xref: /freebsd/contrib/llvm-project/clang/tools/driver/driver.cpp (revision b64c5a0ace59af62eff52bfe110a521dc73c937b)
1 //===-- driver.cpp - Clang GCC-Compatible Driver --------------------------===//
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 is the entry point to the clang driver; it is a thin wrapper
10 // for functionality in the Driver clang library.
11 //
12 //===----------------------------------------------------------------------===//
13 
14 #include "clang/Driver/Driver.h"
15 #include "clang/Basic/DiagnosticOptions.h"
16 #include "clang/Basic/HeaderInclude.h"
17 #include "clang/Basic/Stack.h"
18 #include "clang/Config/config.h"
19 #include "clang/Driver/Compilation.h"
20 #include "clang/Driver/DriverDiagnostic.h"
21 #include "clang/Driver/Options.h"
22 #include "clang/Driver/ToolChain.h"
23 #include "clang/Frontend/ChainedDiagnosticConsumer.h"
24 #include "clang/Frontend/CompilerInvocation.h"
25 #include "clang/Frontend/SerializedDiagnosticPrinter.h"
26 #include "clang/Frontend/TextDiagnosticPrinter.h"
27 #include "clang/Frontend/Utils.h"
28 #include "llvm/ADT/ArrayRef.h"
29 #include "llvm/ADT/SmallString.h"
30 #include "llvm/ADT/SmallVector.h"
31 #include "llvm/ADT/StringSet.h"
32 #include "llvm/Option/ArgList.h"
33 #include "llvm/Option/OptTable.h"
34 #include "llvm/Option/Option.h"
35 #include "llvm/Support/BuryPointer.h"
36 #include "llvm/Support/CommandLine.h"
37 #include "llvm/Support/CrashRecoveryContext.h"
38 #include "llvm/Support/ErrorHandling.h"
39 #include "llvm/Support/FileSystem.h"
40 #include "llvm/Support/LLVMDriver.h"
41 #include "llvm/Support/Path.h"
42 #include "llvm/Support/PrettyStackTrace.h"
43 #include "llvm/Support/Process.h"
44 #include "llvm/Support/Program.h"
45 #include "llvm/Support/Signals.h"
46 #include "llvm/Support/StringSaver.h"
47 #include "llvm/Support/TargetSelect.h"
48 #include "llvm/Support/Timer.h"
49 #include "llvm/Support/raw_ostream.h"
50 #include "llvm/TargetParser/Host.h"
51 #include <memory>
52 #include <optional>
53 #include <set>
54 #include <system_error>
55 using namespace clang;
56 using namespace clang::driver;
57 using namespace llvm::opt;
58 
59 std::string GetExecutablePath(const char *Argv0, bool CanonicalPrefixes) {
60   if (!CanonicalPrefixes) {
61     SmallString<128> ExecutablePath(Argv0);
62     // Do a PATH lookup if Argv0 isn't a valid path.
63     if (!llvm::sys::fs::exists(ExecutablePath))
64       if (llvm::ErrorOr<std::string> P =
65               llvm::sys::findProgramByName(ExecutablePath))
66         ExecutablePath = *P;
67     return std::string(ExecutablePath);
68   }
69 
70   // This just needs to be some symbol in the binary; C++ doesn't
71   // allow taking the address of ::main however.
72   void *P = (void*) (intptr_t) GetExecutablePath;
73   return llvm::sys::fs::getMainExecutable(Argv0, P);
74 }
75 
76 static const char *GetStableCStr(llvm::StringSet<> &SavedStrings, StringRef S) {
77   return SavedStrings.insert(S).first->getKeyData();
78 }
79 
80 extern int cc1_main(ArrayRef<const char *> Argv, const char *Argv0,
81                     void *MainAddr);
82 extern int cc1as_main(ArrayRef<const char *> Argv, const char *Argv0,
83                       void *MainAddr);
84 extern int cc1gen_reproducer_main(ArrayRef<const char *> Argv,
85                                   const char *Argv0, void *MainAddr,
86                                   const llvm::ToolContext &);
87 
88 static void insertTargetAndModeArgs(const ParsedClangName &NameParts,
89                                     SmallVectorImpl<const char *> &ArgVector,
90                                     llvm::StringSet<> &SavedStrings) {
91   // Put target and mode arguments at the start of argument list so that
92   // arguments specified in command line could override them. Avoid putting
93   // them at index 0, as an option like '-cc1' must remain the first.
