| //===--- Errors.cpp - Error reporting utilities ---------------------------===// |
| // |
| // This source file is part of the Swift.org open source project |
| // |
| // Copyright (c) 2014 - 2016 Apple Inc. and the Swift project authors |
| // Licensed under Apache License v2.0 with Runtime Library Exception |
| // |
| // See http://swift.org/LICENSE.txt for license information |
| // See http://swift.org/CONTRIBUTORS.txt for the list of Swift project authors |
| // |
| //===----------------------------------------------------------------------===// |
| // |
| // Utilities for reporting errors to stderr, system console, and crash logs. |
| // |
| //===----------------------------------------------------------------------===// |
| |
| #if defined(__CYGWIN__) || defined(__ANDROID__) || defined(_MSC_VER) |
| # define SWIFT_SUPPORTS_BACKTRACE_REPORTING 0 |
| #else |
| # define SWIFT_SUPPORTS_BACKTRACE_REPORTING 1 |
| #endif |
| |
| #include <stdio.h> |
| #include <stdlib.h> |
| #include <string.h> |
| #include <stdint.h> |
| #if defined(_MSC_VER) |
| #include <io.h> |
| #else |
| #include <unistd.h> |
| #endif |
| #include <stdarg.h> |
| #include "swift/Runtime/Debug.h" |
| #include "swift/Runtime/Mutex.h" |
| #include "swift/Basic/Demangle.h" |
| #include "swift/Basic/LLVM.h" |
| #include "llvm/ADT/StringRef.h" |
| #if !defined(_MSC_VER) |
| #include <cxxabi.h> |
| #endif |
| #if SWIFT_SUPPORTS_BACKTRACE_REPORTING |
| |
| // execinfo.h is not available on Android. Checks in this file ensure that |
| // fatalError behaves as expected, but without stack traces. |
| #include <execinfo.h> |
| // We are only using dlfcn.h in code that is invoked on non cygwin/android |
| // platforms. So I am putting it here. |
| #include <dlfcn.h> |
| #endif |
| |
| #ifdef __APPLE__ |
| #include <asl.h> |
| #endif |
| |
| namespace FatalErrorFlags { |
| enum: uint32_t { |
| ReportBacktrace = 1 << 0 |
| }; |
| } // end namespace FatalErrorFlags |
| |
| using namespace swift; |
| |
| #if SWIFT_SUPPORTS_BACKTRACE_REPORTING |
| |
| static bool getSymbolNameAddr(llvm::StringRef libraryName, Dl_info dlinfo, |
| std::string &symbolName, uintptr_t &addrOut) { |
| |
| // If we failed to find a symbol and thus dlinfo->dli_sname is nullptr, we |
| // need to use the hex address. |
| bool hasUnavailableAddress = dlinfo.dli_sname == nullptr; |
| |
| // If the address is unavailable, just use <unavailable> as the symbol |
| // name. We do not set addrOut, since addrOut will be set to our ptr address. |
| if (hasUnavailableAddress) { |
| symbolName += "<unavailable>"; |
| return false; |
| } |
| |
| // Ok, now we know that we have some sort of "real" name. Set the outAddr. |
| addrOut = uintptr_t(dlinfo.dli_saddr); |
| |
| // First lets try to demangle using cxxabi. If this fails, we will try to |
| // demangle with swift. We are taking advantage of __cxa_demangle actually |
| // providing failure status instead of just returning the original string like |
| // swift demangle. |
| int status; |
| char *demangled = abi::__cxa_demangle(dlinfo.dli_sname, 0, 0, &status); |
| if (status == 0) { |
| assert(demangled != nullptr && "If __cxa_demangle succeeds, demangled " |
| "should never be nullptr"); |
| symbolName += demangled; |
| free(demangled); |
| return true; |
| } |
| assert(demangled == nullptr && "If __cxa_demangle fails, demangled should " |
| "be a nullptr"); |
| |
| // Otherwise, try to demangle with swift. If swift fails to demangle, it will |
| // just pass through the original output. |
| symbolName = demangleSymbolAsString( |
| dlinfo.dli_sname, strlen(dlinfo.dli_sname), |
| Demangle::DemangleOptions::SimplifiedUIDemangleOptions()); |
| return true; |
| } |
| |
| /// This function dumps one line of a stack trace. It is assumed that \p address |
| /// is the address of the stack frame at index \p index. |
| static void dumpStackTraceEntry(unsigned index, void *framePC) { |
| Dl_info dlinfo; |
| |
| // 0 is failure for dladdr. We do not use nullptr since it is an int |
| // argument. This violates normal unix patterns. See man page for dladdr on OS |
| // X. |
| if (0 == dladdr(framePC, &dlinfo)) { |
| return; |
| } |
| |
| // According to the man page of dladdr, if dladdr returns non-zero, then we |
| // know that it must have fname, fbase set. Thus, we find the library name |
| // here. |
| StringRef libraryName = StringRef(dlinfo.dli_fname).rsplit('/').second; |
| |
| // Next we get the symbol name that we are going to use in our backtrace. |
| std::string symbolName; |
