Added support for C backend

czgdp1807 · czgdp1807 · commit 22760baf0550 · 2022-12-15T16:05:32.000+05:30
diff --git a/integration_tests/CMakeLists.txt b/integration_tests/CMakeLists.txt
@@ -335,6 +335,7 @@ RUN(NAME structs_13          LABELS llvm c
     EXTRAFILES structs_13b.c)
 RUN(NAME structs_14          LABELS cpython llvm c)
 RUN(NAME structs_15          LABELS cpython llvm c)
+RUN(NAME structs_16          LABELS cpython llvm c)
 RUN(NAME sizeof_01           LABELS llvm c
         EXTRAFILES sizeof_01b.c)
 RUN(NAME enum_01             LABELS cpython llvm c)
diff --git a/src/libasr/asr_verify.cpp b/src/libasr/asr_verify.cpp
@@ -348,7 +348,8 @@ class VerifyVisitor : public BaseWalkVisitor<VerifyVisitor>
                 ASR::symbol_t* sym = ASR::down_cast<ASR::Union_t>(var_type)->m_union_type;
                 aggregate_type_name = ASRUtils::symbol_name(sym);
             }
-            if( aggregate_type_name ) {
+            if( aggregate_type_name &&
+                !current_symtab->get_symbol(std::string(aggregate_type_name)) ) {
                 struct_dependencies.push_back(std::string(aggregate_type_name));
                 require(present(x.m_dependencies, x.n_dependencies, std::string(aggregate_type_name)),
                     std::string(x.m_name) + " depends on " + std::string(aggregate_type_name)
diff --git a/src/libasr/codegen/asr_to_c.cpp b/src/libasr/codegen/asr_to_c.cpp
@@ -139,6 +139,9 @@ class ASRToCVisitor : public BaseCCPPVisitor<ASRToCVisitor>
     void allocate_array_members_of_struct(ASR::StructType_t* der_type_t, std::string& sub,
         std::string indent, std::string name) {
         for( auto itr: der_type_t->m_symtab->get_scope() ) {
+            if( ASR::is_a<ASR::UnionType_t>(*itr.second) ) {
+                continue ;
+            }
             ASR::ttype_t* mem_type = ASRUtils::symbol_type(itr.second);
             if( ASRUtils::is_character(*mem_type) ) {
                 sub += indent + name + "->" + itr.first + " = (char*) malloc(40 * sizeof(char));\n";
@@ -394,7 +397,8 @@ class ASRToCVisitor : public BaseCCPPVisitor<ASRToCVisitor>
             } else if (ASR::is_a<ASR::Union_t>(*v_m_type)) {
                 std::string indent(indentation_level*indentation_spaces, ' ');
                 ASR::Union_t *t = ASR::down_cast<ASR::Union_t>(v_m_type);
-                std::string der_type_name = ASRUtils::symbol_name(t->m_union_type);
+                std::string der_type_name = ASRUtils::symbol_name(
+                    ASRUtils::symbol_get_past_external(t->m_union_type));
                 if( is_array ) {
                     bool is_fixed_size = true;
                     dims = convert_dims_c(t->n_dims, t->m_dims, v_m_type, is_fixed_size, true);
@@ -682,11 +686,20 @@ R"(
     }
 
     template <typename T>
-    void visit_AggregateTypeUtil(const T& x, std::string c_type_name) {
+    void visit_AggregateTypeUtil(const T& x, std::string c_type_name,
+        std::string& src_dest) {
+        std::string body = "";
+        int indendation_level_copy = indentation_level;
+        for( auto itr: x.m_symtab->get_scope() ) {
+            if(ASR::is_a<ASR::UnionType_t>(*itr.second)) {
+                visit_AggregateTypeUtil(*ASR::down_cast<ASR::UnionType_t>(itr.second),
+                                        "union", src_dest);
+            }
+        }
+        indentation_level = indendation_level_copy;
         std::string indent(indentation_level*indentation_spaces, ' ');
         indentation_level += 1;
         std::string open_struct = indent + c_type_name + " " + std::string(x.m_name) + " {\n";
-        std::string body = "";
         indent.push_back(' ');
         for( size_t i = 0; i < x.n_members; i++ ) {
             ASR::symbol_t* member = x.m_symtab->get_symbol(x.m_members[i]);
@@ -701,7 +714,7 @@ R"(
         }
         indentation_level -= 1;
         std::string end_struct = "};\n\n";
-        array_types_decls += open_struct + body + end_struct;
+        src_dest += open_struct + body + end_struct;
     }
 
     void visit_StructType(const ASR::StructType_t& x) {
@@ -721,12 +734,12 @@ R"(
             attr_args += ")";
             c_type_name += " __attribute__(" + attr_args + ")";
         }
-        visit_AggregateTypeUtil(x, c_type_name);
+        visit_AggregateTypeUtil(x, c_type_name, array_types_decls);
         src = "";
     }
 
     void visit_UnionType(const ASR::UnionType_t& x) {
-        visit_AggregateTypeUtil(x, "union");
+        visit_AggregateTypeUtil(x, "union", array_types_decls);
     }
 
     void visit_EnumType(const ASR::EnumType_t& x) {
diff --git a/src/lpython/semantics/python_ast_to_asr.cpp b/src/lpython/semantics/python_ast_to_asr.cpp
@@ -2414,7 +2414,8 @@ class CommonVisitor : public AST::BaseVisitor<Struct> {
                 aggregate_type_name = ASRUtils::symbol_name(
                     ASR::down_cast<ASR::Union_t>(var_type)->m_union_type);
             }
-            if( aggregate_type_name ) {
+            if( aggregate_type_name &&
+                !current_scope->get_symbol(std::string(aggregate_type_name)) ) {
                 struct_dependencies.push_back(al, aggregate_type_name);
             }
             member_names.push_back(al, n->m_id);

Original file line number	Diff line number	Diff line change
`@@ -2414,7 +2414,8 @@ class CommonVisitor : public AST::BaseVisitor<Struct> {`
`2414`	`2414`	`aggregate_type_name = ASRUtils::symbol_name(`
`2415`	`2415`	`ASR::down_cast<ASR::Union_t>(var_type)->m_union_type);`
`2416`	`2416`	`}`
`2417`		`- if( aggregate_type_name ) {`
	`2417`	`+ if( aggregate_type_name &&`
	`2418`	`+ !current_scope->get_symbol(std::string(aggregate_type_name)) ) {`
`2418`	`2419`	`struct_dependencies.push_back(al, aggregate_type_name);`
`2419`	`2420`	`}`
`2420`	`2421`	`member_names.push_back(al, n->m_id);`