From 58ccbd1cdae4238dee5af09183fcf48729830b77 Mon Sep 17 00:00:00 2001 From: Jakub Jelinek Date: Sat, 23 Dec 2017 09:40:19 +0100 Subject: [PATCH] re PR c++/83553 (compiler removes body of the for-loop, although there is a case label inside) PR c++/83553 * fold-const.c (struct contains_label_data): New type. (contains_label_1): Return non-NULL even for CASE_LABEL_EXPR, unless inside of a SWITCH_BODY seen during the walk. (contains_label_p): Use walk_tree instead of walk_tree_without_duplicates, prepare data for contains_label_1 and provide own pset. * c-c++-common/torture/pr83553.c: New test. From-SVN: r255987 --- gcc/ChangeLog | 10 +++++ gcc/fold-const.c | 41 ++++++++++++++++---- gcc/testsuite/ChangeLog | 5 +++ gcc/testsuite/c-c++-common/torture/pr83553.c | 29 ++++++++++++++ 4 files changed, 78 insertions(+), 7 deletions(-) create mode 100644 gcc/testsuite/c-c++-common/torture/pr83553.c diff --git a/gcc/ChangeLog b/gcc/ChangeLog index aba9ae7ea5a..f8375f7f66d 100644 --- a/gcc/ChangeLog +++ b/gcc/ChangeLog @@ -1,3 +1,13 @@ +2017-12-23 Jakub Jelinek + + PR c++/83553 + * fold-const.c (struct contains_label_data): New type. + (contains_label_1): Return non-NULL even for CASE_LABEL_EXPR, unless + inside of a SWITCH_BODY seen during the walk. + (contains_label_p): Use walk_tree instead of + walk_tree_without_duplicates, prepare data for contains_label_1 and + provide own pset. + 2017-12-22 Jakub Jelinek PR debug/83547 diff --git a/gcc/fold-const.c b/gcc/fold-const.c index b21f35a3736..10a67b2e5f9 100644 --- a/gcc/fold-const.c +++ b/gcc/fold-const.c @@ -11218,22 +11218,48 @@ fold_binary_loc (location_t loc, enum tree_code code, tree type, } /* switch (code) */ } +/* Used by contains_label_[p1]. */ + +struct contains_label_data +{ + hash_set *pset; + bool inside_switch_p; +}; + /* Callback for walk_tree, looking for LABEL_EXPR. Return *TP if it is - a LABEL_EXPR; otherwise return NULL_TREE. Do not check the subtrees - of GOTO_EXPR. */ + a LABEL_EXPR or CASE_LABEL_EXPR not inside of another SWITCH_EXPR; otherwise + return NULL_TREE. Do not check the subtrees of GOTO_EXPR. */ static tree -contains_label_1 (tree *tp, int *walk_subtrees, void *data ATTRIBUTE_UNUSED) +contains_label_1 (tree *tp, int *walk_subtrees, void *data) { + contains_label_data *d = (contains_label_data *) data; switch (TREE_CODE (*tp)) { case LABEL_EXPR: return *tp; + case CASE_LABEL_EXPR: + if (!d->inside_switch_p) + return *tp; + return NULL_TREE; + + case SWITCH_EXPR: + if (!d->inside_switch_p) + { + if (walk_tree (&SWITCH_COND (*tp), contains_label_1, data, d->pset)) + return *tp; + d->inside_switch_p = true; + if (walk_tree (&SWITCH_BODY (*tp), contains_label_1, data, d->pset)) + return *tp; + d->inside_switch_p = false; + *walk_subtrees = 0; + } + return NULL_TREE; + case GOTO_EXPR: *walk_subtrees = 0; - - /* fall through */ + return NULL_TREE; default: return NULL_TREE; @@ -11246,8 +11272,9 @@ contains_label_1 (tree *tp, int *walk_subtrees, void *data ATTRIBUTE_UNUSED) static bool contains_label_p (tree st) { - return - (walk_tree_without_duplicates (&st, contains_label_1 , NULL) != NULL_TREE); + hash_set pset; + contains_label_data data = { &pset, false }; + return walk_tree (&st, contains_label_1, &data, &pset) != NULL_TREE; } /* Fold a ternary expression of code CODE and type TYPE with operands diff --git a/gcc/testsuite/ChangeLog b/gcc/testsuite/ChangeLog index c736ca24258..6e6f67ab71c 100644 --- a/gcc/testsuite/ChangeLog +++ b/gcc/testsuite/ChangeLog @@ -1,3 +1,8 @@ +2017-12-23 Jakub Jelinek + + PR c++/83553 + * c-c++-common/torture/pr83553.c: New test. + 2017-12-22 Jakub Jelinek PR debug/83550 diff --git a/gcc/testsuite/c-c++-common/torture/pr83553.c b/gcc/testsuite/c-c++-common/torture/pr83553.c new file mode 100644 index 00000000000..c12b79b9e77 --- /dev/null +++ b/gcc/testsuite/c-c++-common/torture/pr83553.c @@ -0,0 +1,29 @@ +/* PR c++/83553 */ +/* { dg-do run } */ + +int a[3]; + +int +foo (int n) +{ + switch (n) + { + case 0: + for (n = 7, a[0]++; 0; a[2] = a[1] + 1) + { + case 2: + a[1] = a[0] + 1; + } + } + return n; +} + +int +main () +{ + if (foo (0) != 7 || a[0] != 1 || a[1] || a[2]) + __builtin_abort (); + if (foo (2) != 2 || a[0] != 1 || a[1] != 2 || a[2] != 3) + __builtin_abort (); + return 0; +} -- 2.30.2