toolchain: rework thread options

The selection of linuxthreads, linuxthreads old or NPTL doesn't make a
lot of sense for external toolchains. So, instead, we :

 * Introduce an hidden BR2_TOOLCHAIN_HAS_THREADS option, which must be
   selected by toolchain specific options when thread support is
   available. Package needing to test thread support should use this
   option.

 * Move the none/linuxthreads/linuxthreads old/NPTL selection to
   Buildroot internal toolchain configuration.

 * Add an option in external toolchain to tell if thread support is
   available or not in the external toolchain. We assume that glibc
   without threads is not possible, as Ulrich Drepper said in
   http://sourceware.org/ml/libc-alpha/2005-08/msg00091.html

ffmpeg, dmalloc and openvpn are fixed to use the new
BR2_TOOLCHAIN_HAS_THREADS option. For openvpn, --enable-threads=posix
is no longer used, as the configure script doesn't even understand
this option.

Signed-off-by: Thomas Petazzoni <thomas.petazzoni@free-electrons.com>
Signed-off-by: Peter Korsgaard <jacmet@sunsite.dk>

6 files changed, 46 insertions, 33 deletions

diff --git a/toolchain/Makefile.in b/toolchain/Makefile.in
index 371509f4e..2cb6e95f2 100644
--- a/toolchain/Makefile.in
+++ b/toolchain/Makefile.in
@@ -1,9 +1,3 @@
-ifeq ($(BR2_PTHREADS_NONE),y)
-THREADS:=--disable-threads
-else
-THREADS:=--enable-threads
-endif
-
 BR2_CONFIGURE_DEVEL_SYSROOT=--with-sysroot=$(TOOLCHAIN_DIR)/uClibc_dev/
 BR2_CONFIGURE_STAGING_SYSROOT=--with-sysroot=$(STAGING_DIR)
 BR2_CONFIGURE_BUILD_TOOLS=--with-build-time-tools=$(STAGING_DIR)/usr/$(REAL_GNU_TARGET_NAME)/bin
diff --git a/toolchain/gcc/gcc-uclibc-4.x.mk b/toolchain/gcc/gcc-uclibc-4.x.mk
index eec652343..5f69906ca 100644
--- a/toolchain/gcc/gcc-uclibc-4.x.mk
+++ b/toolchain/gcc/gcc-uclibc-4.x.mk
@@ -138,6 +138,12 @@ else
 GCC_TLS:=--disable-tls
 endif
 
+ifeq ($(BR2_PTHREADS_NONE),y)
+THREADS:=--disable-threads
+else
+THREADS:=--enable-threads
+endif
+
 ifeq ($(BR2_GCC_SUPPORTS_FINEGRAINEDMTUNE),y)
 GCC_DECIMAL_FLOAT:=--disable-decimal-float
 endif
diff --git a/toolchain/toolchain-buildroot/Config.in.2 b/toolchain/toolchain-buildroot/Config.in.2
index f1b0a7c58..fe93e70d5 100644
--- a/toolchain/toolchain-buildroot/Config.in.2
+++ b/toolchain/toolchain-buildroot/Config.in.2
@@ -76,6 +76,33 @@ config BR2_TOOLCHAIN_BUILDROOT_USE_SSP
 	  See http://www.linuxfromscratch.org/hints/downloads/files/ssp.txt
 	  for details.
 
+choice
+	prompt "Thread library implementation"
+	default BR2_PTHREADS_OLD
+	help
+	  Use this option to select the thread library implementation
+	  that should be used in your toolchain. Not all thread
+	  variants work with all versions of uClibc, the "linuxthreads
+	  (stable/old)" may be a working fallback if you need
+	  threading at all.
+
+	config BR2_PTHREADS_NONE
+		bool "none"
+
+	config BR2_PTHREADS
+		bool "linuxthreads"
+	        select BR2_TOOLCHAIN_HAS_THREADS
+
+	config BR2_PTHREADS_OLD
+		bool "linuxthreads (stable/old)"
+	        select BR2_TOOLCHAIN_HAS_THREADS
+
+	config BR2_PTHREADS_NATIVE
+		bool "Native POSIX Threading (NPTL)"
+	        select BR2_TOOLCHAIN_HAS_THREADS
+		depends on BR2_UCLIBC_VERSION_SNAPSHOT
+endchoice
+
 source "toolchain/elf2flt/Config.in"
 source "toolchain/mklibs/Config.in"
 source "toolchain/sstrip/Config.in"
diff --git a/toolchain/toolchain-common.in b/toolchain/toolchain-common.in
index 5502ab4ff..34d70a0fa 100644
--- a/toolchain/toolchain-common.in
+++ b/toolchain/toolchain-common.in
@@ -26,6 +26,9 @@ config BR2_PROGRAM_INVOCATION
 config BR2_INSTALL_LIBSTDCPP
 	bool
 
