From ce1b9eb9a852571412356565544ca1f7207199e1 Mon Sep 17 00:00:00 2001 From: Mark Mitchell Date: Wed, 20 May 1998 11:03:18 +0000 Subject: [PATCH] decl2.c (find_representative_member): New function. * decl2.c (find_representative_member): New function. (finish_anon_union): Use it. From-SVN: r19910 --- gcc/cp/ChangeLog | 3 + gcc/cp/decl2.c | 68 +++++++++++++++----- gcc/testsuite/g++.old-deja/g++.other/anon1.C | 6 ++ 3 files changed, 60 insertions(+), 17 deletions(-) create mode 100644 gcc/testsuite/g++.old-deja/g++.other/anon1.C diff --git a/gcc/cp/ChangeLog b/gcc/cp/ChangeLog index 153aedc220b..ef645d15d18 100644 --- a/gcc/cp/ChangeLog +++ b/gcc/cp/ChangeLog @@ -1,5 +1,8 @@ 1998-05-20 Mark Mitchell + * decl2.c (find_representative_member): New function. + (finish_anon_union): Use it. + * cp-tree.h (MAIN_NAME_P): New macro. (DECL_MAIN_P): Likwise. * decl.c (pushdecl): Avoid crashing on redefinitions of `main'. diff --git a/gcc/cp/decl2.c b/gcc/cp/decl2.c index 57e3def6d9d..63b90d72c31 100644 --- a/gcc/cp/decl2.c +++ b/gcc/cp/decl2.c @@ -52,6 +52,7 @@ static int is_namespace_ancestor PROTO((tree, tree)); static tree namespace_ancestor PROTO((tree, tree)); static void add_using_namespace PROTO((tree, tree, int)); static tree ambiguous_decl PROTO((tree, tree, tree)); +static tree find_representative_member PROTO((tree)); extern int current_class_depth; @@ -2144,6 +2145,43 @@ get_temp_regvar (type, init) return decl; } +/* Hunt through ANON_DECL, which declares an anonymous union, for a named + member of the same size as ANON_DECL. */ + +tree +find_representative_member (anon_decl) + tree anon_decl; +{ + tree field; + tree main_decl = NULL_TREE; + + for (field = TYPE_FIELDS (TREE_TYPE (anon_decl)); + field != NULL_TREE; + field = TREE_CHAIN (field)) + { + if (TREE_CODE (field) != FIELD_DECL) + continue; + + /* Only write out one anon union element--choose the one that + can hold them all. */ + if (main_decl == NULL_TREE + && 1 == simple_cst_equal (DECL_SIZE (field), + DECL_SIZE (anon_decl))) + { + if (DECL_NAME (field)) + main_decl = field; + else if (TREE_CODE (TREE_TYPE (field)) == UNION_TYPE) + main_decl = find_representative_member (field); + } + else + /* ??? This causes there to be no debug info written out + about this decl. */ + TREE_ASM_WRITTEN (field) = 1; + } + + return main_decl; +} + /* Finish off the processing of a UNION_TYPE structure. If there are static members, then all members are static, and must be laid out together. If the @@ -2156,13 +2194,13 @@ finish_anon_union (anon_union_decl) tree anon_union_decl; { tree type = TREE_TYPE (anon_union_decl); - tree field, main_decl = NULL_TREE; + tree field = TYPE_FIELDS (type); tree elems = NULL_TREE; int public_p = TREE_PUBLIC (anon_union_decl); int static_p = TREE_STATIC (anon_union_decl); int external_p = DECL_EXTERNAL (anon_union_decl); - if ((field = TYPE_FIELDS (type)) == NULL_TREE) + if (field == NULL_TREE) return; if (public_p) @@ -2182,6 +2220,14 @@ finish_anon_union (anon_union_decl) else if (TREE_PROTECTED (field)) cp_pedwarn_at ("protected member `%#D' in anonymous union", field); + if (DECL_NAME (field) == NULL_TREE + && TREE_CODE (TREE_TYPE (field)) == UNION_TYPE + && find_representative_member (field) == NULL_TREE) + /* The member is an empty anonymous union. Don't make a + declaration for it, as finish_file will otherwise try to + call make_decl_rtl for it, and crash. */ + continue; + decl = build_decl (VAR_DECL, DECL_NAME (field), TREE_TYPE (field)); /* tell `pushdecl' that this is not tentative. */ DECL_INITIAL (decl) = error_mark_node; @@ -2190,29 +2236,17 @@ finish_anon_union (anon_union_decl) DECL_EXTERNAL (decl) = external_p; decl = pushdecl (decl); - /* Only write out one anon union element--choose the one that - can hold them all. */ - if (main_decl == NULL_TREE - && 1 == simple_cst_equal (DECL_SIZE (decl), - DECL_SIZE (anon_union_decl))) - { - main_decl = decl; - } - else - { - /* ??? This causes there to be no debug info written out - about this decl. */ - TREE_ASM_WRITTEN (decl) = 1; - } - DECL_INITIAL (decl) = NULL_TREE; /* If there's a cleanup to do, it belongs in the TREE_PURPOSE of the following TREE_LIST. */ elems = scratch_tree_cons (NULL_TREE, decl, elems); TREE_TYPE (elems) = type; } + if (static_p) { + tree main_decl = find_representative_member (anon_union_decl); + if (main_decl) { make_decl_rtl (main_decl, 0, toplevel_bindings_p ()); diff --git a/gcc/testsuite/g++.old-deja/g++.other/anon1.C b/gcc/testsuite/g++.old-deja/g++.other/anon1.C new file mode 100644 index 00000000000..87948481d2b --- /dev/null +++ b/gcc/testsuite/g++.old-deja/g++.other/anon1.C @@ -0,0 +1,6 @@ +// Build don't link: + +static union { + union { + }; +}; // ERROR - anonymous union with no members -- 2.30.2