make sure we do not leak buildsystem paths into the image

Author: timfel

graalpython/com.oracle.graal.python/src/com/oracle/graal/python/builtins/modules/GraalPythonModuleBuiltins.java

@@ -133,6 +133,8 @@ public void postInitialize(PythonCore core) {
         if (!ImageInfo.inImageBuildtimeCode()) {
             mod.setAttribute("home", language.getHome());
         }
+        mod.setAttribute("in_image_buildtime", ImageInfo.inImageBuildtimeCode());
+        mod.setAttribute("in_image", ImageInfo.inImageCode());
         String coreHome = context.getCoreHome();
         String stdlibHome = context.getStdlibHome();
         String capiHome = context.getCAPIHome();

graalpython/com.oracle.graal.python/src/com/oracle/graal/python/runtime/PythonContext.java

@@ -534,24 +534,23 @@ public void initializeHomeAndPrefixPaths(Env newEnv, String languageHome) {
                     }
                 } catch (SecurityException | IOException e) {
                 }
-            } else {
-                TruffleFile f = newEnv.getInternalTruffleFile(stdLibHome);
-                if (!f.isAbsolute()) {
-                    try {
-                        // we need to get absolute path due to the caching code, where the filepath
-                        // is the key for caching.
-                        stdLibHome = f.getCanonicalFile().getPath();
-                    } catch (IOException e) {
-                        // if the file does not exists, then it fails during reading.
-                    }
-                }
             }
 
             if (capiHome.isEmpty()) {
                 capiHome = coreHome;
             }
         }
 
+        if (ImageInfo.inImageBuildtimeCode()) {
+            // use relative paths at buildtime to avoid freezing buildsystem paths
+            TruffleFile base = newEnv.getInternalTruffleFile("").getAbsoluteFile();
+            sysPrefix = base.relativize(newEnv.getInternalTruffleFile(sysPrefix)).getPath();
+            basePrefix = base.relativize(newEnv.getInternalTruffleFile(basePrefix)).getPath();
+            coreHome = base.relativize(newEnv.getInternalTruffleFile(coreHome)).getPath();
+            stdLibHome = base.relativize(newEnv.getInternalTruffleFile(stdLibHome)).getPath();
+            capiHome = base.relativize(newEnv.getInternalTruffleFile(capiHome)).getPath();
+        }
+
         PythonCore.writeInfo(() -> MessageFormat.format("Updated locations:" +
                         "\n\tLanguage home: {0}" +
                         "\n\tSysPrefix: {1}" +

graalpython/lib-python/3/importlib/_bootstrap_external.py

@@ -863,6 +863,8 @@ def get_code(self, fullname):
         hash_based = False
         check_source = True
         try:
+            if __graalpython__.in_image_buildtime:
+                raise NotImplementedError
             bytecode_path = cache_from_source(source_path)
         except NotImplementedError:
             bytecode_path = None