fixes semantic error for int (Issue #1926)

src/lpython/semantics/python_ast_to_asr.cpp

@@ -876,7 +876,18 @@ class CommonVisitor : public AST::BaseVisitor<Struct> {
         }
 
         if( !type && raise_error ) {
-            throw SemanticError("Unsupported type annotation: " + var_annotation, loc);
+            if (var_annotation == "int") {
+                std::string msg = "Hint: Use i8, i16, i32 or i64 for now. ";
+                diag.add(diag::Diagnostic(
+                    var_annotation + " type is not supported yet. ",
+                    diag::Level::Error, diag::Stage::Semantic, {
+                        diag::Label(msg, {loc})
+                    })
+                );
+                throw SemanticAbort();
+            } else { 
+                throw SemanticError("Unsupported type annotation: " + var_annotation, loc);
+            }
         }
 
         return type;

tests/errors/test_int_semantic_error.py

@@ -0,0 +1,8 @@
+from lpython import i32
+
+def variable_function():
+    x: int = 1
+    y: i32 = 2
+    print("x + y is", x + y)
+
+variable_function()

tests/reference/asr-test_int_semantic_error-44fe25e.json

@@ -0,0 +1,13 @@
+{
+    "basename": "asr-test_int_semantic_error-44fe25e",
+    "cmd": "lpython --show-asr --no-color {infile} -o {outfile}",
+    "infile": "tests/errors/test_int_semantic_error.py",
+    "infile_hash": "79ca7d3f440b2538aa0819f910bea5ef24820d245b2179e1bf4cce6d",
+    "outfile": null,
+    "outfile_hash": null,
+    "stdout": null,
+    "stdout_hash": null,
+    "stderr": "asr-test_int_semantic_error-44fe25e.stderr",
+    "stderr_hash": "a1cd1ec0fee194e3c1651668753a1666ca46c925fa91335c6230e026",
+    "returncode": 2
+}

tests/reference/asr-test_int_semantic_error-44fe25e.stderr

@@ -0,0 +1,5 @@
+semantic error: int type is not supported yet. 
+ --> tests/errors/test_int_semantic_error.py:4:8
+  |
+4 |     x: int = 1
+  |        ^^^ Hint: Use i8, i16, i32 or i64 for now. 

tests/tests.toml

@@ -1100,6 +1100,10 @@ asr = true
 filename = "errors/test_unsupported_type.py"
 asr = true
 
+[[test]]
+filename = "errors/test_int_semantic_error.py"
+asr = true
+
 [[test]]
 filename = "errors/generics_error_01.py"
 asr = true