From c08d28acf853c3af2651c989acd034d5d6d3f8a4 Mon Sep 17 00:00:00 2001 From: Nathan Sidwell Date: Tue, 5 Apr 2016 23:47:21 +0000 Subject: [PATCH] re PR c++/70512 (ICE on valid code on x86_64-linux-gnu: canonical types differ for identical types) PR c++/70512 * class.c (fixup_may_alias): New. (fixup_attribute_variants): Call it. * g++.dg/ext/attribute-may-alias-5.C: New. From-SVN: r234768 --- gcc/cp/ChangeLog | 6 ++++++ gcc/cp/class.c | 21 +++++++++++++++++++++ gcc/testsuite/ChangeLog | 5 +++++ gcc/testsuite/g++.dg/ext/attribute-may-alias-5.C | 9 +++++++++ 4 files changed, 41 insertions(+) create mode 100644 gcc/testsuite/g++.dg/ext/attribute-may-alias-5.C diff --git a/gcc/cp/ChangeLog b/gcc/cp/ChangeLog index 77c0b5b20..3831b92 100644 --- a/gcc/cp/ChangeLog +++ b/gcc/cp/ChangeLog @@ -1,3 +1,9 @@ +2016-04-05 Nathan Sidwell + + PR c++/70512 + * class.c (fixup_may_alias): New. + (fixup_attribute_variants): Call it. + 2016-04-05 Patrick Palka PR c++/70452 diff --git a/gcc/cp/class.c b/gcc/cp/class.c index 98cbab5..ade2001 100644 --- a/gcc/cp/class.c +++ b/gcc/cp/class.c @@ -1978,6 +1978,21 @@ fixup_type_variants (tree t) } } +/* KLASS is a class that we're applying may_alias to after the body is + parsed. Fixup any POINTER_TO and REFERENCE_TO types. The + canonical type(s) will be implicitly updated. */ + +static void +fixup_may_alias (tree klass) +{ + tree t; + + for (t = TYPE_POINTER_TO (klass); t; t = TYPE_NEXT_PTR_TO (t)) + TYPE_REF_CAN_ALIAS_ALL (t) = true; + for (t = TYPE_REFERENCE_TO (klass); t; t = TYPE_NEXT_REF_TO (t)) + TYPE_REF_CAN_ALIAS_ALL (t) = true; +} + /* Early variant fixups: we apply attributes at the beginning of the class definition, and we need to fix up any variants that have already been made via elaborated-type-specifier so that check_qualified_type works. */ @@ -1993,6 +2008,10 @@ fixup_attribute_variants (tree t) tree attrs = TYPE_ATTRIBUTES (t); unsigned align = TYPE_ALIGN (t); bool user_align = TYPE_USER_ALIGN (t); + bool may_alias = lookup_attribute ("may_alias", attrs); + + if (may_alias) + fixup_may_alias (t); for (variants = TYPE_NEXT_VARIANT (t); variants; @@ -2007,6 +2026,8 @@ fixup_attribute_variants (tree t) else TYPE_USER_ALIGN (variants) = user_align; TYPE_ALIGN (variants) = valign; + if (may_alias) + fixup_may_alias (variants); } } diff --git a/gcc/testsuite/ChangeLog b/gcc/testsuite/ChangeLog index e0ef05b..2e5954c 100644 --- a/gcc/testsuite/ChangeLog +++ b/gcc/testsuite/ChangeLog @@ -1,3 +1,8 @@ +2016-04-05 Nathan Sidwell + + PR c++/70512 + * g++.dg/ext/attribute-may-alias-5.C: New. + 2016-04-05 Jakub Jelinek PR c++/70336 diff --git a/gcc/testsuite/g++.dg/ext/attribute-may-alias-5.C b/gcc/testsuite/g++.dg/ext/attribute-may-alias-5.C new file mode 100644 index 0000000..198e2ba --- /dev/null +++ b/gcc/testsuite/g++.dg/ext/attribute-may-alias-5.C @@ -0,0 +1,9 @@ +// PR c++/70512 + +struct S +{ + S& operator= (int) + { + return *this; + } +} __attribute__ ((__may_alias__)); -- 2.7.4