From 26c9b95b9f712ff1f813351b5d45371620085221 Mon Sep 17 00:00:00 2001 From: Jakub Jelinek Date: Tue, 30 Jan 2024 09:57:21 +0100 Subject: [PATCH] except: Fix __builtin_eh_return_data_regno (-42) expansion [PR101195] The expansion of this builtin emits an error if the argument is not INTEGER_CST, otherwise uses tree_to_uhwi on the argument (which is declared int) and then uses EH_RETURN_DATA_REGNO macro which on most targets returns INVALID_REGNUM for all values but some small number (2 or 4); if it returns INVALID_REGNUM, we silently expand to -1. Now, I think the error for non-INTEGER_CST makes sense to catch when people unintentionally don't call it with a constant (but, users shouldn't really use this builtin anyway, it is for the unwinder only). Initially I thought about emitting an error for the negative values as well on which tree_to_uhwi otherwise ICEs, but given that the function will silently expand to -1 for INT_MAX - 1 or INT_MAX - 3 other values, I think treating the negatives the same silently is fine too. 2024-01-30 Jakub Jelinek PR middle-end/101195 * except.cc (expand_builtin_eh_return_data_regno): If which doesn't fit into unsigned HOST_WIDE_INT, return constm1_rtx. * gcc.dg/pr101195.c: New test. --- gcc/except.cc | 3 +++ gcc/testsuite/gcc.dg/pr101195.c | 8 ++++++++ 2 files changed, 11 insertions(+) create mode 100644 gcc/testsuite/gcc.dg/pr101195.c diff --git a/gcc/except.cc b/gcc/except.cc index 9277a9a80c3..2080fcc22e6 100644 --- a/gcc/except.cc +++ b/gcc/except.cc @@ -2167,6 +2167,9 @@ expand_builtin_eh_return_data_regno (tree exp) return constm1_rtx; } + if (!tree_fits_uhwi_p (which)) + return constm1_rtx; + iwhich = tree_to_uhwi (which); iwhich = EH_RETURN_DATA_REGNO (iwhich); if (iwhich == INVALID_REGNUM) diff --git a/gcc/testsuite/gcc.dg/pr101195.c b/gcc/testsuite/gcc.dg/pr101195.c new file mode 100644 index 00000000000..7b219f80711 --- /dev/null +++ b/gcc/testsuite/gcc.dg/pr101195.c @@ -0,0 +1,8 @@ +/* PR middle-end/101195 */ +/* { dg-do compile } */ + +int +foo (void) +{ + return __builtin_eh_return_data_regno (-42); +}