[2/2,v2] package/mono: new package

This patch adds the complete Mono implementation. This patch builds
both the native and managed parts.

Signed-off-by: Angelo Compagnucci <angelo.compagnucci@gmail.com>
---
Chengelog:

* Passing right configure options to exclude unselected
  .Net runtime libraries from compilation.
* Adding 4.5 as default library version.
* Removed MONO_ASSEMBLY_INCLUDED variable
* Fixed license
* Fixed help strings
* Fixed patch formatting

[Thomas:

  - Merge mono-managed and mono-native as a single package. The
    mono-managed stuff is done by the host variant of the mono
    package, while the mono-native stuff is done as the target variant
    of the mono package.

  - Introduce a BR2_PACKAGE_MONO_ARCH_SUPPORTS blind Config.in option
    to make sure the IPv6 related comment is not displayed when the
    architecture being used anyway doesn't support Mono.

  - Add a patch to Mono to fix the C library path when uClibc and Musl
    is used. This is a better approach than the
    POST_INSTALL_TARGET_HOOKS because this approach can potentially be
    submitted upstreamed, which ultimately allows to simplify the
    Buildroot package.

  - Depend on a 'monolite' package, and use it instead of letting Mono
    download Monolite by itself, which circumvents Buildroot's
    download infrastructure.
    mono-managed stuff is done by the host variant of the mono
    package, while the mono-native stuff is done as the target variant
    of the mono package.

  - Introduce a BR2_PACKAGE_MONO_ARCH_SUPPORTS blind Config.in option
    to make sure the IPv6 related comment is not displayed when the
    architecture being used anyway doesn't support Mono.

  - Add a patch to Mono to fix the C library path when uClibc and Musl
    is used. This is a better approach than the
    POST_INSTALL_TARGET_HOOKS because this approach can potentially be
    submitted upstreamed, which ultimately allows to simplify the
    Buildroot package.

  - Depend on a 'monolite' package, and use it instead of letting Mono
    download Monolite by itself, which circumvents Buildroot's
    download infrastructure.

  - Move the installation of Mono libraries to the target Mono
    package, as a POST_INSTALL_TARGET_HOOKS.]

[Angelo:

  - Bump to the latest Mono version 3.10.0

  - Add selection for .Net runtime compilation and installation in
    target.]

 package/Config.in                               |  1 +
 package/mono/Config.in                          | 40 ++++++++++++
 package/mono/mono-001-gc-fix-uclibc.patch       | 16 +++++
 package/mono/mono-002-support-uclibc-musl.patch | 25 ++++++++
 package/mono/mono.mk                            | 81 +++++++++++++++++++++++++
 5 files changed, 163 insertions(+)
 create mode 100644 package/mono/Config.in
 create mode 100644 package/mono/mono-001-gc-fix-uclibc.patch
 create mode 100644 package/mono/mono-002-support-uclibc-musl.patch
 create mode 100644 package/mono/mono.mk

Dear Angelo Compagnucci,

On Mon, 13 Oct 2014 16:03:50 +0200, Angelo Compagnucci wrote:

> +config BR2_PACKAGE_MONO
> +	bool "mono"
> +	depends on BR2_PACKAGE_MONO_ARCH_SUPPORTS
> +	depends on BR2_INET_IPV6
> +	help
> +	  An open source, cross-platform, implementation of C#
> +	  and the CLR that is binary compatible with Microsoft.NET.
> +
> +	  http://download.mono-project.com/sources/mono/
> +
> +if BR2_PACKAGE_MONO
> +
> +	config BR2_PACKAGE_MONO_20
> +		bool "2.0/3.5 .Net Runtime"
> +		help
> +		  This option enables the installation of
> +		  the 2.0/3.5 version of the Mono .Net runtime to the target
> +
> +	config BR2_PACKAGE_MONO_40
> +		bool "4.0 .Net Runtime"
> +		help
> +		  This option enables the installation of
> +		  the 4.0 version of the Mono .Net runtime to the target
> +
> +	config BR2_PACKAGE_MONO_45
> +		bool "4.5 .Net Runtime"
> +		default y
> +		help
> +		  This option enables the installation of
> +		  the 4.5 version of the Mono .Net runtime to the target

I think I already told you, but I repeat if: no indentation inside
if ... endif, so:

if BR2_PACKAGE_FOO

config BR2_PACKAGE_FOO_BAZ
	bool "..."

config BR2_PACKAGE_FOO_BAZ2
	bool "..."

endif

Also, the wrapping of your help text for the runtime version options is
weird.


