Changeset b947fb2


Ignore:
Timestamp:
Jul 26, 2017, 12:35:39 PM (4 years ago)
Author:
Peter A. Buhr <pabuhr@…>
Branches:
aaron-thesis, arm-eh, cleanup-dtors, deferred_resn, demangler, jacob/cs343-translation, jenkins-sandbox, master, new-ast, new-ast-unique-expr, new-env, no_list, persistent-indexer, resolv-new, with_gc
Children:
15d1cc3, a5f0529, d746bc8
Parents:
33218c6
Message:

temporary hacks to allow build on ARM

File:
1 edited

Legend:

Unmodified
Added
Removed
  • src/libcfa/exception.c

    r33218c6 rb947fb2  
    99// Author           : Andrew Beach
    1010// Created On       : Mon Jun 26 15:13:00 2017
    11 // Last Modified By : Andrew Beach
    12 // Last Modified On : Tus Jul 11 16:36:00 2017
    13 // Update Count     : 1
     11// Last Modified By : Peter A. Buhr
     12// Last Modified On : Wed Jul 26 10:37:51 2017
     13// Update Count     : 2
    1414//
    1515
     
    2121#include <stdio.h>
    2222#include <unwind.h>
     23
     24// FIX ME: temporary hack to keep ARM build working
     25#ifndef _URC_FATAL_PHASE1_ERROR
     26#define _URC_FATAL_PHASE1_ERROR 2
     27#endif // ! _URC_FATAL_PHASE1_ERROR
     28#ifndef _URC_FATAL_PHASE2_ERROR
     29#define _URC_FATAL_PHASE2_ERROR 2
     30#endif // ! _URC_FATAL_PHASE2_ERROR
    2331
    2432#include "lsda.h"
     
    3543
    3644
    37 // This macro should be the only thing that needs to change across machines.
    38 // Used in the personality function, way down in termination.
     45// This macro should be the only thing that needs to change across machines.  Used in the personality function, way down
     46// in termination.
    3947// struct _Unwind_Context * -> _Unwind_Reason_Code(*)(exception *)
    4048#define MATCHER_FROM_CONTEXT(ptr_to_context) \
     
    6977}
    7078
    71 /* Do we control where exceptions get thrown even with concurency?
    72  * If not these are not quite thread safe, the cleanup hook has to be added
    73  * after the node is built but before it is made the top node.
    74  */
     79// Do we control where exceptions get thrown even with concurency?  If not these are not quite thread safe, the cleanup
     80// hook has to be added after the node is built but before it is made the top node.
     81
    7582void __cfaehm__try_resume_setup(struct __cfaehm__try_resume_node * node,
    7683                        int (*handler)(exception * except)) {
     
    8996// Requires -fexceptions to work.
    9097
    91 // Global which defines the current exception
    92 // Currently an int just to make matching easier
     98// Global which defines the current exception.  Currently an int just to make matching easier.
    9399//int this_exception; (became shared_stack.current_exception)
    94100
     
    121127        _Unwind_Reason_Code ret = _Unwind_RaiseException( &this_exception_storage );
    122128
    123         // If we reach here it means something happened
    124         // For resumption to work we need to find a way to return back to here
    125         // Most of them will probably boil down to setting a global flag and making the phase 1 either stop or fail.
    126         // Causing an error on purpose may help avoiding unnecessary work but it might have some weird side effects.
    127         // If we just pretend no handler was found that would work but may be expensive for no reason since we will always
    128         // search the whole stack
     129        // If we reach here it means something happened.  For resumption to work we need to find a way to return back to
     130        // here.  Most of them will probably boil down to setting a global flag and making the phase 1 either stop or
     131        // fail.  Causing an error on purpose may help avoiding unnecessary work but it might have some weird side
     132        // effects.  If we just pretend no handler was found that would work but may be expensive for no reason since we
     133        // will always search the whole stack.
    129134
    130135        if( ret == _URC_END_OF_STACK ) {
    131                 // No proper handler was found
    132                 // This can be handled in several way
    133                 // C++ calls std::terminate
    134                 // Here we force unwind the stack, basically raising a cancellation
     136                // No proper handler was found.  This can be handled in several way.  C++ calls std::terminate Here we
     137                // force unwind the stack, basically raising a cancellation.
    135138                printf("Uncaught exception %p\n", &this_exception_storage);
    136139
     
