1 //===--- ToolChain.cpp - Collections of tools for one platform ------------===//
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 #include "Tools.h"
11 #include "clang/Basic/ObjCRuntime.h"
12 #include "clang/Driver/Action.h"
13 #include "clang/Driver/Driver.h"
14 #include "clang/Driver/DriverDiagnostic.h"
15 #include "clang/Driver/Options.h"
16 #include "clang/Driver/SanitizerArgs.h"
17 #include "clang/Driver/ToolChain.h"
18 #include "llvm/ADT/SmallString.h"
19 #include "llvm/ADT/StringSwitch.h"
20 #include "llvm/Option/Arg.h"
21 #include "llvm/Option/ArgList.h"
22 #include "llvm/Option/Option.h"
23 #include "llvm/Support/ErrorHandling.h"
24 #include "llvm/Support/FileSystem.h"
25 using namespace clang::driver;
26 using namespace clang;
27 using namespace llvm::opt;
28 
29 static llvm::opt::Arg *GetRTTIArgument(const ArgList &Args) {
30   return Args.getLastArg(options::OPT_mkernel, options::OPT_fapple_kext,
31                          options::OPT_fno_rtti, options::OPT_frtti);
32 }
33 
34 static ToolChain::RTTIMode CalculateRTTIMode(const ArgList &Args,
35                                              const llvm::Triple &Triple,
36                                              const Arg *CachedRTTIArg) {
37   // Explicit rtti/no-rtti args
38   if (CachedRTTIArg) {
39     if (CachedRTTIArg->getOption().matches(options::OPT_frtti))
40       return ToolChain::RM_EnabledExplicitly;
41     else
42       return ToolChain::RM_DisabledExplicitly;
43   }
44 
45   // -frtti is default, except for the PS4 CPU.
46   if (!Triple.isPS4CPU())
47     return ToolChain::RM_EnabledImplicitly;
48 
49   // On the PS4, turning on c++ exceptions turns on rtti.
50   // We're assuming that, if we see -fexceptions, rtti gets turned on.
51   Arg *Exceptions = Args.getLastArgNoClaim(
52       options::OPT_fcxx_exceptions, options::OPT_fno_cxx_exceptions,
53       options::OPT_fexceptions, options::OPT_fno_exceptions);
54   if (Exceptions &&
55       (Exceptions->getOption().matches(options::OPT_fexceptions) ||
56        Exceptions->getOption().matches(options::OPT_fcxx_exceptions)))
57     return ToolChain::RM_EnabledImplicitly;
58 
59   return ToolChain::RM_DisabledImplicitly;
60 }
61 
62 ToolChain::ToolChain(const Driver &D, const llvm::Triple &T,
63                      const ArgList &Args)
64     : D(D), Triple(T), Args(Args), CachedRTTIArg(GetRTTIArgument(Args)),
65       CachedRTTIMode(CalculateRTTIMode(Args, Triple, CachedRTTIArg)) {
66   if (Arg *A = Args.getLastArg(options::OPT_mthread_model))
67     if (!isThreadModelSupported(A->getValue()))
68       D.Diag(diag::err_drv_invalid_thread_model_for_target)
69           << A->getValue() << A->getAsString(Args);
70 }
71 
72 ToolChain::~ToolChain() {
73 }
74 
75 const Driver &ToolChain::getDriver() const {
76  return D;
77 }
78 
79 bool ToolChain::useIntegratedAs() const {
80   return Args.hasFlag(options::OPT_fintegrated_as,
81                       options::OPT_fno_integrated_as,
82                       IsIntegratedAssemblerDefault());
83 }
84 
85 const SanitizerArgs& ToolChain::getSanitizerArgs() const {
86   if (!SanitizerArguments.get())
87     SanitizerArguments.reset(new SanitizerArgs(*this, Args));
88   return *SanitizerArguments.get();
89 }
90 
91 StringRef ToolChain::getDefaultUniversalArchName() const {
92   // In universal driver terms, the arch name accepted by -arch isn't exactly
93   // the same as the ones that appear in the triple. Roughly speaking, this is
94   // an inverse of the darwin::getArchTypeForDarwinArchName() function, but the
95   // only interesting special case is powerpc.
