Cut down on -pthread/-lpthread proliferation

Building against libstdc++ effectively always requires -pthread anyway (as
various standard C++ headers require it, see the comment added to
solenv/gbuild/platform/unxgcc.mk), so many explicit uses of -pthread/-lpthread
can be removed.

Doing a (partial) test build on Linux with Clang -stdlib=libc++ suggests that
libc++ indeed doesn't need -pthread as libstdc++ does.

The remaining uses of -pthread/-lpthread are mostly in configure.ac for the
various BSDs (which somebody else might want to clean up now), and related to
external projects.  I tried to be careful to remove -pthread/-lpthread from
makefiles only when C++ object files are involved (so -pthread will now be
included on the link command line by default).

Change-Id: I936e082839cb9a434bd273ce5a1f187a4245dfa1
Reviewed-on: https://gerrit.libreoffice.org/71291
Tested-by: Jenkins
Reviewed-by: Stephan Bergmann <sbergman@redhat.com>

38 files changed, 11 insertions, 65 deletions

diff --git a/canvas/Executable_canvasdemo.mk b/canvas/Executable_canvasdemo.mk
index a86a4a717510..8af599ff1760 100644
--- a/canvas/Executable_canvasdemo.mk
+++ b/canvas/Executable_canvasdemo.mk
@@ -45,7 +45,6 @@ $(eval $(call gb_Executable_use_static_libraries,canvasdemo,\
 ifeq ($(OS), $(filter LINUX %BSD SOLARIS, $(OS)))
 $(eval $(call gb_Executable_add_libs,canvasdemo,\
     -lm $(DLOPEN_LIBS) \
-    -lpthread \
     -lX11 \
 ))
 
diff --git a/connectivity/Library_mysqlc.mk b/connectivity/Library_mysqlc.mk
index 455f9b2224df..0999b46d3eec 100644
--- a/connectivity/Library_mysqlc.mk
+++ b/connectivity/Library_mysqlc.mk
@@ -24,7 +24,7 @@ $(eval $(call gb_Library_set_include,mysqlc,\
 $(eval $(call gb_Library_add_libs,mysqlc,\
 	$(if $(filter-out WNT,$(OS)),$(if $(filter HAIKU MACOSX SOLARIS,$(OS)),\
 	-lz -lm,-rdynamic -lz -lcrypt -lm)) \
-	$(if $(filter LINUX,$(OS)),-lpthread -ldl,) \
+	$(if $(filter LINUX,$(OS)),-ldl,) \
 ))
 
 $(eval $(call gb_Library_use_sdk_api,mysqlc))
diff --git a/connectivity/Library_postgresql-sdbc-impl.mk b/connectivity/Library_postgresql-sdbc-impl.mk
index 3d048f39c49c..6927bbe457e2 100644
--- a/connectivity/Library_postgresql-sdbc-impl.mk
+++ b/connectivity/Library_postgresql-sdbc-impl.mk
@@ -61,7 +61,6 @@ $(eval $(call gb_Library_add_libs,postgresql-sdbc-impl,\
 	$(if $(WITH_GSSAPI),$(GSSAPI_LIBS)) \
 	$(if $(WITH_KRB5),$(KRB5_LIBS)) \
 	$(if $(filter-out MACOSX,$(OS)),-ldl) \
-	$(if $(filter-out MACOSX,$(OS)),-lpthread) \
 ))
 
 endif
diff --git a/desktop/CppunitTest_desktop_app.mk b/desktop/CppunitTest_desktop_app.mk
index cd698aceee5e..adb57add6e7a 100644
--- a/desktop/CppunitTest_desktop_app.mk
+++ b/desktop/CppunitTest_desktop_app.mk
@@ -66,7 +66,6 @@ endif
 
