Sync libasr from LFortran

Co-authored-by: Shaikh Ubaid <shaikhubaid769@gmail.com>

src/libasr/ASR.asdl

@@ -95,7 +95,7 @@ symbol
         symbol external, identifier module_name, identifier* scope_names,
         identifier original_name, access access)
     | StructType(symbol_table symtab, identifier name, identifier* dependencies,
-        identifier* members, abi abi, access access, bool is_packed,
+        identifier* members, abi abi, access access, bool is_packed, bool is_abstract,
         expr? alignment, symbol? parent)
     | EnumType(symbol_table symtab, identifier name, identifier* dependencies,
         identifier* members, abi abi, access access, enumtype enum_value_type,
@@ -107,7 +107,7 @@ symbol
         abi abi, access access, presence presence, bool value_attr)
     | ClassType(symbol_table symtab, identifier name, abi abi, access access)
     | ClassProcedure(symbol_table parent_symtab, identifier name, identifier? self_argument,
-        identifier proc_name, symbol proc, abi abi)
+        identifier proc_name, symbol proc, abi abi, bool is_deferred)
     | AssociateBlock(symbol_table symtab, identifier name, stmt* body)
     | Block(symbol_table symtab, identifier name, stmt* body)
 
@@ -161,15 +161,15 @@ stmt
     | Assign(int label, identifier variable)
     | Assignment(expr target, expr value, stmt? overloaded)
     | Associate(expr target, expr value)
-    | Cycle()
+    | Cycle(identifier? stmt_name)
     -- deallocates if allocated otherwise throws a runtime error
     | ExplicitDeallocate(expr* vars)
     -- deallocates if allocated otherwise does nothing
-    | ImplicitDeallocate(symbol* vars)
+    | ImplicitDeallocate(expr* vars)
     | DoConcurrentLoop(do_loop_head head, stmt* body)
-    | DoLoop(do_loop_head head, stmt* body)
+    | DoLoop(identifier? name, do_loop_head head, stmt* body)
     | ErrorStop(expr? code)
-    | Exit()
+    | Exit(identifier? stmt_name)
     | ForAllSingle(do_loop_head head, stmt assign_stmt)
         -- GoTo points to a GoToTarget with the corresponding target_id within
         -- the same procedure. We currently use `int` IDs to link GoTo with
@@ -201,12 +201,12 @@ stmt
     | Assert(expr test, expr? msg)
     | SubroutineCall(symbol name, symbol? original_name, call_arg* args, expr? dt)
     | Where(expr test, stmt* body, stmt* orelse)
-    | WhileLoop(expr test, stmt* body)
+    | WhileLoop(identifier? name, expr test, stmt* body)
     | Nullify(symbol* vars)
     | Flush(int label, expr unit, expr? err, expr? iomsg, expr? iostat)
     | ListAppend(expr a, expr ele)
     | AssociateBlockCall(symbol m)
-    | SelectType(type_stmt* body, stmt* default)
+    | SelectType(expr selector, type_stmt* body, stmt* default)
     | CPtrToPointer(expr cptr, expr ptr, expr? shape)
     | BlockCall(int label, symbol m)
     | SetInsert(expr a, expr ele)
@@ -420,7 +420,10 @@ do_loop_head = (expr? v, expr? start, expr? end, expr? increment)
 
 case_stmt = CaseStmt(expr* test, stmt* body) | CaseStmt_Range(expr? start, expr? end, stmt* body)
 
-type_stmt = TypeStmtName(symbol sym, stmt* body) | TypeStmtType(ttype type, stmt* body)
+type_stmt
+    = TypeStmtName(symbol sym, stmt* body)
+    | ClassStmt(symbol sym, stmt* body)
+    | TypeStmtType(ttype type, stmt* body)
 
 enumtype = IntegerConsecutiveFromZero | IntegerUnique | IntegerNotUnique | NonInteger
 

src/libasr/asdl_cpp.py

@@ -405,6 +405,111 @@ def visitField(self, field):
             self.emit(  "this->visit_symbol(*a.second);", 3)
             self.emit("}", 2)
 
