From 235f734d821eb0b079d551de729b56cb97800676 Mon Sep 17 00:00:00 2001 From: Mark Mitchell Date: Fri, 16 Apr 1999 00:15:26 +0000 Subject: [PATCH] decl.c (warn_about_implicit_typename_lookup): New function. * decl.c (warn_about_implicit_typename_lookup): New function. (lookup_name_real): Use it. Rework handling of implicit typename extension. From-SVN: r26487 --- gcc/cp/ChangeLog | 6 + gcc/cp/decl.c | 109 ++++++++++-------- .../g++.old-deja/g++.pt/typename18.C | 21 ++++ .../g++.old-deja/g++.pt/typename19.C | 26 +++++ 4 files changed, 113 insertions(+), 49 deletions(-) create mode 100644 gcc/testsuite/g++.old-deja/g++.pt/typename18.C create mode 100644 gcc/testsuite/g++.old-deja/g++.pt/typename19.C diff --git a/gcc/cp/ChangeLog b/gcc/cp/ChangeLog index cdcb7b57457..8f6159813ee 100644 --- a/gcc/cp/ChangeLog +++ b/gcc/cp/ChangeLog @@ -1,3 +1,9 @@ +1999-04-16 Mark Mitchell + + * decl.c (warn_about_implicit_typename_lookup): New function. + (lookup_name_real): Use it. Rework handling of implicit typename + extension. + 1999-04-15 Mark Mitchell * cp-tree.h (lookup_nested_field): Remove. diff --git a/gcc/cp/decl.c b/gcc/cp/decl.c index 163c3d75ef7..fe30586454d 100644 --- a/gcc/cp/decl.c +++ b/gcc/cp/decl.c @@ -192,6 +192,7 @@ static const char *tag_name PROTO((enum tag_types code)); static void find_class_binding_level PROTO((void)); static struct binding_level *innermost_nonclass_level PROTO((void)); static tree poplevel_class PROTO((void)); +static void warn_about_implicit_typename_lookup PROTO((tree, tree)); #if defined (DEBUG_CP_BINDING_LEVELS) static void indent PROTO((void)); @@ -5526,6 +5527,32 @@ qualify_lookup (val, flags) return val; } +/* Any other BINDING overrides an implicit TYPENAME. Warn about + that. */ + +static void +warn_about_implicit_typename_lookup (typename, binding) + tree typename; + tree binding; +{ + tree subtype = TREE_TYPE (TREE_TYPE (typename)); + tree name = DECL_NAME (typename); + + if (! (TREE_CODE (binding) == TEMPLATE_DECL + && CLASSTYPE_TEMPLATE_INFO (subtype) + && CLASSTYPE_TI_TEMPLATE (subtype) == binding) + && ! (TREE_CODE (binding) == TYPE_DECL + && same_type_p (TREE_TYPE (binding), subtype))) + { + cp_warning ("lookup of `%D' finds `%#D'", + name, binding); + cp_warning (" instead of `%D' from dependent base class", + typename); + cp_warning (" (use `typename %T::%D' if that's what you meant)", + constructor_name (current_class_type), name); + } +} + /* Look up NAME in the current binding level and its superiors in the namespace of variables, functions and typedefs. Return a ..._DECL node of some kind representing its definition if there is only one @@ -5545,10 +5572,12 @@ lookup_name_real (name, prefer_type, nonclass, namespaces_only) tree name; int prefer_type, nonclass, namespaces_only; { - register tree val; + tree t; + tree val = NULL_TREE; int yylex = 0; tree from_obj = NULL_TREE; int flags; + int val_is_implicit_typename = 0; /* Hack: copy flag set by parser, if set. */ if (only_namespace_names) @@ -5623,67 +5652,49 @@ lookup_name_real (name, prefer_type, nonclass, namespaces_only) } /* First, look in non-namespace scopes. */ - for (val = IDENTIFIER_BINDING (name); val; val = TREE_CHAIN (val)) + for (t = IDENTIFIER_BINDING (name); t; t = TREE_CHAIN (t)) { - if (!LOCAL_BINDING_P (val) && nonclass) + tree binding; + + if (!LOCAL_BINDING_P (t) && nonclass) /* We're not looking for class-scoped bindings, so keep going. */ continue; /* If this is the kind of thing we're looking for, we're done. */ - if (qualify_lookup (BINDING_VALUE (val), flags)) - { - val = BINDING_VALUE (val); - break; - } + if (qualify_lookup (BINDING_VALUE (t), flags)) + binding = BINDING_VALUE (t); else if ((flags & LOOKUP_PREFER_TYPES) - && qualify_lookup (BINDING_TYPE (val), flags)) - { - val = BINDING_TYPE (val); - break; + && qualify_lookup (BINDING_TYPE (t), flags)) + binding = BINDING_TYPE (t); + else + binding = NULL_TREE; + + if (binding + && (!val || !