 $(eval $(call gb_CppunitTest_add_libs,desktop_app,\
 	-lm $(DLOPEN_LIBS) \
-	-lpthread \
     -lX11 \
 ))
 endif
diff --git a/desktop/CppunitTest_desktop_lokinit.mk b/desktop/CppunitTest_desktop_lokinit.mk
index 502f0807075b..1f648a1ecc83 100644
--- a/desktop/CppunitTest_desktop_lokinit.mk
+++ b/desktop/CppunitTest_desktop_lokinit.mk
@@ -40,7 +40,6 @@ ifeq ($(OS),LINUX)
 $(eval $(call gb_CppunitTest_add_libs,desktop_lok_init,\
     -lm \
     -ldl \
-    -lpthread \
 ))
 endif
 
diff --git a/desktop/Library_crashreport.mk b/desktop/Library_crashreport.mk
index 3b9d6dd34fdc..a2cef785f370 100644
--- a/desktop/Library_crashreport.mk
+++ b/desktop/Library_crashreport.mk
@@ -26,7 +26,6 @@ $(eval $(call gb_Library_add_defs,crashreport,\
 $(eval $(call gb_Library_add_libs,crashreport,\
     $(if $(filter LINUX %BSD SOLARIS, $(OS)), \
         $(DLOPEN_LIBS) \
-        -lpthread \
     ) \
 ))
 
diff --git a/desktop/Library_sofficeapp.mk b/desktop/Library_sofficeapp.mk
index 5c7de54c4ed0..bc5f7df4e483 100644
--- a/desktop/Library_sofficeapp.mk
+++ b/desktop/Library_sofficeapp.mk
@@ -19,7 +19,6 @@ $(eval $(call gb_Library_set_include,sofficeapp,\
 $(eval $(call gb_Library_add_libs,sofficeapp,\
     $(if $(filter LINUX %BSD SOLARIS, $(OS)), \
         $(DLOPEN_LIBS) \
-        -lpthread \
     ) \
 ))
 
@@ -135,7 +134,6 @@ $(eval $(call gb_Library_add_exception_objects,sofficeapp,\
 ifeq ($(DISABLE_GUI),TRUE)
 $(eval $(call gb_Library_add_libs,sofficeapp,\
 	-lm $(DLOPEN_LIBS) \
-	-lpthread \
 ))
 else
 ifeq ($(OS), $(filter LINUX %BSD SOLARIS, $(OS)))
@@ -147,7 +145,6 @@ endif
 
 $(eval $(call gb_Library_add_libs,sofficeapp,\
 	-lm $(DLOPEN_LIBS) \
-	-lpthread \
     -lX11 \
 ))
 endif
diff --git a/external/clucene/Library_clucene.mk b/external/clucene/Library_clucene.mk
index abc14d903f46..f04961398797 100644
--- a/external/clucene/Library_clucene.mk
+++ b/external/clucene/Library_clucene.mk
@@ -48,7 +48,6 @@ ifeq ($(OS),LINUX)
 $(eval $(call gb_Library_add_libs,clucene,\
 	-lm \
 	-ldl \
-	-lpthread \
 ))
 endif
 
diff --git a/external/pdfium/Library_pdfium.mk b/external/pdfium/Library_pdfium.mk
index 1db282edb608..2bfa8210676d 100644
--- a/external/pdfium/Library_pdfium.mk
+++ b/external/pdfium/Library_pdfium.mk
@@ -572,7 +572,6 @@ ifneq (,$(filter LINUX ANDROID,$(OS)))
 $(eval $(call gb_Library_add_libs,pdfium,\
     -ldl \
     -lrt \
-    -lpthread \
 ))
 
 $(eval $(call gb_Library_use_external,pdfium,freetype))
diff --git a/jurt/Library_jpipe.mk b/jurt/Library_jpipe.mk
index 5759baed5175..204da654c553 100644
--- a/jurt/Library_jpipe.mk
+++ b/jurt/Library_jpipe.mk
@@ -74,10 +74,6 @@ $(eval $(call gb_Library_use_system_darwin_frameworks,jpipe, \
 ))
 endif
 