96   switch (Triple.getArch()) {
97   case llvm::Triple::ppc:
98     return "ppc";
99   case llvm::Triple::ppc64:
100     return "ppc64";
101   case llvm::Triple::ppc64le:
102     return "ppc64le";
103   default:
104     return Triple.getArchName();
105   }
106 }
107 
108 bool ToolChain::IsUnwindTablesDefault() const {
109   return false;
110 }
111 
112 Tool *ToolChain::getClang() const {
113   if (!Clang)
114     Clang.reset(new tools::Clang(*this));
115   return Clang.get();
116 }
117 
118 Tool *ToolChain::buildAssembler() const {
119   return new tools::ClangAs(*this);
120 }
121 
122 Tool *ToolChain::buildLinker() const {
123   llvm_unreachable("Linking is not supported by this toolchain");
124 }
125 
126 Tool *ToolChain::getAssemble() const {
127   if (!Assemble)
128     Assemble.reset(buildAssembler());
129   return Assemble.get();
130 }
131 
132 Tool *ToolChain::getClangAs() const {
133   if (!Assemble)
134     Assemble.reset(new tools::ClangAs(*this));
135   return Assemble.get();
136 }
137 
138 Tool *ToolChain::getLink() const {
139   if (!Link)
140     Link.reset(buildLinker());
141   return Link.get();
142 }
143 
144 Tool *ToolChain::getTool(Action::ActionClass AC) const {
145   switch (AC) {
146   case Action::AssembleJobClass:
147     return getAssemble();
148 
149   case Action::LinkJobClass:
150     return getLink();
151 
152   case Action::InputClass:
153   case Action::BindArchClass:
154   case Action::CudaDeviceClass:
155   case Action::CudaHostClass:
156   case Action::LipoJobClass:
157   case Action::DsymutilJobClass:
158   case Action::VerifyDebugInfoJobClass:
159     llvm_unreachable("Invalid tool kind.");
160 
161   case Action::CompileJobClass:
162   case Action::PrecompileJobClass:
163   case Action::PreprocessJobClass:
164   case Action::AnalyzeJobClass:
165   case Action::MigrateJobClass:
166   case Action::VerifyPCHJobClass:
167   case Action::BackendJobClass:
168     return getClang();
169   }
170 
171   llvm_unreachable("Invalid tool kind.");
172 }
173 
174 Tool *ToolChain::SelectTool(const JobAction &JA) const {
175   if (getDriver().ShouldUseClangCompiler(JA))
176     return getClang();
177   Action::ActionClass AC = JA.getKind();
178   if (AC == Action::AssembleJobClass && useIntegratedAs())
179     return getClangAs();
180   return getTool(AC);
181 }
182 
183 std::string ToolChain::GetFilePath(const char *Name) const {
184   return D.GetFilePath(Name, *this);
185 
186 }
187 
188 std::string ToolChain::GetProgramPath(const char *Name) const {
189   return D.GetProgramPath(Name, *this);
190 }
191 
192 std::string ToolChain::GetLinkerPath() const {
193   if (Arg *A = Args.getLastArg(options::OPT_fuse_ld_EQ)) {
194     StringRef Suffix = A->getValue();
195 
196     // If we're passed -fuse-ld= with no argument, or with the argument ld,
197     // then use whatever the default system linker is.
198     if (Suffix.empty() || Suffix == "ld")
199       return GetProgramPath("ld");
200 
201     llvm::SmallString<8> LinkerName("ld.");
202     LinkerName.append(Suffix);
203 
204     std::string LinkerPath(GetProgramPath(LinkerName.c_str()));
205     if (llvm::sys::fs::exists(LinkerPath))
206       return LinkerPath;
207 
208     getDriver().Diag(diag::err_drv_invalid_linker_name) << A->getAsString(Args);
209     return "";
210   }
211 
212   return GetProgramPath("ld");
213 }
214 
215 
216 types::ID ToolChain::LookupTypeForExtension(const char *Ext) const {
217   return types::lookupTypeForExtension(Ext);
218 }
219 
220 bool ToolChain::HasNativeLLVMSupport() const {
221   return false;
222 }
223 
224 bool ToolChain::isCrossCompiling() const {
225   llvm::Triple HostTriple(LLVM_HOST_TRIPLE);
226   switch (HostTriple.getArch()) {
227   // The A32/T32/T16 instruction sets are not separate architectures in this
228   // context.
