diff options
| author | Jakub Jelinek <jakub@redhat.com> | 2025-11-21 11:25:27 +0100 |
|---|---|---|
| committer | Jakub Jelinek <jakub@gcc.gnu.org> | 2025-11-21 11:25:27 +0100 |
| commit | 3012aad2dc6318ab490c4a2511f5b2e4d30652b9 (patch) | |
| tree | 0d822a7212891be37e9e122bb2daa92e9c62b8cd | |
| parent | c435bbdd22a7fc2d18129f261fd2050e72f98411 (diff) | |
gimplify: Fix ICE in collect_fallthrough_labels [PR122773]
In r16-4212 I had to tweak two spots in the gimplifier to ignore
gotos jumping to labels with the new VACUOUS_INIT_LABEL_P flag
(set by C++ FE when implementing goto/case interceptors with
extra .DEFERRED_INIT calls, so that jumps over vacuous initialization
are handled properly with the C++26 erroneous behavior requirements).
Except as the following testcase shows, the checks blindly assumed
that gimple_goto_dest operand is a LABEL_DECL, which is not the case
for computed jumps.
The following patch checks that gimple_goto_dest argument is a LABEL_DECL
before testing VACUOUS_INIT_LABEL_P flag on it.
2025-11-21 Jakub Jelinek <jakub@redhat.com>
PR middle-end/122773
* gimplify.cc (collect_fallthrough_labels): Check whether
gimple_goto_dest is a LABEL_DECL before testing VACUOUS_INIT_LABEL_P.
(expand_FALLTHROUGH_r): Likewise.
* gcc.dg/pr122773.c: New test.
| -rw-r--r-- | gcc/gimplify.cc | 10 | ||||
| -rw-r--r-- | gcc/testsuite/gcc.dg/pr122773.c | 25 |
2 files changed, 33 insertions, 2 deletions
diff --git a/gcc/gimplify.cc b/gcc/gimplify.cc index d8725e4c5e2..d884e8b0d95 100644 --- a/gcc/gimplify.cc +++ b/gcc/gimplify.cc @@ -2673,6 +2673,7 @@ collect_fallthrough_labels (gimple_stmt_iterator *gsi_p, gsi_next (gsi_p); } + tree lab; /* Remember the last statement. Skip labels that are of no interest to us. */ if (gimple_code (gsi_stmt (*gsi_p)) == GIMPLE_LABEL) @@ -2691,7 +2692,9 @@ collect_fallthrough_labels (gimple_stmt_iterator *gsi_p, ; else if (flag_auto_var_init > AUTO_INIT_UNINITIALIZED && gimple_code (gsi_stmt (*gsi_p)) == GIMPLE_GOTO - && VACUOUS_INIT_LABEL_P (gimple_goto_dest (gsi_stmt (*gsi_p)))) + && (lab = gimple_goto_dest (gsi_stmt (*gsi_p))) + && TREE_CODE (lab) == LABEL_DECL + && VACUOUS_INIT_LABEL_P (lab)) ; else if (!is_gimple_debug (gsi_stmt (*gsi_p))) prev = gsi_stmt (*gsi_p); @@ -2928,9 +2931,12 @@ expand_FALLTHROUGH_r (gimple_stmt_iterator *gsi_p, bool *handled_ops_p, gimple_stmt_iterator gsi2 = *gsi_p; stmt = gsi_stmt (gsi2); + tree lab; if (flag_auto_var_init > AUTO_INIT_UNINITIALIZED && gimple_code (stmt) == GIMPLE_GOTO - && VACUOUS_INIT_LABEL_P (gimple_goto_dest (stmt))) + && (lab = gimple_goto_dest (stmt)) + && TREE_CODE (lab) == LABEL_DECL + && VACUOUS_INIT_LABEL_P (lab)) { /* Handle for C++ artificial -ftrivial-auto-var-init= sequences. Those look like: diff --git a/gcc/testsuite/gcc.dg/pr122773.c b/gcc/testsuite/gcc.dg/pr122773.c new file mode 100644 index 00000000000..a3860e9c7a2 --- /dev/null +++ b/gcc/testsuite/gcc.dg/pr122773.c @@ -0,0 +1,25 @@ +/* PR middle-end/122773 */ +/* { dg-do compile } */ +/* { dg-options "-Wimplicit-fallthrough -O2 -ftrivial-auto-var-init=zero" } */ + +void *l; +int +foo (int x) +{ + __label__ l1, l2, l3; + static void *l[] = { &&l1, &&l2, &&l3 }; + switch (0) + { + case 0: + while (0) + ; + goto *l[x]; + } + l1: + ++x; + l2: + ++x; + l3: + ++x; + return x; +} |