From db465e443f3cd5ef3ba52304ab8b5dc6e0d7e620 Mon Sep 17 00:00:00 2001 From: Jani Nikula Date: Sun, 18 Aug 2013 00:30:01 +0300 Subject: [PATCH] lib: fix clang build Long story short, fix build on recent (3.2+) clang. The long story for posterity follows. gcc 4.6 added new warnings about structs with greater visibility than their fields. The warnings were silenced by adjusting visibility in commit d5523ead90b6be2b07d4af745b8ed9b980a6b9f1 Author: Carl Worth Date: Wed May 11 13:23:13 2011 -0700 Mark some structures in the library interface with visibility=default attribute. Later on, commit 3b76adf9e2c026dd03b820f4c6eab50e25444113 Author: Austin Clements Date: Sat Jan 14 19:17:33 2012 -0500 lib: Add support for automatically excluding tags from queries changed visibility of struct _notmuch_string_list for the same reason, and commit 1a53f9f116fa7c460cda3df532be921baaafb082 Author: Mark Walters Date: Thu Mar 1 22:30:38 2012 +0000 lib: Add the exclude flag to notmuch_query_search_threads split the struct _notmuch_string_list and its typedef notmuch_string_list_t as a way to make a forward declaration for _notmuch_thread_create(). The subtle difference was that the struct definition now had 'visible' in it, while the typedef didn't, and it was within the #pragma GCC visibility push(hidden) block. This went unnoticed, as the then common versions of clang didn't care about this. A later change in clang (I did not dig into when this change was introduced) caused the following error: CXX -O2 lib/database.o In file included from lib/database.cc:21: In file included from ./lib/database-private.h:33: ./lib/notmuch-private.h:479:8: error: visibility does not match previous declaration struct visible _notmuch_string_list { ^ ./lib/notmuch-private.h:67:33: note: expanded from macro 'visible' ^ ./lib/notmuch-private.h:52:13: note: previous attribute is here ^ 1 error generated. make: *** [lib/database.o] Error 1 This is slightly misleading due to the reference to the #pragma. The real culprit is the typedef within the #pragma. We could just add 'visible' to the typedef, or move the typedef outside of the #pragma, and be done with it, but juggle the declarations a bit to accommodate moving the typedef back with the struct, and keep the visibility attribute in one place. The problem was originally reported by Simonas Kazlauskas in id:20130418102507.GA23688@godbox but I was only able to reproduce and investigate now that I upgraded clang. --- lib/notmuch-private.h | 28 +++++++++++++--------------- 1 file changed, 13 insertions(+), 15 deletions(-) diff --git a/lib/notmuch-private.h b/lib/notmuch-private.h index eced03e8..af185c7c 100644 --- a/lib/notmuch-private.h +++ b/lib/notmuch-private.h @@ -162,8 +162,6 @@ typedef enum _notmuch_find_flags { typedef struct _notmuch_doc_id_set notmuch_doc_id_set_t; -typedef struct _notmuch_string_list notmuch_string_list_t; - /* database.cc */ /* Lookup a prefix value by name. @@ -228,17 +226,6 @@ _notmuch_directory_create (notmuch_database_t *notmuch, unsigned int _notmuch_directory_get_document_id (notmuch_directory_t *directory); -/* thread.cc */ - -notmuch_thread_t * -_notmuch_thread_create (void *ctx, - notmuch_database_t *notmuch, - unsigned int seed_doc_id, - notmuch_doc_id_set_t *match_set, - notmuch_string_list_t *excluded_terms, - notmuch_exclude_t omit_exclude, - notmuch_sort_t sort); - /* message.cc */ notmuch_message_t * @@ -476,11 +463,11 @@ typedef struct _notmuch_string_node { struct _notmuch_string_node *next; } notmuch_string_node_t; -struct visible _notmuch_string_list { +typedef struct visible _notmuch_string_list { int length; notmuch_string_node_t *head; notmuch_string_node_t **tail; -}; +} notmuch_string_list_t; notmuch_string_list_t * _notmuch_string_list_create (const void *ctx); @@ -509,6 +496,17 @@ notmuch_filenames_t * _notmuch_filenames_create (const void *ctx, notmuch_string_list_t *list); +/* thread.cc */ + +notmuch_thread_t * +_notmuch_thread_create (void *ctx, + notmuch_database_t *notmuch, + unsigned int seed_doc_id, + notmuch_doc_id_set_t *match_set, + notmuch_string_list_t *excluded_terms, + notmuch_exclude_t omit_exclude, + notmuch_sort_t sort); + NOTMUCH_END_DECLS #ifdef __cplusplus -- 2.43.0