| //===-- Debug.cpp - An easy way to add debug output to your code ----------===// |
| // |
| // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions. |
| // See https://llvm.org/LICENSE.txt for license information. |
| // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception |
| // |
| //===----------------------------------------------------------------------===// |
| // |
| // This file implements a handy way of adding debugging information to your |
| // code, without it being enabled all of the time, and without having to add |
| // command line options to enable it. |
| // |
| // In particular, just wrap your code with the LLVM_DEBUG() macro, and it will |
| // be enabled automatically if you specify '-debug' on the command-line. |
| // Alternatively, you can also use the SET_DEBUG_TYPE("foo") macro to specify |
| // that your debug code belongs to class "foo". Then, on the command line, you |
| // can specify '-debug-only=foo' to enable JUST the debug information for the |
| // foo class. |
| // |
| // When compiling without assertions, the -debug-* options and all code in |
| // LLVM_DEBUG() statements disappears, so it does not affect the runtime of the |
| // code. |
| // |
| //===----------------------------------------------------------------------===// |
| |
| #include "llvm/Support/Debug.h" |
| #include "llvm/Support/CommandLine.h" |
| #include "llvm/Support/ManagedStatic.h" |
| #include "llvm/Support/Signals.h" |
| #include "llvm/Support/circular_raw_ostream.h" |
| #include "llvm/Support/raw_ostream.h" |
| |
| #include "DebugOptions.h" |
| |
| #undef isCurrentDebugType |
| #undef setCurrentDebugType |
| #undef setCurrentDebugTypes |
| |
| using namespace llvm; |
| |
| // Even though LLVM might be built with NDEBUG, define symbols that the code |
| // built without NDEBUG can depend on via the llvm/Support/Debug.h header. |
| namespace llvm { |
| /// Exported boolean set by the -debug option. |
| bool DebugFlag = false; |
| |
| static ManagedStatic<std::vector<std::string>> CurrentDebugType; |
| |
| /// Return true if the specified string is the debug type |
| /// specified on the command line, or if none was specified on the command line |
| /// with the -debug-only=X option. |
| bool isCurrentDebugType(const char *DebugType) { |
| if (CurrentDebugType->empty()) |
| return true; |
| // See if DebugType is in list. Note: do not use find() as that forces us to |
| // unnecessarily create an std::string instance. |
| for (auto &d : *CurrentDebugType) { |
| if (d == DebugType) |
| return true; |
| } |
| return false; |
| } |
| |
| /// Set the current debug type, as if the -debug-only=X |
| /// option were specified. Note that DebugFlag also needs to be set to true for |
| /// debug output to be produced. |
| /// |
| void setCurrentDebugTypes(const char **Types, unsigned Count); |
| |
| void setCurrentDebugType(const char *Type) { |
| setCurrentDebugTypes(&Type, 1); |
| } |
| |
| void setCurrentDebugTypes(const char **Types, unsigned Count) { |
| CurrentDebugType->clear(); |
| for (size_t T = 0; T < Count; ++T) |
| CurrentDebugType->push_back(Types[T]); |
| } |
| } // namespace llvm |
| |
| // All Debug.h functionality is a no-op in NDEBUG mode. |
| #ifndef NDEBUG |
| |
| namespace { |
| struct CreateDebug { |
| static void *call() { |
| return new cl::opt<bool, true>("debug", cl::desc("Enable debug output"), |
| cl::Hidden, cl::location(DebugFlag)); |
| } |
| }; |
| |
| // -debug-buffer-size - Buffer the last N characters of debug output |
| //until program termination. |
| struct CreateDebugBufferSize { |
| static void *call() { |
| return new cl::opt<unsigned>( |
| "debug-buffer-size", |
| cl::desc("Buffer the last N characters of debug output " |
| "until program termination. " |
| "[default 0 -- immediate print-out]"), |
| cl::Hidden, cl::init(0)); |
| } |
| }; |
| } // namespace |
| |
| // -debug - Command line option to enable the DEBUG statements in the passes. |
| // This flag may only be enabled in debug builds. |
| static ManagedStatic<cl::opt<bool, true>, CreateDebug> Debug; |
| static ManagedStatic<cl::opt<unsigned>, CreateDebugBufferSize> DebugBufferSize; |
| |
| namespace { |
| |
| struct DebugOnlyOpt { |
| void operator=(const std::string &Val) const { |
| if (Val.empty()) |
| return; |
| DebugFlag = true; |
| SmallVector<StringRef,8> dbgTypes; |
| StringRef(Val).split(dbgTypes, ',', -1, false); |
| for (auto dbgType : dbgTypes) |
| CurrentDebugType->push_back(std::string(dbgType)); |
| } |
| }; |
| } // namespace |
| |
| static DebugOnlyOpt DebugOnlyOptLoc; |
| |
| namespace { |
| struct CreateDebugOnly { |
| static void *call() { |
| return new cl::opt<DebugOnlyOpt, true, cl::parser<std::string>>( |
| "debug-only", |
| cl::desc("Enable a specific type of debug output (comma separated list " |
| "of types)"), |
| cl::Hidden, cl::ZeroOrMore, cl::value_desc("debug string"), |
| cl::location(DebugOnlyOptLoc), cl::ValueRequired); |
| } |
| }; |
| } // namespace |
| |
| static ManagedStatic<cl::opt<DebugOnlyOpt, true, cl::parser<std::string>>, |
| CreateDebugOnly> |
| DebugOnly; |
| |
| void llvm::initDebugOptions() { |
| *Debug; |
| *DebugBufferSize; |
| *DebugOnly; |
| } |
| |
| // Signal handlers - dump debug output on termination. |
| static void debug_user_sig_handler(void *Cookie) { |
| // This is a bit sneaky. Since this is under #ifndef NDEBUG, we |
| // know that debug mode is enabled and dbgs() really is a |
| // circular_raw_ostream. If NDEBUG is defined, then dbgs() == |
| // errs() but this will never be invoked. |
| llvm::circular_raw_ostream &dbgout = |
| static_cast<circular_raw_ostream &>(llvm::dbgs()); |
| dbgout.flushBufferWithBanner(); |
| } |
| |
| /// dbgs - Return a circular-buffered debug stream. |
| raw_ostream &llvm::dbgs() { |
| // Do one-time initialization in a thread-safe way. |
| static struct dbgstream { |
| circular_raw_ostream strm; |
| |
| dbgstream() |
| : strm(errs(), "*** Debug Log Output ***\n", |
| (!EnableDebugBuffering || !DebugFlag) ? 0 : *DebugBufferSize) { |
| if (EnableDebugBuffering && DebugFlag && *DebugBufferSize != 0) |
| // TODO: Add a handler for SIGUSER1-type signals so the user can |
| // force a debug dump. |
| sys::AddSignalHandler(&debug_user_sig_handler, nullptr); |
| // Otherwise we've already set the debug stream buffer size to |
| // zero, disabling buffering so it will output directly to errs(). |
| } |
| } thestrm; |
| |
| return thestrm.strm; |
| } |
| |
| #else |
| // Avoid "has no symbols" warning. |
| namespace llvm { |
| /// dbgs - Return errs(). |
| raw_ostream &dbgs() { |
| return errs(); |
| } |
| } |
| void llvm::initDebugOptions() {} |
| #endif |
| |
| /// EnableDebugBuffering - Turn on signal handler installation. |
| /// |
| bool llvm::EnableDebugBuffering = false; |