[babl] Meson build: Improve host environment detection / handling

[Øyvind Kolås <ok src gnome org>]

commit 3e25c8f93f6bb3076a9e5e875bfdab651c818cc9
Author: John Marshall <jtm home gmail com>
Date:   Sat May 19 11:36:45 2018 +0100

    Meson build: Improve host environment detection / handling

 babl/meson.build          |    6 ++--
 docs/graphics/meson.build |   38 ++++++++++++++-------------
 docs/meson.build          |    6 +++-
 meson.build               |   62 ++++++++++++++++++++++++++++++++++----------
 tests/meson.build         |   22 ++++++++++------
 5 files changed, 89 insertions(+), 45 deletions(-)
---
diff --git a/babl/meson.build b/babl/meson.build
index b3058cc..b5b6cba 100644
--- a/babl/meson.build
+++ b/babl/meson.build
@@ -10,21 +10,21 @@ babl_version_h = configure_file(
 gitversion_h1 = vcs_tag(
   input : 'git-version.h.in',
   output: 'git-version.h.in.1',
-  command: [ 'git', 'describe', '--always', ],
+  command: [ git_bin.path(), 'describe', '--always', ],
   replace_string: '@BABL_GIT_VERSION@',
   fallback: '',
 )
 gitversion_h2 = vcs_tag(
   input : gitversion_h1,
   output: 'git-version.h.in.2',
-  command: [ 'git', 'rev-parse', '--short', 'HEAD', ],
+  command: [ git_bin.path(), 'rev-parse', '--short', 'HEAD', ],
   replace_string: '@BABL_GIT_VERSION_ABBREV@',
   fallback: '',
 )
 gitversion_h = vcs_tag(
   input : gitversion_h2,
   output: 'git-version.h',
-  command: [ 'git', 'log', '-n1', '--date=format:%Y', '--pretty=%cd', ],
+  command: [ git_bin.path(), 'log', '-n1', '--date=format:%Y', '--pretty=%cd', ],
   replace_string: '@BABL_GIT_LAST_COMMIT_YEAR@',
   fallback: '',
 )
diff --git a/docs/graphics/meson.build b/docs/graphics/meson.build
index 5b1715a..e7fe9f7 100644
--- a/docs/graphics/meson.build
+++ b/docs/graphics/meson.build
@@ -9,22 +9,24 @@ graphic_files_install = [
   files('index.html'),
 ]
 
-foreach file : graphic_files
-  sizeinfo = (
-    file.contains('a4poster')
-    ? [ '-w', '256', ]
-    : []
-  )
+if rsvg_convert_bin.found()
+  foreach file : graphic_files
+    sizeinfo = (
+      file.contains('a4poster')
+      ? [ '-w', '256', ]
+      : []
+    )
 
-  graphic_files_install += custom_target(file,
-    input : [ file + '.svg' ],
-    output: [ file + '.png' ],
-    command: [
-      rsvg_convert,
-      sizeinfo,
-      '-o', '@OUTPUT@',
-      '@INPUT@',
-    ],
-    install: false,
-  )
-endforeach
+    graphic_files_install += custom_target(file,
+      input : [ file + '.svg' ],
+      output: [ file + '.png' ],
+      command: [
+        rsvg_convert_bin,
+        sizeinfo,
+        '-o', '@OUTPUT@',
+        '@INPUT@',
+      ],
+      install: false,
+    )
+  endforeach
+endif
diff --git a/docs/meson.build b/docs/meson.build
index 95f77a2..1c33c44 100644
--- a/docs/meson.build
+++ b/docs/meson.build
@@ -18,7 +18,8 @@ index_static_html = configure_file(
 index_html_tmp = custom_target('index.html.tmp',
   input : [ babl_html_dump, ],
   output: [ 'index.html.tmp', ],
-  command: [ find_program('env'),
+  command: [
+    env_bin,
     'BABL_PATH='+ join_paths(meson.build_root(), 'extensions'),
     babl_html_dump
   ],
@@ -34,7 +35,8 @@ index_html = custom_target('index.html',
     join_paths(meson.source_root(), 'NEWS'),
   ],
   output: [ 'index.html', ],
-  command: [ find_program('env'),
+  command: [
+    env_bin,
     'cp', '@INPUT0@', '@OUTPUT@',
     '&&', xml_insert, '@OUTPUT@', 'BablBase', '@INPUT1@',
     '&&', xml_insert, '@OUTPUT@', 'AUTHORS',  '@INPUT2@',
diff --git a/meson.build b/meson.build
index 8909092..d53ae46 100644
--- a/meson.build
+++ b/meson.build
@@ -3,6 +3,7 @@ project('babl', 'c',
   version: '0.1.49',
   meson_version: '>=0.40.0',
   default_options: [
+    'libdir=lib',
     'sysconfdir=/etc',
     'localstatedir=/var',
     'sharedstatedir=/var/lib'
@@ -68,7 +69,11 @@ conf.set_quoted('BABL_CURRENT_MINUS_AGE','@0@'.format(0))
 conf.set_quoted('BABL_LIBRARY',          '@0@'.format(lib_name))
 