-$(eval $(call gb_Library_add_libs,jpipe, \
-    $(if $(filter-out $(OS),ANDROID),-lpthread) \
-))
-
 $(call gb_LinkTarget_get_target,$(call gb_Library_get_linktarget,jpipe)): \
     gb_CC := $(filter-out -fsanitize%,$(gb_CC))
 $(call gb_LinkTarget_get_target,$(call gb_Library_get_linktarget,jpipe)): \
diff --git a/libreofficekit/CppunitTest_libreofficekit_tiledrendering.mk b/libreofficekit/CppunitTest_libreofficekit_tiledrendering.mk
index d58923f45194..da3be044e853 100644
--- a/libreofficekit/CppunitTest_libreofficekit_tiledrendering.mk
+++ b/libreofficekit/CppunitTest_libreofficekit_tiledrendering.mk
@@ -28,7 +28,6 @@ ifeq ($(OS),LINUX)
 $(eval $(call gb_CppunitTest_add_libs,libreofficekit_tiledrendering,\
     -lm \
     -ldl \
-    -lpthread \
 ))
 endif
 
diff --git a/libreofficekit/Executable_gtktiledviewer.mk b/libreofficekit/Executable_gtktiledviewer.mk
index 5dd89e6065f6..99ef51af8975 100644
--- a/libreofficekit/Executable_gtktiledviewer.mk
+++ b/libreofficekit/Executable_gtktiledviewer.mk
@@ -43,7 +43,6 @@ $(eval $(call gb_Executable_use_libraries,gtktiledviewer,\
 ifeq ($(OS), $(filter LINUX %BSD SOLARIS, $(OS)))
 $(eval $(call gb_Executable_add_libs,gtktiledviewer,\
     -lm $(DLOPEN_LIBS) \
-    -lpthread \
 ))
 endif
 
diff --git a/libreofficekit/Executable_tilebench.mk b/libreofficekit/Executable_tilebench.mk
index 9977a93351ed..ae0a3b1f099b 100644
--- a/libreofficekit/Executable_tilebench.mk
+++ b/libreofficekit/Executable_tilebench.mk
@@ -24,7 +24,6 @@ $(eval $(call gb_Executable_use_libraries,tilebench,\
 
 $(eval $(call gb_Executable_add_libs,tilebench,\
     -lm $(DLOPEN_LIBS) \
-    -lpthread \
 ))
 
 $(eval $(call gb_Executable_add_exception_objects,tilebench,\
diff --git a/onlineupdate/Executable_test_updater_dialog.mk b/onlineupdate/Executable_test_updater_dialog.mk
index 877f380eb71c..bd144c8bca18 100644
--- a/onlineupdate/Executable_test_updater_dialog.mk
+++ b/onlineupdate/Executable_test_updater_dialog.mk
@@ -57,7 +57,6 @@ $(eval $(call gb_Executable_add_libs,test_updater_dialog,\
 	-lXrender \
 	-lSM \
 	-lICE \
-	-lpthread \
 ))
 endif
 
diff --git a/onlineupdate/Executable_updater.mk b/onlineupdate/Executable_updater.mk
index 9860e3cf38ef..7c24b7beb3bb 100644
--- a/onlineupdate/Executable_updater.mk
+++ b/onlineupdate/Executable_updater.mk
@@ -70,7 +70,6 @@ $(eval $(call gb_Executable_add_libs,updater,\
 	-lXrender \
 	-lSM \
 	-lICE \
-	-lpthread \
 ))
 endif
 
diff --git a/sal/Library_sal.mk b/sal/Library_sal.mk
index ff42255673d2..a02c333852b7 100644
--- a/sal/Library_sal.mk
+++ b/sal/Library_sal.mk
@@ -56,9 +56,6 @@ $(eval $(call gb_Library_use_system_win32_libs,sal,\
 ))
 