+config BR2_TOOLCHAIN_HAS_THREADS
+	bool
+
 config BR2_ENABLE_LOCALE_PURGE
 	bool "Purge unwanted locales"
 	help
@@ -76,32 +79,6 @@ config BR2_SOFT_FLOAT
 	  functions, then everything will need to be compiled with soft
 	  floating point support (-msoft-float).
 
-choice
-	prompt "Thread library implementation"
-	default BR2_PTHREADS_OLD
-	help
-	  If you are building your own toolchain then select the type of 
-	  libpthreads you want to use.
-	  Not all thread variants work with all versions of uClibc,
-	  the "linuxthreads (stable/old)" may be a working fallback
-	  if you need threading at all.
-	  If you have an external binary toolchain then select the type 
-	  of libpthreads it was built with.
-
-	config BR2_PTHREADS_NONE
-		bool "none"
-
-	config BR2_PTHREADS
-		bool "linuxthreads"
-
-	config BR2_PTHREADS_OLD
-		bool "linuxthreads (stable/old)"
-
-	config BR2_PTHREADS_NATIVE
-		bool "Native POSIX Threading (NPTL)"
-		depends on BR2_UCLIBC_VERSION_SNAPSHOT
-endchoice
-
 config BR2_TARGET_OPTIMIZATION
 	string "Target Optimizations"
 	default "-pipe"
diff --git a/toolchain/toolchain-external/Config.in b/toolchain/toolchain-external/Config.in
index bd22e0cc3..2ed65bf30 100644
--- a/toolchain/toolchain-external/Config.in
+++ b/toolchain/toolchain-external/Config.in
@@ -149,6 +149,7 @@ config BR2_TOOLCHAIN_EXTERNAL_GLIBC
 	select BR2_USE_WCHAR
 	select BR2_ENABLE_LOCALE
 	select BR2_PROGRAM_INVOCATION
+	select BR2_TOOLCHAIN_HAS_THREADS
 
 config BR2_TOOLCHAIN_EXTERNAL_UCLIBC
 	bool
@@ -220,6 +221,14 @@ config BR2_TOOLCHAIN_EXTERNAL_PROGRAM_INVOCATION
 	  invocation support. If you don't know, leave the default
 	  value, Buildroot will tell you if it's correct or not.
 
+config BR2_TOOLCHAIN_EXTERNAL_HAS_THREADS
+	bool "Toolchain has threads support?"
+	select BR2_TOOLCHAIN_HAS_THREADS
+	help
+	  Select this option if your external toolchain has thread
+	  support. If you don't know, leave the default value,
+	  Buildroot will tell you if it's correct or not.
+
 endif # BR2_TOOLCHAIN_EXTERNAL_CUSTOM_UCLIBC
 
 config BR2_TOOLCHAIN_EXTERNAL_CXX
diff --git a/toolchain/toolchain-external/ext-tool.mk b/toolchain/toolchain-external/ext-tool.mk
index 027fbbdf5..d6153f14d 100644
--- a/toolchain/toolchain-external/ext-tool.mk
+++ b/toolchain/toolchain-external/ext-tool.mk
@@ -53,7 +53,7 @@ ifeq ($(BR2_INSTALL_LIBSTDCPP),y)
 USR_LIB_EXTERNAL_LIBS+=libstdc++.so
 endif
 
-ifneq ($(BR2_PTHREADS_NONE),y)
+ifeq ($(BR2_TOOLCHAIN_HAS_THREADS),y)
 LIB_EXTERNAL_LIBS+=libpthread.so
 ifeq ($(BR2_PACKAGE_GDB_SERVER),y)
 LIB_EXTERNAL_LIBS+=libthread_db.so