Options.UnsafeFPMath = EnableUnsafeFPMath;
274  Options.NoInfsFPMath = EnableNoInfsFPMath;
275  Options.NoNaNsFPMath = EnableNoNaNsFPMath;
276  Options.NoSignedZerosFPMath = EnableNoSignedZerosFPMath;
277  Options.NoTrappingFPMath = EnableNoTrappingFPMath;
278  Options.FPDenormalMode = DenormalMode;
279  Options.HonorSignDependentRoundingFPMathOption =
280      EnableHonorSignDependentRoundingFPMath;
281  if (FloatABIForCalls != FloatABI::Default)
282    Options.FloatABIType = FloatABIForCalls;
283  Options.NoZerosInBSS = DontPlaceZerosInBSS;
284  Options.GuaranteedTailCallOpt = EnableGuaranteedTailCallOpt;
285  Options.StackAlignmentOverride = OverrideStackAlignment;
286  Options.StackSymbolOrdering = StackSymbolOrdering;
287  Options.UseInitArray = !UseCtors;
288  Options.RelaxELFRelocations = RelaxELFRelocations;
289  Options.DataSections = DataSections;
290  Options.FunctionSections = FunctionSections;
291  Options.UniqueSectionNames = UniqueSectionNames;
292  Options.EmulatedTLS = EmulatedTLS;
293  Options.ExplicitEmulatedTLS = EmulatedTLS.getNumOccurrences() > 0;
294  Options.ExceptionModel = ExceptionModel;
295  Options.EmitStackSizeSection = EnableStackSizeSection;
296  Options.EmitAddrsig = EnableAddrsig;
297
298  Options.MCOptions = InitMCTargetOptionsFromFlags();
299
300  Options.ThreadModel = TMModel;
301  Options.EABIVersion = EABIVersion;
302  Options.DebuggerTuning = DebuggerTuningOpt;
303
304  return Options;
305}
306
307LLVM_ATTRIBUTE_UNUSED static std::string getCPUStr() {
308  // If user asked for the 'native' CPU, autodetect here. If autodection fails,
309  // this will set the CPU to an empty string which tells the target to
310  // pick a basic default.
311  if (MCPU == "native")
312    return sys::getHostCPUName();
313
314  return MCPU;
315}
316
317LLVM_ATTRIBUTE_UNUSED static std::string getFeaturesStr() {
318  SubtargetFeatures Features;
319
320  // If user asked for the 'native' CPU, we need to autodetect features.
321  // This is necessary for x86 where the CPU might not support all the
322  // features the autodetected CPU name lists in the target. For example,
323  // not all Sandybridge processors support AVX.
324  if (MCPU == "native") {
325    StringMap<bool> HostFeatures;
326    if (sys::getHostCPUFeatures(HostFeatures))
327      for (auto &F : HostFeatures)
328        Features.AddFeature(F.first(), F.second);
329  }
330
331  for (unsigned i = 0; i != MAttrs.size(); ++i)
332    Features.AddFeature(MAttrs[i]);
333
334  return Features.getString();
335}
336
337LLVM_ATTRIBUTE_UNUSED static std::vector<std::string> getFeatureList() {
338  SubtargetFeatures Features;
339
340  // If user asked for the 'native' CPU, we need to autodetect features.
341  // This is necessary for x86 where the CPU might not support all the
342  // features the autodetected CPU name lists in the target. For example,
343  // not all Sandybridge processors support AVX.
344  if (MCPU == "native") {
345    StringMap<bool> HostFeatures;
346    if (sys::getHostCPUFeatures(HostFeatures))
347      for (auto &F : HostFeatures)
348        Features.AddFeature(F.first(), F.second);
349  }
350
351  for (unsigned i = 0; i != MAttrs.size(); ++i)
352    Features.AddFeature(MAttrs[i]);
353
354  return Features.getFeatures();
355}
356
357/// Set function attributes of functions in Module M based on CPU,
358/// Features, and command line flags.
359LLVM_ATTRIBUTE_UNUSED static void
360setFunctionAttributes(StringRef CPU, StringRef Features, Module &M) {
361  for (auto &F : M) {
362    auto &Ctx = F.getContext();
363    AttributeList Attrs = F.getAttributes();
364    AttrBuilder NewAttrs;
365
366    if (!CPU.empty())
367      NewAttrs.addAttribute("target-cpu", CPU);
368    if (!Features.empty())
369      NewAttrs.addAttribute("target-features", Features);
370    if (DisableFPElim.getNumOccurrences() > 0)
371      NewAttrs.addAttribute("no-frame-pointer-elim",
372                            DisableFPElim ? "true" : "false");
373    if (DisableTailCalls.getNumOccurrences() > 0)
374      NewAttrs.addAttribute("disable-tail-calls",
375                            toStringRef(DisableTailCalls));
376    if (StackRealign)
377      NewAttrs.addAttribute("stackrealign");
378
379    if (TrapFuncName.getNumOccurrences() > 0)
380      for (auto &B : F)
381        for (auto &I : B)
382          if (auto *Call = dyn_cast<CallInst>(&I))
383            if (const auto *F = Call->getCalledFunction())
384              if (F->getIntrinsicID() == Intrinsic::debugtrap ||
385                  F->getIntrinsicID() == Intrinsic::trap)
386                Call->addAttribute(
387                    llvm::AttributeList::FunctionIndex,
388                    Attribute::get(Ctx, "trap-func-name", TrapFuncName));
389
390    // Let NewAttrs override Attrs.
391    F.setAttributes(
392        Attrs.addAttributes(Ctx, AttributeList::FunctionIndex, NewAttrs));
393  }
394}
395