 $(eval $(call gb_Library_add_libs,sal,\
-	$(if $(filter-out ANDROID HAIKU WNT,$(OS)), \
-		-lpthread \
-	) \
 	$(if $(filter LINUX,$(OS)), \
 		-ldl \
 		-lrt \
diff --git a/sc/CppunitTest_sc_ucalc.mk b/sc/CppunitTest_sc_ucalc.mk
index 0258d9117814..8822fbc8dead 100644
--- a/sc/CppunitTest_sc_ucalc.mk
+++ b/sc/CppunitTest_sc_ucalc.mk
@@ -118,12 +118,6 @@ $(eval $(call gb_CppunitTest_add_libs,sc_ucalc,\
 ))
 endif
 
-ifeq ($(OS), $(filter LINUX %BSD SOLARIS, $(OS)))
-$(eval $(call gb_CppunitTest_add_libs,sc_ucalc,\
-    -lpthread \
-))
-endif
-
 $(eval $(call gb_CppunitTest_use_configuration,sc_ucalc))
 
 # vim: set noet sw=4 ts=4:
diff --git a/sc/Library_sc.mk b/sc/Library_sc.mk
index aa596d001a26..91a29e021a49 100644
--- a/sc/Library_sc.mk
+++ b/sc/Library_sc.mk
@@ -718,12 +718,6 @@ $(eval $(call gb_Library_add_libs,sc,\
 ))
 endif
 
-ifeq ($(OS), $(filter LINUX %BSD SOLARIS, $(OS)))
-$(eval $(call gb_Library_add_libs,sc,\
-    -lpthread \
-))
-endif
-
 $(eval $(call gb_SdiTarget_SdiTarget,sc/sdi/scslots,sc/sdi/scalc))
 
 $(eval $(call gb_SdiTarget_set_include,sc/sdi/scslots,\
diff --git a/smoketest/Executable_libtest.mk b/smoketest/Executable_libtest.mk
index e16c95073976..c1e33d35e10e 100644
--- a/smoketest/Executable_libtest.mk
+++ b/smoketest/Executable_libtest.mk
@@ -16,7 +16,6 @@ $(eval $(call gb_Executable_set_include,libtest,\
 ifeq ($(OS),LINUX)
 $(eval $(call gb_Executable_add_libs,libtest,\
 	-ldl \
-	-pthread \
 ))
 endif
 
diff --git a/solenv/gbuild/platform/linux.mk b/solenv/gbuild/platform/linux.mk
index 727418b8ea61..77d4dbe679e8 100644
--- a/solenv/gbuild/platform/linux.mk
+++ b/solenv/gbuild/platform/linux.mk
@@ -18,7 +18,7 @@ gb_LinkTarget_LDFLAGS += $(gb__LinkTarget_LDFLAGS_zdefs)
 include $(GBUILDDIR)/platform/unxgcc.mk
 
 ifeq ($(DISABLE_DYNLOADING),TRUE)
-gb_STDLIBS := -lpthread -ldl
+gb_STDLIBS := -ldl
 endif
 
 # vim: set noet sw=4 ts=4:
diff --git a/solenv/gbuild/platform/unxgcc.mk b/solenv/gbuild/platform/unxgcc.mk
index 27edd2932589..0cd205891d2e 100644
--- a/solenv/gbuild/platform/unxgcc.mk
+++ b/solenv/gbuild/platform/unxgcc.mk
@@ -42,12 +42,20 @@ gb_CFLAGS := \
 	-Wdeclaration-after-statement \
 	-Wshadow \
 
+# At least libstdc++ (which is approximated here with !HAVE_LIBCXX) needs -pthread when including
+# various C++ headers like <thread>, see <https://gcc.gnu.org/onlinedocs/gcc-8.3.0/libstdc++/manual/
+# manual/using.html#manual.intro.using.flags>:
+ifeq ($(HAVE_LIBCXX),)
+gb_CXX_LINKFLAGS := -pthread
+endif
+
 gb_CXXFLAGS := \
 	$(gb_CXXFLAGS_COMMON) \
 	-fPIC \
 	-Wshadow \
 	-Woverloaded-virtual \
 	$(CXXFLAGS_CXX11) \
+	$(gb_CXX_LINKFLAGS) \
 