    140143        }
    141144
    142         // We did not simply reach the end of the stack without finding a handler,
    143         // Something wen't wrong
     145        // We did not simply reach the end of the stack without finding a handler.  Something wen't wrong
    144146        printf("UNWIND ERROR %d after raise exception\n", ret);
    145147        abort();
     
    154156}
    155157
    156 // This is our personality routine
    157 // For every stack frame anotated with ".cfi_personality 0x3,__gcfa_personality_v0"
    158 // This function will be called twice when unwinding
    159 // Once in the search phased and once in the cleanup phase
     158// This is our personality routine.  For every stack frame anotated with ".cfi_personality 0x3,__gcfa_personality_v0".
     159// This function will be called twice when unwinding.  Once in the search phased and once in the cleanup phase.
    160160_Unwind_Reason_Code __gcfa_personality_v0 (
    161161                int version, _Unwind_Action actions, unsigned long long exceptionClass,
     
    293293                                // I assume this sets the instruction pointer to the adress of the landing pad
    294294                                // It doesn't actually set it, it only state the value that needs to be set once we return _URC_INSTALL_CONTEXT
    295                                 _Unwind_SetIP( context, lsd_info.LPStart + callsite_landing_pad );
     295                                _Unwind_SetIP( context, ((lsd_info.LPStart) + (callsite_landing_pad)) );
    296296
    297297                                // DEBUG
     
    317317}
    318318
    319 // Try statements are hoisted out see comments for details
    320 // With this could probably be unique and simply linked from
    321 // libcfa but there is one problem left, see the exception table
    322 // for details
     319// Try statements are hoisted out see comments for details.  With this could probably be unique and simply linked from
     320// libcfa but there is one problem left, see the exception table for details
    323321__attribute__((noinline))
    324322void __cfaehm__try_terminate(void (*try_block)(),
     
    328326        //! printf("%p %p %p %p\n", &try_block, &catch_block, &match_block, &xy);
    329327
    330         // Setup statments
    331         // These 2 statments won't actually result in any code,
    332         // they only setup global tables.
    333         // However, they clobber gcc cancellation support from gcc.
    334         // We can replace the personality routine but replacing the exception
    335         // table gcc generates is not really doable, it generates labels based
    336         // on how the assembly works.
     328        // Setup statments: These 2 statments won't actually result in any code, they only setup global tables.
     329        // However, they clobber gcc cancellation support from gcc.  We can replace the personality routine but
     330        // replacing the exception table gcc generates is not really doable, it generates labels based on how the
     331        // assembly works.
     332
    337333        // Setup the personality routine
    338334        asm volatile (".cfi_personality 0x3,__gcfa_personality_v0");
     
    340336        asm volatile (".cfi_lsda 0x3, .LLSDACFA2");
    341337
    342         // Label which defines the start of the area for which the handler is setup
     338        // Label which defines the start of the area for which the handler is setup.
    343339        asm volatile (".TRYSTART:");
    344340
     
    354350        // Exceptionnal path
    355351        CATCH : __attribute__(( unused ));
    356         // Label which defines the end of the area for which the handler is setup
     352        // Label which defines the end of the area for which the handler is setup.
    357353        asm volatile (".TRYEND:");
    358         // Label which defines the start of the exception landing pad
    359         // basically what will be called when the exception is caught
    360         // Note, if multiple handlers are given, the multiplexing should be done
    361         // by the generated code, not the exception runtime
     354        // Label which defines the start of the exception landing pad.  Basically what is called when the exception is
     355        // caught.  Note, if multiple handlers are given, the multiplexing should be done by the generated code, not the
     356        // exception runtime.
    362357        asm volatile (".CATCH:");
    363358
    364359        // Exception handler
    365         catch_block(shared_stack.current_handler_index,
    366                     &shared_stack.current_exception);
    367 }
    368 
    369 // Exception table data we need to generate
    370 // While this is almost generic, the custom data refers to
    371 // foo_try_match try match, which is no way generic
    372 // Some more works need to be done if we want to have a single
    373 // call to the try routine
     360        catch_block( shared_stack.current_handler_index,
     361                    &shared_stack.current_exception );
     362}
     363
     364// Exception table data we need to generate.  While this is almost generic, the custom data refers to foo_try_match try
     365// 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.
     366
     367#if defined( __x86_64__ ) || defined( __i386__ )
    374368asm (
    375369        //HEADER
     
    394388//      "       .section        .note.GNU-stack,\"x\",@progbits\n"
    395389);
     390#endif // __x86_64__ || __i386__
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