Merge pull request #1916 from Smit-create/i-1914

ASR: Allow importing union

Author: certik

integration_tests/CMakeLists.txt

@@ -561,6 +561,8 @@ RUN(NAME enum_07             IMPORT_PATH ..
 RUN(NAME union_01            LABELS cpython llvm c)
 RUN(NAME union_02            LABELS llvm c)
 RUN(NAME union_03            LABELS cpython llvm c)
+RUN(NAME union_04            IMPORT_PATH ..
+                             LABELS cpython llvm c)
 RUN(NAME test_str_to_int     LABELS cpython llvm c)
 RUN(NAME test_platform       LABELS cpython llvm c)
 RUN(NAME test_vars_01        LABELS cpython llvm)

integration_tests/union_04.py

@@ -0,0 +1,24 @@
+from union_01 import u_type
+from lpython import f32, f64, i64
+
+# Test taken from union_01.py but checks importing union
+
+def test_union_04():
+    unionobj: u_type = u_type()
+    unionobj.integer32 = 1
+    print(unionobj.integer32)
+    assert unionobj.integer32 == 1
+
+    unionobj.real32 = f32(2.0)
+    print(unionobj.real32)
+    assert abs(f64(unionobj.real32) - 2.0) <= 1e-6
+
+    unionobj.real64 = 3.5
+    print(unionobj.real64)
+    assert abs(unionobj.real64 - 3.5) <= 1e-12
+
+    unionobj.integer64 = i64(4)
+    print(unionobj.integer64)
+    assert unionobj.integer64 == i64(4)
+
+test_union_04()

src/lpython/semantics/python_ast_to_asr.cpp

@@ -483,6 +483,20 @@ ASR::symbol_t* import_from_module(Allocator &al, ASR::Module_t *m, SymbolTable *
             ASR::accessType::Public
             );
         return ASR::down_cast<ASR::symbol_t>(est);
+    } else if (ASR::is_a<ASR::UnionType_t>(*t)) {
+        ASR::UnionType_t *ut = ASR::down_cast<ASR::UnionType_t>(t);
+        Str name;
+        name.from_str(al, new_sym_name);
+        char *cname = name.c_str(al);
+        ASR::asr_t *est = ASR::make_ExternalSymbol_t(
+            al, loc,
+            /* a_symtab */ current_scope,
+            /* a_name */ cname,
+            (ASR::symbol_t*)ut,
+            m->m_name, nullptr, 0, ut->m_name,
+            ASR::accessType::Public
+            );
+        return ASR::down_cast<ASR::symbol_t>(est);
     } else if (ASR::is_a<ASR::Variable_t>(*t)) {
         ASR::Variable_t *mv = ASR::down_cast<ASR::Variable_t>(t);
         // `mv` is the Variable in a module. Now we construct