1//===-- cc1_main.cpp - Clang CC1 Compiler Frontend ------------------------===//
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 -cc1 functionality, which implements the
10// core compiler functionality along with a number of additional tools for
11// demonstration and testing purposes.
12//
13//===----------------------------------------------------------------------===//
14
15#include "clang/Basic/Stack.h"
16#include "clang/Basic/TargetOptions.h"
17#include "clang/CodeGen/ObjectFilePCHContainerWriter.h"
18#include "clang/Config/config.h"
19#include "clang/Driver/DriverDiagnostic.h"
20#include "clang/Driver/Options.h"
21#include "clang/Frontend/CompilerInstance.h"
22#include "clang/Frontend/CompilerInvocation.h"
23#include "clang/Frontend/FrontendDiagnostic.h"
24#include "clang/Frontend/TextDiagnosticBuffer.h"
25#include "clang/Frontend/TextDiagnosticPrinter.h"
26#include "clang/Frontend/Utils.h"
27#include "clang/FrontendTool/Utils.h"
28#include "clang/Serialization/ObjectFilePCHContainerReader.h"
29#include "llvm/ADT/Statistic.h"
30#include "llvm/ADT/StringExtras.h"
31#include "llvm/Config/llvm-config.h"
32#include "llvm/LinkAllPasses.h"
33#include "llvm/MC/MCSubtargetInfo.h"
34#include "llvm/MC/TargetRegistry.h"
35#include "llvm/Option/Arg.h"
36#include "llvm/Option/ArgList.h"
37#include "llvm/Option/OptTable.h"
38#include "llvm/Support/BuryPointer.h"
39#include "llvm/Support/Compiler.h"
40#include "llvm/Support/ErrorHandling.h"
41#include "llvm/Support/ManagedStatic.h"
42#include "llvm/Support/Path.h"
43#include "llvm/Support/Process.h"
44#include "llvm/Support/Signals.h"
45#include "llvm/Support/TargetSelect.h"
46#include "llvm/Support/TimeProfiler.h"
47#include "llvm/Support/Timer.h"
48#include "llvm/Support/VirtualFileSystem.h"
49#include "llvm/Support/raw_ostream.h"
50#include "llvm/Target/TargetMachine.h"
51#include "llvm/TargetParser/AArch64TargetParser.h"
52#include "llvm/TargetParser/ARMTargetParser.h"
53#include "llvm/TargetParser/RISCVISAInfo.h"
54#include <cstdio>
55
56#ifdef CLANG_HAVE_RLIMITS
57#include <sys/resource.h>
58#endif
59
60using namespace clang;
61using namespace llvm::opt;
62
63//===----------------------------------------------------------------------===//
64// Main driver
65//===----------------------------------------------------------------------===//
66
67static void LLVMErrorHandler(void *UserData, const char *Message,
68 bool GenCrashDiag) {
69 DiagnosticsEngine &Diags = *static_cast<DiagnosticsEngine*>(UserData);
70
71 Diags.Report(DiagID: diag::err_fe_error_backend) << Message;
72
73 // Run the interrupt handlers to make sure any special cleanups get done, in
74 // particular that we remove files registered with RemoveFileOnSignal.
75 llvm::sys::RunInterruptHandlers();
76
77 // We cannot recover from llvm errors. When reporting a fatal error, exit
78 // with status 70 to generate crash diagnostics. For BSD systems this is
79 // defined as an internal software error. Otherwise, exit with status 1.
80 llvm::sys::Process::Exit(RetCode: GenCrashDiag ? 70 : 1);
81}
82
83#ifdef CLANG_HAVE_RLIMITS
84/// Attempt to ensure that we have at least 8MiB of usable stack space.
85static void ensureSufficientStack() {
86 struct rlimit rlim;
87 if (getrlimit(RLIMIT_STACK, rlimits: &rlim) != 0)
88 return;
89
90 // Increase the soft stack limit to our desired level, if necessary and
91 // possible.
92 if (rlim.rlim_cur != RLIM_INFINITY &&
93 rlim.rlim_cur < rlim_t(DesiredStackSize)) {
94 // Try to allocate sufficient stack.