229   case llvm::Triple::arm:
230   case llvm::Triple::armeb:
231   case llvm::Triple::thumb:
232   case llvm::Triple::thumbeb:
233     return getArch() != llvm::Triple::arm && getArch() != llvm::Triple::thumb &&
234            getArch() != llvm::Triple::armeb && getArch() != llvm::Triple::thumbeb;
235   default:
236     return HostTriple.getArch() != getArch();
237   }
238 }
239 
240 ObjCRuntime ToolChain::getDefaultObjCRuntime(bool isNonFragile) const {
241   return ObjCRuntime(isNonFragile ? ObjCRuntime::GNUstep : ObjCRuntime::GCC,
242                      VersionTuple());
243 }
244 
245 bool ToolChain::isThreadModelSupported(const StringRef Model) const {
246   if (Model == "single") {
247     // FIXME: 'single' is only supported on ARM and WebAssembly so far.
248     return Triple.getArch() == llvm::Triple::arm ||
249            Triple.getArch() == llvm::Triple::armeb ||
250            Triple.getArch() == llvm::Triple::thumb ||
251            Triple.getArch() == llvm::Triple::thumbeb ||
252            Triple.getArch() == llvm::Triple::wasm32 ||
253            Triple.getArch() == llvm::Triple::wasm64;
254   } else if (Model == "posix")
255     return true;
256 
257   return false;
258 }
259 
260 std::string ToolChain::ComputeLLVMTriple(const ArgList &Args,
261                                          types::ID InputType) const {
262   switch (getTriple().getArch()) {
263   default:
264     return getTripleString();
265 
266   case llvm::Triple::x86_64: {
267     llvm::Triple Triple = getTriple();
268     if (!Triple.isOSBinFormatMachO())
269       return getTripleString();
270 
271     if (Arg *A = Args.getLastArg(options::OPT_march_EQ)) {
272       // x86_64h goes in the triple. Other -march options just use the
273       // vanilla triple we already have.
274       StringRef MArch = A->getValue();
275       if (MArch == "x86_64h")
276         Triple.setArchName(MArch);
277     }
278     return Triple.getTriple();
279   }
280   case llvm::Triple::aarch64: {
281     llvm::Triple Triple = getTriple();
282     if (!Triple.isOSBinFormatMachO())
283       return getTripleString();
284 
285     // FIXME: older versions of ld64 expect the "arm64" component in the actual
286     // triple string and query it to determine whether an LTO file can be
287     // handled. Remove this when we don't care any more.
288     Triple.setArchName("arm64");
289     return Triple.getTriple();
290   }
291   case llvm::Triple::arm:
292   case llvm::Triple::armeb:
293   case llvm::Triple::thumb:
294   case llvm::Triple::thumbeb: {
295     // FIXME: Factor into subclasses.
296     llvm::Triple Triple = getTriple();
297     bool IsBigEndian = getTriple().getArch() == llvm::Triple::armeb ||
298                        getTriple().getArch() == llvm::Triple::thumbeb;
299 
300     // Handle pseudo-target flags '-mlittle-endian'/'-EL' and
301     // '-mbig-endian'/'-EB'.
302     if (Arg *A = Args.getLastArg(options::OPT_mlittle_endian,
303                                  options::OPT_mbig_endian)) {
304       IsBigEndian = !A->getOption().matches(options::OPT_mlittle_endian);
305     }
306 
307     // Thumb2 is the default for V7 on Darwin.
308     //
309     // FIXME: Thumb should just be another -target-feaure, not in the triple.