 
 # enable debug STL
@@ -112,7 +120,7 @@ gb_LinkTarget_CXXFLAGS := $(gb_CXXFLAGS)
 # contains .c sources:
 define gb_LinkTarget__command_dynamiclink
 $(call gb_Helper_abbreviate_dirs,\
-	$(if $(CXXOBJECTS)$(GENCXXOBJECTS)$(EXTRAOBJECTLISTS)$(filter-out XTRUE,X$(ENABLE_RUNTIME_OPTIMIZATIONS)),$(gb_CXX),$(gb_CC)) \
+	$(if $(CXXOBJECTS)$(GENCXXOBJECTS)$(EXTRAOBJECTLISTS)$(filter-out XTRUE,X$(ENABLE_RUNTIME_OPTIMIZATIONS)),$(gb_CXX) $(gb_CXX_LINKFLAGS),$(gb_CC)) \
 		$(if $(filter Library CppunitTest,$(TARGETTYPE)),$(gb_Library_TARGETTYPEFLAGS)) \
 		$(gb_LTOFLAGS) \
 		$(if $(SOVERSIONSCRIPT),-Wl$(COMMA)--soname=$(notdir $(1)) \
diff --git a/svl/Library_svl.mk b/svl/Library_svl.mk
index 28a043bdb310..64e2feb8f834 100644
--- a/svl/Library_svl.mk
+++ b/svl/Library_svl.mk
@@ -111,11 +111,6 @@ $(eval $(call gb_Library_use_externals,svl,\
     nss3 \
     plc4 \
 ))
-ifeq ($(OS),LINUX)
-$(eval $(call gb_Library_add_libs,svl, \
-    -lpthread \
-))
-endif
 endif # BUILD_TYPE=DESKTOP
 endif
 
diff --git a/svx/Executable_gengal.mk b/svx/Executable_gengal.mk
index e4c73928711b..f505e9e5c7f0 100644
--- a/svx/Executable_gengal.mk
+++ b/svx/Executable_gengal.mk
@@ -64,13 +64,11 @@ endif
 ifeq ($(DISABLE_GUI),TRUE)
 $(eval $(call gb_Executable_add_libs,gengal,\
 	$(DLOPEN_LIBS) \
-	-lpthread \
 ))
 else
 ifeq ($(OS), $(filter LINUX %BSD SOLARIS, $(OS)))
 $(eval $(call gb_Executable_add_libs,gengal,\
 	$(DLOPEN_LIBS) \
-	-lpthread \
     -lX11 \
 ))
 
diff --git a/vcl/Executable_icontest.mk b/vcl/Executable_icontest.mk
index b162800e72fd..6faf33703aa1 100644
--- a/vcl/Executable_icontest.mk
+++ b/vcl/Executable_icontest.mk
@@ -37,7 +37,6 @@ $(eval $(call gb_Executable_use_static_libraries,icontest,\
 ifeq ($(OS), $(filter LINUX %BSD SOLARIS, $(OS)))
 $(eval $(call gb_Executable_add_libs,icontest,\
 	-lm $(DLOPEN_LIBS) \
-	-lpthread \
     -lX11 \
 ))
 
diff --git a/vcl/Executable_lo_kde5filepicker.mk b/vcl/Executable_lo_kde5filepicker.mk
index 2eee2cd8711b..f3e940953601 100644
--- a/vcl/Executable_lo_kde5filepicker.mk
+++ b/vcl/Executable_lo_kde5filepicker.mk
@@ -92,7 +92,6 @@ ifeq ($(OS),LINUX)
 $(eval $(call gb_Executable_add_libs,lo_kde5filepicker,\
 	-lm \
 	-ldl \
-	-lpthread \
 ))
 endif
 
