diff options
Diffstat (limited to 'gcc/flow.c')
| -rw-r--r-- | gcc/flow.c | 58 |
1 files changed, 56 insertions, 2 deletions
@@ -721,6 +721,7 @@ make_edges (i) int i; { rtx insn, x; + rtx pending_eh_region = NULL_RTX; /* See if control drops into the next block. */ if (i + 1 < n_basic_blocks) @@ -801,6 +802,40 @@ make_edges (i) } } + /* If this is a call with an EH_RETHROW note, then we + know its a rethrow call, and we know exactly where + this call can end up going. */ + else if (GET_CODE (insn) == CALL_INSN + && (note = find_reg_note (insn, REG_EH_RETHROW, NULL_RTX))) + { + int region = XINT (XEXP (note, 0), 0); + /* if nested region is not 0, we know for sure it has been + processed. If it is zero, we dont know whether its an + outer region, or hasn't been seen yet, so defer it */ + if (nested_eh_region[region] != 0) + { + /* start with the first region OUTSIDE the one specified + in the rethrow parameter. (since a rethrow behaves + as if a handler in the region didn't handle the + exception, so the handlers for the next outer region + are going to get a shot at it.*/ + for ( region = nested_eh_region[region]; region; + region = nested_eh_region[region]) + { + handler_info *ptr = get_first_handler (region); + for ( ; ptr ; ptr = ptr->next) + add_edge_to_label (i, ptr->handler_label); + } + } + else + { + /* Push this region onto a list, and after we've done the + whole procedure, we'll process everything on the list */ + pending_eh_region = gen_rtx_EXPR_LIST (VOIDmode, insn, + pending_eh_region); + } + } + /* If this is a CALL_INSN, then mark it as reaching the active EH handler for this CALL_INSN. If we're handling asynchronous exceptions mark every insn as reaching the active EH handler. @@ -837,6 +872,24 @@ make_edges (i) } } } + + while (pending_eh_region != NULL_RTX) + { + rtx insn = XEXP (pending_eh_region, 0); + rtx note = find_reg_note (insn, REG_EH_RETHROW, NULL_RTX); + int region = XINT (XEXP (note, 0), 0); + /* start with the first region OUTSIDE the one specified + in the rethrow parameter */ + for ( region = nested_eh_region[region]; region; + region = nested_eh_region[region]) + { + handler_info *ptr = get_first_handler (region); + for ( ; ptr ; ptr = ptr->next) + add_edge_to_label (BLOCK_NUM (insn), ptr->handler_label); + } + pending_eh_region = XEXP (pending_eh_region, 1); + } + /* We know something about the structure of the function __throw in libgcc2.c. It is the only function that ever contains eh_stub labels. It modifies its return address so that the last block returns to one of @@ -918,8 +971,9 @@ delete_unreachable_blocks () NOTE_LINE_NUMBER (insn) == NOTE_INSN_EH_REGION_END) { int num = CODE_LABEL_NUMBER (insn); - /* A NULL handler indicates a region is no longer needed */ - if (get_first_handler (num) == NULL) + /* A NULL handler indicates a region is no longer needed, + unless its the target of a rethrow. */ + if (get_first_handler (num) == NULL && !rethrow_used (num)) { NOTE_LINE_NUMBER (insn) = NOTE_INSN_DELETED; NOTE_SOURCE_FILE (insn) = 0; |