[igt-dev] [PATCH i-g-t] lib: Make libunwind optional again

[Sean Paul]

On Mon, Oct 29, 2018 at 06:20:26PM +0100, Daniel Vetter wrote:
> Apparently it's really not great to require it for a bunch of
> platforms. Requested by Sean and Eric.
> 
> v2: Use combo option (Petri).
> 
> v3: Fix the right option (Petri)
> 
> v4: try a bit harder ...
> 
> Cc: Petri Latvala <petri.latvala at intel.com>
> Reviewed-by: Eric Anholt <eric at anholt.net> (v1)
> Cc: Sean Paul <sean at poorly.run>

Reviewed-by: Sean Paul <sean at poorly.run>

> Cc: Eric Anholt <eric at anholt.net>
> Signed-off-by: Daniel Vetter <daniel.vetter at intel.com>
> ---
>  lib/meson.build                 |  7 ++++-
>  lib/stubs/libunwind/libunwind.h | 46 +++++++++++++++++++++++++++++++++
>  meson.build                     | 13 +++++++++-
>  meson_options.txt               |  6 +++++
>  4 files changed, 70 insertions(+), 2 deletions(-)
>  create mode 100644 lib/stubs/libunwind/libunwind.h
> 
> diff --git a/lib/meson.build b/lib/meson.build
> index 7e2c9b7a98e0..8961ca494af8 100644
> --- a/lib/meson.build
> +++ b/lib/meson.build
> @@ -59,7 +59,6 @@ lib_deps = [
>  	libkmod,
>  	libprocps,
>  	libudev,
> -	libunwind,
>  	libdw,
>  	pciaccess,
>  	pthreads,
> @@ -76,6 +75,12 @@ else
>  	inc = [ inc, include_directories('stubs/drm') ]
>  endif
>  
> +if libunwind.found()
> +	lib_deps += libunwind
> +else
> +	inc = [ inc, include_directories('stubs/libunwind') ]
> +endif
> +
>  if valgrind.found()
>  	lib_deps += valgrind
>  endif
> diff --git a/lib/stubs/libunwind/libunwind.h b/lib/stubs/libunwind/libunwind.h
> new file mode 100644
> index 000000000000..ce5f30df6ce1
> --- /dev/null
> +++ b/lib/stubs/libunwind/libunwind.h
> @@ -0,0 +1,46 @@
> +/*
> + * Copyright © 2018 Intel Corporation
> + *
> + * Permission is hereby granted, free of charge, to any person obtaining a
> + * copy of this software and associated documentation files (the "Software"),
> + * to deal in the Software without restriction, including without limitation
> + * the rights to use, copy, modify, merge, publish, distribute, sublicense,
> + * and/or sell copies of the Software, and to permit persons to whom the
> + * Software is furnished to do so, subject to the following conditions:
> + *
> + * The above copyright notice and this permission notice (including the next
> + * paragraph) shall be included in all copies or substantial portions of the
> + * Software.
> + *
> + * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
> + * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
> + * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.  IN NO EVENT SHALL
> + * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
> + * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
> + * FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS
> + * IN THE SOFTWARE.
> + *
> + * Authors:
> + *    Daniel Vetter <daniel.vetter at ffwll.ch>
> + */
> +
> +/* dummy libunwind header with stubs, only the minimal amount we need to get by */
> +
> +
> +typedef int unw_cursor_t;
> +typedef int unw_context_t;
> +typedef int unw_word_t;
> +
> +#define UNW_REG_IP 0
> +
> +static inline void unw_getcontext(unw_context_t *uc) {}
> +static inline void unw_init_local(unw_cursor_t *cursor, unw_context_t *uc) {}
> +static inline int unw_step(unw_cursor_t *cursor) { return 0; }
> +static inline int unw_get_reg (unw_cursor_t *cursor, int i, unw_word_t * word)
> +{
> +	return 0;
> +}
> +static inline int unw_get_proc_name (unw_cursor_t *cursor, char *c, size_t s, unw_word_t *word)
> +{
> +	return 0;
> +}
> diff --git a/meson.build b/meson.build
> index eff35585f619..861d7f88a3e1 100644
> --- a/meson.build
> +++ b/meson.build
> @@ -50,6 +50,7 @@ build_chamelium = get_option('build_chamelium')
>  build_docs = get_option('build_docs')
>  build_tests = get_option('build_tests')
>  with_libdrm = get_option('with_libdrm')
> +with_libunwind = get_option('with_libunwind')
>  build_runner = get_option('build_runner')
>  
>  _build_overlay = build_overlay != 'false'
> @@ -102,7 +103,17 @@ build_info += 'With libdrm: ' + ','.join(libdrm_info)
>  pciaccess = dependency('pciaccess', version : '>=0.10')
>  libkmod = dependency('libkmod')
>  libprocps = dependency('libprocps', required : true)
> -libunwind = dependency('libunwind', required : true)
> +
> +libunwind = null_dep
> +libunwindinfo = 'No'
> +if with_libunwind == 'auto' or with_libunwind == 'true'
> +	libunwind = dependency('libunwind', required : with_libunwind == 'true')
> +	if libunwind.found()
> +		libunwindinfo = 'Yes'
> +	endif
> +endif
> +build_info += 'With libunwind: ' + libunwindinfo
> +
>  libdw = dependency('libdw', required : true)
>  ssl = dependency('openssl', required : true)
>  pixman = dependency('pixman-1', required : true)
> diff --git a/meson_options.txt b/meson_options.txt
> index 89a3731c19ee..0cd3b350d994 100644
> --- a/meson_options.txt
> +++ b/meson_options.txt
> @@ -52,6 +52,12 @@ option('with_libdrm',
>         choices : ['', 'auto', 'intel', 'nouveau', 'amdgpu'],
>         description : 'libdrm libraries to be used')
>  
> +option('with_libunwind',
> +       type : 'combo',
> +       value : 'auto',
> +       choices : ['auto', 'true', 'false'],
> +       description : 'Use libunwind')
> +
>  option('build_runner',
>         type : 'combo',
>         value : 'auto',
> -- 
> 2.19.1
> 

-- 
Sean Paul, Software Engineer, Google / Chromium OS