meson: add a option where to find the clang library and header

with having them people can just specify where the clang stuff is
installed, if its not possible to find it in the default location.

This fixes a bug where clang was not found, dirs: is meant as exclusive
parameter, so if you specify there a custom directory, then only THIS
specific directory will be used for the search. This fixes also that bug
and only specifies that argument if a custom location is given.

meson.build

@@ -40,17 +40,37 @@ else
   config_h.set_quoted('BEAR_COMMAND', '')
 endif
 
-if get_option('libclang') == true and cc.has_header('clang-c/Index.h')
-  has_clang_header = true
-  clang = cc.find_library('clang', dirs : ['/usr/local/opt/llvm/lib'])
+opt_clang_header_dir = get_option('libclang-libdir')
+opt_clang_link_dir = get_option('libclang-headerdir')
+
+if get_option('libclang') == true
+
+  #check for the header
+  found = false
+  if opt_clang_header_dir != ''
+    found = cc.has_header('clang-c/Index.h', args : '-I'+opt_clang_header_dir)
+  else
+    found = cc.has_header('clang-c/Index.h')
+  endif
+
+  if found == false
+    error('Clang header not found!')
+  endif
+
+  clang_inc = include_directories(opt_clang_header_dir)
+
+  #check for the library to link
+  if opt_clang_link_dir != ''
+    clang = cc.find_library('clang', dirs : [opt_clang_link_dir])
+  else
+    clang = cc.find_library('clang')
+  endif
 
   clang_include_dir_command = run_command(find_program('scripts/clang_include_dir.sh'))
   clang_include_dir = clang_include_dir_command.stdout().strip()
 
   config_h.set_quoted('CLANG_INCLUDES', clang_include_dir)
   config_h.set('HAVE_LIBCLANG', '1')
-else
-  has_clang_header = false
 endif
 
 subdir('po')

meson_options.txt

@@ -1,2 +1,4 @@
 option('libclang', type : 'boolean', value : true, description : 'Weather to have libclang support')
 option('bear', type : 'boolean', value : true, description : 'Weather to have bear support')
+option('libclang-libdir', type : 'string', value : '', description : 'Specify a none default location for your clang installation')
+option('libclang-headerdir', type : 'string', value : '', description : 'Specify a none default location for your clang installation')

scripts/clang_build_include_dir.sh

@@ -1,6 +0,0 @@
-#!/bin/sh
-
-if [[ -d /usr/local/opt/llvm ]]; then
-  echo "/usr/local/opt/llvm/include"
-fi
-

src/bin/meson.build

@@ -28,14 +28,9 @@ endforeach
 deps = [elm, edi_lib, intl]
 incls = []
 
-if get_option('libclang') == true and has_clang_header == true
+if get_option('libclang') == true
    deps += [clang]
-
-   clang_build_include_dir_command = run_command(find_program('../../scripts/clang_build_include_dir.sh'))
-   clang_build_include_dir = clang_build_include_dir_command.stdout().strip()
-   if clang_build_include_dir != ''
-      incls += include_directories(clang_build_include_dir)
-   endif
+   incls += [clang_inc]
 endif
 
 executable('edi', src,

src/tests/meson.build

@@ -13,8 +13,9 @@ check = dependency('check')
 
 deps = [elm, check, edi_lib]
 
-if get_option('libclang') == true and has_clang_header == true
+if get_option('libclang') == true
    deps += [clang]
+   incls += [clang_inc]
 endif
 
 exe = executable('edi_suite', src,