(TREE_CODE (binding) == TYPE_DECL + && IMPLICIT_TYPENAME_P (TREE_TYPE (binding))))) + { + if (val_is_implicit_typename && !yylex) + warn_about_implicit_typename_lookup (val, binding); + val = binding; + val_is_implicit_typename + = (TREE_CODE (val) == TYPE_DECL + && IMPLICIT_TYPENAME_P (TREE_TYPE (val))); + if (!val_is_implicit_typename) + break; } } - /* If we found a type from a dependent base class (using the - implicit typename extension) make sure that there's not some - global name which should be chosen instead. */ - if (val && TREE_CODE (val) == TYPE_DECL - && IMPLICIT_TYPENAME_P (TREE_TYPE (val))) + /* Now lookup in namespace scopes. */ + if (!val || val_is_implicit_typename) { - tree global_val; - - /* Any other name takes precedence over an implicit typename. Warn the - user about this potentially confusing lookup. */ - global_val = unqualified_namespace_lookup (name, flags); - - if (global_val) + t = unqualified_namespace_lookup (name, flags); + if (t) { - tree subtype; - - /* Only warn when not lexing; we don't want to warn if they - use this name as a declarator. */ - subtype = TREE_TYPE (TREE_TYPE (val)); - if (! yylex - && ! (TREE_CODE (global_val) == TEMPLATE_DECL - && CLASSTYPE_TEMPLATE_INFO (subtype) - && CLASSTYPE_TI_TEMPLATE (subtype) == global_val) - && ! (TREE_CODE (global_val) == TYPE_DECL - && same_type_p (TREE_TYPE (global_val), subtype))) - { - cp_warning ("lookup of `%D' finds `%#D'", name, global_val); - cp_warning (" instead of `%D' from dependent base class", - val); - cp_warning (" (use `typename %T::%D' if that's what you meant)", - constructor_name (current_class_type), name); - } - - /* Use the global value instead of the implicit typename. */ - val = global_val; + if (val_is_implicit_typename && !yylex) + warn_about_implicit_typename_lookup (val, t); + val = t; } } - else if (!val) - /* No local, or class-scoped binding. Look for a namespace-scope - declaration. */ - val = unqualified_namespace_lookup (name, flags); done: if (val) diff --git a/gcc/testsuite/g++.old-deja/g++.pt/typename18.C b/gcc/testsuite/g++.old-deja/g++.pt/typename18.C new file mode 100644 index 00000000000..ed423e77bec --- /dev/null +++ b/gcc/testsuite/g++.old-deja/g++.pt/typename18.C @@ -0,0 +1,21 @@ +// Build don't link: +// Special g++ Options: +// Origin: Mark Mitchell + +void X(); + +template +struct J { + typedef T X; +}; + +template +struct S { + typedef T X; + + struct I : public J { + static X* f(); + }; +}; + +S si; diff --git a/gcc/testsuite/g++.old-deja/g++.pt/typename19.C b/gcc/testsuite/g++.old-deja/g++.pt/typename19.C new file mode 100644 index 00000000000..be93a983267 --- /dev/null +++ b/gcc/testsuite/g++.old-deja/g++.pt/typename19.C @@ -0,0 +1,26 @@ +// Special g++ Options: +// Origin: Mark Mitchell + +template +struct O { + typedef char X; +}; + +template +struct S { + typedef double X; + + template + struct I : public O { + static X x; // WARNING - lookup finds S::X + }; +}; + +template +template +typename S::X S::I::x; + +int main() +{ + return sizeof (S::I::x) == 1; +} -- 2.30.2