+class ASRPassWalkVisitorVisitor(ASDLVisitor):
+
+    def visitModule(self, mod):
+        self.emit("/" + "*"*78 + "/")
+        self.emit("// Walk Visitor base class")
+        self.emit("")
+        self.emit("template <class Struct>")
+        self.emit("class ASRPassBaseWalkVisitor : public BaseVisitor<Struct>")
+        self.emit("{")
+        self.emit("private:")
+        self.emit("    Struct& self() { return static_cast<Struct&>(*this); }")
+        self.emit("public:")
+        self.emit("    SymbolTable* current_scope;")
+        self.emit("    void transform_stmts(ASR::stmt_t **&m_body, size_t &n_body) {")
+        self.emit("    for (size_t i = 0; i < n_body; i++) {", 1)
+        self.emit("        self().visit_stmt(*m_body[i]);", 1)
+        self.emit("    }", 1)
+        self.emit("}", 1)
+        super(ASRPassWalkVisitorVisitor, self).visitModule(mod)
+        self.emit("};")
+
+    def visitType(self, tp):
+        if not (isinstance(tp.value, asdl.Sum) and
+                is_simple_sum(tp.value)):
+            super(ASRPassWalkVisitorVisitor, self).visitType(tp, tp.name)
+
+    def visitProduct(self, prod, name):
+        self.make_visitor(name, prod.fields)
+
+    def visitConstructor(self, cons, _):
+        self.make_visitor(cons.name, cons.fields)
+
+    def make_visitor(self, name, fields):
+        self.emit("void visit_%s(const %s_t &x) {" % (name, name), 1)
+        is_symtab_present = False
+        is_stmt_present = False
+        symtab_field_name = ""
+        for field in fields:
+            if field.type == "stmt":
+                is_stmt_present = True
+            if field.type == "symbol_table":
+                is_symtab_present = True
+                symtab_field_name = field.name
+            if is_stmt_present and is_symtab_present:
+                break
+        if is_stmt_present and name not in ("Assignment", "ForAllSingle"):
+            self.emit("    %s_t& xx = const_cast<%s_t&>(x);" % (name, name), 1)
+        self.used = False
+
+        if is_symtab_present:
+            self.emit("SymbolTable* current_scope_copy = current_scope;", 2)
+            self.emit("current_scope = x.m_%s;" % symtab_field_name, 2)
+
+        for field in fields:
+            self.visitField(field)
+        if not self.used:
+            # Note: a better solution would be to change `&x` to `& /* x */`
+            # above, but we would need to change emit to return a string.
+            self.emit("if ((bool&)x) { } // Suppress unused warning", 2)
+
+        if is_symtab_present:
+            self.emit("current_scope = current_scope_copy;", 2)
+
+        self.emit("}", 1)
+
+    def visitField(self, field):
+        if (field.type not in asdl.builtin_types and
+            field.type not in self.data.simple_types):
+            level = 2
+            if field.seq:
+                if field.type == "stmt":
+                    self.emit("self().transform_stmts(xx.m_%s, xx.n_%s);" % (field.name, field.name), level)
+                    return
+                self.used = True
+                self.emit("for (size_t i=0; i<x.n_%s; i++) {" % field.name, level)
+                if field.type in products:
+                    self.emit("    self().visit_%s(x.m_%s[i]);" % (field.type, field.name), level)
+                else:
+                    if field.type != "symbol":
+                        self.emit("    self().visit_%s(*x.m_%s[i]);" % (field.type, field.name), level)
+                self.emit("}", level)
+            else:
+                if field.type in products:
+                    self.used = True
+                    if field.opt:
+                        self.emit("if (x.m_%s)" % field.name, 2)
+                        level = 3
+                    if field.opt:
+                        self.emit("self().visit_%s(*x.m_%s);" % (field.type, field.name), level)
+                    else:
+                        self.emit("self().visit_%s(x.m_%s);" % (field.type, field.name), level)
+                else:
+                    if field.type != "symbol":
+                        self.used = True
+                        if field.opt:
+                            self.emit("if (x.m_%s)" % field.name, 2)
+                            level = 3
+                        self.emit("self().visit_%s(*x.m_%s);" % (field.type, field.name), level)
+        elif field.type == "symbol_table" and field.name in["symtab",
+                "global_scope"]:
+            self.used = True
+            self.emit("for (auto &a : x.m_%s->get_scope()) {" % field.name, 2)
+            self.emit(  "this->visit_symbol(*a.second);", 3)
+            self.emit("}", 2)
+
 class CallReplacerOnExpressionsVisitor(ASDLVisitor):
 
