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| author | Richard Biener <rguenther@suse.de> | 2022-06-15 10:54:48 +0200 |
|---|---|---|
| committer | Richard Biener <rguenther@suse.de> | 2022-06-15 13:14:58 +0200 |
| commit | edb9330c29fe8a0a0b76df6fafd6a223a4d0e41f (patch) | |
| tree | 26277e1e4b868300d3036ae30c845da550efa9f9 | |
| parent | f4c3ce32fa54c1aefac0b3a825d8a3f73de95939 (diff) | |
| download | gcc-edb9330c29fe8a0a0b76df6fafd6a223a4d0e41f.zip gcc-edb9330c29fe8a0a0b76df6fafd6a223a4d0e41f.tar.gz gcc-edb9330c29fe8a0a0b76df6fafd6a223a4d0e41f.tar.bz2 | |
tree-optimization/105969 - FPE with array diagnostics
For a [0][0] array we have to be careful when dividing by the element
size which is zero for the outermost dimension. Luckily the division
is only for an overflow check which is pointless for array size zero.
2022-06-15 Richard Biener <rguenther@suse.de>
PR tree-optimization/105969
* gimple-ssa-sprintf.cc (get_origin_and_offset_r): Avoid division
by zero in overflow check.
* gcc.dg/pr105969.c: New testcase.
| -rw-r--r-- | gcc/gimple-ssa-sprintf.cc | 2 | ||||
| -rw-r--r-- | gcc/testsuite/gcc.dg/pr105969.c | 13 |
2 files changed, 14 insertions, 1 deletions
diff --git a/gcc/gimple-ssa-sprintf.cc b/gcc/gimple-ssa-sprintf.cc index 6bd2730..a888b5a 100644 --- a/gcc/gimple-ssa-sprintf.cc +++ b/gcc/gimple-ssa-sprintf.cc @@ -2319,7 +2319,7 @@ get_origin_and_offset_r (tree x, HOST_WIDE_INT *fldoff, HOST_WIDE_INT *fldsize, if (byteoff < HOST_WIDE_INT_MAX && elbytes < HOST_WIDE_INT_MAX - && byteoff / elbytes == idx) + && (elbytes == 0 || byteoff / elbytes == idx)) { /* For in-bounds constant offsets into constant-sized arrays bump up *OFF, and for what's likely arrays or structs of diff --git a/gcc/testsuite/gcc.dg/pr105969.c b/gcc/testsuite/gcc.dg/pr105969.c new file mode 100644 index 0000000..52c63fc --- /dev/null +++ b/gcc/testsuite/gcc.dg/pr105969.c @@ -0,0 +1,13 @@ +/* { dg-do compile } */ +/* { dg-options "-Wall" } */ + +struct A +{ + char a[0][0][0]; +}; +extern struct A b[][2]; +void f (void) +{ + __builtin_sprintf (b[0][0].a[1][0], "%s", b[0][0].a[1][0]); /* { dg-warning "past the end" } */ + /* { dg-warning "overlaps destination" "" { target *-*-* } .-1 } */ +} |