[gimp] meson: improve/fix previous commit from MR !725.

[Jehan <jehanp src gnome org>]

commit 9ce27be989882c262f38f58629f1f96865c29d98
Author: Jehan <jehan girinstud io>
Date:   Mon Aug 29 12:39:49 2022 +0200

    meson: improve/fix previous commit from MR !725.
    
    - Setting an exec_dir variable is an error. As meson docs says, if
      relative, it is installed relatively to prefix anyway: "If this is a
      relative path, it is assumed to be relative to the prefix."
      On the other hand, it would make problems if someone tried to set an
      absolute bindir.
      Moreover it is a lot clearer now. When we want to install in the
      binary directory unconditionally, then get_option('bindir') is the
      meson way, hence the way to go.
    - On the other hand, the `gimp-debug-tool` is installed either in bindir
      for Windows or macOS and libexecdir for all other platforms, at least
      that's how it's set in the autotools build. So let's keep both builds
      consistent.
    - Make a hopefully clearer description for enable-default-bin option.
      Let's clarify this is just about creating unversionning links pointing
      to versionned files.
    - Adding an item in the "Optional Features" part of the summary listing
      during meson configure, for better discovery.
    
    For the ".exe" extension on Windows, I wished we had an $(EXEEXT)
    equivalent on meson rather than trying to set it ourselves (are there
    other platforms where we must set a different extension?). But I could
    not find any.

 app-tools/meson.build                      | 10 ++++++++--
 app/meson.build                            |  4 ++--
 meson.build                                |  2 +-
 meson_options.txt                          |  2 +-
 plug-ins/script-fu/interpreter/meson.build |  2 +-
 tools/meson.build                          |  4 ++--
 6 files changed, 15 insertions(+), 9 deletions(-)
---
diff --git a/app-tools/meson.build b/app-tools/meson.build
index 1803dd37db..d6ae993176 100644
--- a/app-tools/meson.build
+++ b/app-tools/meson.build
@@ -1,3 +1,9 @@
+if platform_windows or platform_osx
+  gimp_debug_tool_dir = get_option('bindir')
+else
+  gimp_debug_tool_dir = get_option('libexecdir')
+endif
+
 
 gimp_debug_tool = executable('gimp-debug-tool-' + gimp_app_version,
   'gimp-debug-tool.c',
@@ -14,12 +20,12 @@ gimp_debug_tool = executable('gimp-debug-tool-' + gimp_app_version,
     libgimpbase,
   ],
   install: true,
-  install_dir: exec_dir
+  install_dir: gimp_debug_tool_dir
 )
 
 if enable_default_bin and meson.version().version_compare('>=0.61.0')
   install_symlink('gimp-debug-tool' + exec_ext,
     pointing_to: 'gimp-debug-tool-' + gimp_app_version + exec_ext,
-    install_dir: exec_dir
+    install_dir: gimp_debug_tool_dir
   )
 endif
diff --git a/app/meson.build b/app/meson.build
index acc86be4b2..4d7935e9f4 100644
--- a/app/meson.build
+++ b/app/meson.build
@@ -221,12 +221,12 @@ gimpmain_exe = executable('gimp-'+gimp_app_version,
 if enable_default_bin and meson.version().version_compare('>=0.61.0')
   install_symlink('gimp' + exec_ext,
     pointing_to: 'gimp-' + gimp_app_version + exec_ext,
-    install_dir: exec_dir
+    install_dir: get_option('bindir')
   )
   if enable_console_bin
     install_symlink('gimp-console' + exec_ext,
       pointing_to: 'gimp-console-' + gimp_app_version + exec_ext,
-      install_dir: exec_dir
+      install_dir: get_option('bindir')
     )
   endif
 endif
diff --git a/meson.build b/meson.build
index 9d4f2b37f1..2efdfe3f3b 100644
--- a/meson.build
+++ b/meson.build
@@ -92,7 +92,6 @@ cc        = meson.get_compiler('c')
 cxx       = meson.get_compiler('cpp')
 prefix    = get_option('prefix')
 buildtype = get_option('buildtype')
-exec_dir  = prefix + '/' + get_option('bindir')
 exec_ext  = ''
 
 compiler_args = []
@@ -1807,6 +1806,7 @@ final_message = [
 '''  Default ICC directory:     @0@'''.format(icc_directory),
 '''  32-bit DLL folder (Win32): @0@'''.format(get_option('win32-32bits-dll-folder')),
 '''  Detailed backtraces:       @0@'''.format(detailed_backtraces),
+'''  Binary symlinks:           @0@'''.format(enable_default_bin),
 '',
 '''Optional Plug-Ins:''',
 '''  Ascii Art:           @0@'''.format(libaa.found()),
diff --git a/meson_options.txt b/meson_options.txt
index 6558c65e49..1d7194c847 100644
--- a/meson_options.txt
+++ b/meson_options.txt
@@ -2,7 +2,7 @@
 option('ansi',              type: 'boolean', value: false,  description: 'Turn on strict ansi')
 option('enable-console-bin',type: 'boolean', value: true,   description: 'Build a console-only binary which 
does not link GTK')
 option('win32-debug-console',type:'boolean', value: true,   description: 'Open a console when starting the 
program')
-option('enable-default-bin',type: 'boolean', value: true,   description: 'Install default app links pointing 
to the executables')
+option('enable-default-bin',type: 'boolean', value: true,   description: 'Install unversioned symlinks 
pointing to versioned executables')
 option('enable-multiproc',  type: 'boolean', value: true,   description: 'Support for multiple processors')
 option('profiling',         type: 'boolean', value: false,  description: 'Enable profiling')
 option('windows-installer', type: 'boolean', value: false,  description: 'Generate files needed for the 
Windows installer')
diff --git a/plug-ins/script-fu/interpreter/meson.build b/plug-ins/script-fu/interpreter/meson.build
index 33f7afcf2a..c57e61100c 100644
--- a/plug-ins/script-fu/interpreter/meson.build
+++ b/plug-ins/script-fu/interpreter/meson.build
@@ -44,6 +44,6 @@ executable(executable_name,
 if enable_default_bin and meson.version().version_compare('>=0.61.0')
   install_symlink('gimp-script-fu-interpreter' + exec_ext,
     pointing_to: executable_name + exec_ext,
-    install_dir: exec_dir
+    install_dir: get_option('bindir')
   )
 endif
diff --git a/tools/meson.build b/tools/meson.build
index 02d9cd8ab2..2ae0fc9bc2 100644
--- a/tools/meson.build
+++ b/tools/meson.build
@@ -33,11 +33,11 @@ executable('gimp-test-clipboard-' + gimp_app_version,
 if enable_default_bin and meson.version().version_compare('>=0.61.0')
   install_symlink('gimptool' + exec_ext,
     pointing_to: 'gimptool-' + gimp_app_version + exec_ext,
-    install_dir: exec_dir
+    install_dir: get_option('bindir')
   )
   install_symlink('gimp-test-clipboard' + exec_ext,
     pointing_to: 'gimp-test-clipboard-' + gimp_app_version + exec_ext,
-    install_dir: exec_dir
+    install_dir: get_option('bindir')
   )
 endif