X-Git-Url: http://demsky.eecs.uci.edu/git/?a=blobdiff_plain;f=include%2Fllvm%2FSupport%2FErrorHandling.h;h=9afd52d1abc72765d27ada096baf85e4a42f6631;hb=9130d115d6ec4e7b8e795b2f1e06ff6e660daa35;hp=a65fbe697420406b17ae96580f1160786648eab8;hpb=ab7c09b6b6f4516a631fd6788918c237c83939af;p=oota-llvm.git diff --git a/include/llvm/Support/ErrorHandling.h b/include/llvm/Support/ErrorHandling.h index a65fbe69742..9afd52d1abc 100644 --- a/include/llvm/Support/ErrorHandling.h +++ b/include/llvm/Support/ErrorHandling.h @@ -1,4 +1,4 @@ -//===- llvm/Support/ErrorHandling.h - Callbacks for errors ------*- C++ -*-===// +//===- llvm/Support/ErrorHandling.h - Fatal error handling ------*- C++ -*-===// // // The LLVM Compiler Infrastructure // @@ -7,49 +7,100 @@ // //===----------------------------------------------------------------------===// // -// This file defines an API used to indicate error conditions. -// Callbacks can be registered for these errors through this API. +// This file defines an API used to indicate fatal error conditions. Non-fatal +// errors (most of them) should be handled through LLVMContext. // //===----------------------------------------------------------------------===// #ifndef LLVM_SUPPORT_ERRORHANDLING_H #define LLVM_SUPPORT_ERRORHANDLING_H +#include "llvm/ADT/StringRef.h" #include "llvm/Support/Compiler.h" #include namespace llvm { + class Twine; + /// An error handler callback. - typedef void (*llvm_error_handler_t)(const std::string& reason); + typedef void (*fatal_error_handler_t)(void *user_data, + const std::string& reason, + bool gen_crash_diag); - /// Installs a new error handler: this function will be called whenever a - /// serious error is encountered by LLVM. - /// If you are using llvm_start_multithreaded, you should register the handler - /// before doing that. + /// install_fatal_error_handler - Installs a new error handler to be used + /// whenever a serious (non-recoverable) error is encountered by LLVM. /// /// If no error handler is installed the default is to print the error message - /// to stderr, and call exit(1). - /// If an error handler is installed then it is the handler's responsibility - /// to log the message, it will no longer be printed to stderr. - /// If the error handler returns, then exit(1) will be called. - void llvm_install_error_handler(llvm_error_handler_t handler); + /// to stderr, and call exit(1). If an error handler is installed then it is + /// the handler's responsibility to log the message, it will no longer be + /// printed to stderr. If the error handler returns, then exit(1) will be + /// called. + /// + /// It is dangerous to naively use an error handler which throws an exception. + /// Even though some applications desire to gracefully recover from arbitrary + /// faults, blindly throwing exceptions through unfamiliar code isn't a way to + /// achieve this. + /// + /// \param user_data - An argument which will be passed to the install error + /// handler. + void install_fatal_error_handler(fatal_error_handler_t handler, + void *user_data = nullptr); /// Restores default error handling behaviour. - /// This must not be called between llvm_start_multithreaded() and - /// llvm_stop_multithreaded(). - void llvm_remove_error_handler(void); + void remove_fatal_error_handler(); + + /// ScopedFatalErrorHandler - This is a simple helper class which just + /// calls install_fatal_error_handler in its constructor and + /// remove_fatal_error_handler in its destructor. + struct ScopedFatalErrorHandler { + explicit ScopedFatalErrorHandler(fatal_error_handler_t handler, + void *user_data = nullptr) { + install_fatal_error_handler(handler, user_data); + } - /// Reports a serious error, calling any installed error handler. + ~ScopedFatalErrorHandler() { remove_fatal_error_handler(); } + }; + + /// Reports a serious error, calling any installed error handler. These + /// functions are intended to be used for error conditions which are outside + /// the control of the compiler (I/O errors, invalid user input, etc.) + /// /// If no error handler is installed the default is to print the message to - void llvm_report_error(const std::string &reason) NORETURN; + /// standard error, followed by a newline. + /// After the error handler is called this function will call exit(1), it + /// does not return. + LLVM_ATTRIBUTE_NORETURN void report_fatal_error(const char *reason, + bool gen_crash_diag = true); + LLVM_ATTRIBUTE_NORETURN void report_fatal_error(const std::string &reason, + bool gen_crash_diag = true); + LLVM_ATTRIBUTE_NORETURN void report_fatal_error(StringRef reason, + bool gen_crash_diag = true); + LLVM_ATTRIBUTE_NORETURN void report_fatal_error(const Twine &reason, + bool gen_crash_diag = true); - /// This function calls abort(). - /// Call this after assert(0), so that compiler knows the path is not - /// reachable. - void llvm_unreachable(void) NORETURN; + /// This function calls abort(), and prints the optional message to stderr. + /// Use the llvm_unreachable macro (that adds location info), instead of + /// calling this function directly. + LLVM_ATTRIBUTE_NORETURN void + llvm_unreachable_internal(const char *msg=nullptr, const char *file=nullptr, + unsigned line=0); } -#define LLVM_UNREACHABLE(msg) do { assert(0 && msg); llvm_unreachable(); } while(0); - +/// Marks that the current location is not supposed to be reachable. +/// In !NDEBUG builds, prints the message and location info to stderr. +/// In NDEBUG builds, becomes an optimizer hint that the current location +/// is not supposed to be reachable. On compilers that don't support +/// such hints, prints a reduced message instead. +/// +/// Use this instead of assert(0). It conveys intent more clearly and +/// allows compilers to omit some unnecessary code. +#ifndef NDEBUG +#define llvm_unreachable(msg) \ + ::llvm::llvm_unreachable_internal(msg, __FILE__, __LINE__) +#elif defined(LLVM_BUILTIN_UNREACHABLE) +#define llvm_unreachable(msg) LLVM_BUILTIN_UNREACHABLE +#else +#define llvm_unreachable(msg) ::llvm::llvm_unreachable_internal() #endif +#endif