meson: Invoke scripts explicitly

To avoid issues with environments where python3 doesn't exist.

Also drop exec bit and shebang from scripts.

bindings/gumjs/generate-bindings.py

@@ -1,5 +1,3 @@
-#!/usr/bin/env python3
-
 from __future__ import unicode_literals, print_function
 import codecs
 import os

bindings/gumjs/generate-runtime.py

@@ -1,5 +1,3 @@
-#!/usr/bin/env python3
-
 from base64 import b64decode
 import json
 import os

bindings/gumjs/meson.build

@@ -207,7 +207,8 @@ gumjs_generated_bindings = custom_target('gumjs-generated-bindings',
   input: gumjs_generated_inputs,
   output: gumjs_generated_outputs,
   command: [
-    find_program('generate-bindings.py'),
+    python,
+    files('generate-bindings.py'),
     meson.current_build_dir(),
     meson.project_source_root() / 'gum',
   ],
@@ -236,7 +237,8 @@ gumjs_runtime = custom_target('gumjs-runtime',
   input: gumjs_runtime_sources,
   output: gumjs_runtime_outputs,
   command: [
-    find_program('generate-runtime.py'),
+    python,
+    files('generate-runtime.py'),
     meson.current_build_dir(),
     '@PRIVATE_DIR@',
     meson.current_source_dir(),

meson.build

@@ -6,14 +6,16 @@ project('frida-gum', 'c', 'cpp',
   ],
 )
 
+python = import('python').find_installation()
+
 releng = meson.global_source_root() / 'releng'
 if not import('fs').exists(releng)
   releng = meson.project_source_root() / 'releng'
 endif
 
 frida_version = get_option('frida_version')
 if frida_version == ''
-  frida_version = run_command(releng / 'frida_version.py', meson.project_source_root(), check: true).stdout().strip()
+  frida_version = run_command(python, files(releng / 'frida_version.py'), meson.project_source_root(), check: true).stdout().strip()
 endif
 
 api_version = '1.0'
@@ -441,7 +443,7 @@ if get_option('devkits').length() != 0
   if not static
     error('Devkits can only be generated from static libraries')
   endif
-  mkdevkit = find_program(releng / 'mkdevkit.py')
+  mkdevkit = [python, files(releng / 'mkdevkit.py')]
   uninstalled_dir = meson.global_build_root() / 'meson-uninstalled'
   devkit_options = [
     '--cc', '>>>', cc.cmd_array(), '<<<',

tests/meson.build

@@ -123,7 +123,7 @@ else
   runner = raw_runner
 endif
 
-test('gum', find_program('./run.py'),
-  args: runner.full_path(),
+test('gum', python,
+  args: [files('run.py'), runner.full_path()],
   timeout: 120,
 )

tests/run.py

@@ -1,5 +1,3 @@
-#!/usr/bin/env python3
-
 import os
 from pathlib import Path
 import platform