310     StringRef MCPU, MArch;
311     if (const Arg *A = Args.getLastArg(options::OPT_mcpu_EQ))
312       MCPU = A->getValue();
313     if (const Arg *A = Args.getLastArg(options::OPT_march_EQ))
314       MArch = A->getValue();
315     std::string CPU =
316         Triple.isOSBinFormatMachO()
317             ? tools::arm::getARMCPUForMArch(MArch, Triple).str()
318             : tools::arm::getARMTargetCPU(MCPU, MArch, Triple);
319     StringRef Suffix =
320       tools::arm::getLLVMArchSuffixForARM(CPU, MArch, Triple);
321     bool ThumbDefault = Suffix.startswith("v6m") || Suffix.startswith("v7m") ||
322       Suffix.startswith("v7em") ||
323       (Suffix.startswith("v7") && getTriple().isOSBinFormatMachO());
324     // FIXME: this is invalid for WindowsCE
325     if (getTriple().isOSWindows())
326       ThumbDefault = true;
327     std::string ArchName;
328     if (IsBigEndian)
329       ArchName = "armeb";
330     else
331       ArchName = "arm";
332 
333     // Assembly files should start in ARM mode.
334     if (InputType != types::TY_PP_Asm &&
335         Args.hasFlag(options::OPT_mthumb, options::OPT_mno_thumb, ThumbDefault))
336     {
337       if (IsBigEndian)
338         ArchName = "thumbeb";
339       else
340         ArchName = "thumb";
341     }
342     Triple.setArchName(ArchName + Suffix.str());
343 
344     return Triple.getTriple();
345   }
346   }
347 }
348 
349 std::string ToolChain::ComputeEffectiveClangTriple(const ArgList &Args,
350                                                    types::ID InputType) const {
351   return ComputeLLVMTriple(Args, InputType);
352 }
353 
354 void ToolChain::AddClangSystemIncludeArgs(const ArgList &DriverArgs,
355                                           ArgStringList &CC1Args) const {
356   // Each toolchain should provide the appropriate include flags.
357 }
358 
359 void ToolChain::addClangTargetOptions(const ArgList &DriverArgs,
360                                       ArgStringList &CC1Args) const {
361 }
362 
363 void ToolChain::addClangWarningOptions(ArgStringList &CC1Args) const {}
364 
365 ToolChain::RuntimeLibType ToolChain::GetRuntimeLibType(
366   const ArgList &Args) const
367 {
368   if (Arg *A = Args.getLastArg(options::OPT_rtlib_EQ)) {
369     StringRef Value = A->getValue();
370     if (Value == "compiler-rt")
371       return ToolChain::RLT_CompilerRT;
372     if (Value == "libgcc")
373       return ToolChain::RLT_Libgcc;
374     getDriver().Diag(diag::err_drv_invalid_rtlib_name)
375       << A->getAsString(Args);
376   }
377 
378   return GetDefaultRuntimeLibType();
379 }
380 
381 ToolChain::CXXStdlibType ToolChain::GetCXXStdlibType(const ArgList &Args) const{
382   if (Arg *A = Args.getLastArg(options::OPT_stdlib_EQ)) {
383     StringRef Value = A->getValue();
384     if (Value == "libc++")
385       return ToolChain::CST_Libcxx;
386     if (Value == "libstdc++")
387       return ToolChain::CST_Libstdcxx;
388     getDriver().Diag(diag::err_drv_invalid_stdlib_name)
389       << A->getAsString(Args);
390   }
391 
392   return ToolChain::CST_Libstdcxx;
393 }
394 
395 /// \brief Utility function to add a system include directory to CC1 arguments.
396 /*static*/ void ToolChain::addSystemInclude(const ArgList &DriverArgs,
397                                             ArgStringList &CC1Args,
398                                             const Twine &Path) {
399   CC1Args.push_back("-internal-isystem");
400   CC1Args.push_back(DriverArgs.MakeArgString(Path));
401 }
402 
403 /// \brief Utility function to add a system include directory with extern "C"
404 /// semantics to CC1 arguments.
405 ///
406 /// Note that this should be used rarely, and only for directories that
407 /// historically and for legacy reasons are treated as having implicit extern
408 /// "C" semantics. These semantics are *ignored* by and large today, but its
409 /// important to preserve the preprocessor changes resulting from the
410 /// classification.