94   int InsertionPoint = 0;
95   if (ArgVector.size() > 0)
96     ++InsertionPoint;
97 
98   if (NameParts.DriverMode) {
99     // Add the mode flag to the arguments.
100     ArgVector.insert(ArgVector.begin() + InsertionPoint,
101                      GetStableCStr(SavedStrings, NameParts.DriverMode));
102   }
103 
104   if (NameParts.TargetIsValid) {
105     const char *arr[] = {"-target", GetStableCStr(SavedStrings,
106                                                   NameParts.TargetPrefix)};
107     ArgVector.insert(ArgVector.begin() + InsertionPoint,
108                      std::begin(arr), std::end(arr));
109   }
110 }
111 
112 static void getCLEnvVarOptions(std::string &EnvValue, llvm::StringSaver &Saver,
113                                SmallVectorImpl<const char *> &Opts) {
114   llvm::cl::TokenizeWindowsCommandLine(EnvValue, Saver, Opts);
115   // The first instance of '#' should be replaced with '=' in each option.
116   for (const char *Opt : Opts)
117     if (char *NumberSignPtr = const_cast<char *>(::strchr(Opt, '#')))
118       *NumberSignPtr = '=';
119 }
120 
121 template <class T>
122 static T checkEnvVar(const char *EnvOptSet, const char *EnvOptFile,
123                      std::string &OptFile) {
124   const char *Str = ::getenv(EnvOptSet);
125   if (!Str)
126     return T{};
127 
128   T OptVal = Str;
129   if (const char *Var = ::getenv(EnvOptFile))
130     OptFile = Var;
131   return OptVal;
132 }
133 
134 static bool SetBackdoorDriverOutputsFromEnvVars(Driver &TheDriver) {
135   TheDriver.CCPrintOptions =
136       checkEnvVar<bool>("CC_PRINT_OPTIONS", "CC_PRINT_OPTIONS_FILE",
137                         TheDriver.CCPrintOptionsFilename);
138   if (checkEnvVar<bool>("CC_PRINT_HEADERS", "CC_PRINT_HEADERS_FILE",
139                         TheDriver.CCPrintHeadersFilename)) {
140     TheDriver.CCPrintHeadersFormat = HIFMT_Textual;
141     TheDriver.CCPrintHeadersFiltering = HIFIL_None;
142   } else {
143     std::string EnvVar = checkEnvVar<std::string>(
144         "CC_PRINT_HEADERS_FORMAT", "CC_PRINT_HEADERS_FILE",
145         TheDriver.CCPrintHeadersFilename);
146     if (!EnvVar.empty()) {
147       TheDriver.CCPrintHeadersFormat =
148           stringToHeaderIncludeFormatKind(EnvVar.c_str());
149       if (!TheDriver.CCPrintHeadersFormat) {
150         TheDriver.Diag(clang::diag::err_drv_print_header_env_var)
151             << 0 << EnvVar;
152         return false;
153       }
154 
155       const char *FilteringStr = ::getenv("CC_PRINT_HEADERS_FILTERING");
156       HeaderIncludeFilteringKind Filtering;
157       if (!stringToHeaderIncludeFiltering(FilteringStr, Filtering)) {
158         TheDriver.Diag(clang::diag::err_drv_print_header_env_var)
159             << 1 << FilteringStr;
160         return false;
161       }
162 
163       if ((TheDriver.CCPrintHeadersFormat == HIFMT_Textual &&
164            Filtering != HIFIL_None) ||
165           (TheDriver.CCPrintHeadersFormat == HIFMT_JSON &&
166            Filtering != HIFIL_Only_Direct_System)) {
167         TheDriver.Diag(clang::diag::err_drv_print_header_env_var_combination)
168             << EnvVar << FilteringStr;
169         return false;
170       }
171       TheDriver.CCPrintHeadersFiltering = Filtering;
172     }
173   }
174 
175   TheDriver.CCLogDiagnostics =
176       checkEnvVar<bool>("CC_LOG_DIAGNOSTICS", "CC_LOG_DIAGNOSTICS_FILE",
177                         TheDriver.CCLogDiagnosticsFilename);
178   TheDriver.CCPrintProcessStats =
179       checkEnvVar<bool>("CC_PRINT_PROC_STAT", "CC_PRINT_PROC_STAT_FILE",
180                         TheDriver.CCPrintStatReportFilename);
181   TheDriver.CCPrintInternalStats =
182       checkEnvVar<bool>("CC_PRINT_INTERNAL_STAT", "CC_PRINT_INTERNAL_STAT_FILE",
183                         TheDriver.CCPrintInternalStatReportFilename);
184 
185   return true;
186 }
187 
188 static void FixupDiagPrefixExeName(TextDiagnosticPrinter *DiagClient,
189                                    const std::string &Path) {
190   // If the clang binary happens to be named cl.exe for compatibility reasons,
191   // use clang-cl.exe as the prefix to avoid confusion between clang and MSVC.
