{"id":2221614,"url":"http://patchwork.ozlabs.org/api/1.1/patches/2221614/?format=json","web_url":"http://patchwork.ozlabs.org/project/gcc/patch/20260409235842.842438-1-sloosemore@baylibre.com/","project":{"id":17,"url":"http://patchwork.ozlabs.org/api/1.1/projects/17/?format=json","name":"GNU Compiler Collection","link_name":"gcc","list_id":"gcc-patches.gcc.gnu.org","list_email":"gcc-patches@gcc.gnu.org","web_url":null,"scm_url":null,"webscm_url":null},"msgid":"<20260409235842.842438-1-sloosemore@baylibre.com>","date":"2026-04-09T23:58:42","name":"[PUSHED] doc, c++: Document that anonymous namespaces have internal linkage [PR124773]","commit_ref":null,"pull_url":null,"state":"new","archived":false,"hash":"c5172bb7b020bb3513179ac084d0a38cfdb42fbf","submitter":{"id":87955,"url":"http://patchwork.ozlabs.org/api/1.1/people/87955/?format=json","name":"Sandra Loosemore","email":"sloosemore@baylibre.com"},"delegate":null,"mbox":"http://patchwork.ozlabs.org/project/gcc/patch/20260409235842.842438-1-sloosemore@baylibre.com/mbox/","series":[{"id":499371,"url":"http://patchwork.ozlabs.org/api/1.1/series/499371/?format=json","web_url":"http://patchwork.ozlabs.org/project/gcc/list/?series=499371","date":"2026-04-09T23:58:42","name":"[PUSHED] doc, c++: Document that anonymous namespaces have internal linkage [PR124773]","version":1,"mbox":"http://patchwork.ozlabs.org/series/499371/mbox/"}],"comments":"http://patchwork.ozlabs.org/api/patches/2221614/comments/","check":"pending","checks":"http://patchwork.ozlabs.org/api/patches/2221614/checks/","tags":{},"headers":{"Return-Path":"","X-Original-To":["incoming@patchwork.ozlabs.org","gcc-patches@gcc.gnu.org"],"Delivered-To":["patchwork-incoming@legolas.ozlabs.org","gcc-patches@gcc.gnu.org"],"Authentication-Results":["legolas.ozlabs.org;\n\tdkim=pass (2048-bit key;\n unprotected) header.d=baylibre-com.20251104.gappssmtp.com\n header.i=@baylibre-com.20251104.gappssmtp.com header.a=rsa-sha256\n header.s=20251104 header.b=Ct7I16on;\n\tdkim-atps=neutral","legolas.ozlabs.org;\n spf=pass (sender SPF authorized) smtp.mailfrom=gcc.gnu.org\n (client-ip=2620:52:6:3111::32; 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With such an\n operator, the application can define whether and how the virtual base\n subobject is assigned.\n \n+@node Linkage in Anonymous Namespaces\n+@subsection Linkage in Anonymous Namespaces\n+\n+The C++11 standard changed the linkage of anonymous namespaces from\n+external (using a unique generated name) to internal. That means that\n+names declared in such a namespace now also have internal linkage, and\n+@code{extern \"C\"} has no effect. GCC implemented this change in\n+behavior starting with the GCC 15 release; code using this idiom that\n+worked in earlier versions of GCC, or with @option{-std=} options\n+prior to C++11, may encounter unexpected linker issues due to changes\n+in name mangling.\n+\n+For more information about the change to the C++ standard, see\n+@uref{https://cplusplus.github.io/CWG/issues/2772.html}.\n+\n @node Non-bugs\n @section Certain Changes We Don't Want to Make\n \n","prefixes":["PUSHED"]}