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