diff --git a/vcl/Executable_mtfdemo.mk b/vcl/Executable_mtfdemo.mk
index d637439a17ba..5c4c45165535 100644
--- a/vcl/Executable_mtfdemo.mk
+++ b/vcl/Executable_mtfdemo.mk
@@ -43,7 +43,6 @@ $(eval $(call gb_Executable_use_static_libraries,mtfdemo,\
 ifeq ($(OS), $(filter LINUX %BSD SOLARIS, $(OS)))
 $(eval $(call gb_Executable_add_libs,mtfdemo,\
 	-lm $(DLOPEN_LIBS) \
-	-lpthread \
     -lX11 \
 ))
 
diff --git a/vcl/Executable_ui-previewer.mk b/vcl/Executable_ui-previewer.mk
index 0925e575ee67..cf6a2d3de6c7 100644
--- a/vcl/Executable_ui-previewer.mk
+++ b/vcl/Executable_ui-previewer.mk
@@ -37,7 +37,6 @@ $(eval $(call gb_Executable_add_exception_objects,ui-previewer,\
 ifeq ($(OS), $(filter LINUX %BSD SOLARIS, $(OS)))
 $(eval $(call gb_Executable_add_libs,ui-previewer,\
 	-lm $(DLOPEN_LIBS) \
-	-lpthread \
     -lX11 \
 ))
 
diff --git a/vcl/Executable_vcldemo.mk b/vcl/Executable_vcldemo.mk
index 125a151dec99..55848b280339 100644
--- a/vcl/Executable_vcldemo.mk
+++ b/vcl/Executable_vcldemo.mk
@@ -53,7 +53,6 @@ $(eval $(call gb_Executable_use_static_libraries,vcldemo,\
 ifeq ($(OS), $(filter LINUX %BSD SOLARIS, $(OS)))
 $(eval $(call gb_Executable_add_libs,vcldemo,\
 	-lm $(DLOPEN_LIBS) \
-	-lpthread \
     -lX11 \
 ))
 
diff --git a/vcl/Executable_visualbackendtest.mk b/vcl/Executable_visualbackendtest.mk
index 87044535f03e..41c641a5ff14 100644
--- a/vcl/Executable_visualbackendtest.mk
+++ b/vcl/Executable_visualbackendtest.mk
@@ -45,7 +45,6 @@ ifeq ($(OS),LINUX)
 $(eval $(call gb_Executable_add_libs,visualbackendtest,\
 	-lm \
 	-ldl \
-	-lpthread \
     -lX11 \
 ))
 
diff --git a/vcl/Library_desktop_detector.mk b/vcl/Library_desktop_detector.mk
index 3edd0015e243..f28ff9078e64 100644
--- a/vcl/Library_desktop_detector.mk
+++ b/vcl/Library_desktop_detector.mk
@@ -66,7 +66,6 @@ $(eval $(call gb_Library_add_exception_objects,desktop_detector,\
 ifeq ($(OS), $(filter LINUX %BSD SOLARIS, $(OS)))
 $(eval $(call gb_Library_add_libs,desktop_detector,\
 	-lm $(DLOPEN_LIBS) \
-	-lpthread \
 ))
 endif
 
diff --git a/vcl/Library_vcl.mk b/vcl/Library_vcl.mk
index e400051df526..1ebdafdf6b18 100644
--- a/vcl/Library_vcl.mk
+++ b/vcl/Library_vcl.mk
@@ -545,11 +545,6 @@ $(eval $(call gb_Library_use_externals,vcl,\
     freetype \
     fontconfig \
 ))
-ifeq ($(OS), $(filter LINUX %BSD SOLARIS, $(OS)))
-$(eval $(call gb_Library_add_libs,vcl,\
-    -lpthread \
-))
-endif
 
