Kotlin: Use 'which' to find kotlinc

This means we handle kotlinc.batr and kotlinc.cmd on Windows.

java/kotlin-extractor/build.py

@@ -35,8 +35,12 @@ def is_windows():
         return True
     return False
 
+# kotlinc might be kotlinc.bat or kotlinc.cmd on Windows, so we use `which` to find out what it is
+kotlinc = shutil.which('kotlinc')
+if kotlinc is None:
+    print("Cannot build the Kotlin extractor: no kotlinc found on your PATH", file = sys.stderr)
+    sys.exit(1)
 
-kotlinc = 'kotlinc.bat' if is_windows() else 'kotlinc'
 javac = 'javac'
 kotlin_dependency_folder = args.dependencies
 
@@ -201,10 +205,6 @@ def compile_standalone(version):
             'build/temp_src',
             version)
 
-if shutil.which(kotlinc) == None:
-    print("Cannot build the Kotlin extractor: no '%s' found on your PATH" % kotlinc, file = sys.stderr)
-    sys.exit(1)
-
 if args.many:
     for version in kotlin_plugin_versions.many_versions:
         compile_standalone(version)

java/kotlin-extractor/kotlin_plugin_versions.py

@@ -1,5 +1,6 @@
 import platform
 import re
+import shutil
 import subprocess
 import sys
 
@@ -26,11 +27,11 @@ class KotlincNotFoundException(Exception):
     pass
 
 def get_single_version(fakeVersionOutput = None):
-    # TODO: `shell=True` is a workaround to get CI working on Windows. It breaks the build on Linux.
-    try:
-        versionOutput = subprocess.run(['kotlinc', '-version'], stdout=subprocess.PIPE, stderr=subprocess.PIPE, universal_newlines=True, shell=is_windows()).stderr if fakeVersionOutput is None else fakeVersionOutput
-    except FileNotFoundError as e:
-        raise KotlincNotFoundException(e)
+    # kotlinc might be kotlinc.bat or kotlinc.cmd on Windows, so we use `which` to find out what it is
+    kotlinc = shutil.which('kotlinc')
+    if kotlinc is None:
+        raise KotlincNotFoundException()
+    versionOutput = subprocess.run(['kotlinc', '-version'], stdout=subprocess.PIPE, stderr=subprocess.PIPE, universal_newlines=True).stderr if fakeVersionOutput is None else fakeVersionOutput
     m = re.match(r'.* kotlinc-jvm ([0-9]+\.[0-9]+\.[0-9]+) .*', versionOutput)
     if m is None:
         raise Exception('Cannot detect version of kotlinc (got ' + str(versionOutput) + ')')