name_lookup::search_unqualified uses a statically allocated vector in order to avoid repeated reallocation, under the assumption that the function can't be called recursively. With modules however, this assumption turns out to be false, and search_unqualified can be called recursively as demonstrated by testcase in comment #19 of PR99479[1] where the recursive call causes the vector to get reallocated which invalidates the reference held by the parent call.
This patch makes search_unqualified instead use an auto_vec with 16 elements of internal storage (since with the various libraries I tested, the size of the vector never exceeded 12). In turn we can simplify the API of subroutines to take the vector by reference and return void. Bootstrapped and regtested on x86_64-pc-linux-gnu, does this look OK for trunk? [1]: https://gcc.gnu.org/PR99479#c19 PR c++/99479 gcc/cp/ChangeLog: * name-lookup.cc (name_lookup::using_queue): Change to an auto_vec (with 16 elements of internal storage). (name_lookup::queue_namespace): Change return type to void, take queue parameter by reference and adjust function body accordingly. (name_lookup::do_queue_usings): Inline into ... (name_lookup::queue_usings): ... here. As in queue_namespace. (name_lookup::search_unqualified): Don't make queue static, assume its incoming length is 0, and adjust function body accordingly. --- gcc/cp/name-lookup.cc | 62 +++++++++++++++---------------------------- 1 file changed, 22 insertions(+), 40 deletions(-) diff --git a/gcc/cp/name-lookup.cc b/gcc/cp/name-lookup.cc index 93c4eb7193b..5c965d6fba1 100644 --- a/gcc/cp/name-lookup.cc +++ b/gcc/cp/name-lookup.cc @@ -429,7 +429,7 @@ class name_lookup { public: typedef std::pair<tree, tree> using_pair; - typedef vec<using_pair, va_heap, vl_embed> using_queue; + typedef auto_vec<using_pair, 16> using_queue; public: tree name; /* The identifier being looked for. */ @@ -528,16 +528,8 @@ private: bool search_usings (tree scope); private: - using_queue *queue_namespace (using_queue *queue, int depth, tree scope); - using_queue *do_queue_usings (using_queue *queue, int depth, - vec<tree, va_gc> *usings); - using_queue *queue_usings (using_queue *queue, int depth, - vec<tree, va_gc> *usings) - { - if (usings) - queue = do_queue_usings (queue, depth, usings); - return queue; - } + void queue_namespace (using_queue& queue, int depth, tree scope); + void queue_usings (using_queue& queue, int depth, vec<tree, va_gc> *usings); private: void add_fns (tree); @@ -1084,39 +1076,35 @@ name_lookup::search_qualified (tree scope, bool usings) /* Add SCOPE to the unqualified search queue, recursively add its inlines and those via using directives. */ -name_lookup::using_queue * -name_lookup::queue_namespace (using_queue *queue, int depth, tree scope) +void +name_lookup::queue_namespace (using_queue& queue, int depth, tree scope) { if (see_and_mark (scope)) - return queue; + return; /* Record it. */ tree common = scope; while (SCOPE_DEPTH (common) > depth) common = CP_DECL_CONTEXT (common); - vec_safe_push (queue, using_pair (common, scope)); + queue.safe_push (using_pair (common, scope)); /* Queue its inline children. */ if (vec<tree, va_gc> *inlinees = DECL_NAMESPACE_INLINEES (scope)) for (unsigned ix = inlinees->length (); ix--;) - queue = queue_namespace (queue, depth, (*inlinees)[ix]); + queue_namespace (queue, depth, (*inlinees)[ix]); /* Queue its using targets. */ - queue = queue_usings (queue, depth, NAMESPACE_LEVEL (scope)->using_directives); - - return queue; + queue_usings (queue, depth, NAMESPACE_LEVEL (scope)->using_directives); } /* Add the namespaces in USINGS to the unqualified search queue. */ -name_lookup::using_queue * -name_lookup::do_queue_usings (using_queue *queue, int depth, - vec<tree, va_gc> *usings) +void +name_lookup::queue_usings (using_queue& queue, int depth, vec<tree, va_gc> *usings) { - for (unsigned ix = usings->length (); ix--;) - queue = queue_namespace (queue, depth, (*usings)[ix]); - - return queue; + if (usings) + for (unsigned ix = usings->length (); ix--;) + queue_namespace (queue, depth, (*usings)[ix]); } /* Unqualified namespace lookup in SCOPE. @@ -1128,15 +1116,12 @@ name_lookup::do_queue_usings (using_queue *queue, int depth, bool name_lookup::search_unqualified (tree scope, cp_binding_level *level) { - /* Make static to avoid continual reallocation. We're not - recursive. */ - static using_queue *queue = NULL; + using_queue queue; bool found = false; - int length = vec_safe_length (queue); /* Queue local using-directives. */ for (; level->kind != sk_namespace; level = level->level_chain) - queue = queue_usings (queue, SCOPE_DEPTH (scope), level->using_directives); + queue_usings (queue, SCOPE_DEPTH (scope), level->using_directives); for (; !found; scope = CP_DECL_CONTEXT (scope)) { @@ -1144,19 +1129,19 @@ name_lookup::search_unqualified (tree scope, cp_binding_level *level) int depth = SCOPE_DEPTH (scope); /* Queue namespaces reachable from SCOPE. */ - queue = queue_namespace (queue, depth, scope); + queue_namespace (queue, depth, scope); /* Search every queued namespace where SCOPE is the common ancestor. Adjust the others. */ - unsigned ix = length; + unsigned ix = 0; do { - using_pair &pair = (*queue)[ix]; + using_pair &pair = queue[ix]; while (pair.first == scope) { found |= search_namespace_only (pair.second); - pair = queue->pop (); - if (ix == queue->length ()) + pair = queue.pop (); + if (ix == queue.length ()) goto done; } /* The depth is the same as SCOPE, find the parent scope. */ @@ -1164,7 +1149,7 @@ name_lookup::search_unqualified (tree scope, cp_binding_level *level) pair.first = CP_DECL_CONTEXT (pair.first); ix++; } - while (ix < queue->length ()); + while (ix < queue.length ()); done:; if (scope == global_namespace) break; @@ -1181,9 +1166,6 @@ name_lookup::search_unqualified (tree scope, cp_binding_level *level) dedup (false); - /* Restore to incoming length. */ - vec_safe_truncate (queue, length); - return found; } -- 2.35.1.193.g45fe28c951