| // We initialize symbolAddr to framePC so that if we succeed in finding the |
| // symbol, we get the offset in the function and if we fail to find the symbol |
| // we just get HexAddr + 0. |
| uintptr_t symbolAddr = uintptr_t(framePC); |
| bool foundSymbol = |
| getSymbolNameAddr(libraryName, dlinfo, symbolName, symbolAddr); |
| |
| // We do not use %p here for our pointers since the format is implementation |
| // defined. This makes it logically impossible to check the output. Forcing |
| // hexadecimal solves this issue. |
| static const char *backtraceEntryFormat = "%-4u %-34s 0x%0.16lx %s + %td\n"; |
| |
| // Then dump the backtrace. |
| fprintf(stderr, backtraceEntryFormat, index, libraryName.data(), |
| foundSymbol ? symbolAddr : uintptr_t(framePC), symbolName.c_str(), |
| ptrdiff_t(uintptr_t(framePC) - symbolAddr)); |
| } |
| |
| #endif |
| |
| #ifdef SWIFT_HAVE_CRASHREPORTERCLIENT |
| #include <malloc/malloc.h> |
| |
| // Instead of linking to CrashReporterClient.a (because it complicates the |
| // build system), define the only symbol from that static archive ourselves. |
| // |
| // The layout of this struct is CrashReporter ABI, so there are no ABI concerns |
| // here. |
| extern "C" { |
| CRASH_REPORTER_CLIENT_HIDDEN |
| struct crashreporter_annotations_t gCRAnnotations |
| __attribute__((__section__("__DATA," CRASHREPORTER_ANNOTATIONS_SECTION))) = { |
| CRASHREPORTER_ANNOTATIONS_VERSION, 0, 0, 0, 0, 0, 0, 0}; |
| } |
| |
| // Report a message to any forthcoming crash log. |
| static void |
| reportOnCrash(uint32_t flags, const char *message) |
| { |
| // We must use an "unsafe" mutex in this pathway since the normal "safe" |
| // mutex calls fatalError when an error is detected and fatalError ends up |
| // calling us. In other words we could get infinite recursion if the |
| // mutex errors. |
| static swift::StaticUnsafeMutex crashlogLock; |
| |
| crashlogLock.lock(); |
| |
| char *oldMessage = (char *)CRGetCrashLogMessage(); |
| char *newMessage; |
| if (oldMessage) { |
| asprintf(&newMessage, "%s%s", oldMessage, message); |
| if (malloc_size(oldMessage)) free(oldMessage); |
| } else { |
| newMessage = strdup(message); |
| } |
| |
| CRSetCrashLogMessage(newMessage); |
| |
| crashlogLock.unlock(); |
| } |
| |
| #else |
| |
| static void |
| reportOnCrash(uint32_t flags, const char *message) |
| { |
| // empty |
| } |
| |
| #endif |
| |
| // Report a message to system console and stderr. |
| static void |
| reportNow(uint32_t flags, const char *message) |
| { |
| #if defined(_MSC_VER) |
| #define STDERR_FILENO 2 |
| _write(STDERR_FILENO, message, strlen(message)); |
| #else |
| write(STDERR_FILENO, message, strlen(message)); |
| #endif |
| #ifdef __APPLE__ |
| asl_log(NULL, NULL, ASL_LEVEL_ERR, "%s", message); |
| #endif |
| #if SWIFT_SUPPORTS_BACKTRACE_REPORTING |
| if (flags & FatalErrorFlags::ReportBacktrace) { |
| fputs("Current stack trace:\n", stderr); |
| constexpr unsigned maxSupportedStackDepth = 128; |
| void *addrs[maxSupportedStackDepth]; |
| |
| int symbolCount = backtrace(addrs, maxSupportedStackDepth); |
| for (int i = 0; i < symbolCount; ++i) { |
| dumpStackTraceEntry(i, addrs[i]); |
| } |
| } |
| #endif |
| } |
| |
| /// Report a fatal error to system console, stderr, and crash logs. |
| /// Does not crash by itself. |
| void swift::swift_reportError(uint32_t flags, |
| const char *message) { |
| reportNow(flags, message); |
| reportOnCrash(flags, message); |
| } |
| |
| static int swift_vasprintf(char **strp, const char *fmt, va_list ap) { |
| #if defined(_MSC_VER) |
| int len = _vscprintf(fmt, ap); |
| if (len < 0) |
| return -1; |
| char *buffer = reinterpret_cast<char *>(malloc(len + 1)); |
| if (!buffer) |
| return -1; |
| int result = vsprintf(*strp, fmt, ap); |
| if (result < 0) { |
| free(buffer); |
| return -1; |
| } |
| *strp = buffer; |
| return result; |
| #else |
| return vasprintf(strp, fmt, ap); |
| #endif |
| } |
| |
| // Report a fatal error to system console, stderr, and crash logs, then abort. |
| LLVM_ATTRIBUTE_NORETURN |
| void |
| swift::fatalError(uint32_t flags, const char *format, ...) |
| { |
| va_list args; |
| va_start(args, format); |
| |
| char *log; |
| swift_vasprintf(&log, format, args); |
| |
| swift_reportError(flags, log); |
| abort(); |
| } |
| |
| // Crash when a deleted method is called by accident. |
| SWIFT_RUNTIME_EXPORT |
| LLVM_ATTRIBUTE_NORETURN |
| extern "C" void |
| swift_deletedMethodError() { |
| swift::fatalError(/* flags = */ 0, |
| "fatal error: call of deleted method\n"); |
| } |