95 if (rlim.rlim_max == RLIM_INFINITY ||
96 rlim.rlim_max >= rlim_t(DesiredStackSize))
97 rlim.rlim_cur = DesiredStackSize;
98 else if (rlim.rlim_cur == rlim.rlim_max)
99 return;
100 else
101 rlim.rlim_cur = rlim.rlim_max;
102
103 if (setrlimit(RLIMIT_STACK, rlimits: &rlim) != 0 ||
104 rlim.rlim_cur != DesiredStackSize)
105 return;
106 }
107}
108#else
109static void ensureSufficientStack() {}
110#endif
111
112/// Print supported cpus of the given target.
113static int PrintSupportedCPUs(std::string TargetStr) {
114 llvm::Triple Triple(TargetStr);
115 std::string Error;
116 const llvm::Target *TheTarget =
117 llvm::TargetRegistry::lookupTarget(TheTriple: Triple, Error);
118 if (!TheTarget) {
119 llvm::errs() << Error;
120 return 1;
121 }
122
123 // the target machine will handle the mcpu printing
124 llvm::TargetOptions Options;
125 std::unique_ptr<llvm::TargetMachine> TheTargetMachine(
126 TheTarget->createTargetMachine(TT: Triple, CPU: "", Features: "+cpuhelp", Options,
127 RM: std::nullopt));
128 return 0;
129}
130
131static int PrintSupportedExtensions(std::string TargetStr) {
132 llvm::Triple Triple(TargetStr);
133 std::string Error;
134 const llvm::Target *TheTarget =
135 llvm::TargetRegistry::lookupTarget(TheTriple: Triple, Error);
136 if (!TheTarget) {
137 llvm::errs() << Error;
138 return 1;
139 }
140
141 llvm::TargetOptions Options;
142 std::unique_ptr<llvm::TargetMachine> TheTargetMachine(
143 TheTarget->createTargetMachine(TT: Triple, CPU: "", Features: "", Options, RM: std::nullopt));
144 const llvm::Triple &MachineTriple = TheTargetMachine->getTargetTriple();
145 const llvm::MCSubtargetInfo *MCInfo = TheTargetMachine->getMCSubtargetInfo();
146 const llvm::ArrayRef<llvm::SubtargetFeatureKV> Features =
147 MCInfo->getAllProcessorFeatures();
148
149 llvm::StringMap<llvm::StringRef> DescMap;
150 for (const llvm::SubtargetFeatureKV &feature : Features)
151 DescMap.insert(KV: {feature.Key, feature.Desc});
152
153 if (MachineTriple.isRISCV())
154 llvm::RISCVISAInfo::printSupportedExtensions(DescMap);
155 else if (MachineTriple.isAArch64())
156 llvm::AArch64::PrintSupportedExtensions();
157 else if (MachineTriple.isARM())
158 llvm::ARM::PrintSupportedExtensions(DescMap);
159 else {
160 // The option was already checked in Driver::HandleImmediateArgs,
161 // so we do not expect to get here if we are not a supported architecture.
162 assert(0 && "Unhandled triple for --print-supported-extensions option.");
163 return 1;
164 }
165
166 return 0;
167}
168
169static int PrintEnabledExtensions(const TargetOptions& TargetOpts) {
170 llvm::Triple Triple(TargetOpts.Triple);
171 std::string Error;
172 const llvm::Target *TheTarget =
173 llvm::TargetRegistry::lookupTarget(TheTriple: Triple, Error);
174 if (!TheTarget) {
175 llvm::errs() << Error;
176 return 1;
177 }
178
179 // Create a target machine using the input features, the triple information
180 // and a dummy instance of llvm::TargetOptions. Note that this is _not_ the
181 // same as the `clang::TargetOptions` instance we have access to here.
182 llvm::TargetOptions BackendOptions;
183 std::string FeaturesStr = llvm::join(R: TargetOpts.FeaturesAsWritten, Separator: ",");
184 std::unique_ptr<llvm::TargetMachine> TheTargetMachine(
185 TheTarget->createTargetMachine(TT: Triple, CPU: TargetOpts.CPU, Features: FeaturesStr,
186 Options: BackendOptions, RM: std::nullopt));
187 const llvm::Triple &MachineTriple = TheTargetMachine->getTargetTriple();
188 const llvm::MCSubtargetInfo *MCInfo = TheTargetMachine->getMCSubtargetInfo();
189
190 // Extract the feature names that are enabled for the given target.