 else # ! DISABLE_GUI
 
@@ -578,7 +573,6 @@ endif
 ifeq ($(OS), $(filter LINUX %BSD SOLARIS, $(OS)))
 $(eval $(call gb_Library_add_libs,vcl,\
     -lm $(DLOPEN_LIBS) \
-    -lpthread \
     -lX11 \
     -lXext \
 ))
diff --git a/vcl/Library_vclplug_gen.mk b/vcl/Library_vclplug_gen.mk
index f9b73e637d03..8781324a6da6 100644
--- a/vcl/Library_vclplug_gen.mk
+++ b/vcl/Library_vclplug_gen.mk
@@ -145,7 +145,6 @@ ifeq ($(OS),LINUX)
 $(eval $(call gb_Library_add_libs,vclplug_gen,\
 	-lm \
 	-ldl \
-	-lpthread \
 ))
 endif
 
diff --git a/vcl/Library_vclplug_gtk.mk b/vcl/Library_vclplug_gtk.mk
index 67d405d4c8fa..360eabf46020 100644
--- a/vcl/Library_vclplug_gtk.mk
+++ b/vcl/Library_vclplug_gtk.mk
@@ -126,7 +126,6 @@ ifeq ($(OS),LINUX)
 $(eval $(call gb_Library_add_libs,vclplug_gtk,\
 	-lm \
 	-ldl \
-	-lpthread \
 ))
 endif
 
diff --git a/vcl/Library_vclplug_gtk3.mk b/vcl/Library_vclplug_gtk3.mk
index cfb2f1b2d30b..a77f3b300ad6 100644
--- a/vcl/Library_vclplug_gtk3.mk
+++ b/vcl/Library_vclplug_gtk3.mk
@@ -116,7 +116,6 @@ ifeq ($(OS),LINUX)
 $(eval $(call gb_Library_add_libs,vclplug_gtk3,\
 	-lm \
 	-ldl \
-	-lpthread \
 ))
 endif
 
diff --git a/vcl/Library_vclplug_gtk3_kde5.mk b/vcl/Library_vclplug_gtk3_kde5.mk
index 20a8dc1ee228..e725e077f55e 100644
--- a/vcl/Library_vclplug_gtk3_kde5.mk
+++ b/vcl/Library_vclplug_gtk3_kde5.mk
@@ -124,7 +124,6 @@ ifeq ($(OS),LINUX)
 $(eval $(call gb_Library_add_libs,vclplug_gtk3_kde5,\
 	-lm \
 	-ldl \
-	-lpthread \
 ))
 endif
 
diff --git a/vcl/Library_vclplug_kde5.mk b/vcl/Library_vclplug_kde5.mk
index f011f397d7d3..e60ea79c1f5e 100644
--- a/vcl/Library_vclplug_kde5.mk
+++ b/vcl/Library_vclplug_kde5.mk
@@ -89,7 +89,6 @@ ifeq ($(OS),LINUX)
 $(eval $(call gb_Library_add_libs,vclplug_kde5,\
 	-lm \
 	-ldl \
-	-lpthread \
 ))
 endif
 
diff --git a/vcl/Library_vclplug_qt5.mk b/vcl/Library_vclplug_qt5.mk
index f7fbfd1cdbdb..8aead5fa60f6 100644
--- a/vcl/Library_vclplug_qt5.mk
+++ b/vcl/Library_vclplug_qt5.mk
@@ -114,7 +114,6 @@ ifeq ($(OS),LINUX)
 $(eval $(call gb_Library_add_libs,vclplug_qt5,\
 	-lm \
 	-ldl \
-	-lpthread \
 ))
 endif
 
diff --git a/vcl/StaticLibrary_glxtest.mk b/vcl/StaticLibrary_glxtest.mk
index 227cbaa574c1..1a285875c828 100644
--- a/vcl/StaticLibrary_glxtest.mk
+++ b/vcl/StaticLibrary_glxtest.mk
@@ -31,7 +31,6 @@ $(eval $(call gb_StaticLibrary_use_api,glxtest,\
 
 $(eval $(call gb_StaticLibrary_add_libs,glxtest,\
 	-lm $(DLOPEN_LIBS) \
-	-lpthread \
     -lX11 \
 ))