Add runtime information (like index range, missing element) in the error message

Author: Thirumalai-Shaktivel

src/libasr/codegen/llvm_utils.cpp

@@ -969,10 +969,16 @@ namespace LFortran {
         builder->CreateCondBr(cond, thenBB, elseBB);
         builder->SetInsertPoint(thenBB);
         {
-            std::string message = "list index out of range";
-            llvm::Value *fmt_ptr = builder->CreateGlobalStringPtr("IndexError: %s\n");
-            llvm::Value *fmt_ptr2 = builder->CreateGlobalStringPtr(message);
-            print_error(context, module, *builder, {fmt_ptr, fmt_ptr2});
+            std::string index_error = "IndexError: %s%d%s%d\n",
+            message1 = "List index is out of range. Index range is (0, ",
+            message2 = "), but the given index is ";
+            llvm::Value *fmt_ptr = builder->CreateGlobalStringPtr(index_error);
+            llvm::Value *fmt_ptr1 = builder->CreateGlobalStringPtr(message1);
+            llvm::Value *fmt_ptr2 = builder->CreateGlobalStringPtr(message2);
+            llvm::Value *end_minus_one = builder->CreateSub(end_point,
+                llvm::ConstantInt::get(context, llvm::APInt(32, 1)));
+            print_error(context, module, *builder, {fmt_ptr, fmt_ptr1,
+                end_minus_one, fmt_ptr2, pos});
             int exit_code_int = 1;
             llvm::Value *exit_code = llvm::ConstantInt::get(context,
                     llvm::APInt(32, exit_code_int));
@@ -2417,12 +2423,10 @@ namespace LFortran {
         builder->CreateCondBr(cond, thenBB, elseBB);
         builder->SetInsertPoint(thenBB);
         {
-            // TODO: Allow runtime information like the exact element which is
-            // not found.
-            std::string message = "The list does not contain the element";
-            llvm::Value *fmt_ptr = builder->CreateGlobalStringPtr("ValueError: %s\n");
+            std::string message = "The list does not contain the element: ";
+            llvm::Value *fmt_ptr = builder->CreateGlobalStringPtr("ValueError: %s%d\n");
             llvm::Value *fmt_ptr2 = builder->CreateGlobalStringPtr(message);
-            print_error(context, module, *builder, {fmt_ptr, fmt_ptr2});
+            print_error(context, module, *builder, {fmt_ptr, fmt_ptr2, item});
             int exit_code_int = 1;
             llvm::Value *exit_code = llvm::ConstantInt::get(context,
                     llvm::APInt(32, exit_code_int));

tests/reference/runtime-test_list_01-3ee9b3e.json

@@ -8,6 +8,6 @@
     "stdout": null,
     "stdout_hash": null,
     "stderr": "runtime-test_list_01-3ee9b3e.stderr",
-    "stderr_hash": "3bc6c29af7798c771cee99ac69fb9beacafd9e95479b08e47032ecf1",
+    "stderr_hash": "c9cbdc4df1e7fbe0a6e73db7ac7809f71102fb524c8aa86139271006",
     "returncode": 1
 }

tests/reference/runtime-test_list_01-3ee9b3e.stderr

@@ -1 +1 @@
-ValueError: The list does not contain the element
+ValueError: The list does not contain the element: 4

tests/reference/runtime-test_list_02-5f7db5f.json

@@ -2,12 +2,12 @@
     "basename": "runtime-test_list_02-5f7db5f",
     "cmd": "lpython {infile}",
     "infile": "tests/runtime_errors/test_list_02.py",
-    "infile_hash": "73803ffe5a87f1ac9a76ea16075d8fbfabb4968b40c7265952a529e1",
+    "infile_hash": "f74ffd3eeb1f4a61b105d50f030fcd9e1095cc70d0a618763bbf367b",
     "outfile": null,
     "outfile_hash": null,
     "stdout": null,
     "stdout_hash": null,
     "stderr": "runtime-test_list_02-5f7db5f.stderr",
-    "stderr_hash": "6c43f8d578ad68cecf9f508bf6469418796f38489b3eb524f98391d7",
+    "stderr_hash": "f45ba86e610eeb2cc11fc176120e56d153a896f486e9b04d94fa3de1",
     "returncode": 1
 }

tests/reference/runtime-test_list_02-5f7db5f.stderr

@@ -1 +1 @@
-IndexError: list index out of range
+IndexError: List index is out of range. Index range is (0, 2), but the given index is 3

tests/runtime_errors/test_list_02.py

@@ -4,6 +4,6 @@
 def test_list():
     x: list[i32]
     x = [1, 2, 3]
-    x[4] = 0
+    x[3] = 0
 
 test_list()