From cf6e58d63c9876f1ab4d3417fc0d6865ef351c19 Mon Sep 17 00:00:00 2001 From: Nick Wellnhofer Date: Tue, 5 Dec 2023 20:40:20 +0100 Subject: [PATCH] build: Disable compiler TLS by default The global struct is quite large (~700 bytes on 64-bit systems which will be allocated for each thread whether it uses libxml2 or not) and already close to the total size limit on some platforms. Disable compiler TLS by default. --- CMakeLists.txt | 47 +++++++++++++++++++++++++---------------------- configure.ac | 2 +- 2 files changed, 26 insertions(+), 23 deletions(-) diff --git a/CMakeLists.txt b/CMakeLists.txt index cc733c1f..53742945 100644 --- a/CMakeLists.txt +++ b/CMakeLists.txt @@ -52,6 +52,7 @@ option(LIBXML2_WITH_SCHEMATRON "Add Schematron support" ON) option(LIBXML2_WITH_TESTS "Build tests" ON) option(LIBXML2_WITH_THREADS "Add multithread support" ON) option(LIBXML2_WITH_THREAD_ALLOC "Add per-thread memory" OFF) +option(LIBXML2_WITH_TLS "Enable thread-local storage" OFF) option(LIBXML2_WITH_TREE "Add the DOM like tree manipulation APIs" ON) set(LIBXML2_WITH_UNICODE ON) option(LIBXML2_WITH_VALID "Add the DTD validation support" ON) @@ -182,28 +183,30 @@ if (NOT MSVC) endif() endif() -check_c_source_compiles( - "_Thread_local int v; int main(){return 0;}" - XML_THREAD_LOCAL_C11 -) -if (XML_THREAD_LOCAL_C11) - set(XML_THREAD_LOCAL "_Thread_local") -else() - check_c_source_compiles( - "__thread int v; int main(){return 0;}" - XML_THREAD_LOCAL_THREAD - ) - if (XML_THREAD_LOCAL_THREAD) - set(XML_THREAD_LOCAL "__thread") - else() - check_c_source_compiles( - "__declspec(thread) int v; int main(){return 0;}" - XML_THREAD_LOCAL_DECLSPEC - ) - if (XML_THREAD_LOCAL_DECLSPEC) - set(XML_THREAD_LOCAL "__declspec(thread)") - endif() - endif() +if(LIBXML2_WITH_TLS) + check_c_source_compiles( + "_Thread_local int v; int main(){return 0;}" + XML_THREAD_LOCAL_C11 + ) + if (XML_THREAD_LOCAL_C11) + set(XML_THREAD_LOCAL "_Thread_local") + else() + check_c_source_compiles( + "__thread int v; int main(){return 0;}" + XML_THREAD_LOCAL_THREAD + ) + if (XML_THREAD_LOCAL_THREAD) + set(XML_THREAD_LOCAL "__thread") + else() + check_c_source_compiles( + "__declspec(thread) int v; int main(){return 0;}" + XML_THREAD_LOCAL_DECLSPEC + ) + if (XML_THREAD_LOCAL_DECLSPEC) + set(XML_THREAD_LOCAL "__declspec(thread)") + endif() + endif() + endif() endif() set( diff --git a/configure.ac b/configure.ac index f495d02e..906856b7 100644 --- a/configure.ac +++ b/configure.ac @@ -408,7 +408,7 @@ XML_INCLUDEDIR='-I${includedir}/libxml2' XML_CFLAGS="" dnl Thread-local storage -if test "$with_tls" != "no"; then +if test "$with_tls" = "yes"; then AC_COMPILE_IFELSE([ AC_LANG_SOURCE([_Thread_local int v;]) ], [ AC_DEFINE([XML_THREAD_LOCAL], [_Thread_local], [TLS specifier]) ], [