Hi! On Sat, 20 Sep 2014 01:59:25 +0200, Jan Hubicka <hubi...@ucw.cz> wrote: > Bootstrapped/regtested x86_64-linux, comitted.
(In r215409.) > PR c++/61825 > * c-family/c-common.c (handle_alias_ifunc_attribute): Check > that visibility change is possible > (handle_weakref_attribute): Likewise. > * cgraph.h (symtab_node): Add method get_create and > field refuse_visibility_changes. > (symtab_node::get_create): New method. > * fold-const.c (tree_single_nonzero_warnv_p): Use get_create. > * varasm.c (mark_weak): Verify that visibility change is > possible. > > * gcc.dg/tree-ssa/nonzero-1.c: Require error to be output. This patch is causing <https://gcc.gnu.org/PR63325> and similar issues, with --enable-checking=fold. Could you please have a look? > Index: c-family/c-common.c > =================================================================== > --- c-family/c-common.c (revision 215401) > +++ c-family/c-common.c (working copy) > @@ -7757,6 +7757,19 @@ handle_alias_ifunc_attribute (bool is_al > *no_add_attrs = true; > } > > + if (decl_in_symtab_p (*node)) > + { > + struct symtab_node *n = symtab_node::get (decl); > + if (n && n->refuse_visibility_changes) > + { > + if (is_alias) > + error ("%+D declared alias after being used", decl); > + else > + error ("%+D declared ifunc after being used", decl); > + } > + } > + > + > return NULL_TREE; > } > > @@ -7833,6 +7846,13 @@ handle_weakref_attribute (tree *node, tr > DECL_WEAK (*node) = 1; > } > > + if (decl_in_symtab_p (*node)) > + { > + struct symtab_node *n = symtab_node::get (*node); > + if (n && n->refuse_visibility_changes) > + error ("%+D declared weakref after being used", *node); > + } > + > return NULL_TREE; > } > > Index: cgraph.h > =================================================================== > --- cgraph.h (revision 215401) > +++ cgraph.h (working copy) > @@ -346,6 +346,10 @@ public: > return decl->decl_with_vis.symtab_node; > } > > + /* Try to find a symtab node for declaration DECL and if it does not > + exist or if it corresponds to an inline clone, create a new one. */ > + static inline symtab_node * get_create (tree node); > + > /* Return the cgraph node that has ASMNAME for its DECL_ASSEMBLER_NAME. > Return NULL if there's no such node. */ > static symtab_node *get_for_asmname (const_tree asmname); > @@ -394,7 +398,9 @@ public: > unsigned analyzed : 1; > /* Set for write-only variables. */ > unsigned writeonly : 1; > - > + /* Visibility of symbol was used for further optimization; do not > + permit further changes. */ > + unsigned refuse_visibility_changes : 1; > > /*** Visibility and linkage flags. ***/ > > @@ -2519,4 +2525,12 @@ cgraph_node::mark_force_output (void) > gcc_checking_assert (!global.inlined_to); > } > > +inline symtab_node * symtab_node::get_create (tree node) > +{ > + if (TREE_CODE (node) == VAR_DECL) > + return varpool_node::get_create (node); > + else > + return cgraph_node::get_create (node); > +} > + > #endif /* GCC_CGRAPH_H */ > Index: fold-const.c > =================================================================== > --- fold-const.c (revision 215401) > +++ fold-const.c (working copy) > @@ -15850,7 +15850,7 @@ tree_single_nonzero_warnv_p (tree t, boo > { > struct symtab_node *symbol; > > - symbol = symtab_node::get (base); > + symbol = symtab_node::get_create (base); > if (symbol) > return symbol->nonzero_address (); > else > Index: testsuite/gcc.dg/tree-ssa/nonzero-1.c > =================================================================== > --- testsuite/gcc.dg/tree-ssa/nonzero-1.c (revision 215401) > +++ testsuite/gcc.dg/tree-ssa/nonzero-1.c (working copy) > @@ -1,11 +1,8 @@ > /* { dg-do compile } */ > -/* { dg-options "-O2 -fdump-tree-optimized" } */ > -extern int a; > +/* { dg-options "-O2" } */ > +extern int a; /* { dg-error "declared weak after being used" } */ > t() > { > return &a!=0; > } > extern int a __attribute__ ((weak)); > - > -/* { dg-final { scan-tree-dump-not "return 1" "optimized"} } */ > -/* { dg-final { cleanup-tree-dump "optimized" } } */ > Index: varasm.c > =================================================================== > --- varasm.c (revision 215401) > +++ varasm.c (working copy) > @@ -5230,6 +5230,12 @@ output_constructor (tree exp, unsigned H > static void > mark_weak (tree decl) > { > + if (DECL_WEAK (decl)) > + return; > + > + struct symtab_node *n = symtab_node::get (decl); > + if (n && n->refuse_visibility_changes) > + error ("%+D declared weak after being used", decl); > DECL_WEAK (decl) = 1; > > if (DECL_RTL_SET_P (decl) > Index: symtab.c > =================================================================== > --- symtab.c (revision 215401) > +++ symtab.c (working copy) > @@ -1811,9 +1811,9 @@ bool > symtab_node::nonzero_address () > { > /* Weakrefs may be NULL when their target is not defined. */ > - if (this->alias && this->weakref) > + if (alias && weakref) > { > - if (this->analyzed) > + if (analyzed) > { > symtab_node *target = ultimate_alias_target (); > > @@ -1828,7 +1828,7 @@ symtab_node::nonzero_address () > could be useful to eliminate the NULL pointer checks in LTO > programs. */ > if (target->definition && !DECL_EXTERNAL (target->decl)) > - return true; > + return true; > if (target->resolution != LDPR_UNKNOWN > && target->resolution != LDPR_UNDEF > && flag_delete_null_pointer_checks) > @@ -1847,22 +1847,28 @@ symtab_node::nonzero_address () > Those are handled by later check for definition. > > When parsing, beware the cases when WEAK attribute is added later. */ > - if (!DECL_WEAK (this->decl) > - && flag_delete_null_pointer_checks > - && symtab->state > PARSING) > - return true; > + if (!DECL_WEAK (decl) > + && flag_delete_null_pointer_checks) > + { > + refuse_visibility_changes = true; > + return true; > + } > > /* If target is defined and not extern, we know it will be output and thus > it will bind to non-NULL. > Play safe for flag_delete_null_pointer_checks where weak definition maye > be re-defined by NULL. */ > - if (this->definition && !DECL_EXTERNAL (this->decl) > - && (flag_delete_null_pointer_checks || !DECL_WEAK (this->decl))) > - return true; > + if (definition && !DECL_EXTERNAL (decl) > + && (flag_delete_null_pointer_checks || !DECL_WEAK (decl))) > + { > + if (!DECL_WEAK (decl)) > + refuse_visibility_changes = true; > + return true; > + } > > /* As the last resort, check the resolution info. */ > - if (this->resolution != LDPR_UNKNOWN > - && this->resolution != LDPR_UNDEF > + if (resolution != LDPR_UNKNOWN > + && resolution != LDPR_UNDEF > && flag_delete_null_pointer_checks) > return true; > return false; Grüße, Thomas
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