1 //===-- cc1_main.cpp - Clang CC1 Compiler Frontend ------------------------===//
3 // The LLVM Compiler Infrastructure
5 // This file is distributed under the University of Illinois Open Source
6 // License. See LICENSE.TXT for details.
8 //===----------------------------------------------------------------------===//
10 // This is the entry point to the clang -cc1 functionality, which implements the
11 // core compiler functionality along with a number of additional tools for
12 // demonstration and testing purposes.
14 //===----------------------------------------------------------------------===//
16 #include "llvm/Option/Arg.h"
17 #include "clang/CodeGen/ObjectFilePCHContainerOperations.h"
18 #include "clang/Config/config.h"
19 #include "clang/Basic/Stack.h"
20 #include "clang/Driver/DriverDiagnostic.h"
21 #include "clang/Driver/Options.h"
22 #include "clang/Frontend/CompilerInstance.h"
23 #include "clang/Frontend/CompilerInvocation.h"
24 #include "clang/Frontend/FrontendDiagnostic.h"
25 #include "clang/Frontend/TextDiagnosticBuffer.h"
26 #include "clang/Frontend/TextDiagnosticPrinter.h"
27 #include "clang/Frontend/Utils.h"
28 #include "clang/FrontendTool/Utils.h"
29 #include "llvm/ADT/Statistic.h"
30 #include "llvm/Config/llvm-config.h"
31 #include "llvm/LinkAllPasses.h"
32 #include "llvm/Option/ArgList.h"
33 #include "llvm/Option/OptTable.h"
34 #include "llvm/Support/Compiler.h"
35 #include "llvm/Support/ErrorHandling.h"
36 #include "llvm/Support/ManagedStatic.h"
37 #include "llvm/Support/Signals.h"
38 #include "llvm/Support/TargetSelect.h"
39 #include "llvm/Support/Timer.h"
40 #include "llvm/Support/raw_ostream.h"
43 #ifdef CLANG_HAVE_RLIMITS
44 #include <sys/resource.h>
47 using namespace clang;
48 using namespace llvm::opt;
50 //===----------------------------------------------------------------------===//
52 //===----------------------------------------------------------------------===//
54 static void LLVMErrorHandler(void *UserData, const std::string &Message,
56 DiagnosticsEngine &Diags = *static_cast<DiagnosticsEngine*>(UserData);
58 Diags.Report(diag::err_fe_error_backend) << Message;
60 // Run the interrupt handlers to make sure any special cleanups get done, in
61 // particular that we remove files registered with RemoveFileOnSignal.
62 llvm::sys::RunInterruptHandlers();
64 // We cannot recover from llvm errors. When reporting a fatal error, exit
65 // with status 70 to generate crash diagnostics. For BSD systems this is
66 // defined as an internal software error. Otherwise, exit with status 1.
67 exit(GenCrashDiag ? 70 : 1);
70 #ifdef LINK_POLLY_INTO_TOOLS
72 void initializePollyPasses(llvm::PassRegistry &Registry);
76 #ifdef CLANG_HAVE_RLIMITS
77 #if defined(__linux__) && defined(__PIE__)
78 static size_t getCurrentStackAllocation() {
79 // If we can't compute the current stack usage, allow for 512K of command
80 // line arguments and environment.
81 size_t Usage = 512 * 1024;
82 if (FILE *StatFile = fopen("/proc/self/stat", "r")) {
83 // We assume that the stack extends from its current address to the end of
84 // the environment space. In reality, there is another string literal (the
85 // program name) after the environment, but this is close enough (we only
86 // need to be within 100K or so).
87 unsigned long StackPtr, EnvEnd;
88 // Disable silly GCC -Wformat warning that complains about length
89 // modifiers on ignored format specifiers. We want to retain these
90 // for documentation purposes even though they have no effect.
91 #if defined(__GNUC__) && !defined(__clang__)
92 #pragma GCC diagnostic push
93 #pragma GCC diagnostic ignored "-Wformat"
96 "%*d %*s %*c %*d %*d %*d %*d %*d %*u %*lu %*lu %*lu %*lu %*lu "
97 "%*lu %*ld %*ld %*ld %*ld %*ld %*ld %*llu %*lu %*ld %*lu %*lu "
98 "%*lu %*lu %lu %*lu %*lu %*lu %*lu %*lu %*llu %*lu %*lu %*d %*d "
99 "%*u %*u %*llu %*lu %*ld %*lu %*lu %*lu %*lu %*lu %*lu %lu %*d",
100 &StackPtr, &EnvEnd) == 2) {
101 #if defined(__GNUC__) && !defined(__clang__)
102 #pragma GCC diagnostic pop
104 Usage = StackPtr < EnvEnd ? EnvEnd - StackPtr : StackPtr - EnvEnd;
113 LLVM_ATTRIBUTE_NOINLINE
114 static void ensureStackAddressSpace() {
115 // Linux kernels prior to 4.1 will sometimes locate the heap of a PIE binary
116 // relatively close to the stack (they are only guaranteed to be 128MiB
117 // apart). This results in crashes if we happen to heap-allocate more than
118 // 128MiB before we reach our stack high-water mark.
