{
struct cgraph_node *node = ipa_ref_node (ref);
if (!node->reachable
+ && node->analyzed
&& (!DECL_EXTERNAL (node->decl)
|| before_inlining_p))
- {
- node->reachable = true;
- enqueue_cgraph_node (node, first);
- }
+ node->reachable = true;
+ enqueue_cgraph_node (node, first);
}
else
{
}
}
-/* Return true when function NODE can be removed from callgraph
- if all direct calls are eliminated. */
-
-static inline bool
-varpool_can_remove_if_no_refs (struct varpool_node *node)
-{
- return (!node->force_output && !node->used_from_other_partition
- && (DECL_COMDAT (node->decl) || !node->externally_visible));
-}
-
/* Return true when function can be marked local. */
static bool
{
vnode->next_needed = NULL;
vnode->prev_needed = NULL;
- if (!varpool_can_remove_if_no_refs (vnode))
+ if (vnode->analyzed
+ && !varpool_can_remove_if_no_refs (vnode))
{
vnode->needed = false;
varpool_mark_needed_node (vnode);
if (node->reachable)
{
for (e = node->callees; e; e = e->next_callee)
- if (!e->callee->reachable
- && node->analyzed
- && (!e->inline_failed || !e->callee->analyzed
- || (!DECL_EXTERNAL (e->callee->decl))
- || before_inlining_p))
- {
+ {
+ if (!e->callee->reachable
+ && node->analyzed
+ && (!e->inline_failed
+ || !DECL_EXTERNAL (e->callee->decl)
+ || before_inlining_p))
e->callee->reachable = true;
- enqueue_cgraph_node (e->callee, &first);
- }
+ enqueue_cgraph_node (e->callee, &first);
+ }
process_references (&node->ref_list, &first, &first_varpool, before_inlining_p);
}
found = true;
/* If so, we need to keep node in the callgraph. */
- if (found || node->needed)
+ if (found)
{
if (node->analyzed)
{
fprintf (dump_file, "\n");
}
+/* Return true when there is a reference to node and it is not vtable. */
+static bool
+cgraph_address_taken_from_non_vtable_p (struct cgraph_node *node)
+{
+ int i;
+ struct ipa_ref *ref;
+ for (i = 0; ipa_ref_list_reference_iterate (&node->ref_list, i, ref); i++)
+ {
+ struct varpool_node *node;
+ if (ref->refered_type == IPA_REF_CGRAPH)
+ return true;
+ node = ipa_ref_varpool_node (ref);
+ if (!DECL_VIRTUAL_P (node->decl))
+ return true;
+ }
+ return false;
+}
+
+/* COMDAT functions must be shared only if they have address taken,
+ otherwise we can produce our own private implementation with
+ -fwhole-program.
+ Return true when turning COMDAT functoin static can not lead to wrong
+ code when the resulting object links with a library defining same COMDAT.
+
+ Virtual functions do have their addresses taken from the vtables,
+ but in C++ there is no way to compare their addresses for equality. */
+
+bool
+cgraph_comdat_can_be_unshared_p (struct cgraph_node *node)
+{
+ if ((cgraph_address_taken_from_non_vtable_p (node)
+ && !DECL_VIRTUAL_P (node->decl))
+ || !node->analyzed)
+ return false;
+ if (node->same_comdat_group)
+ {
+ struct cgraph_node *next;
+
+ /* If more than one function is in the same COMDAT group, it must
+ be shared even if just one function in the comdat group has
+ address taken. */
+ for (next = node->same_comdat_group;
+ next != node; next = next->same_comdat_group)
+ if (cgraph_address_taken_from_non_vtable_p (node)
+ && !DECL_VIRTUAL_P (next->decl))
+ return false;
+ }
+ return true;
+}
+
/* Return true when function NODE should be considered externally visible. */
static bool
cgraph_externally_visible_p (struct cgraph_node *node, bool whole_program, bool aliased)
{
+ struct cgraph_node *alias;
if (!node->local.finalized)
return false;
if (!DECL_COMDAT (node->decl)
return true;
if (lookup_attribute ("externally_visible", DECL_ATTRIBUTES (node->decl)))
return true;
+ if (TARGET_DLLIMPORT_DECL_ATTRIBUTES
+ && lookup_attribute ("dllexport", DECL_ATTRIBUTES (node->decl)))
+ return true;
+ /* When doing LTO or whole program, we can bring COMDAT functoins static.
