Merge pull request #611 from czgdp1807/structs_01

Initial support for structs at ASR, LLVM levels.

Author: certik

integration_tests/CMakeLists.txt

@@ -168,6 +168,7 @@ RUN(NAME test_integer_bitnot LABELS cpython llvm)
 RUN(NAME test_unary_minus    LABELS cpython llvm)
 RUN(NAME test_unary_plus     LABELS cpython llvm)
 RUN(NAME test_issue_518      LABELS cpython llvm)
+RUN(NAME structs_01          LABELS cpython llvm)
 
 # Just CPython
 RUN(NAME test_builtin_bin    LABELS cpython)

integration_tests/structs_01.py

@@ -0,0 +1,27 @@
+from ltypes import i32, f32, dataclass
+
+@dataclass
+class A:
+    x: i32
+    y: f32
+
+def f(a: A):
+    print(a.x)
+    print(a.y)
+
+def g():
+    x: A
+    x = A(3, 3.3)
+    f(x)
+    # TODO: the above constructor does not initialize `A` in LPython yet, so
+    # the below does not work:
+    #assert x.x == 3
+    #assert x.y == 3.3
+
+    x.x = 5
+    x.y = 5.5
+    f(x)
+    assert x.x == 5
+    assert x.y == 5.5
+
+g()

src/libasr/pass/class_constructor.cpp

@@ -37,10 +37,13 @@ class ClassConstructorVisitor : public PassUtils::PassVisitor<ClassConstructorVi
     }
 
     void visit_DerivedTypeConstructor(const ASR::DerivedTypeConstructor_t &x) {
+        if( x.n_args == 0 ) {
+            remove_original_stmt = true;
+        }
         ASR::Derived_t* dt_der = down_cast<ASR::Derived_t>(x.m_type);
-        ASR::DerivedType_t* dt_dertype = (ASR::DerivedType_t*)(&(
-                                         LFortran::ASRUtils::symbol_get_past_external(dt_der->m_derived_type)->base));
-        for( size_t i = 0; i < dt_dertype->n_members; i++ ) {
+        ASR::DerivedType_t* dt_dertype = ASR::down_cast<ASR::DerivedType_t>(
+                                         LFortran::ASRUtils::symbol_get_past_external(dt_der->m_derived_type));
+        for( size_t i = 0; i < std::min(dt_dertype->n_members, x.n_args); i++ ) {
             ASR::symbol_t* member = dt_dertype->m_symtab->resolve_symbol(std::string(dt_dertype->m_members[i], strlen(dt_dertype->m_members[i])));
             ASR::expr_t* derived_ref = LFortran::ASRUtils::EXPR(ASRUtils::getDerivedRef_t(al, x.base.base.loc, (ASR::asr_t*)result_var, member, current_scope));
             ASR::stmt_t* assign = LFortran::ASRUtils::STMT(ASR::make_Assignment_t(al, x.base.base.loc, derived_ref, x.m_args[i], nullptr));

src/libasr/pass/pass_utils.h

@@ -68,7 +68,7 @@ namespace LFortran {
 
             public:
 
-                bool asr_changed, retain_original_stmt;
+                bool asr_changed, retain_original_stmt, remove_original_stmt;
                 Allocator& al;
                 Vec<ASR::stmt_t*> pass_result;
                 SymbolTable* current_scope;
@@ -86,6 +86,7 @@ namespace LFortran {
                         // visitor method:
                         pass_result.n = 0;
                         retain_original_stmt = false;
+                        remove_original_stmt = false;
                         self().visit_stmt(*m_body[i]);
                         if (pass_result.size() > 0) {
                             asr_changed = true;
@@ -97,7 +98,7 @@ namespace LFortran {
                                 retain_original_stmt = false;
                             }
                             pass_result.n = 0;
-                        } else {
+                        } else if(!remove_original_stmt) {
                             body.push_back(al, m_body[i]);
                         }
                     }