191 // We do that by capturing the key from the set of SubtargetFeatureKV entries
192 // provided by MCSubtargetInfo, which match the '-target-feature' values.
193 const std::vector<llvm::SubtargetFeatureKV> Features =
194 MCInfo->getEnabledProcessorFeatures();
195 std::set<llvm::StringRef> EnabledFeatureNames;
196 for (const llvm::SubtargetFeatureKV &feature : Features)
197 EnabledFeatureNames.insert(x: feature.Key);
198
199 if (MachineTriple.isAArch64())
200 llvm::AArch64::printEnabledExtensions(EnabledFeatureNames);
201 else if (MachineTriple.isRISCV()) {
202 llvm::StringMap<llvm::StringRef> DescMap;
203 for (const llvm::SubtargetFeatureKV &feature : Features)
204 DescMap.insert(KV: {feature.Key, feature.Desc});
205 llvm::RISCVISAInfo::printEnabledExtensions(IsRV64: MachineTriple.isArch64Bit(),
206 EnabledFeatureNames, DescMap);
207 } else {
208 // The option was already checked in Driver::HandleImmediateArgs,
209 // so we do not expect to get here if we are not a supported architecture.
210 assert(0 && "Unhandled triple for --print-enabled-extensions option.");
211 return 1;
212 }
213
214 return 0;
215}
216
217int cc1_main(ArrayRef<const char *> Argv, const char *Argv0, void *MainAddr) {
218 ensureSufficientStack();
219
220 IntrusiveRefCntPtr<DiagnosticIDs> DiagID(new DiagnosticIDs());
221
222 // Register the support for object-file-wrapped Clang modules.
223 auto PCHOps = std::make_shared<PCHContainerOperations>();
224 PCHOps->registerWriter(Writer: std::make_unique<ObjectFilePCHContainerWriter>());
225 PCHOps->registerReader(Reader: std::make_unique<ObjectFilePCHContainerReader>());
226
227 // Initialize targets first, so that --version shows registered targets.
228 llvm::InitializeAllTargets();
229 llvm::InitializeAllTargetMCs();
230 llvm::InitializeAllAsmPrinters();
231 llvm::InitializeAllAsmParsers();
232
233 // Buffer diagnostics from argument parsing so that we can output them using a
234 // well formed diagnostic object.
235 DiagnosticOptions DiagOpts;
236 TextDiagnosticBuffer *DiagsBuffer = new TextDiagnosticBuffer;
237 DiagnosticsEngine Diags(DiagID, DiagOpts, DiagsBuffer);
238
239 // Setup round-trip remarks for the DiagnosticsEngine used in CreateFromArgs.
240 if (find(Range&: Argv, Val: StringRef("-Rround-trip-cc1-args")) != Argv.end())
241 Diags.setSeverity(Diag: diag::remark_cc1_round_trip_generated,
242 Map: diag::Severity::Remark, Loc: {});
243
244 auto Invocation = std::make_shared<CompilerInvocation>();
245 bool Success =
246 CompilerInvocation::CreateFromArgs(Res&: *Invocation, CommandLineArgs: Argv, Diags, Argv0);
247
248 auto Clang = std::make_unique<CompilerInstance>(args: std::move(Invocation),
249 args: std::move(PCHOps));
250
251 if (!Clang->getFrontendOpts().TimeTracePath.empty()) {
252 llvm::timeTraceProfilerInitialize(
253 TimeTraceGranularity: Clang->getFrontendOpts().TimeTraceGranularity, ProcName: Argv0,
254 TimeTraceVerbose: Clang->getFrontendOpts().TimeTraceVerbose);
255 }
256 // --print-supported-cpus takes priority over the actual compilation.
257 if (Clang->getFrontendOpts().PrintSupportedCPUs)
258 return PrintSupportedCPUs(TargetStr: Clang->getTargetOpts().Triple);
259
260 // --print-supported-extensions takes priority over the actual compilation.
