From c9e94ae448ba309dba74de3ee1974a3ed9248889 Mon Sep 17 00:00:00 2001 From: Jakub Jelinek Date: Fri, 12 Apr 2024 10:59:54 +0200 Subject: [PATCH] Limit special asan/ubsan/bitint returns_twice handling to calls in bbs with abnormal pred [PR114687] The tree-cfg.cc verifier only diagnoses returns_twice calls preceded by non-label/debug stmts if it is in a bb with abnormal predecessor. The following testcase shows that if a user lies in the attributes (a function which never returns can't be pure, and can't return twice when it doesn't ever return at all), when we figure it out, we can remove the abnormal edges to the "returns_twice" call and perhaps whole .ABNORMAL_DISPATCHER etc. edge_before_returns_twice_call then ICEs because it can't find such an edge. The following patch limits the special handling to calls in bbs where the verifier requires that. 2024-04-12 Jakub Jelinek PR sanitizer/114687 * gimple-iterator.cc (gsi_safe_insert_before): Only use edge_before_returns_twice_call if bb_has_abnormal_pred. (gsi_safe_insert_seq_before): Likewise. * gimple-lower-bitint.cc (bitint_large_huge::lower_call): Only push to m_returns_twice_calls if bb_has_abnormal_pred. * gcc.dg/asan/pr114687.c: New test. --- gcc/gimple-iterator.cc | 6 ++++-- gcc/gimple-lower-bitint.cc | 2 +- gcc/testsuite/gcc.dg/asan/pr114687.c | 22 ++++++++++++++++++++++ 3 files changed, 27 insertions(+), 3 deletions(-) create mode 100644 gcc/testsuite/gcc.dg/asan/pr114687.c diff --git a/gcc/gimple-iterator.cc b/gcc/gimple-iterator.cc index ac6cb4aa414d..93646262eac5 100644 --- a/gcc/gimple-iterator.cc +++ b/gcc/gimple-iterator.cc @@ -1049,7 +1049,8 @@ gsi_safe_insert_before (gimple_stmt_iterator *iter, gimple *g) gimple *stmt = gsi_stmt (*iter); if (stmt && is_gimple_call (stmt) - && (gimple_call_flags (stmt) & ECF_RETURNS_TWICE) != 0) + && (gimple_call_flags (stmt) & ECF_RETURNS_TWICE) != 0 + && bb_has_abnormal_pred (gsi_bb (*iter))) { edge e = edge_before_returns_twice_call (gsi_bb (*iter)); basic_block new_bb = gsi_insert_on_edge_immediate (e, g); @@ -1072,7 +1073,8 @@ gsi_safe_insert_seq_before (gimple_stmt_iterator *iter, gimple_seq seq) gimple *stmt = gsi_stmt (*iter); if (stmt && is_gimple_call (stmt) - && (gimple_call_flags (stmt) & ECF_RETURNS_TWICE) != 0) + && (gimple_call_flags (stmt) & ECF_RETURNS_TWICE) != 0 + && bb_has_abnormal_pred (gsi_bb (*iter))) { edge e = edge_before_returns_twice_call (gsi_bb (*iter)); gimple *f = gimple_seq_first_stmt (seq); diff --git a/gcc/gimple-lower-bitint.cc b/gcc/gimple-lower-bitint.cc index 4c3b7f7b68ed..7e8b6e3c51a0 100644 --- a/gcc/gimple-lower-bitint.cc +++ b/gcc/gimple-lower-bitint.cc @@ -5320,7 +5320,7 @@ bitint_large_huge::lower_call (tree obj, gimple *stmt) arg = make_ssa_name (TREE_TYPE (arg)); gimple *g = gimple_build_assign (arg, v); gsi_insert_before (&gsi, g, GSI_SAME_STMT); - if (returns_twice) + if (returns_twice && bb_has_abnormal_pred (gimple_bb (stmt))) { m_returns_twice_calls.safe_push (stmt); returns_twice = false; diff --git a/gcc/testsuite/gcc.dg/asan/pr114687.c b/gcc/testsuite/gcc.dg/asan/pr114687.c new file mode 100644 index 000000000000..48cc86881767 --- /dev/null +++ b/gcc/testsuite/gcc.dg/asan/pr114687.c @@ -0,0 +1,22 @@ +/* PR sanitizer/114687 */ +/* { dg-do compile } */ + +int a; +int foo (int); + +__attribute__((pure, returns_twice)) int +bar (void) +{ + a = 1; + while (a) + a = 2; + return a; +} + +int +baz (void) +{ + int d = bar (); + foo (d); + return 0; +} -- 2.47.2