On Sun, May 25, 2014 at 6:54 AM, Jan Hubicka <hubi...@ucw.cz> wrote: > Hi, > this patch adds code to rerite references in vtable initializers to local > aliases > when doing so is a win. > > Bootstrapped/regtested x86_64-linux, comitted.
This is the most likely patch to have caused build failures on arm-linux-gnueabihf My last successful build was 210908 as is evident from http://gcc.gnu.org/ml/gcc-testresults/2014-05/msg02245.html and between that and 210913 builds failed with the following error message. I haven't dug further yet. libtool: compile: /work/trunk-nightlies/builds/build-210913/./gcc/xgcc -shared-libgcc -B/work/trunk-nightlies/builds/build-210913/./gcc -nostdinc++ -L/work/trunk-nightlies/builds/build-210913/armv7l-unknown-linux-gnueabihf/libstdc++-v3/src -L/work/trunk-nightlies/builds/build-210913/armv7l-unknown-linux-gnueabihf/libstdc++-v3/src/.libs -L/work/trunk-nightlies/builds/build-210913/armv7l-unknown-linux-gnueabihf/libstdc++-v3/libsupc++/.libs -B/work/trunk-nightlies/installs/install-210913/armv7l-unknown-linux-gnueabihf/bin/ -B/work/trunk-nightlies/installs/install-210913/armv7l-unknown-linux-gnueabihf/lib/ -isystem /work/trunk-nightlies/installs/install-210913/armv7l-unknown-linux-gnueabihf/include -isystem /work/trunk-nightlies/installs/install-210913/armv7l-unknown-linux-gnueabihf/sys-include -I/work/gcc/libstdc++-v3/../libgcc -I/work/trunk-nightlies/builds/build-210913/armv7l-unknown-linux-gnueabihf/libstdc++-v3/include/armv7l-unknown-linux-gnueabihf -I/work/trunk-nightlies/builds/build-210913/armv7l-unknown-linux-gnueabihf/libstdc++-v3/include -I/work/gcc/libstdc++-v3/libsupc++ -D_GLIBCXX_SHARED -fno-implicit-templates -Wall -Wextra -Wwrite-strings -Wcast-qual -Wabi -fdiagnostics-show-location=once -ffunction-sections -fdata-sections -frandom-seed=strstream.lo -g -O2 -D_GNU_SOURCE -I/work/trunk-nightlies/builds/build-210913/armv7l-unknown-linux-gnueabihf/libstdc++-v3/include/backward -Wno-deprecated -c /work/gcc/libstdc++-v3/src/c++98/strstream.cc -fPIC -DPIC -D_GLIBCXX_SHARED -o strstream.o In file included from /work/gcc/libstdc++-v3/src/c++98/strstream.cc:44:0: /work/trunk-nightlies/builds/build-210913/armv7l-unknown-linux-gnueabihf/libstdc++-v3/include/backward/strstream:126:9: error: std::istrstream::_ZTVSt10istrstream.localalias.0 causes a section type conflict with std::istrstream::_ZTVSt10istrstream class istrstream : public basic_istream<char> ^ /work/trunk-nightlies/builds/build-210913/armv7l-unknown-linux-gnueabihf/libstdc++-v3/include/backward/strstream:126:9: note: _std::istrstream::_ZTVSt10istrstream_ was declared here /work/trunk-nightlies/builds/build-210913/armv7l-unknown-linux-gnueabihf/libstdc++-v3/include/backward/strstream:143:9: error: std::ostrstream::_ZTVSt10ostrstream.localalias.1 causes a section type conflict with std::ostrstream::_ZTVSt10ostrstream class ostrstream : public basic_ostream<char> ^ /work/trunk-nightlies/builds/build-210913/armv7l-unknown-linux-gnueabihf/libstdc++-v3/include/backward/strstream:143:9: note: _std::ostrstream::_ZTVSt10ostrstream_ was declared here /work/trunk-nightlies/builds/build-210913/armv7l-unknown-linux-gnueabihf/libstdc++-v3/include/backward/strstream:160:9: error: std::strstream::_ZTVSt9strstream.localalias.2 causes a section type conflict with std::strstream::_ZTVSt9strstream