261 if (Clang->getFrontendOpts().PrintSupportedExtensions)
262 return PrintSupportedExtensions(TargetStr: Clang->getTargetOpts().Triple);
263
264 // --print-enabled-extensions takes priority over the actual compilation.
265 if (Clang->getFrontendOpts().PrintEnabledExtensions)
266 return PrintEnabledExtensions(TargetOpts: Clang->getTargetOpts());
267
268 // Infer the builtin include path if unspecified.
269 if (Clang->getHeaderSearchOpts().UseBuiltinIncludes &&
270 Clang->getHeaderSearchOpts().ResourceDir.empty())
271 Clang->getHeaderSearchOpts().ResourceDir =
272 CompilerInvocation::GetResourcesPath(Argv0, MainAddr);
273
274 // Create the actual diagnostics engine.
275 Clang->createDiagnostics(VFS&: *llvm::vfs::getRealFileSystem());
276 if (!Clang->hasDiagnostics())
277 return 1;
278
279 // Set an error handler, so that any LLVM backend diagnostics go through our
280 // error handler.
281 llvm::install_fatal_error_handler(handler: LLVMErrorHandler,
282 user_data: static_cast<void*>(&Clang->getDiagnostics()));
283
284 DiagsBuffer->FlushDiagnostics(Diags&: Clang->getDiagnostics());
285 if (!Success) {
286 Clang->getDiagnosticClient().finish();
287 return 1;
288 }
289
290 // Execute the frontend actions.
291 {
292 llvm::TimeTraceScope TimeScope("ExecuteCompiler");
293 bool TimePasses = Clang->getCodeGenOpts().TimePasses;
294 if (TimePasses)
295 Clang->createFrontendTimer();
296 llvm::TimeRegion Timer(TimePasses ? &Clang->getFrontendTimer() : nullptr);
297 Success = ExecuteCompilerInvocation(Clang: Clang.get());
298 }
299
300 // If any timers were active but haven't been destroyed yet, print their
301 // results now. This happens in -disable-free mode.
302 std::unique_ptr<raw_ostream> IOFile = llvm::CreateInfoOutputFile();
303 if (Clang->getCodeGenOpts().TimePassesJson) {
304 *IOFile << "{\n";
305 llvm::TimerGroup::printAllJSONValues(OS&: *IOFile, delim: "");
306 *IOFile << "\n}\n";
307 } else {
308 llvm::TimerGroup::printAll(OS&: *IOFile);
309 }
310 llvm::TimerGroup::clearAll();
311
312 if (llvm::timeTraceProfilerEnabled()) {
313 // It is possible that the compiler instance doesn't own a file manager here
314 // if we're compiling a module unit. Since the file manager are owned by AST
315 // when we're compiling a module unit. So the file manager may be invalid
316 // here.
317 //
318 // It should be fine to create file manager here since the file system
319 // options are stored in the compiler invocation and we can recreate the VFS
320 // from the compiler invocation.
321 if (!Clang->hasFileManager())
322 Clang->createFileManager(VFS: createVFSFromCompilerInvocation(
323 CI: Clang->getInvocation(), Diags&: Clang->getDiagnostics()));
324
325 if (auto profilerOutput = Clang->createOutputFile(
326 OutputPath: Clang->getFrontendOpts().TimeTracePath, /*Binary=*/false,
327 /*RemoveFileOnSignal=*/false,
328 /*useTemporary=*/UseTemporary: false)) {
329 llvm::timeTraceProfilerWrite(OS&: *profilerOutput);
330 profilerOutput.reset();
331 llvm::timeTraceProfilerCleanup();
332 Clang->clearOutputFiles(EraseFiles: false);
333 }
334 }
335
336 // Our error handler depends on the Diagnostics object, which we're
337 // potentially about to delete. Uninstall the handler now so that any
338 // later errors use the default handling behavior instead.
339 llvm::remove_fatal_error_handler();
340
341 // When running with -disable-free, don't do any destruction or shutdown.
342 if (Clang->getFrontendOpts().DisableFree) {
343 llvm::BuryPointer(Ptr: std::move(Clang));
344 return !Success;
345 }
346
347 return !Success;
348}
349