192   StringRef ExeBasename(llvm::sys::path::stem(Path));
193   if (ExeBasename.equals_insensitive("cl"))
194     ExeBasename = "clang-cl";
195   DiagClient->setPrefix(std::string(ExeBasename));
196 }
197 
198 static int ExecuteCC1Tool(SmallVectorImpl<const char *> &ArgV,
199                           const llvm::ToolContext &ToolContext) {
200   // If we call the cc1 tool from the clangDriver library (through
201   // Driver::CC1Main), we need to clean up the options usage count. The options
202   // are currently global, and they might have been used previously by the
203   // driver.
204   llvm::cl::ResetAllOptionOccurrences();
205 
206   llvm::BumpPtrAllocator A;
207   llvm::cl::ExpansionContext ECtx(A, llvm::cl::TokenizeGNUCommandLine);
208   if (llvm::Error Err = ECtx.expandResponseFiles(ArgV)) {
209     llvm::errs() << toString(std::move(Err)) << '\n';
210     return 1;
211   }
212   StringRef Tool = ArgV[1];
213   void *GetExecutablePathVP = (void *)(intptr_t)GetExecutablePath;
214   if (Tool == "-cc1")
215     return cc1_main(ArrayRef(ArgV).slice(1), ArgV[0], GetExecutablePathVP);
216   if (Tool == "-cc1as")
217     return cc1as_main(ArrayRef(ArgV).slice(2), ArgV[0], GetExecutablePathVP);
218   if (Tool == "-cc1gen-reproducer")
219     return cc1gen_reproducer_main(ArrayRef(ArgV).slice(2), ArgV[0],
220                                   GetExecutablePathVP, ToolContext);
221   // Reject unknown tools.
222   llvm::errs()
223       << "error: unknown integrated tool '" << Tool << "'. "
224       << "Valid tools include '-cc1', '-cc1as' and '-cc1gen-reproducer'.\n";
225   return 1;
226 }
227 
228 int clang_main(int Argc, char **Argv, const llvm::ToolContext &ToolContext) {
229   noteBottomOfStack();
230   llvm::setBugReportMsg("PLEASE submit a bug report to " BUG_REPORT_URL
231                         " and include the crash backtrace, preprocessed "
232                         "source, and associated run script.\n");
233   SmallVector<const char *, 256> Args(Argv, Argv + Argc);
234 
235   if (llvm::sys::Process::FixupStandardFileDescriptors())
236     return 1;
237 
238   llvm::InitializeAllTargets();
239 
240   llvm::BumpPtrAllocator A;
241   llvm::StringSaver Saver(A);
242 
243   const char *ProgName =
244       ToolContext.NeedsPrependArg ? ToolContext.PrependArg : ToolContext.Path;
245 
246   bool ClangCLMode =
247       IsClangCL(getDriverMode(ProgName, llvm::ArrayRef(Args).slice(1)));
248 
249   if (llvm::Error Err = expandResponseFiles(Args, ClangCLMode, A)) {
250     llvm::errs() << toString(std::move(Err)) << '\n';
251     return 1;
252   }
253 
254   // Handle -cc1 integrated tools.
255   if (Args.size() >= 2 && StringRef(Args[1]).starts_with("-cc1"))
256     return ExecuteCC1Tool(Args, ToolContext);
257 
258   // Handle options that need handling before the real command line parsing in
259   // Driver::BuildCompilation()
260   bool CanonicalPrefixes = true;
261   for (int i = 1, size = Args.size(); i < size; ++i) {
262     // Skip end-of-line response file markers
263     if (Args[i] == nullptr)
264       continue;
265     if (StringRef(Args[i]) == "-canonical-prefixes")
266       CanonicalPrefixes = true;
267     else if (StringRef(Args[i]) == "-no-canonical-prefixes")
268       CanonicalPrefixes = false;
269   }
270 
271   // Handle CL and _CL_ which permits additional command line options to be
272   // prepended or appended.