     def __init__(self, stream, data):
@@ -477,10 +582,10 @@ def make_visitor(self, name, fields):
         self.emit("}", 1)
 
     def insert_call_replacer_code(self, name, level, index=""):
-        self.emit("    ASR::expr_t** current_expr_copy_%d = current_expr;" % (self.current_expr_copy_variable_count), level)
-        self.emit("    current_expr = const_cast<ASR::expr_t**>(&(x.m_%s%s));" % (name, index), level)
-        self.emit("    self().call_replacer();", level)
-        self.emit("    current_expr = current_expr_copy_%d;" % (self.current_expr_copy_variable_count), level)
+        self.emit("ASR::expr_t** current_expr_copy_%d = current_expr;" % (self.current_expr_copy_variable_count), level)
+        self.emit("current_expr = const_cast<ASR::expr_t**>(&(x.m_%s%s));" % (name, index), level)
+        self.emit("self().call_replacer();", level)
+        self.emit("current_expr = current_expr_copy_%d;" % (self.current_expr_copy_variable_count), level)
         self.current_expr_copy_variable_count += 1
 
     def visitField(self, field):
@@ -495,12 +600,14 @@ def visitField(self, field):
                 self.emit("for (size_t i=0; i<x.n_%s; i++) {" % field.name, level)
                 if field.type in products:
                     if field.type == "expr":
-                        self.insert_call_replacer_code(field.name, level, "[i]")
+                        self.insert_call_replacer_code(field.name, level + 1, "[i]")
+                        self.emit("if( x.m_%s[i] )" % (field.name), level)
                     self.emit("    self().visit_%s(x.m_%s[i]);" % (field.type, field.name), level)
                 else:
                     if field.type != "symbol":
                         if field.type == "expr":
-                            self.insert_call_replacer_code(field.name, level, "[i]")
+                            self.insert_call_replacer_code(field.name, level + 1, "[i]")
+                            self.emit("if( x.m_%s[i] )" % (field.name), level + 1)
                         self.emit("    self().visit_%s(*x.m_%s[i]);" % (field.type, field.name), level)
                 self.emit("}", level)
             else:
@@ -511,6 +618,7 @@ def visitField(self, field):
                         level = 3
                         if field.type == "expr":
                             self.insert_call_replacer_code(field.name, level)
+                            self.emit("if( x.m_%s )" % (field.name), level)
                     if field.opt:
                         self.emit("self().visit_%s(*x.m_%s);" % (field.type, field.name), level)
                         self.emit("}", 2)
@@ -524,6 +632,7 @@ def visitField(self, field):
                             level = 3
                         if field.type == "expr":
                             self.insert_call_replacer_code(field.name, level)
+                            self.emit("if( x.m_%s )" % (field.name), level)
                         self.emit("self().visit_%s(*x.m_%s);" % (field.type, field.name), level)
                         if field.opt:
                             self.emit("}", 2)
@@ -2595,6 +2704,8 @@ def main(argv):
 
     try:
         if is_asr:
+            ASRPassWalkVisitorVisitor(fp, data).visit(mod)
+            fp.write("\n\n")
             ExprStmtDuplicatorVisitor(fp, data).visit(mod)
             fp.write("\n\n")
             ExprBaseReplacerVisitor(fp, data).visit(mod)

src/libasr/asr_scopes.h

@@ -71,7 +71,21 @@ struct SymbolTable {
         scope.erase(name);
     }
 
+    // Add a new symbol that did not exist before
     void add_symbol(const std::string &name, ASR::symbol_t* symbol) {
+        LCOMPILERS_ASSERT(scope.find(name) == scope.end())
+        scope[name] = symbol;
+    }
+
+    // Overwrite an existing symbol
+    void overwrite_symbol(const std::string &name, ASR::symbol_t* symbol) {
+        LCOMPILERS_ASSERT(scope.find(name) != scope.end())
+        scope[name] = symbol;
+    }
+
+    // Use as the last resort, prefer to always either add a new symbol
+    // or overwrite an existing one, not both
+    void add_or_overwrite_symbol(const std::string &name, ASR::symbol_t* symbol) {
         scope[name] = symbol;
     }