From: Chris Lattner Date: Sat, 30 Aug 2003 23:29:22 +0000 (+0000) Subject: initial checkin of SJLJ exception handling runtime X-Git-Url: http://plrg.eecs.uci.edu/git/?a=commitdiff_plain;h=214191f4739cc476bce61000edbe1ac0ddc9a93c;p=oota-llvm.git initial checkin of SJLJ exception handling runtime git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@8235 91177308-0d34-0410-b5e6-96231b3b80d8 --- diff --git a/runtime/GCCLibraries/crtend/SJLJ-Exception.cpp b/runtime/GCCLibraries/crtend/SJLJ-Exception.cpp new file mode 100644 index 00000000000..fea2d4128fe --- /dev/null +++ b/runtime/GCCLibraries/crtend/SJLJ-Exception.cpp @@ -0,0 +1,123 @@ + +#include "SJLJ-Exception.h" +#include +#include + +inline llvm_sjlj_exception *get_sjlj_exception(llvm_exception *E) { + assert(E->ExceptionType == SJLJException); + return (llvm_sjlj_exception*)(E+1) - 1; +} + +// SetJmpMapEntry - One entry in a linked list of setjmps for the current +// function. +struct SetJmpMapEntry { + void *JmpBuf; + unsigned SetJmpID; + SetJmpMapEntry *Next; +}; + +static void SJLJDestructor(llvm_exception *E) { + free(get_sjlj_exception(E)); +} + + +// __llvm_sjljeh_throw_longjmp - This function creates the longjmp exception and +// returns. It takes care of mapping the longjmp value from 0 -> 1 as +// appropriate. The caller should immediately call llvm.unwind after this +// function call. +void __llvm_sjljeh_throw_longjmp(void *JmpBuffer, int Val) throw() { + llvm_sjlj_exception *E = + (llvm_sjlj_exception *)malloc(sizeof(llvm_sjlj_exception)); + E->BaseException.ExceptionDestructor = SJLJDestructor; + E->BaseException.ExceptionType = SJLJException; + E->BaseException.HandlerCount = 0; + E->BaseException.isRethrown = 0; + E->JmpBuffer = JmpBuffer; + E->LongJmpValue = Val ? Val : 1; + + __llvm_eh_add_uncaught_exception(&E->BaseException); +} + +// __llvm_sjljeh_init_setjmpmap - This funciton initializes the pointer provided +// to an empty setjmp map, and should be called on entry to a function which +// calls setjmp. +void __llvm_sjljeh_init_setjmpmap(void **SetJmpMap) throw() { + *SetJmpMap = 0; +} + +// __llvm_sjljeh_destroy_setjmpmap - This function frees all memory associated +// with the specified setjmpmap structure. It should be called on all exits +// (returns or unwinds) from the function which calls ...init_setjmpmap. +void __llvm_sjljeh_destroy_setjmpmap(void **SetJmpMap) throw() { + SetJmpMapEntry *Next; + for (SetJmpMapEntry *SJE = *(SetJmpMapEntry**)SetJmpMap; SJE; SJE = Next) { + Next = SJE->Next; + free(SJE); + } +} + +// __llvm_sjljeh_add_setjmp_to_map - This function adds or updates an entry to +// the map, to indicate which setjmp should be returned to if a longjmp happens. +void __llvm_sjljeh_add_setjmp_to_map(void **SetJmpMap, void *JmpBuf, + unsigned SetJmpID) throw() { + SetJmpMapEntry **SJE = (SetJmpMapEntry**)SetJmpMap; + + // Scan for a pre-existing entry... + for (; *SJE; SJE = &(*SJE)->Next) + if ((*SJE)->JmpBuf == JmpBuf) { + (*SJE)->SetJmpID = SetJmpID; + return; + } + + // No prexisting entry found, append to the end of the list... + SetJmpMapEntry *New = (SetJmpMapEntry *)malloc(sizeof(SetJmpMapEntry)); + *SJE = New; + New->JmpBuf = JmpBuf; + New->SetJmpID = SetJmpID; + New->Next = 0; +} + +// __llvm_sjljeh_is_longjmp_exception - This function returns true if the +// current uncaught exception is a longjmp exception. This is the first step of +// catching a sjlj exception. +bool __llvm_sjljeh_is_longjmp_exception() throw() { + return __llvm_eh_current_uncaught_exception_type(SJLJException) != 0; +} + +// __llvm_sjljeh_get_longjmp_value - This function returns the value that the +// setjmp call should "return". This requires that the current uncaught +// exception be a sjlj exception, though it does not require the exception to be +// caught by this function. +int __llvm_sjljeh_get_longjmp_value() throw() { + llvm_sjlj_exception *E = + get_sjlj_exception(__llvm_eh_get_uncaught_exception()); + return E->LongJmpValue; +} + +// __llvm_sjljeh_try_catching_longjmp_exception - This function checks to see if +// the current uncaught longjmp exception matches any of the setjmps collected +// in the setjmpmap structure. If so, it catches and destroys the exception, +// returning the index of the setjmp which caught the exception. If not, it +// leaves the exception uncaught and returns a value of ~0. +unsigned __llvm_sjljeh_try_catching_longjmp_exception(void **SetJmpMap) throw(){ + llvm_sjlj_exception *E = + get_sjlj_exception(__llvm_eh_get_uncaught_exception()); + + // Scan for a matching entry in the SetJmpMap... + SetJmpMapEntry *SJE = *(SetJmpMapEntry**)SetJmpMap; + for (; SJE; SJE = SJE->Next) + if (SJE->JmpBuf == E->JmpBuffer) { + // "Catch" and destroy the exception... + __llvm_eh_pop_from_uncaught_stack(); + + // We know it's a longjmp exception, so we can just free it instead of + // calling