Index: src/libcfa/exception.c =================================================================== --- src/libcfa/exception.c (revision 33218c6845f9825be5a63043ef89bb8a0a80d009) +++ src/libcfa/exception.c (revision b947fb2e40ff1eb3c74f2ca17397c8a24c9a2a9c) @@ -9,7 +9,7 @@ // Author : Andrew Beach // Created On : Mon Jun 26 15:13:00 2017 -// Last Modified By : Andrew Beach -// Last Modified On : Tus Jul 11 16:36:00 2017 -// Update Count : 1 +// Last Modified By : Peter A. Buhr +// Last Modified On : Wed Jul 26 10:37:51 2017 +// Update Count : 2 // @@ -21,4 +21,12 @@ #include #include + +// FIX ME: temporary hack to keep ARM build working +#ifndef _URC_FATAL_PHASE1_ERROR +#define _URC_FATAL_PHASE1_ERROR 2 +#endif // ! _URC_FATAL_PHASE1_ERROR +#ifndef _URC_FATAL_PHASE2_ERROR +#define _URC_FATAL_PHASE2_ERROR 2 +#endif // ! _URC_FATAL_PHASE2_ERROR #include "lsda.h" @@ -35,6 +43,6 @@ -// This macro should be the only thing that needs to change across machines. -// Used in the personality function, way down in termination. +// This macro should be the only thing that needs to change across machines. Used in the personality function, way down +// in termination. // struct _Unwind_Context * -> _Unwind_Reason_Code(*)(exception *) #define MATCHER_FROM_CONTEXT(ptr_to_context) \ @@ -69,8 +77,7 @@ } -/* Do we control where exceptions get thrown even with concurency? - * If not these are not quite thread safe, the cleanup hook has to be added - * after the node is built but before it is made the top node. - */ +// Do we control where exceptions get thrown even with concurency? If not these are not quite thread safe, the cleanup +// hook has to be added after the node is built but before it is made the top node. + void __cfaehm__try_resume_setup(struct __cfaehm__try_resume_node * node, int (*handler)(exception * except)) { @@ -89,6 +96,5 @@ // Requires -fexceptions to work. -// Global which defines the current exception -// Currently an int just to make matching easier +// Global which defines the current exception. Currently an int just to make matching easier. //int this_exception; (became shared_stack.current_exception) @@ -121,16 +127,13 @@ _Unwind_Reason_Code ret = _Unwind_RaiseException( &this_exception_storage ); - // If we reach here it means something happened - // For resumption to work we need to find a way to return back to here - // Most of them will probably boil down to setting a global flag and making the phase 1 either stop or fail. - // Causing an error on purpose may help avoiding unnecessary work but it might have some weird side effects. - // If we just pretend no handler was found that would work but may be expensive for no reason since we will always - // search the whole stack + // If we reach here it means something happened. For resumption to work we need to find a way to return back to + // here. Most of them will probably boil down to setting a global flag and making the phase 1 either stop or + // fail. Causing an error on purpose may help avoiding unnecessary work but it might have some weird side + // effects. If we just pretend no handler was found that would work but may be expensive for no reason since we + // will always search the whole stack. if( ret == _URC_END_OF_STACK ) { - // No proper handler was found - // This can be handled in several way - // C++ calls std::terminate - // Here we force unwind the stack, basically raising a cancellation + // No proper handler was found. This can be handled in several way. C++ calls std::terminate Here we + // force unwind the stack, basically raising a cancellation. printf("Uncaught exception %p\n", &this_exception_storage); @@ -140,6 +143,5 @@ } - // We did not simply reach the end of the stack without finding a handler, - // Something wen't wrong + // We did not simply reach the end of the stack without finding a handler. Something wen't wrong printf("UNWIND ERROR %d after raise exception\n", ret); abort(); @@ -154,8 +156,6 @@ } -// This is our personality routine -// For every stack frame anotated with ".cfi_personality 0x3,__gcfa_personality_v0" -// This function will be called twice when unwinding -// Once in the search phased and once in the cleanup phase +// This is our personality routine. For every stack frame anotated with ".cfi_personality 0x3,__gcfa_personality_v0". +// This function will be called twice when unwinding. Once in the search phased and once in the cleanup phase. _Unwind_Reason_Code __gcfa_personality_v0 ( int version, _Unwind_Action actions, unsigned long long exceptionClass, @@ -293,5 +293,5 @@ // I assume this sets the instruction pointer to the adress of the landing pad // It doesn't actually set it, it only state the value that needs to be set once we return _URC_INSTALL_CONTEXT - _Unwind_SetIP( context, lsd_info.LPStart + callsite_landing_pad ); + _Unwind_SetIP( context, ((lsd_info.LPStart) + (callsite_landing_pad)) ); // DEBUG @@ -317,8 +317,6 @@ } -// Try statements are hoisted out see comments for details -// With this could probably be unique and simply linked from -// libcfa but there is one problem left, see the exception table -// for details +// Try statements are hoisted out see comments for details. With this could probably be unique and simply linked from +// libcfa but there is one problem left, see the exception table for details __attribute__((noinline)) void __cfaehm__try_terminate(void (*try_block)(), @@ -328,11 +326,9 @@ //! printf("%p %p %p %p\n", &try_block, &catch_block, &match_block, &xy); - // Setup statments - // These 2 statments won't actually result in any code, - // they only setup global tables. - // However, they clobber gcc cancellation support from gcc. - // We can replace the personality routine but replacing the exception - // table gcc generates is not really doable, it generates labels based - // on how the assembly works. + // Setup statments: These 2 statments won't actually result in any code, they only setup global tables. + // However, they clobber gcc cancellation support from gcc. We can replace the personality routine but + // replacing the exception table gcc generates is not really doable, it generates labels based on how the + // assembly works. + // Setup the personality routine asm volatile (".cfi_personality 0x3,__gcfa_personality_v0"); @@ -340,5 +336,5 @@ asm volatile (".cfi_lsda 0x3, .LLSDACFA2"); - // Label which defines the start of the area for which the handler is setup + // Label which defines the start of the area for which the handler is setup. asm volatile (".TRYSTART:"); @@ -354,22 +350,20 @@ // Exceptionnal path CATCH : __attribute__(( unused )); - // Label which defines the end of the area for which the handler is setup + // Label which defines the end of the area for which the handler is setup. asm volatile (".TRYEND:"); - // Label which defines the start of the exception landing pad - // basically what will be called when the exception is caught - // Note, if multiple handlers are given, the multiplexing should be done - // by the generated code, not the exception runtime + // Label which defines the start of the exception landing pad. Basically what is called when the exception is + // caught. Note, if multiple handlers are given, the multiplexing should be done by the generated code, not the + // exception runtime. asm volatile (".CATCH:"); // Exception handler - catch_block(shared_stack.current_handler_index, - &shared_stack.current_exception); -} - -// Exception table data we need to generate -// While this is almost generic, the custom data refers to -// foo_try_match try match, which is no way generic -// Some more works need to be done if we want to have a single -// call to the try routine + catch_block( shared_stack.current_handler_index, + &shared_stack.current_exception ); +} + +// Exception table data we need to generate. While this is almost generic, the custom data refers to foo_try_match try +// match, which is no way generic. Some more works need to be done if we want to have a single call to the try routine. + +#if defined( __x86_64__ ) || defined( __i386__ ) asm ( //HEADER @@ -394,2 +388,3 @@ // " .section .note.GNU-stack,\"x\",@progbits\n" ); +#endif // __x86_64__ || __i386__