[Buildroot] [PATCH v2 3/8] mongrel2: allow using uClibc but only on certain architectures

[Thomas Petazzoni]

mongrel2 uses  the {get,make,swap}context functions:

 - With glibc, no problem, they are available on all supported
   architectures

 - With uClibc, they are available only on a subset of the
   architectures. Until now, only BR2_UCLIBC_VERSION_SNAPSHOT
   configurations were allowed to select mongrel2, but we are going to
   get rid of the uClibc snapshot version, and uClibc-ng is as capable
   as the uClibc snapshot. However, only certain architectures have
   the *context() functions.

 - With musl, there is no *context() support.

Since this dependency is quite complicated, we introduce a
BR2_PACKAGE_MONGREL2_LIBC_SUPPORTS hidden boolean to encode which C
libraries are supported.

Also, listing the supported uClibc architectures would be too long in
the comment, so we simply indicate that the package needs uClibc or
glibc.

Signed-off-by: Thomas Petazzoni <thomas.petazzoni at free-electrons.com>
---
 package/mongrel2/Config.in | 22 ++++++++++++----------
 1 file changed, 12 insertions(+), 10 deletions(-)

diff --git a/package/mongrel2/Config.in b/package/mongrel2/Config.in
index 1c7b495..49dd6fd 100644
--- a/package/mongrel2/Config.in
+++ b/package/mongrel2/Config.in
@@ -1,10 +1,16 @@
-comment "mongrel2 needs a toolchain w/ C++, threads, wchar, dynamic library"
-	depends on BR2_UCLIBC_VERSION_SNAPSHOT || \
-		BR2_TOOLCHAIN_USES_GLIBC || \
-		BR2_arm
+# mongrel2 uses {get,make,swap}context() functions, which are
+# available in glibc for all architectures and in uClibc only for a
+# subset of the architectures
+config BR2_PACKAGE_MONGREL2_LIBC_SUPPORTS
+	bool
+	default y if BR2_TOOLCHAIN_USES_GLIBC
+	default y if BR2_TOOLCHAIN_USES_UCLIBC && \
+		(BR2_arm || BR2_armeb || BR2_i386 || BR2_mips || BR2_mipsel || BR2_mips64 || BR2_mips64el || BR2_x86_64)
+
+comment "mongrel2 needs a uClibc or glibc toolchain w/ C++, threads, wchar, dynamic library"
 	depends on !BR2_INSTALL_LIBSTDCPP || \
 		!BR2_TOOLCHAIN_HAS_THREADS || !BR2_USE_WCHAR || \
-		BR2_STATIC_LIBS
+		BR2_STATIC_LIBS || !BR2_PACKAGE_MONGREL2_LIBC_SUPPORTS
 
 config BR2_PACKAGE_MONGREL2
 	bool "mongrel2"
@@ -14,11 +20,7 @@ config BR2_PACKAGE_MONGREL2
 	depends on BR2_TOOLCHAIN_HAS_THREADS # zeromq
 	depends on BR2_USE_WCHAR # zeromq -> util-linux
 	depends on !BR2_STATIC_LIBS # uses dlopen()
-	# {get,make,swap}context functions present in
-	# {e,}glibc and in uClibc's master branch. Source has arm workaround
-	depends on BR2_UCLIBC_VERSION_SNAPSHOT || \
-		BR2_TOOLCHAIN_USES_GLIBC || \
-		BR2_arm
+	depends on BR2_PACKAGE_MONGREL2_LIBC_SUPPORTS
 	help
 	  Mongrel2 is an application, language, and network architecture
 	  agnostic web server that focuses on web applications using
-- 
2.6.4