Hi!
pot_dummy_types is a hash_set from whose traversal the code prints some type
lines. hash_set normally uses default_hash_traits which for pointer types
(the hash set hashes const char *) uses pointer_hash which hashes the
addresses of the pointers except of the least significant 3 bits.
With address space randomization, that results in non-determinism in the
-fdump-go-specs= generated file, each invocation can have different order of
the lines emitted from pot_dummy_types traversal.
This patch fixes it by hashing the string contents instead to make the
hashes reproduceable.
Bootstrapped/regtested on x86_64-linux and i686-linux, ok for trunk?
2021-07-13 Jakub Jelinek <ja...@redhat.com>
PR go/101407
* godump.c (godump_str_hash): New type.
(godump_container::pot_dummy_types): Use string_hash instead of
ptr_hash in the hash_set.
--- gcc/godump.c.jj 2021-05-07 10:34:46.255123614 +0200
+++ gcc/godump.c 2021-07-12 15:00:31.328761742 +0200
@@ -56,6 +56,8 @@ static FILE *go_dump_file;
static GTY(()) vec<tree, va_gc> *queue;
+struct godump_str_hash : string_hash, ggc_remove <const char *> {};
+
/* A hash table of macros we have seen. */
static htab_t macro_hash;
@@ -535,7 +537,7 @@ public:
/* Types which may potentially have to be defined as dummy
types. */
- hash_set<const char *> pot_dummy_types;
+ hash_set<const char *, false, godump_str_hash> pot_dummy_types;
/* Go keywords. */
htab_t keyword_hash;
Jakub