273   if (ClangCLMode) {
274     // Arguments in "CL" are prepended.
275     std::optional<std::string> OptCL = llvm::sys::Process::GetEnv("CL");
276     if (OptCL) {
277       SmallVector<const char *, 8> PrependedOpts;
278       getCLEnvVarOptions(*OptCL, Saver, PrependedOpts);
279 
280       // Insert right after the program name to prepend to the argument list.
281       Args.insert(Args.begin() + 1, PrependedOpts.begin(), PrependedOpts.end());
282     }
283     // Arguments in "_CL_" are appended.
284     std::optional<std::string> Opt_CL_ = llvm::sys::Process::GetEnv("_CL_");
285     if (Opt_CL_) {
286       SmallVector<const char *, 8> AppendedOpts;
287       getCLEnvVarOptions(*Opt_CL_, Saver, AppendedOpts);
288 
289       // Insert at the end of the argument list to append.
290       Args.append(AppendedOpts.begin(), AppendedOpts.end());
291     }
292   }
293 
294   llvm::StringSet<> SavedStrings;
295   // Handle CCC_OVERRIDE_OPTIONS, used for editing a command line behind the
296   // scenes.
297   if (const char *OverrideStr = ::getenv("CCC_OVERRIDE_OPTIONS")) {
298     // FIXME: Driver shouldn't take extra initial argument.
299     driver::applyOverrideOptions(Args, OverrideStr, SavedStrings,
300                                  &llvm::errs());
301   }
302 
303   std::string Path = GetExecutablePath(ToolContext.Path, CanonicalPrefixes);
304 
305   // Whether the cc1 tool should be called inside the current process, or if we
306   // should spawn a new clang subprocess (old behavior).
307   // Not having an additional process saves some execution time of Windows,
308   // and makes debugging and profiling easier.
309   bool UseNewCC1Process = CLANG_SPAWN_CC1;
310   for (const char *Arg : Args)
311     UseNewCC1Process = llvm::StringSwitch<bool>(Arg)
312                            .Case("-fno-integrated-cc1", true)
313                            .Case("-fintegrated-cc1", false)
314                            .Default(UseNewCC1Process);
315 
316   IntrusiveRefCntPtr<DiagnosticOptions> DiagOpts =
317       CreateAndPopulateDiagOpts(Args);
318 
319   TextDiagnosticPrinter *DiagClient
320     = new TextDiagnosticPrinter(llvm::errs(), &*DiagOpts);
321   FixupDiagPrefixExeName(DiagClient, ProgName);
322 
323   IntrusiveRefCntPtr<DiagnosticIDs> DiagID(new DiagnosticIDs());
324 
325   DiagnosticsEngine Diags(DiagID, &*DiagOpts, DiagClient);
326 
327   if (!DiagOpts->DiagnosticSerializationFile.empty()) {
328     auto SerializedConsumer =
329         clang::serialized_diags::create(DiagOpts->DiagnosticSerializationFile,
330                                         &*DiagOpts, /*MergeChildRecords=*/true);
331     Diags.setClient(new ChainedDiagnosticConsumer(
332         Diags.takeClient(), std::move(SerializedConsumer)));
333   }
334 
335   ProcessWarningOptions(Diags, *DiagOpts, /*ReportDiags=*/false);
336 
337   Driver TheDriver(Path, llvm::sys::getDefaultTargetTriple(), Diags);
338   auto TargetAndMode = ToolChain::getTargetAndModeFromProgramName(ProgName);
339   TheDriver.setTargetAndMode(TargetAndMode);
340   // If -canonical-prefixes is set, GetExecutablePath will have resolved Path
341   // to the llvm driver binary, not clang. In this case, we need to use
342   // PrependArg which should be clang-*. Checking just CanonicalPrefixes is
343   // safe even in the normal case because PrependArg will be null so
344   // setPrependArg will be a no-op.
