| Message ID | 20210410061133.GJ1179226@tucnak |
|---|---|
| State | New |
| Headers | show |
| Series | gimple-ssa-warn-alloca: Always initialize limit [PR99989] | expand |
On April 10, 2021 8:11:33 AM GMT+02:00, Jakub Jelinek <jakub@redhat.com> wrote: >Hi! > >This PR is about a -W*uninitialized warning on riscv64. >alloca_type_and_limit is documented to have limit member only defined >when type is ALLOCA_BOUND_MAYBE_LARGE or ALLOCA_BOUND_DEFINITELY_LARGE >and otherwise just default constructs limit, which for wide_int means >no initialization at all. IMHO it is fine not to use the limit >member otherwise, but trying to not initialize it when it can be e.g. >copied around and then invoke UB doesn't look like a good idea. > >Bootstrapped/regtested on x86_64-linux and i686-linux, though I don't >have >riscv64 access to verify if it fixes the reported warning. Ok for >trunk? Ok. Richard. > >2021-04-10 Jakub Jelinek <jakub@redhat.com> > > PR middle-end/99989 > * gimple-ssa-warn-alloca.c > (alloca_type_and_limit::alloca_type_and_limit): Initialize limit to > 0 with integer precision unconditionally. > >--- gcc/gimple-ssa-warn-alloca.c.jj 2021-01-04 10:25:38.892233156 +0100 >+++ gcc/gimple-ssa-warn-alloca.c 2021-04-09 12:46:27.466847728 +0200 >@@ -124,9 +124,8 @@ public: > alloca_type_and_limit (enum alloca_type type, > wide_int i) : type(type), limit(i) { } > alloca_type_and_limit (enum alloca_type type) : type(type) >- { if (type == ALLOCA_BOUND_MAYBE_LARGE >- || type == ALLOCA_BOUND_DEFINITELY_LARGE) >- limit = wi::to_wide (integer_zero_node); >+ { >+ limit = wi::to_wide (integer_zero_node); > } > }; > > > Jakub
--- gcc/gimple-ssa-warn-alloca.c.jj 2021-01-04 10:25:38.892233156 +0100 +++ gcc/gimple-ssa-warn-alloca.c 2021-04-09 12:46:27.466847728 +0200 @@ -124,9 +124,8 @@ public: alloca_type_and_limit (enum alloca_type type, wide_int i) : type(type), limit(i) { } alloca_type_and_limit (enum alloca_type type) : type(type) - { if (type == ALLOCA_BOUND_MAYBE_LARGE - || type == ALLOCA_BOUND_DEFINITELY_LARGE) - limit = wi::to_wide (integer_zero_node); + { + limit = wi::to_wide (integer_zero_node); } };