On Mon, 27 Jul 2020, Sergei Trofimovich wrote:
> From: Sergei Trofimovich <[email protected]>
>
> In PR ipa/96291 the test contained an SCC with one
> unoptimized function. This tricked ipa-cp into NULL dereference.
>
> has_undead_caller_from_outside_scc_p() did not take into account
> that unoptimized funtions don't have IPA summary analysis. And
> dereferenced NULL pointer causing an ICE.
OK. The dg-options -O0 use in _2.c looks exactly correct.
Thanks,
Richard.
> gcc/
> PR ipa/96291
> * ipa-cp.c (has_undead_caller_from_outside_scc_p): Consider
> unoptimized callers as undead.
>
> gcc/testsuite/
> PR ipa/96291
> * gcc.dg/lto/pr96291_0.c: New testcase.
> * gcc.dg/lto/pr96291_1.c: Support file.
> * gcc.dg/lto/pr96291_2.c: Likewise.
> * gcc.dg/lto/pr96291.h: Likewise.
> ---
> gcc/ipa-cp.c | 5 +++--
> gcc/testsuite/gcc.dg/lto/pr96291.h | 4 ++++
> gcc/testsuite/gcc.dg/lto/pr96291_0.c | 11 +++++++++++
> gcc/testsuite/gcc.dg/lto/pr96291_1.c | 3 +++
> gcc/testsuite/gcc.dg/lto/pr96291_2.c | 7 +++++++
> 5 files changed, 28 insertions(+), 2 deletions(-)
> create mode 100644 gcc/testsuite/gcc.dg/lto/pr96291.h
> create mode 100644 gcc/testsuite/gcc.dg/lto/pr96291_0.c
> create mode 100644 gcc/testsuite/gcc.dg/lto/pr96291_1.c
> create mode 100644 gcc/testsuite/gcc.dg/lto/pr96291_2.c
>
> diff --git a/gcc/ipa-cp.c b/gcc/ipa-cp.c
> index b0c8f405260..fe010ff457c 100644
> --- a/gcc/ipa-cp.c
> +++ b/gcc/ipa-cp.c
> @@ -5667,8 +5667,9 @@ has_undead_caller_from_outside_scc_p (struct
> cgraph_node *node,
> (has_undead_caller_from_outside_scc_p, NULL, true))
> return true;
> else if (!ipa_edge_within_scc (cs)
> - && !IPA_NODE_REF (cs->caller)->node_dead)
> - return true;
> + && (!IPA_NODE_REF (cs->caller) /* Unoptimized caller. */
> + || !IPA_NODE_REF (cs->caller)->node_dead))
> + return true;
> return false;
> }
>
> diff --git a/gcc/testsuite/gcc.dg/lto/pr96291.h
> b/gcc/testsuite/gcc.dg/lto/pr96291.h
> new file mode 100644
> index 00000000000..70eb3cb71b8
> --- /dev/null
> +++ b/gcc/testsuite/gcc.dg/lto/pr96291.h
> @@ -0,0 +1,4 @@
> +void e(void);
> +void f(void);
> +void a(void *, void *);
> +void c(int);
> diff --git a/gcc/testsuite/gcc.dg/lto/pr96291_0.c
> b/gcc/testsuite/gcc.dg/lto/pr96291_0.c
> new file mode 100644
> index 00000000000..07e63038e03
> --- /dev/null
> +++ b/gcc/testsuite/gcc.dg/lto/pr96291_0.c
> @@ -0,0 +1,11 @@
> +/* { dg-lto-do link } */
> +
> +#include "pr96291.h"
> +
> +static void * b;
> +void c(int d) {
> + f();
> + a(b, b);
> +}
> +
> +void e(void) { c(0); }
> diff --git a/gcc/testsuite/gcc.dg/lto/pr96291_1.c
> b/gcc/testsuite/gcc.dg/lto/pr96291_1.c
> new file mode 100644
> index 00000000000..44744a94941
> --- /dev/null
> +++ b/gcc/testsuite/gcc.dg/lto/pr96291_1.c
> @@ -0,0 +1,3 @@
> +#include "pr96291.h"
> +
> +void f(void) { c(0); }
> diff --git a/gcc/testsuite/gcc.dg/lto/pr96291_2.c
> b/gcc/testsuite/gcc.dg/lto/pr96291_2.c
> new file mode 100644
> index 00000000000..5febffbb00c
> --- /dev/null
> +++ b/gcc/testsuite/gcc.dg/lto/pr96291_2.c
> @@ -0,0 +1,7 @@
> +/* { dg-options {-O0} } */
> +
> +#include "pr96291.h"
> +
> +void a(void * a1, void * a2) { e(); }
> +
> +int main(){}
>
--
Richard Biener <[email protected]>
SUSE Software Solutions Germany GmbH, Maxfeldstrasse 5, 90409 Nuernberg,
Germany; GF: Felix Imendörffer; HRB 36809 (AG Nuernberg)