> +ifneq ($(BR2_PACKAGE_MONO_20),y) 
> +ifneq ($(BR2_PACKAGE_MONO_40),y)
> +ifneq ($(BR2_PACKAGE_MONO_45),y)
> +	BR2_PACKAGE_MONO_45 = y
> +endif
> +endif
> +endif

Noooooooo! Where have you seen that we're allowed to change the value
of Config.in options from within Makefiles?

Please handle this inside the Config.in directly in a proper way:

config BR2_PACKAGE_MONO
	bool "mono"
	...
	select BR2_PACKAGE_MONO_45 if !BR2_PACKAGE_MONO20 && !BR2_PACKAGE_MONO40

This way, you are guaranteed that if neither mono 2.0 nor mono 4.0 are
selected, then mono 4.5 is selected.

> +ifeq ($(BR2_PACKAGE_MONO_20),y)
> +	HOST_MONO_CONF_OPTS := $(patsubst --with-profile2=no,--with-profile2=yes,$(HOST_MONO_CONF_OPTS))
> +endif
> +
> +ifeq ($(BR2_PACKAGE_MONO_40),y)
> +	HOST_MONO_CONF_OPTS := $(patsubst --with-profile4=no,--with-profile4=yes,$(HOST_MONO_CONF_OPTS))
> +endif
> +
> +ifeq ($(BR2_PACKAGE_MONO_45),y)
> +	HOST_MONO_CONF_OPTS := $(patsubst --with-profile4_5=no,--with-profile4_5=yes,$(HOST_MONO_CONF_OPTS))
> +endif

Whaaat?

Remove:

+	--with-profile2=no \
+	--with-profile4=no \
+	--with-profile4_5=no

from the unconditional HOST_MONO_CONF_OPTS. And then simply do:

ifeq ($(BR2_PACKAGE_MONO_20),y)
HOST_MONO_CONF_OPTS += --with-profile2=yes
else
HOST_MONO_CONF_OPTS += --with-profile2=no
endif

And do it for each version. Or if you want a shorter version:

HOST_MONO_CONF_OPTS += --with-profile2=$(if $(BR2_PACKAGE_MONO_20),yes,no)

I'm not sure where you found this crazy patsubst solution, since what
I'm proposing here is what is done in *all* Buildroot packages. Maybe
you should spend a bit of time reading the .mk files of a few other
packages to get some idea on how we generally do things.

There's still on things that bothers me a bit: those options
(BR2_PACKAGE_MONO_{20,40,45}) are target options, but they are in fact
used when building host-mono, which isn't very clean. I assume it's not
possible to have the target mono package build the runtime libraries
using the compiler built by the host-mono package, right?

If not, then keep things as they are today, but put a comment above the
place where BR2_PAKCAGE_MONO_{20,40,45} is used in the .mk file
explaining why we're using those target options for a host package.

Thomas

Hi Thomas,

Sorry for all the confusion I infused in the patch.

> There's still on things that bothers me a bit: those options
> (BR2_PACKAGE_MONO_{20,40,45}) are target options, but they are in fact
> used when building host-mono, which isn't very clean. I assume it's not
> possible to have the target mono package build the runtime libraries
> using the compiler built by the host-mono package, right?

Nope. To compile mono runtime without the host I should run mono inside qemu.
Probably it's feasible, but I really don't know if it's a raccomanded way to do.

> If not, then keep things as they are today, but put a comment above the
> place where BR2_PAKCAGE_MONO_{20,40,45} is used in the .mk file
> explaining why we're using those target options for a host package.

I did it in the new patch I sent.

Thank you again for your time!

>
> Thomas
> --
> Thomas Petazzoni, CTO, Free Electrons
> Embedded Linux, Kernel and Android engineering
> http://free-electrons.com