the destructor. + free(E); + + // Return the setjmp ID which we should branch to... + return SJE->SetJmpID; + } + + // No setjmp in this function catches the exception! + return ~0; +} diff --git a/runtime/GCCLibraries/libexception/SJLJ-Exception.cpp b/runtime/GCCLibraries/libexception/SJLJ-Exception.cpp new file mode 100644 index 00000000000..fea2d4128fe --- /dev/null +++ b/runtime/GCCLibraries/libexception/SJLJ-Exception.cpp @@ -0,0 +1,123 @@ + +#include "SJLJ-Exception.h" +#include +#include + +inline llvm_sjlj_exception *get_sjlj_exception(llvm_exception *E) { + assert(E->ExceptionType == SJLJException); + return (llvm_sjlj_exception*)(E+1) - 1; +} + +// SetJmpMapEntry - One entry in a linked list of setjmps for the current +// function. +struct SetJmpMapEntry { + void *JmpBuf; + unsigned SetJmpID; + SetJmpMapEntry *Next; +}; + +static void SJLJDestructor(llvm_exception *E) { + free(get_sjlj_exception(E)); +} + + +// __llvm_sjljeh_throw_longjmp - This function creates the longjmp exception and +// returns. It takes care of mapping the longjmp value from 0 -> 1 as +// appropriate. The caller should immediately call llvm.unwind after this +// function call. +void __llvm_sjljeh_throw_longjmp(void *JmpBuffer, int Val) throw() { + llvm_sjlj_exception *E = + (llvm_sjlj_exception *)malloc(sizeof(llvm_sjlj_exception)); + E->BaseException.ExceptionDestructor = SJLJDestructor; + E->BaseException.ExceptionType = SJLJException; + E->BaseException.HandlerCount = 0; + E->BaseException.isRethrown = 0; + E->JmpBuffer = JmpBuffer; + E->LongJmpValue = Val ? Val : 1; + + __llvm_eh_add_uncaught_exception(&E->BaseException); +} + +// __llvm_sjljeh_init_setjmpmap - This funciton initializes the pointer provided +// to an empty setjmp map, and should be called on entry to a function which +// calls setjmp. +void __llvm_sjljeh_init_setjmpmap(void **SetJmpMap) throw() { + *SetJmpMap = 0; +} + +// __llvm_sjljeh_destroy_setjmpmap - This function frees all memory associated +// with the specified setjmpmap structure. It should be called on all exits +// (returns or unwinds) from the function which calls ...init_setjmpmap. +void __llvm_sjljeh_destroy_setjmpmap(void **SetJmpMap) throw() { + SetJmpMapEntry *Next; + for (SetJmpMapEntry *SJE = *(SetJmpMapEntry**)SetJmpMap; SJE; SJE = Next) { + Next = SJE->Next; + free(SJE); + } +} + +// __llvm_sjljeh_add_setjmp_to_map - This function adds or updates an entry to +// the map, to indicate which setjmp should be returned to if a longjmp happens. +void __llvm_sjljeh_add_setjmp_to_map(void **SetJmpMap, void *JmpBuf, + unsigned SetJmpID) throw() { + SetJmpMapEntry **SJE = (SetJmpMapEntry**)SetJmpMap; + + // Scan for a pre-existing entry... + for (; *SJE; SJE = &(*SJE)->Next) + if ((*SJE)->JmpBuf == JmpBuf) { + (*SJE)->SetJmpID = SetJmpID; + return; + } + + // No prexisting entry found, append to the end of the list... + SetJmpMapEntry *New = (SetJmpMapEntry *)malloc(sizeof(SetJmpMapEntry)); + *SJE = New; + New->JmpBuf = JmpBuf; + New->SetJmpID = SetJmpID; + New->Next = 0; +} + +// __llvm_sjljeh_is_longjmp_exception - This function returns true if the +// current uncaught exception is a longjmp exception. This is the first step of +// catching a sjlj exception. +bool __llvm_sjljeh_is_longjmp_exception() throw() { + return __llvm_eh_current_uncaught_exception_type(SJLJException) != 0; +} + +// __llvm_sjljeh_get_longjmp_value - This function returns the value that the +// setjmp call should "return". This requires that the current uncaught +// exception be a sjlj exception, though it does not require the exception to be +// caught by this function. +int __llvm_sjljeh_get_longjmp_value() throw() { + llvm_sjlj_exception *E = + get_sjlj_exception(__llvm_eh_get_uncaught_exception()); + return E->LongJmpValue; +} + +// __llvm_sjljeh_try_catching_longjmp_exception - This function checks to see if +// the current uncaught longjmp exception matches any of the setjmps collected +// in the setjmpmap structure. If so, it catches and destroys the exception, +// returning the index of the setjmp which caught the exception. If not, it +// leaves the exception uncaught and returns a value of ~0. +unsigned __llvm_sjljeh_try_catching_longjmp_exception(void **SetJmpMap) throw(){ + llvm_sjlj_exception *E = + get_sjlj_exception(__llvm_eh_get_uncaught_exception()); + + // Scan for a matching entry in the SetJmpMap... + SetJmpMapEntry *SJE = *(SetJmpMapEntry**)SetJmpMap; + for (; SJE; SJE = SJE->Next) + if (SJE->JmpBuf == E->JmpBuffer) { + // "Catch" and destroy the exception... + __llvm_eh_pop_from_uncaught_stack(); + + // We know it's a longjmp exception, so we can just free it instead of + // calling the destructor. + free(E); + + // Return the setjmp ID which we should branch to... + return SJE->SetJmpID; + } + + // No setjmp in this function catches the exception! + return ~0; +}