fix(translate): detect unclosed control flow and add REPEAT mismatch tests

Author: tetsuo-cpp

lib/Translation/ForthToMLIR/ForthToMLIR.cpp

@@ -1031,6 +1031,11 @@ LogicalResult ForthParser::parseBody(Value &stack) {
     }
   }
 
+  if (!cfStack.empty()) {
+    cfStack.clear();
+    return emitError("unclosed control flow (missing THEN, REPEAT, or UNTIL?)");
+  }
+
   return success();
 }
 

test/Translation/Forth/begin-begin-repeat-mismatch-error.forth

@@ -0,0 +1,4 @@
+\ RUN: %not %warpforth-translate --forth-to-mlir %s 2>&1 | %FileCheck %s
+\ CHECK: REPEAT without matching WHILE
+\! kernel main
+BEGIN BEGIN REPEAT

test/Translation/Forth/if-repeat-mismatch-error.forth

@@ -0,0 +1,4 @@
+\ RUN: %not %warpforth-translate --forth-to-mlir %s 2>&1 | %FileCheck %s
+\ CHECK: REPEAT without matching WHILE
+\! kernel main
+1 IF REPEAT

test/Translation/Forth/unclosed-begin-while-error.forth

@@ -0,0 +1,4 @@
+\ RUN: %not %warpforth-translate --forth-to-mlir %s 2>&1 | %FileCheck %s
+\ CHECK: unclosed control flow (missing THEN, REPEAT, or UNTIL?)
+\! kernel main
+BEGIN 1 WHILE 42

test/Translation/Forth/unclosed-if-error.forth

@@ -0,0 +1,4 @@
+\ RUN: %not %warpforth-translate --forth-to-mlir %s 2>&1 | %FileCheck %s
+\ CHECK: unclosed control flow (missing THEN, REPEAT, or UNTIL?)
+\! kernel main
+1 IF 42