345   if (ToolContext.NeedsPrependArg || CanonicalPrefixes)
346     TheDriver.setPrependArg(ToolContext.PrependArg);
347 
348   insertTargetAndModeArgs(TargetAndMode, Args, SavedStrings);
349 
350   if (!SetBackdoorDriverOutputsFromEnvVars(TheDriver))
351     return 1;
352 
353   if (!UseNewCC1Process) {
354     TheDriver.CC1Main = [ToolContext](SmallVectorImpl<const char *> &ArgV) {
355       return ExecuteCC1Tool(ArgV, ToolContext);
356     };
357     // Ensure the CC1Command actually catches cc1 crashes
358     llvm::CrashRecoveryContext::Enable();
359   }
360 
361   std::unique_ptr<Compilation> C(TheDriver.BuildCompilation(Args));
362 
363   Driver::ReproLevel ReproLevel = Driver::ReproLevel::OnCrash;
364   if (Arg *A = C->getArgs().getLastArg(options::OPT_gen_reproducer_eq)) {
365     auto Level =
366         llvm::StringSwitch<std::optional<Driver::ReproLevel>>(A->getValue())
367             .Case("off", Driver::ReproLevel::Off)
368             .Case("crash", Driver::ReproLevel::OnCrash)
369             .Case("error", Driver::ReproLevel::OnError)
370             .Case("always", Driver::ReproLevel::Always)
371             .Default(std::nullopt);
372     if (!Level) {
373       llvm::errs() << "Unknown value for " << A->getSpelling() << ": '"
374                    << A->getValue() << "'\n";
375       return 1;
376     }
377     ReproLevel = *Level;
378   }
379   if (!!::getenv("FORCE_CLANG_DIAGNOSTICS_CRASH"))
380     ReproLevel = Driver::ReproLevel::Always;
381 
382   int Res = 1;
383   bool IsCrash = false;
384   Driver::CommandStatus CommandStatus = Driver::CommandStatus::Ok;
385   // Pretend the first command failed if ReproStatus is Always.
386   const Command *FailingCommand = nullptr;
387   if (!C->getJobs().empty())
388     FailingCommand = &*C->getJobs().begin();
389   if (C && !C->containsError()) {
390     SmallVector<std::pair<int, const Command *>, 4> FailingCommands;
391     Res = TheDriver.ExecuteCompilation(*C, FailingCommands);
392 
393     for (const auto &P : FailingCommands) {
394       int CommandRes = P.first;
395       FailingCommand = P.second;
396       if (!Res)
397         Res = CommandRes;
398 
399       // If result status is < 0, then the driver command signalled an error.
400       // If result status is 70, then the driver command reported a fatal error.
401       // On Windows, abort will return an exit code of 3.  In these cases,
402       // generate additional diagnostic information if possible.
403       IsCrash = CommandRes < 0 || CommandRes == 70;
404 #ifdef _WIN32
405       IsCrash |= CommandRes == 3;
406 #endif
407 #if LLVM_ON_UNIX
408       // When running in integrated-cc1 mode, the CrashRecoveryContext returns
409       // the same codes as if the program crashed. See section "Exit Status for
410       // Commands":
411       // https://pubs.opengroup.org/onlinepubs/9699919799/xrat/V4_xcu_chap02.html
412       IsCrash |= CommandRes > 128;
413 #endif
414       CommandStatus =
415           IsCrash ? Driver::CommandStatus::Crash : Driver::CommandStatus::Error;
416       if (IsCrash)
417         break;
418     }
419   }
420 
421   // Print the bug report message that would be printed if we did actually
422   // crash, but only if we're crashing due to FORCE_CLANG_DIAGNOSTICS_CRASH.
423   if (::getenv("FORCE_CLANG_DIAGNOSTICS_CRASH"))
424     llvm::dbgs() << llvm::getBugReportMsg();
425   if (FailingCommand != nullptr &&
426     TheDriver.maybeGenerateCompilationDiagnostics(CommandStatus, ReproLevel,
427                                                   *C, *FailingCommand))
428     Res = 1;
429 
430   Diags.getClient()->finish();
431 
432   if (!UseNewCC1Process && IsCrash) {
433     // When crashing in -fintegrated-cc1 mode, bury the timer pointers, because
434     // the internal linked list might point to already released stack frames.
435     llvm::BuryPointer(llvm::TimerGroup::aquireDefaultGroup());
436   } else {
437     // If any timers were active but haven't been destroyed yet, print their
438     // results now.  This happens in -disable-free mode.
439     llvm::TimerGroup::printAll(llvm::errs());
440     llvm::TimerGroup::clearAll();
441   }
442 
443 #ifdef _WIN32
444   // Exit status should not be negative on Win32, unless abnormal termination.
445   // Once abnormal termination was caught, negative status should not be
446   // propagated.
447   if (Res < 0)
448     Res = 1;
449 #endif
450 
451   // If we have multiple failing commands, we return the result of the first
452   // failing command.
453   return Res;
454 }
455