X-Git-Url: http://demsky.eecs.uci.edu/git/?a=blobdiff_plain;f=include%2Fllvm%2FSupport%2FErrorHandling.h;h=95b01095c1b25c89ae98ad52a22cf60b6043e15f;hb=536a88ad5bf160232205192a7ce72e50bfadbded;hp=c14eed98850b2e6ed4ae8fc7a3dea4061044761e;hpb=93990d775ea4ac13c9c2614e84fc19a7a2161771;p=oota-llvm.git diff --git a/include/llvm/Support/ErrorHandling.h b/include/llvm/Support/ErrorHandling.h index c14eed98850..95b01095c1b 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 // @@ -7,8 +7,8 @@ // //===----------------------------------------------------------------------===// // -// 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. // //===----------------------------------------------------------------------===// @@ -16,51 +16,91 @@ #define LLVM_SUPPORT_ERRORHANDLING_H #include "llvm/Support/Compiler.h" +#include "llvm/ADT/StringRef.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); - /// Installs a new error handler: this function will be called whenever a - /// serious error is encountered by LLVM. + /// install_fatal_error_handler - Installs a new error handler to be used + /// whenever a serious (non-recoverable) error is encountered by LLVM. + /// /// If you are using llvm_start_multithreaded, you should register the handler /// before doing that. /// /// 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 = 0); /// 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(); - /// Reports a serious error, calling any installed 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 = 0) { + install_fatal_error_handler(handler, user_data); + } + + ~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 /// standard error, followed by a newline. /// After the error handler is called this function will call exit(1), it /// does not return. - void llvm_report_error(const std::string &reason) NORETURN; + LLVM_ATTRIBUTE_NORETURN void report_fatal_error(const char *reason); + LLVM_ATTRIBUTE_NORETURN void report_fatal_error(const std::string &reason); + LLVM_ATTRIBUTE_NORETURN void report_fatal_error(StringRef reason); + LLVM_ATTRIBUTE_NORETURN void report_fatal_error(const Twine &reason); /// This function calls abort(), and prints the optional message to stderr. - /// Call this instead of assert(0), so that compiler knows the path is not - /// reachable even for NDEBUG builds. - /// Use the LLVM_UNREACHABLE macro instead that adds location info. - void llvm_unreachable(const char *msg=0, const char *file=0, - unsigned line=0) NORETURN; + /// 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=0, + const char *file=0, + unsigned line=0); } -/// Macro that calls llvm_unreachable with location info and message in -/// debug mode. In NDEBUG mode it calls llvm_unreachable with no message. +/// 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_unreachable(msg, __FILE__, __LINE__) +#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_unreachable() +#define llvm_unreachable(msg) ::llvm::llvm_unreachable_internal() #endif #endif -