 ################################################################################
-# Host system detection
+# Host system environment
+
+platform_android = false
+platform_osx = false
+platform_win32 = false
 
 host_cpu = host_machine.cpu()
 message('Architecture: ' + host_cpu)
@@ -91,16 +96,17 @@ else
   error('Unknown host architecture')
 endif
 
-
 host_os = host_machine.system()
 message('Host os: ' + host_os)
 
-platform_win32 = host_os.startswith('mingw') or host_os.startswith('cygwin') or host_os.startswith('windows')
+platform_win32 = (host_os.startswith('mingw') or
+                  host_os.startswith('cygwin') or
+                  host_os.startswith('windows'))
 
 platform_osx = host_os.startswith('darwin')
 if platform_osx
   if cc.get_id() != 'clang'
-    error('You should use CLang++ on OSx.')
+    error('You should use Clang/Clang++ on OSX.')
   endif
 endif
 
@@ -108,12 +114,31 @@ platform_android = host_os.contains('android')
 
 path_sep = ( platform_win32 ? ';'     : ':' )
 dirs_sep = ( platform_win32 ? '\\\\'  : '/' )
+bin_ext  = ( platform_win32 ? '.exe'  : '' )
 lib_ext  = ( platform_win32 ? '.dll'  : '.so' )
 
 conf.set       ('BABL_PATH_SEPARATOR', '\'' + path_sep + '\'')
 conf.set_quoted('BABL_DIR_SEPARATOR',  dirs_sep)
 conf.set_quoted('SHREXT',              lib_ext)
 
+# assume *nix if not android/osx/win32
+platform_unix = not (
+  platform_android or
+  platform_osx or
+  platform_win32
+)
+
+# Build system environment
+build_os = build_machine.system()
+message('Build os: ' + build_os)
+
+build_platform_win32 = (build_os.startswith('mingw') or
+                        build_os.startswith('cygwin') or
+                        build_os.startswith('windows'))
+
+native_bin_ext  = ( build_platform_win32 ? '.exe'  : '' )
+
+
 ################################################################################
 # Extra warnings
 
@@ -210,20 +235,29 @@ endif
 conf.set('HAVE_DLFCN_H', have_dlfcn_h)
 conf.set('HAVE_DL_H',    have_dl_h)
 
+
 ################################################################################
-# Utilities
+# Dependencies
 
-rsvg_convert = find_program('rsvg-convert', required: false)
-w3m          = find_program('w3m', required: false)
+math   = cc.find_library('m',   required: false)
+log    = cc.find_library('log', required: false)
+dl     = cc.find_library('dl',  required: false)
+
+thread = dependency('threads',  required: false)
 
 
 ################################################################################
-# Dependencies
+# Build utilities
+
+env_bin = find_program('env' + native_bin_ext, required: true,
+  native: true)
+git_bin = find_program('git' + native_bin_ext, required: true,
+  native: true)
+rsvg_convert_bin = find_program('rsvg-convert' + native_bin_ext,
+  required: false, native: true)
+w3m_bin = find_program('w3m' + native_bin_ext, required: false,
+  native: true)
 
-math  = cc.find_library('m',       required: false)
-thread= cc.find_library('pthread', required: false)
-log   = cc.find_library('log',     required: false)
-dl    = cc.find_library('dl',      required: false)
 
 
 pkgconfig.generate(filebase: 'babl',
@@ -263,12 +297,12 @@ if get_option('with-docs')
 endif
 
 
-if w3m.found()
+if w3m_bin.found()
   custom_target('README',
     input : [ join_paths('docs', 'index.html'), ] ,
     output: [ 'README' ] ,
     command: [
-      w3m,
+      w3m_bin,
       '-cols', '72',
       '-dump',
       '@INPUT@',
diff --git a/tests/meson.build b/tests/meson.build
index 0490c2c..46313c5 100644
--- a/tests/meson.build
+++ b/tests/meson.build
@@ -21,25 +21,31 @@ test_names = [
   'transparent',
   'types',
 ]
-if true or os_unix
-  test_names += [ 'concurrency-stress-test', 'palette-concurrency-stress-test' ]
+if platform_unix
+  test_names += [
+    'concurrency-stress-test',
+    'palette-concurrency-stress-test',
+  ]
 endif
 
+test_env = environment()
+test_env.prepend('LD_LIBRARY_PATH', join_paths(meson.build_root(), 'babl'))
+test_env.set('GI_TYPELIB_PATH', join_paths(meson.build_root(), 'babl'))
+test_env.set('BABL_PATH', join_paths(meson.build_root(), 'extensions'))
 foreach test_name : test_names
-  test = executable(test_name,
+  test = executable(
+    test_name,
     test_name + '.c',
     include_directories: [ rootInclude, bablInclude, ],
     link_with: [ babl, ],
     dependencies: [ thread, ],
+    export_dynamic: true,
     install: false,
   )
 
   test(test_name,
     test,
-    env: [
-      'LD_LIBRARY_PATH='+ join_paths(meson.build_root(), 'babl') + ':$LD_LIBRARY_PATH',
-      'GI_TYPELIB_PATH='+ join_paths(meson.build_root(), 'babl'),
-      'BABL_PATH='      + join_paths(meson.build_root(), 'extensions'),
-    ],
+    env: test_env,
+    workdir: meson.current_build_dir(),
   )
 endforeach