diff options
Diffstat (limited to 'llvm/runtime')
6 files changed, 166 insertions, 58 deletions
diff --git a/llvm/runtime/GCCLibraries/crtend/C++-Exception.cpp b/llvm/runtime/GCCLibraries/crtend/C++-Exception.cpp index 5e589301141..e22d61c823a 100644 --- a/llvm/runtime/GCCLibraries/crtend/C++-Exception.cpp +++ b/llvm/runtime/GCCLibraries/crtend/C++-Exception.cpp @@ -11,6 +11,12 @@ #include <cstdlib> #include <cstdarg> +//#define DEBUG + +#ifdef DEBUG +#include <stdio.h> +#endif + //===----------------------------------------------------------------------===// // Generic exception support // @@ -18,7 +24,11 @@ // Thread local state for exception handling. // FIXME: This should really be made thread-local! // -static llvm_exception *CaughtExceptionStack = 0; + +// LastCaughtException - The last exception caught by this handler. This is for +// implementation of _rethrow and _get_last_caught. +// +static llvm_exception *LastCaughtException = 0; // UncaughtExceptionStack - The stack of exceptions currently being thrown. static llvm_exception *UncaughtExceptionStack = 0; @@ -76,13 +86,9 @@ void __llvm_cxxeh_free_exception(void *ObjectPtr) throw() { // exception. // static void cxx_destructor(llvm_exception *LE) /* might throw */{ + assert(LE->Next == 0 && "On the uncaught stack??"); llvm_cxx_exception *E = get_cxx_exception(LE); - // The exception is no longer caught. - assert(CaughtExceptionStack == LE && - "Destroying an exception which is not the current caught exception?"); - CaughtExceptionStack = LE->Next; - struct ExceptionFreer { void *Ptr; ExceptionFreer(void *P) : Ptr(P) {} @@ -110,6 +116,7 @@ void __llvm_cxxeh_throw(void *ObjectPtr, void *TypeInfoPtr, E->BaseException.Next = UncaughtExceptionStack; UncaughtExceptionStack = &E->BaseException; E->BaseException.HandlerCount = 0; + E->BaseException.isRethrown = 0; E->TypeInfo = (const std::type_info*)TypeInfoPtr; E->ExceptionObjectDestructor = DtorPtr; @@ -121,14 +128,16 @@ void __llvm_cxxeh_throw(void *ObjectPtr, void *TypeInfoPtr, // CXXExceptionISA - use the type info object stored in the exception to see if // TypeID matches and, if so, to adjust the exception object pointer. // -static void *CXXExceptionISA(llvm_cxx_exception *E, const std::type_info *Type){ +static void *CXXExceptionISA(llvm_cxx_exception *E, + const std::type_info *Type) throw() { // ThrownPtr is a pointer to the object being thrown... void *ThrownPtr = E+1; const std::type_info *ThrownType = E->TypeInfo; +#if 0 // FIXME: this code exists in the GCC exception handling library: I haven't // thought about this yet, so it should be verified at some point! -#if 1 + // Pointer types need to adjust the actual pointer, not // the pointer to pointer that is the exception object. // This also has the effect of passing pointer types @@ -137,8 +146,13 @@ static void *CXXExceptionISA(llvm_cxx_exception *E, const std::type_info *Type){ ThrownPtr = *(void **)ThrownPtr; #endif - if (Type->__do_catch(ThrownType, &ThrownPtr, 1)) + if (Type->__do_catch(ThrownType, &ThrownPtr, 1)) { +#ifdef DEBUG + printf("isa<%s>(%s): 0x%p -> 0x%p\n", Type->name(), ThrownType->name(), + E+1, ThrownPtr); +#endif return ThrownPtr; + } return 0; } @@ -175,11 +189,17 @@ void *__llvm_cxxeh_begin_catch() throw() { UncaughtExceptionStack = E->Next; // The exception is now caught. - E->Next = CaughtExceptionStack; - CaughtExceptionStack = E; + LastCaughtException = E; + E->Next = 0; + E->isRethrown = 0; // Increment the handler count for this exception. E->HandlerCount++; + +#ifdef DEBUG + printf("Exiting begin_catch Ex=0x%p HandlerCount=%d!