diff options
Diffstat (limited to 'gcc/ipa.c')
| -rw-r--r-- | gcc/ipa.c | 88 |
1 files changed, 64 insertions, 24 deletions
@@ -607,6 +607,11 @@ cgraph_externally_visible_p (struct cgraph_node *node, bool whole_program, bool /* If linker counts on us, we must preserve the function. */ if (cgraph_used_from_object_file_p (node)) return true; + if (DECL_PRESERVE_P (node->decl)) + return true; + if (lookup_attribute ("externally_visible", DECL_ATTRIBUTES (node->decl))) + return true; + /* When doing link time optimizations, hidden symbols become local. */ if (in_lto_p && (DECL_VISIBILITY (node->decl) == VISIBILITY_HIDDEN @@ -638,11 +643,64 @@ cgraph_externally_visible_p (struct cgraph_node *node, bool whole_program, bool return true; } } - if (DECL_PRESERVE_P (node->decl)) - return true; + if (MAIN_NAME_P (DECL_NAME (node->decl))) return true; - if (lookup_attribute ("externally_visible", DECL_ATTRIBUTES (node->decl))) + + return false; +} + +/* Return true when variable VNODE should be considered externally visible. */ + +static bool +varpool_externally_visible_p (struct varpool_node *vnode, bool aliased) +{ + if (!DECL_COMDAT (vnode->decl) && !TREE_PUBLIC (vnode->decl)) + return false; + + /* Do not even try to be smart about aliased nodes. Until we properly + represent everything by same body alias, these are just evil. */ + if (aliased) + return true; + + /* If linker counts on us, we must preserve the function. */ + if (varpool_used_from_object_file_p (vnode)) + return true; + + if (DECL_PRESERVE_P (vnode->decl)) + return true; + if (lookup_attribute ("externally_visible", + 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. + + 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. */ + if (varpool_used_from_object_file_p (vnode)) + return true; + + /* When doing link time optimizations, hidden symbols become local. */ + if (in_lto_p + && (DECL_VISIBILITY (vnode->decl) == VISIBILITY_HIDDEN + || DECL_VISIBILITY (vnode->decl) == VISIBILITY_INTERNAL) + /* Be sure that node is defined in IR file, not in other object + file. In that case we don't set used_from_other_object_file. */ + && vnode->finalized) + ; + else if (!flag_whole_program) + return true; + + /* Do not attempt to privatize COMDATS by default. + This would break linking with C++ libraries sharing + inline definitions. + + FIXME: We can do so for readonly vars with no address taken and + possibly also for vtables since no direct pointer comparsion is done. + It might be interesting to do so to reduce linking overhead. */ + if (DECL_COMDAT (vnode->decl) || DECL_WEAK (vnode->decl)) return true; return false; } @@ -798,27 +856,9 @@ function_and_variable_visibility (bool whole_program) if (!vnode->finalized) continue; if (vnode->needed - && (DECL_COMDAT (vnode->decl) || TREE_PUBLIC (vnode->decl)) - && (((!whole_program - /* We can privatize comdat readonly variables whose address is - not taken, but doing so is not going to bring us - optimization oppurtunities until we start reordering - datastructures. */ - || DECL_COMDAT (vnode->decl) - || DECL_WEAK (vnode->decl)) - /* When doing linktime optimizations, all hidden symbols will - become local. */ - && (!in_lto_p - || (DECL_VISIBILITY (vnode->decl) != VISIBILITY_HIDDEN - && DECL_VISIBILITY (vnode->decl) != VISIBILITY_INTERNAL) - /* We can get prevailing decision in other object file. - In this case we do not sed used_from_object_file. */ - || !vnode->finalized)) - || DECL_PRESERVE_P (vnode->decl) - || varpool_used_from_object_file_p (vnode) - || pointer_set_contains (aliased_vnodes, vnode) - || lookup_attribute ("externally_visible", - DECL_ATTRIBUTES (vnode->decl)))) + && varpool_externally_visible_p + (vnode, + pointer_set_contains (aliased_vnodes, vnode))) vnode->externally_visible = true; else vnode->externally_visible = false; |