From a3bf6ce7f2e17f2c977c13df23eb718e7b433dcd Mon Sep 17 00:00:00 2001 From: Patrick Palka Date: Tue, 30 Mar 2021 22:57:11 -0400 Subject: c++: Adjust mangling of __alignof__ [PR88115] r11-4926 made __alignof__ get mangled differently from alignof, encoding __alignof__ as a vendor extended operator. But this mangling is problematic for the reasons mentioned in https://gcc.gnu.org/bugzilla/show_bug.cgi?id=88115#c6. This patch changes our mangling of __alignof__ to instead use the new "vendor extended expression" syntax that's proposed in https://github.com/itanium-cxx-abi/cxx-abi/issues/112. Clang does the same thing already, so after this patch Clang and GCC agree about the mangling of __alignof__(type) and __alignof__(expr). gcc/cp/ChangeLog: PR c++/88115 * mangle.c (write_expression): Adjust the mangling of __alignof__. include/ChangeLog: PR c++/88115 * demangle.h (enum demangle_component_type): Add DEMANGLE_COMPONENT_VENDOR_EXPR. libiberty/ChangeLog: PR c++/88115 * cp-demangle.c (d_dump, d_make_comp, d_expression_1) (d_count_templates_scopes): Handle DEMANGLE_COMPONENT_VENDOR_EXPR. (d_print_comp_inner): Likewise. : Revert r11-4926 change. : Likewise. * testsuite/demangle-expected: Adjust __alignof__ tests. gcc/testsuite/ChangeLog: PR c++/88115 * g++.dg/cpp0x/alignof7.C: Adjust expected mangling. --- include/demangle.h | 3 +++ 1 file changed, 3 insertions(+) (limited to 'include') diff --git a/include/demangle.h b/include/demangle.h index 23b4726..295d58c 100644 --- a/include/demangle.h +++ b/include/demangle.h @@ -408,6 +408,9 @@ enum demangle_component_type number which involves neither modifying the mangled string nor allocating a new copy of the literal in memory. */ DEMANGLE_COMPONENT_LITERAL_NEG, + /* A vendor's builtin expression. The left subtree holds the + expression's name, and the right subtree is a argument list. */ + DEMANGLE_COMPONENT_VENDOR_EXPR, /* A libgcj compiled resource. The left subtree is the name of the resource. */ DEMANGLE_COMPONENT_JAVA_RESOURCE, -- cgit v1.1