bytecompile: switch to handling destdir in the script launcher env

mesonbuild/modules/python.py

@@ -322,13 +322,13 @@ class PythonModule(ExtensionModule):
 
         for t in installdata.targets:
             if should_append(t.out_name):
-                py_files.append(os.path.join(installdata.prefix, t.outdir, os.path.basename(t.fname)))
+                py_files.append((t.out_name, os.path.join(installdata.prefix, t.outdir, os.path.basename(t.fname))))
         for d in installdata.data:
             if should_append(d.install_path_name):
-                py_files.append(os.path.join(installdata.prefix, d.install_path))
+                py_files.append((d.install_path_name, os.path.join(installdata.prefix, d.install_path)))
         for d in installdata.install_subdirs:
             if should_append(d.install_path_name, True):
-                py_files.append(os.path.join(installdata.prefix, d.install_path))
+                py_files.append((d.install_path_name, os.path.join(installdata.prefix, d.install_path)))
 
         import importlib.resources
         pycompile = os.path.join(self.interpreter.environment.get_scratch_dir(), 'pycompile.py')
@@ -340,13 +340,15 @@ class PythonModule(ExtensionModule):
                 i = T.cast(PythonExternalProgram, i)
                 manifest = f'python-{i.info["version"]}-installed.json'
                 manifest_json = []
-                for f in py_files:
+                for name, f in py_files:
                     if f.startswith((os.path.join(installdata.prefix, i.platlib), os.path.join(installdata.prefix, i.purelib))):
-                        manifest_json.append(f)
+                        manifest_json.append(name)
                 with open(os.path.join(self.interpreter.environment.get_scratch_dir(), manifest), 'w', encoding='utf-8') as f:
                     json.dump(manifest_json, f)
                 cmd = i.command + [pycompile, manifest, str(optlevel)]
-                script = backend.get_executable_serialisation(cmd, verbose=True)
+
+                script = backend.get_executable_serialisation(cmd, verbose=True,
+                                                              installdir_map={'py_purelib': i.purelib, 'py_platlib': i.platlib})
                 ret.append(script)
         return ret
 

mesonbuild/scripts/pycompile.py

@@ -20,28 +20,26 @@
 import json, os, subprocess, sys
 from compileall import compile_file
 
-destdir = os.environ.get('DESTDIR')
 quiet = int(os.environ.get('MESON_INSTALL_QUIET', 0))
 
-def destdir_join(d1, d2):
-    if not d1:
-        return d2
-    # c:\destdir + c:\prefix must produce c:\destdir\prefix
-    parts = os.path.splitdrive(d2)
-    return d1 + parts[1]
-
 def compileall(files):
     for f in files:
-        if destdir is not None:
+        # f is prefixed by {py_xxxxlib}, both variants are 12 chars
+        # the key is the middle 10 chars of the prefix
+        key = f[1:11].upper()
+        f = f[12:]
+
+        ddir = None
+        fullpath = os.environ['MESON_INSTALL_DESTDIR_'+key] + f
+        f = os.environ['MESON_INSTALL_'+key] + f
+
+        if fullpath != f:
             ddir = os.path.dirname(f)
-            fullpath = destdir_join(destdir, f)
-        else:
-            ddir = None
-            fullpath = f
 
         if os.path.isdir(fullpath):
             for root, _, files in os.walk(fullpath):
-                ddir = os.path.dirname(os.path.splitdrive(f)[0] + root[len(destdir):])
+                if ddir is not None:
+                    ddir = root.replace(fullpath, f, 1)
                 for dirf in files:
                     if dirf.endswith('.py'):
                         fullpath = os.path.join(root, dirf)