Fix llvm-kompile pythonast (#1047)

This PR addresses an issue experienced by @gtrepta and @theo25 where the
Python AST bindings for the LLVM backend incorrectly reference runtime
symbols like `FIRST_INJ_TAG` when loaded.

The solution is pretty straightforward; rather than trying to rely on
the linker implicitly stripping out undefined symbols when the library
is built, we just split the components into two parts (runtime and
non-runtime) and selectively include them.

The test case added in
0eb1d7f
fails before the script is amended.

---------

Co-authored-by: rv-jenkins <[email protected]>

bin/llvm-kompile-clang

@@ -226,23 +226,38 @@ else
 fi
 
 if $link; then
+  runtime_components=(
+    "$LIBDIR"/libarithmetic.a
+    "$LIBDIR"/libutil.a
+    "$LIBDIR"/libstrings.a
+    "$LIBDIR"/libnumeric_strings.a
+    "$LIBDIR"/libio.a
+    "$LIBDIR"/libcollections.a
+    "$LIBDIR"/libBindingsCore.a
+    "$LIBDIR"/libKOREPrinter.a
+    "$LIBDIR"/liballoc.a
+    "$LIBDIR"/libcollect.a
+    "$LIBDIR"/libmeta.a
+    "$LIBDIR"/libjson.a
+  )
+
+  components=(
+    "$LIBDIR"/libParser.a
+    "$LIBDIR"/libAST.a
+    "$LIBDIR"/libBinaryKore.a
+  )
+
+  # If we're linking a Python AST bindings module, then we don't want to include
+  # the backend's runtime components. On some platforms and build type
+  # combinations, the linker won't strip undefined symbols for us, which
+  # produces an error on trying to load the Python library.
+  if [ "$main" != "python_ast" ]; then
+    components=("${components[@]}" "${runtime_components[@]}")
+  fi
+
   run @CMAKE_CXX_COMPILER@ -Wno-override-module -Wno-return-type-c-linkage "$modopt" "${files[@]}" \
-    "$LIBDIR"/libarithmetic.a \
     "$MAINFILES" \
-    "$LIBDIR"/libutil.a \
-    "$LIBDIR"/libstrings.a \
-    "$LIBDIR"/libnumeric_strings.a \
-    "$LIBDIR"/libio.a \
-    "$LIBDIR"/libcollections.a \
-    "$LIBDIR"/libParser.a \
-    "$LIBDIR"/libAST.a \
-    "$LIBDIR"/libBindingsCore.a \
-    "$LIBDIR"/libBinaryKore.a \
-    "$LIBDIR"/libKOREPrinter.a \
-    "$LIBDIR"/liballoc.a \
-    "$LIBDIR"/libcollect.a \
-    "$LIBDIR"/libmeta.a \
-    "$LIBDIR"/libjson.a \
+    "${components[@]}" \
     "${flags[@]}" \
     "${all_libraries[@]}" \
     -I "$(dirname "$0")"/../include/kllvm \

test/python/test_pythonast.py

@@ -0,0 +1,6 @@
+# RUN: mkdir -p %t
+# RUN: llvm-kompile pythonast --python %py-interpreter --python-output-dir %t
+# RUN: cd %t
+# RUN: PYTHONPATH=. %py-interpreter %s
+
+import _kllvm