411 /*static*/ void ToolChain::addExternCSystemInclude(const ArgList &DriverArgs,
412                                                    ArgStringList &CC1Args,
413                                                    const Twine &Path) {
414   CC1Args.push_back("-internal-externc-isystem");
415   CC1Args.push_back(DriverArgs.MakeArgString(Path));
416 }
417 
418 void ToolChain::addExternCSystemIncludeIfExists(const ArgList &DriverArgs,
419                                                 ArgStringList &CC1Args,
420                                                 const Twine &Path) {
421   if (llvm::sys::fs::exists(Path))
422     addExternCSystemInclude(DriverArgs, CC1Args, Path);
423 }
424 
425 /// \brief Utility function to add a list of system include directories to CC1.
426 /*static*/ void ToolChain::addSystemIncludes(const ArgList &DriverArgs,
427                                              ArgStringList &CC1Args,
428                                              ArrayRef<StringRef> Paths) {
429   for (StringRef Path : Paths) {
430     CC1Args.push_back("-internal-isystem");
431     CC1Args.push_back(DriverArgs.MakeArgString(Path));
432   }
433 }
434 
435 void ToolChain::AddClangCXXStdlibIncludeArgs(const ArgList &DriverArgs,
436                                              ArgStringList &CC1Args) const {
437   // Header search paths should be handled by each of the subclasses.
438   // Historically, they have not been, and instead have been handled inside of
439   // the CC1-layer frontend. As the logic is hoisted out, this generic function
440   // will slowly stop being called.
441   //
442   // While it is being called, replicate a bit of a hack to propagate the
443   // '-stdlib=' flag down to CC1 so that it can in turn customize the C++
444   // header search paths with it. Once all systems are overriding this
445   // function, the CC1 flag and this line can be removed.
446   DriverArgs.AddAllArgs(CC1Args, options::OPT_stdlib_EQ);
447 }
448 
449 void ToolChain::AddCXXStdlibLibArgs(const ArgList &Args,
450                                     ArgStringList &CmdArgs) const {
451   CXXStdlibType Type = GetCXXStdlibType(Args);
452 
453   switch (Type) {
454   case ToolChain::CST_Libcxx:
455     CmdArgs.push_back("-lc++");
456     break;
457 
458   case ToolChain::CST_Libstdcxx:
459     CmdArgs.push_back("-lstdc++");
460     break;
461   }
462 }
463 
464 void ToolChain::AddCCKextLibArgs(const ArgList &Args,
465                                  ArgStringList &CmdArgs) const {
466   CmdArgs.push_back("-lcc_kext");
467 }
468 
469 bool ToolChain::AddFastMathRuntimeIfAvailable(const ArgList &Args,
470                                               ArgStringList &CmdArgs) const {
471   // Do not check for -fno-fast-math or -fno-unsafe-math when -Ofast passed
472   // (to keep the linker options consistent with gcc and clang itself).
473   if (!isOptimizationLevelFast(Args)) {
474     // Check if -ffast-math or -funsafe-math.
475     Arg *A =
476         Args.getLastArg(options::OPT_ffast_math, options::OPT_fno_fast_math,
477                         options::OPT_funsafe_math_optimizations,
478                         options::OPT_fno_unsafe_math_optimizations);
479 
480     if (!A || A->getOption().getID() == options::OPT_fno_fast_math ||
481         A->getOption().getID() == options::OPT_fno_unsafe_math_optimizations)
482       return false;
483   }
484   // If crtfastmath.o exists add it to the arguments.
485   std::string Path = GetFilePath("crtfastmath.o");
486   if (Path == "crtfastmath.o") // Not found.
487     return false;
488 
489   CmdArgs.push_back(Args.MakeArgString(Path));
490   return true;
491 }
492 
493 SanitizerMask ToolChain::getSupportedSanitizers() const {
494   // Return sanitizers which don't require runtime support and are not
495   // platform dependent.
496   using namespace SanitizerKind;
497   SanitizerMask Res = (Undefined & ~Vptr & ~Function) | (CFI & ~CFIICall) |
498                       CFICastStrict | UnsignedIntegerOverflow | LocalBounds;
499   if (getTriple().getArch() == llvm::Triple::x86 ||
500       getTriple().getArch() == llvm::Triple::x86_64)
501     Res |= CFIICall;
502   return Res;
503 }
504