120 // To avoid these crashes, ensure that we have sufficient virtual memory
121 // pages allocated before we start running.
122 size_t Curr = getCurrentStackAllocation();
123 const int kTargetStack = DesiredStackSize - 256 * 1024;
124 if (Curr < kTargetStack) {
125 volatile char *volatile Alloc =
126 static_cast<volatile char *>(alloca(kTargetStack - Curr));
128 Alloc[kTargetStack - Curr - 1] = 0;
132 static void ensureStackAddressSpace() {}
135 /// Attempt to ensure that we have at least 8MiB of usable stack space.
136 static void ensureSufficientStack() {
138 if (getrlimit(RLIMIT_STACK, &rlim) != 0)
141 // Increase the soft stack limit to our desired level, if necessary and
143 if (rlim.rlim_cur != RLIM_INFINITY &&
144 rlim.rlim_cur < rlim_t(DesiredStackSize)) {
145 // Try to allocate sufficient stack.
146 if (rlim.rlim_max == RLIM_INFINITY ||
147 rlim.rlim_max >= rlim_t(DesiredStackSize))
148 rlim.rlim_cur = DesiredStackSize;
149 else if (rlim.rlim_cur == rlim.rlim_max)
152 rlim.rlim_cur = rlim.rlim_max;
154 if (setrlimit(RLIMIT_STACK, &rlim) != 0 ||
155 rlim.rlim_cur != DesiredStackSize)
159 // We should now have a stack of size at least DesiredStackSize. Ensure
160 // that we can actually use that much, if necessary.
161 ensureStackAddressSpace();
164 static void ensureSufficientStack() {}
167 int cc1_main(ArrayRef<const char *> Argv, const char *Argv0, void *MainAddr) {
168 ensureSufficientStack();
170 std::unique_ptr<CompilerInstance> Clang(new CompilerInstance());
171 IntrusiveRefCntPtr<DiagnosticIDs> DiagID(new DiagnosticIDs());
173 // Register the support for object-file-wrapped Clang modules.
174 auto PCHOps = Clang->getPCHContainerOperations();
175 PCHOps->registerWriter(llvm::make_unique<ObjectFilePCHContainerWriter>());
176 PCHOps->registerReader(llvm::make_unique<ObjectFilePCHContainerReader>());
178 // Initialize targets first, so that --version shows registered targets.
179 llvm::InitializeAllTargets();
180 llvm::InitializeAllTargetMCs();
181 llvm::InitializeAllAsmPrinters();
182 llvm::InitializeAllAsmParsers();
184 #ifdef LINK_POLLY_INTO_TOOLS
185 llvm::PassRegistry &Registry = *llvm::PassRegistry::getPassRegistry();
186 polly::initializePollyPasses(Registry);
189 // Buffer diagnostics from argument parsing so that we can output them using a
190 // well formed diagnostic object.
191 IntrusiveRefCntPtr<DiagnosticOptions> DiagOpts = new DiagnosticOptions();
192 TextDiagnosticBuffer *DiagsBuffer = new TextDiagnosticBuffer;
193 DiagnosticsEngine Diags(DiagID, &*DiagOpts, DiagsBuffer);
194 bool Success = CompilerInvocation::CreateFromArgs(
195 Clang->getInvocation(), Argv.begin(), Argv.end(), Diags);
197 // Infer the builtin include path if unspecified.
198 if (Clang->getHeaderSearchOpts().UseBuiltinIncludes &&
199 Clang->getHeaderSearchOpts().ResourceDir.empty())
200 Clang->getHeaderSearchOpts().ResourceDir =
201 CompilerInvocation::GetResourcesPath(Argv0, MainAddr);
203 // Create the actual diagnostics engine.
204 Clang->createDiagnostics();
205 if (!Clang->hasDiagnostics())
208 // Set an error handler, so that any LLVM backend diagnostics go through our
210 llvm::install_fatal_error_handler(LLVMErrorHandler,
211 static_cast<void*>(&Clang->getDiagnostics()));
213 DiagsBuffer->FlushDiagnostics(Clang->getDiagnostics());
217 // Execute the frontend actions.
218 Success = ExecuteCompilerInvocation(Clang.get());
220 // If any timers were active but haven't been destroyed yet, print their
221 // results now. This happens in -disable-free mode.
222 llvm::TimerGroup::printAll(llvm::errs());
224 // Our error handler depends on the Diagnostics object, which we're
225 // potentially about to delete. Uninstall the handler now so that any
226 // later errors use the default handling behavior instead.
227 llvm::remove_fatal_error_handler();
229 // When running with -disable-free, don't do any destruction or shutdown.
230 if (Clang->getFrontendOpts().DisableFree) {
231 BuryPointer(std::move(Clang));