\n", E+1, + E->HandlerCount); +#endif // Return a pointer to the raw exception object. return E+1; @@ -200,22 +220,44 @@ void *__llvm_cxxeh_begin_catch_if_isa(void *CatchType) throw() { return ObjPtr; } +// __llvm_cxxeh_get_last_caught - Return the last exception that was caught by +// ...begin_catch. +// +void *__llvm_cxxeh_get_last_caught() throw() { + assert(LastCaughtException && "No exception caught!!"); + return LastCaughtException+1; +} // __llvm_cxxeh_end_catch - This function decrements the HandlerCount of the // top-level caught exception, destroying it if this is the last handler for the // exception. // -void __llvm_cxxeh_end_catch() /* might throw */ { - llvm_exception *E = CaughtExceptionStack; +void __llvm_cxxeh_end_catch(void *Ex) /* might throw */ { + llvm_exception *E = (llvm_exception*)Ex - 1; assert(E && "There are no caught exceptions!"); // If this is the last handler using the exception, destroy it now! - if (--E->HandlerCount == 0) + if (--E->HandlerCount == 0 && !E->isRethrown) { +#ifdef DEBUG + printf("Destroying exception!\n"); +#endif E->ExceptionDestructor(E); // Release memory for the exception + } +#ifdef DEBUG + printf("Exiting end_catch Ex=0x%p HandlerCount=%d!\n", Ex, E->HandlerCount); +#endif } +// __llvm_cxxeh_call_terminate - This function is called when the dtor for an +// object being destroyed due to an exception throw throws an exception. This +// is illegal because it would cause multiple exceptions to be active at one +// time. void __llvm_cxxeh_call_terminate() throw() { - __terminate(__terminate_handler); + void (*Handler)(void) = __terminate_handler; + if (UncaughtExceptionStack) + if (UncaughtExceptionStack->ExceptionType == CXXException) + Handler = get_cxx_exception(UncaughtExceptionStack)->TerminateHandler; + __terminate(Handler); } @@ -225,19 +267,21 @@ void __llvm_cxxeh_call_terminate() throw() { // prepared to deal with foreign exceptions. // void __llvm_cxxeh_rethrow() throw() { - llvm_exception *E = CaughtExceptionStack; + llvm_exception *E = LastCaughtException; if (E == 0) - // 15.1.8 - If there are no uncaught exceptions being thrown, 'throw;' - // should call terminate. + // 15.1.8 - If there are no exceptions being thrown, 'throw;' should call + // terminate. // __terminate(__terminate_handler); - // Otherwise we have an exception to rethrow. Move it back to the uncaught - // stack. - CaughtExceptionStack = E->Next; + // Otherwise we have an exception to rethrow. Mark the exception as such. + E->isRethrown = 1; + + // Add the exception to the top of the uncaught stack, to preserve the + // invariant that the top of the uncaught stack is the current exception. E->Next = UncaughtExceptionStack; UncaughtExceptionStack = E; - + // Return to the caller, which should perform the unwind now. } @@ -283,8 +327,8 @@ void __llvm_cxxeh_check_eh_spec(void *Info, ...) { // Whatever exception this is, it is not allowed by the (empty) spec, call // unexpected, according to 15.4.8. try { - __llvm_cxxeh_begin_catch(); // Start the catch - __llvm_cxxeh_end_catch(); // Free the exception + void *Ex = __llvm_cxxeh_begin_catch(); // Start the catch + __llvm_cxxeh_end_catch(Ex); // Free the exception __unexpected(__unexpected_handler); } catch (...) { // Any exception thrown by unexpected cannot match the ehspec. Call @@ -307,10 +351,10 @@ void __llvm_cxxeh_check_eh_spec(void *Info, ...) { // permitted to pass through) or not a C++ exception that is allowed. Kill // the exception and call the unexpected handler. try { - __llvm_cxxeh_begin_catch(); // Start the catch - __llvm_cxxeh_end_catch(); // Free the exception + void *Ex = __llvm_cxxeh_begin_catch(); // Start the catch + __llvm_cxxeh_end_catch(Ex); // Free the exception } catch (...) { - __terminate(__terminate_handler); // Exception dtor threw + __terminate(__terminate_handler); // Exception dtor threw } try { diff --git a/llvm/runtime/GCCLibraries/crtend/C++-Exception.h b/llvm/runtime/GCCLibraries/crtend/C++-Exception.h index 2a16ad05312..56cc21ae256 100644 --- a/llvm/runtime/GCCLibraries/crtend/C++-Exception.h +++ b/llvm/runtime/GCCLibraries/crtend/C++-Exception.h @@ -55,7 +55,7 @@ inline llvm_cxx_exception *get_cxx_exception(llvm_exception *E) throw() { namespace __cxxabiv1 { // Invokes given handler, dying appropriately if the user handler was // so inconsiderate as to return. - extern void __terminate(std::terminate_handler) __attribute__((noreturn)); + extern void __terminate(std::terminate_handler) throw() __attribute__((noreturn)); extern void __unexpected(std::unexpected_handler) __attribute__((noreturn)); // The current installed user handlers. @@ -74,8 +74,10 @@ extern "C" { throw(); void *__llvm_cxxeh_begin_catch() throw(); void *__llvm_cxxeh_begin_catch_if_isa(void *CatchType) throw(); - void __llvm_cxxeh_end_catch() /* might throw */; + void __llvm_cxxeh_end_catch(void *Exception) /* might throw */; void __llvm_cxxeh_rethrow() throw(); + void *__llvm_cxxeh_get_last_caught() throw(); + void __llvm_cxxeh_check_eh_spec(void *Info, ...); } diff --git a/llvm/runtime/GCCLibraries/crtend/Exception.h b/llvm/runtime/GCCLibraries/crtend/Exception.h index 4d886cd9203..a3489991749 100644 --- a/llvm/runtime/GCCLibraries/crtend/Exception.h +++ b/llvm/runtime/GCCLibraries/crtend/Exception.h @@ -31,6 +31,14 @@ struct llvm_exception { // falls to zero, the exception is destroyed. // unsigned HandlerCount; + + // isRethrown - This field is set on an exception if it has been 'throw;'n. + // This is needed because the exception might exit through a number of the + // end_catch statements matching the number of begin_catch statements that + // have been processed. When this happens, the exception should become + // uncaught, not dead. + // + int isRethrown; }; enum { diff --git a/llvm/runtime/GCCLibraries/libexception/C++-Exception.cpp b/llvm/runtime/GCCLibraries/libexception/C++-Exception.cpp index 5e589301141..e22d61c823a 100644 --- a/llvm/runtime/GCCLibraries/libexception/C++-Exception.cpp +++ b/llvm/runtime/GCCLibraries/libexception/C++-Exception.cpp @@ -11,6 +11,12 @@ #include <cstdlib> #include <cstdarg> +//#define DEBUG + +#ifdef DEBUG +#include <stdio.h> +#endif + //===----------------------------------------------------------------------===// // Generic exception support // @@ -18,7 +24,11 @@ // Thread local state for exception handling. // FIXME: This should really be made thread-local! // -static llvm_exception *CaughtExceptionStack = 0; + +// LastCaughtException - The last exception caught by this handler. This is for +// implementation of _rethrow and _get_last_caught. +// +static llvm_exception *LastCaughtException = 0; // UncaughtExceptionStack - The stack of exceptions currently being thrown. static llvm_exception *UncaughtExceptionStack = 0; @@ -76,13 +86,9 @@ void __llvm_cxxeh_free_exception(void *ObjectPtr) throw() { // exception. // static void cxx_destructor(llvm_exception *LE) /* might throw */{ + assert(LE->Next == 0 && "On the uncaught stack??"); llvm_cxx_exception *E = get_cxx_exception(LE); - // The exception is no longer caught. - assert(CaughtExceptionStack == LE && - "Destroying an exception which is not the current caught exception?"); - CaughtExceptionStack = LE->Next; - struct ExceptionFreer { void *Ptr; ExceptionFreer(void *P) : Ptr(P) {} @@ -110,6 +116,7 @@ void __llvm_cxxeh_throw(void *ObjectPtr, void *TypeInfoPtr, E->BaseException.Next = UncaughtExceptionStack; UncaughtExceptionStack = &E->BaseException; E->BaseException.HandlerCount = 0; + E->BaseException.isRethrown = 0; E->TypeInfo = (const std::type_info*)TypeInfoPtr; E->ExceptionObjectDestructor = DtorPtr; @@ -121,14 +128,16 @@ void __llvm_cxxeh_throw(void *ObjectPtr, void *TypeInfoPtr, // CXXExceptionISA - use the type info object stored in the exception to see if // TypeID matches and, if so, to adjust the exception object pointer. // -static void *CXXExceptionISA(llvm_cxx_exception *E, const std::type_info *Type){ +static void *CXXExceptionISA(llvm_cxx_exception *E, + const std::type_info *Type) throw() { // ThrownPtr is a pointer to the object being thrown... void *ThrownPtr = E+1; const std::type_info *ThrownType = E->TypeInfo; +#if 0 // FIXME: this code exists in the GCC exception handling library: I haven't // thought about this yet, so it should be verified at some point! -#if 1 + // Pointer types need to adjust the actual pointer, not // the pointer to pointer that is the exception object. // This also has the effect of passing pointer types @@ -137,8 +146,13 @@ static void *CXXExceptionISA(llvm_cxx_exception *E, const std::type_info *Type){ ThrownPtr = *(void **)ThrownPtr; #endif - if (Type->__do_catch(ThrownType, &ThrownPtr, 1)) + if (Type->__do_catch(ThrownType, &ThrownPtr, 1)) { +#ifdef DEBUG + printf("isa<%s>(%s): 0x%p -> 0x%p\n", Type->name(), ThrownType->name(), + E+1, ThrownPtr); +#endif return ThrownPtr; + } return 0; } @@ -175,11 +189,17 @@ void *__llvm_cxxeh_begin_catch() throw() { UncaughtExceptionStack = E->Next; // The exception is now caught. - E->Next = CaughtExceptionStack; - CaughtExceptionStack = E; + LastCaughtException = E; + E->Next = 0; + E->isRethrown = 0; // Increment the handler count for this exception. E->HandlerCount++; + +#ifdef DEBUG + printf("Exiting begin_catch Ex=0x%p HandlerCount=%d!\n", E+1, + E->HandlerCount); +#endif // Return a pointer to the raw exception object. return E+1; @@ -200,22 +220,44 @@ void *__llvm_cxxeh_begin_catch_if_isa(void *CatchType) throw() { return ObjPtr; } +// __llvm_cxxeh_get_last_caught - Return the last exception that was caught by +// ...begin_catch. +// +void *__llvm_cxxeh_get_last_caught() throw() { + assert(LastCaughtException && "No exception caught!!"); + return LastCaughtException+1; +} // __llvm_cxxeh_end_catch - This function decrements the HandlerCount of the // top-level caught exception, destroying it if this is the last handler for the // exception. // -void __llvm_cxxeh_end_catch() /* might throw */ { - llvm_exception *E = CaughtExceptionStack; +void __llvm_cxxeh_end_catch(void *Ex) /* might throw */ { + llvm_exception *E = (llvm_exception*)Ex - 1; assert(E && "There are no caught exceptions!"); // If this is the last handler using the exception, destroy it now! - if (--E->HandlerCount == 0) + if (--E->HandlerCount == 0 && !E->isRethrown) { +#ifdef DEBUG + printf("Destroying exception!\n"); +#endif E->ExceptionDestructor(E); // Release memory for the exception + } +#ifdef DEBUG + printf("Exiting end_catch Ex=0x%p HandlerCount=%d!\n", Ex, E->HandlerCount); +#endif } +// __llvm_cxxeh_call_terminate - This function is called when the dtor for an +// object being destroyed due to an exception throw throws an exception. This +// is illegal because it would cause multiple exceptions to be active at one +// time. void __llvm_cxxeh_call_terminate() throw() { - __terminate(__terminate_handler); + void (*Handler)(void) = __terminate_handler; + if (UncaughtExceptionStack) + if (UncaughtExceptionStack->ExceptionType == CXXException) + Handler = get_cxx_exception(UncaughtExceptionStack)->TerminateHandler; + __terminate(Handler); } @@ -225,19 +267,21 @@ void __llvm_cxxeh_call_terminate() throw() { // prepared to deal with foreign exceptions. // void __llvm_cxxeh_rethrow() throw() { - llvm_exception *E = CaughtExceptionStack; + llvm_exception *E = LastCaughtException; if (E == 0) - // 15.1.8 - If there are no uncaught exceptions being thrown, 'throw;' - // should call terminate. + // 15.1.8 - If there are no exceptions being thrown, 'throw;' should call + // terminate. // __terminate(__terminate_handler); - // Otherwise we have an exception to rethrow. Move it back to the uncaught - // stack. - CaughtExceptionStack = E->Next; + // Otherwise we have an exception to rethrow. Mark the exception as such. + E->isRethrown = 1; + + // Add the exception to the top of the uncaught stack, to preserve the + // invariant that the top of the uncaught stack is the current exception. E->Next = UncaughtExceptionStack; UncaughtExceptionStack = E; - + // Return to the caller, which should perform the unwind now. } @@ -283,8 +327,8 @@ void __llvm_cxxeh_check_eh_spec(void *Info, ...) { // Whatever exception this is, it is not allowed by the (empty) spec, call // unexpected, according to 15.4.8. try { - __llvm_cxxeh_begin_catch(); // Start the catch - __llvm_cxxeh_end_catch(); // Free the exception + void *Ex = __llvm_cxxeh_begin_catch(); // Start the catch + __llvm_cxxeh_end_catch(Ex); // Free the exception __unexpected(__unexpected_handler); } catch (...) { // Any exception thrown by unexpected cannot match the ehspec. Call @@ -307,10 +351,10 @@ void __llvm_cxxeh_check_eh_spec(void *Info, ...) { // permitted to pass through) or not a C++ exception that is allowed. Kill // the exception and call the unexpected handler. try { - __llvm_cxxeh_begin_catch(); // Start the catch - __llvm_cxxeh_end_catch(); // Free the exception + void *Ex = __llvm_cxxeh_begin_catch(); // Start the catch + __llvm_cxxeh_end_catch(Ex); // Free the exception } catch (...) { - __terminate(__terminate_handler); // Exception dtor threw + __terminate(__terminate_handler); // Exception dtor threw } try { diff --git a/llvm/runtime/GCCLibraries/libexception/C++-Exception.h b/llvm/runtime/GCCLibraries/libexception/C++-Exception.h index 2a16ad05312..56cc21ae256 100644 --- a/llvm/runtime/GCCLibraries/libexception/C++-Exception.h +++ b/llvm/runtime/GCCLibraries/libexception/C++-Exception.h @@ -55,7 +55,7 @@ inline llvm_cxx_exception *get_cxx_exception(llvm_exception *E) throw() { namespace __cxxabiv1 { // Invokes given handler, dying appropriately if the user handler was // so inconsiderate as to return. - extern void __terminate(std::terminate_handler) __attribute__((noreturn)); + extern void __terminate(std::terminate_handler) throw() __attribute__((noreturn)); extern void __unexpected(std::unexpected_handler) __attribute__((noreturn)); // The current installed user handlers. @@ -74,8 +74,10 @@ extern "C" { throw(); void *__llvm_cxxeh_begin_catch() throw(); void *__llvm_cxxeh_begin_catch_if_isa(void *CatchType) throw(); - void __llvm_cxxeh_end_catch() /* might throw */; + void __llvm_cxxeh_end_catch(void *Exception) /* might throw */; void __llvm_cxxeh_rethrow() throw(); + void *__llvm_cxxeh_get_last_caught() throw(); + void __llvm_cxxeh_check_eh_spec(void *Info, ...); } diff --git a/llvm/runtime/GCCLibraries/libexception/Exception.h b/llvm/runtime/GCCLibraries/libexception/Exception.h index 4d886cd9203..a3489991749 100644 --- a/llvm/runtime/GCCLibraries/libexception/Exception.h +++ b/llvm/runtime/GCCLibraries/libexception/Exception.h @@ -31,6 +31,14 @@ struct llvm_exception { // falls to zero, the exception is destroyed. // unsigned HandlerCount; + + // isRethrown - This field is set on an exception if it has been 'throw;'n. + // This is needed because the exception might exit through a number of the + // end_catch statements matching the number of begin_catch statements that + // have been processed. When this happens, the exception should become + // uncaught, not dead. + // + int isRethrown; }; enum { |