class strstream : public basic_iostream<char> ^ /work/trunk-nightlies/builds/build-210913/armv7l-unknown-linux-gnueabihf/libstdc++-v3/include/backward/strstream:160:9: note: _std::strstream::_ZTVSt9strstream_ was declared here regards Ramana > > Honza > > * ipa-visibility.c (can_replace_by_local_alias_in_vtable): New > function. > (update_vtable_references): New function. > (function_and_variable_visibility): Rewrite also vtable initializers. > * varpool.c (cgraph_variable_initializer_availability): Remove assert. > Index: varpool.c > =================================================================== > --- varpool.c (revision 210908) > +++ varpool.c (working copy) > @@ -355,7 +355,6 @@ varpool_add_new_variable (tree decl) > enum availability > cgraph_variable_initializer_availability (varpool_node *node) > { > - gcc_assert (cgraph_function_flags_ready); > if (!node->definition) > return AVAIL_NOT_AVAILABLE; > if (!TREE_PUBLIC (node->decl)) > Index: ipa-visibility.c > =================================================================== > --- ipa-visibility.c (revision 210908) > +++ ipa-visibility.c (working copy) > @@ -343,6 +343,36 @@ can_replace_by_local_alias (symtab_node > && !symtab_can_be_discarded (node)); > } > > +/* Return true if we can replace refernece to NODE by local alias > + within a virtual table. Generally we can replace function pointers > + and virtual table pointers. */ > + > +bool > +can_replace_by_local_alias_in_vtable (symtab_node *node) > +{ > + if (is_a <varpool_node *> (node) > + && !DECL_VIRTUAL_P (node->decl)) > + return false; > + return can_replace_by_local_alias (node); > +} > + > +/* walk_tree callback that rewrites initializer references. */ > + > +static tree > +update_vtable_references (tree *tp, int *walk_subtrees, void *data > ATTRIBUTE_UNUSED) > +{ > + if (TREE_CODE (*tp) == VAR_DECL > + || TREE_CODE (*tp) == FUNCTION_DECL) > + { > + if (can_replace_by_local_alias_in_vtable (symtab_get_node (*tp))) > + *tp = symtab_nonoverwritable_alias (symtab_get_node (*tp))->decl; > + *walk_subtrees = 0; > + } > + else if (IS_TYPE_OR_DECL_P (*tp)) > + *walk_subtrees = 0; > + return NULL; > +} > + > /* In LTO we can remove COMDAT groups and weak symbols. > Either turn them into normal symbols or external symbol depending on > resolution info. */ > @@ -625,6 +655,34 @@ function_and_variable_visibility (bool w > vnode->resolution = LDPR_PREVAILING_DEF_IRONLY; > } > update_visibility_by_resolution_info (vnode); > + > + /* Update virutal tables to point to local aliases where possible. */ > + if (DECL_VIRTUAL_P (vnode->decl) > + && !DECL_EXTERNAL (vnode->decl)) > + { > + int i; > + struct ipa_ref *ref; > + bool found = false; > + > + /* See if there is something to update. */ > + for (i = 0; ipa_ref_list_referring_iterate (&vnode->ref_list, > + i, ref); i++) > + if (ref->use == IPA_REF_ADDR > + && can_replace_by_local_alias_in_vtable (ref->referred)) > + { > + found = true; > + break; > + } > + if (found) > + { > + struct pointer_set_t *visited_nodes = pointer_set_create (); > + walk_tree (&DECL_INITIAL (vnode->decl), > + update_vtable_references, NULL, visited_nodes); > + pointer_set_destroy (visited_nodes); > + ipa_remove_all_references (&vnode->ref_list); > + record_references_in_initializer (vnode->decl, false); > + } > + } > } > > if (dump_file)