+ This improves code quality and we know we will duplicate them at most twice
+ (in the case that we are not using plugin and link with object file
+ implementing same COMDAT) */
+ if ((in_lto_p || whole_program)
+ && DECL_COMDAT (node->decl)
+ && cgraph_comdat_can_be_unshared_p (node))
+ return false;
+
+ /* See if we have linker information about symbol not being used or
+ if we need to make guess based on the declaration.
+
+ Even if the linker clams the symbol is unused, never bring internal
+ symbols that are declared by user as used or externally visible.
+ This is needed for i.e. references from asm statements. */
+ for (alias = node->same_body; alias; alias = alias->next)
+ if (alias->resolution != LDPR_PREVAILING_DEF_IRONLY)
+ break;
+ if (!alias && node->resolution == LDPR_PREVAILING_DEF_IRONLY)
+ return false;
/* When doing link time optimizations, hidden symbols become local. */
if (in_lto_p
;
else if (!whole_program)
return true;
- /* COMDAT functions must be shared only if they have address taken,
- otherwise we can produce our own private implementation with
- -fwhole-program. */
- else if (DECL_COMDAT (node->decl))
- {
- if (node->address_taken || !node->analyzed)
- return true;
- if (node->same_comdat_group)
- {
- struct cgraph_node *next;
-
- /* If more than one function is in the same COMDAT group, it must
- be shared even if just one function in the comdat group has
- address taken. */
- for (next = node->same_comdat_group;
- next != node;
- next = next->same_comdat_group)
- if (next->address_taken || !next->analyzed)
- return true;
- }
- }
if (MAIN_NAME_P (DECL_NAME (node->decl)))
return true;
static bool
varpool_externally_visible_p (struct varpool_node *vnode, bool aliased)
{
+ struct varpool_node *alias;
if (!DECL_COMDAT (vnode->decl) && !TREE_PUBLIC (vnode->decl))
return false;
if (lookup_attribute ("externally_visible",
DECL_ATTRIBUTES (vnode->decl)))
return true;
+ if (TARGET_DLLIMPORT_DECL_ATTRIBUTES
+ && lookup_attribute ("dllexport",
+ DECL_ATTRIBUTES (vnode->decl)))
+ return true;
/* See if we have linker information about symbol not being used or
if we need to make guess based on the declaration.
This is needed for i.e. references from asm statements. */
if (varpool_used_from_object_file_p (vnode))
return true;
+ for (alias = vnode->extra_name; alias; alias = alias->next)
+ if (alias->resolution != LDPR_PREVAILING_DEF_IRONLY)
+ break;
+ if (!alias && vnode->resolution == LDPR_PREVAILING_DEF_IRONLY)
+ return false;
+
+ /* As a special case, the COMDAT virutal tables can be unshared.
+ In LTO mode turn vtables into static variables. The variable is readonly,
+ so this does not enable more optimization, but referring static var
+ is faster for dynamic linking. Also this match logic hidding vtables
+ from LTO symbol tables. */
+ if ((in_lto_p || flag_whole_program)
+ && !vnode->force_output
+ && DECL_COMDAT (vnode->decl) && DECL_VIRTUAL_P (vnode->decl))
+ return false;
/* When doing link time optimizations, hidden symbols become local. */
if (in_lto_p
static unsigned int
local_function_and_variable_visibility (void)
{
- return function_and_variable_visibility (flag_whole_program && !flag_lto && !flag_whopr);
+ return function_and_variable_visibility (flag_whole_program && !flag_lto);
}
struct simple_ipa_opt_pass pass_ipa_function_and_variable_visibility =
OSDN Git Service
