[PCompiler] Correct foreach -> while transformation (#684)

* [PCompiler] Correct foreach -> while transformation to account for continue in loop body * [Tst] Adds more regression tests for foreach with break/continue * [Tst] Minor commments * [Tst] Exclude unsupported tests from PSym regression suite
p-org · Nov 27, 2023 · 19f9e97 · 19f9e97
1 parent 2f3eff7
commit 19f9e97
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Showing 9 changed files with 226 additions and 16 deletions.
diff --git a/Src/PCompiler/CompilerCore/Backend/CSharp/CSharpCodeGenerator.cs b/Src/PCompiler/CompilerCore/Backend/CSharp/CSharpCodeGenerator.cs
@@ -1435,7 +1435,7 @@ private void WriteExpr(CompilationContext context, StringWriter output, IPExpr p
                     break;
 
                 case IntLiteralExpr intLiteralExpr:
-                    context.Write(output, $"((PrtInt){intLiteralExpr.Value})");
+                    context.Write(output, $"((PrtInt)({intLiteralExpr.Value}))");
                     break;
 
                 case KeysExpr keysExpr:

diff --git a/Src/PCompiler/CompilerCore/Backend/IRTransformer.cs b/Src/PCompiler/CompilerCore/Backend/IRTransformer.cs
@@ -581,12 +581,12 @@ private IPStmt SimplifyForeachStmt(ForeachStmt foreachStmt)
             // collectionCopy = collection;
             // var i: int;
             // var sizeof: int;
-            // i = 0;
+            // i = -1;
             // sizeof = sizeof(collectionCopy);
-            // while(i < sizeof) {
+            // while(i < (sizeof - 1)) {
+            //     i = i + 1;
             //     item = collectionCopy[i];
             //     body;
-            //     i = i + 1;
             // }
 
             var location = foreachStmt.SourceLocation;
@@ -608,14 +608,25 @@ private IPStmt SimplifyForeachStmt(ForeachStmt foreachStmt)
             sizeVar.Type = PrimitiveType.Int;
             function.AddLocalVariable(sizeVar);
 
-            // i = 0;
-            newBody.Add(new AssignStmt(location, new VariableAccessExpr(location, iVar), new IntLiteralExpr(location, 0)));
+            // i = -1;
+            newBody.Add(new AssignStmt(location, new VariableAccessExpr(location, iVar), new IntLiteralExpr(location, -1)));
 
             // sizeof = sizeof(collection)
             newBody.Add(new AssignStmt(location, new VariableAccessExpr(location, sizeVar), new SizeofExpr(location, collectionCopy)));
 
-            // while(i < sizeof)
-            IPExpr cond = new BinOpExpr(location, BinOpType.Lt, new VariableAccessExpr(location, iVar), new VariableAccessExpr(location, sizeVar));
+            // while(i < (sizeof - 1))
+            IPExpr cond = new BinOpExpr(location, BinOpType.Lt, 
+                            new VariableAccessExpr(location, iVar), 
+                            new BinOpExpr(location, BinOpType.Sub, 
+                                new VariableAccessExpr(location, sizeVar), 
+                                new IntLiteralExpr(location, 1)));
+
+            // inside loop: i = i+1;
+            IPStmt incrementI = new AssignStmt(location, new VariableAccessExpr(location, iVar), 
+                new BinOpExpr(location, 
+                    BinOpType.Add,
+                    new VariableAccessExpr(location, iVar), 
+                    new IntLiteralExpr(location, 1)));
 
             // inside loop: item = collection[i]
             IPExpr accessExpr;
@@ -634,14 +645,7 @@ private IPStmt SimplifyForeachStmt(ForeachStmt foreachStmt)
             }
             IPStmt assignItem = new AssignStmt(location, new VariableAccessExpr(location, item), accessExpr);
 
-            // inside loop: i = i+1;
-            IPStmt incrementI = new AssignStmt(location, new VariableAccessExpr(location, iVar), 
-                                                            new BinOpExpr(location, 
-                                                                            BinOpType.Add,
-                                                                            new VariableAccessExpr(location, iVar), 
-                                                                            new IntLiteralExpr(location, 1)));
-
-            newBody.Add(new WhileStmt(location, cond, new CompoundStmt(location, new List<IPStmt>{ assignItem,  body, incrementI })));
+            newBody.Add(new WhileStmt(location, cond, new CompoundStmt(location, new List<IPStmt>{ incrementI, assignItem,  body })));
             return new CompoundStmt(location, newBody);
         }
 

diff --git a/Src/PRuntimes/PSymRuntime/src/test/java/psym/TestSymbolicRegression.java b/Src/PRuntimes/PSymRuntime/src/test/java/psym/TestSymbolicRegression.java
@@ -80,6 +80,10 @@ private static void createExcludeList() {
     excluded.add("../../../Tst/RegressionTests/Feature2Stmts/DynamicError/receive7");
 
     // TODO Unsupported: continue statement
+    excluded.add("../../../Tst/RegressionTests/Feature2Stmts/Correct/foreach2");
+    excluded.add("../../../Tst/RegressionTests/Feature2Stmts/Correct/foreach4");
+    excluded.add("../../../Tst/RegressionTests/Feature2Stmts/DynamicError/foreach2");
+    excluded.add("../../../Tst/RegressionTests/Feature2Stmts/DynamicError/foreach4");
     excluded.add("../../../Tst/RegressionTests/Feature2Stmts/DynamicError/continue1");
 
     // TODO Unsupported: receive in state exit functions

diff --git a/Tst/RegressionTests/Feature2Stmts/Correct/foreach2/foreach2.p b/Tst/RegressionTests/Feature2Stmts/Correct/foreach2/foreach2.p
@@ -0,0 +1,32 @@
+/********************
+ * This example explains the usage of foreach iterator with continue
+ * ******************/
+
+
+ machine Main {
+ 	var ss: set[int];
+
+ 	start state Init {
+ 		entry {
+ 			var iter: int;
+ 			var sum: int;
+ 			ss += (100);
+ 			ss += (134);
+ 			ss += (245);
+
+ 			foreach(iter in ss)
+ 			{
+ 			    print format ("Iter = {0}, Sum = {1}", iter, sum);
+ 			    assert sum <= 345, "Incorrect sum inside loop";
+ 				if (iter == 134) {
+ 				    continue;
+ 				}
+ 				sum = sum + iter;
+ 			}
+
+            print format ("Final Sum = {0}", sum);
+ 			assert sum == 345, "Incorrect sum outside loop";
+ 		}
+ 	}
+ } 
+
diff --git a/Tst/RegressionTests/Feature2Stmts/Correct/foreach3/foreach3.p b/Tst/RegressionTests/Feature2Stmts/Correct/foreach3/foreach3.p
@@ -0,0 +1,33 @@
+/********************
+ * This example explains the usage of foreach iterator with break
+ * ******************/
+
+
+ machine Main {
+ 	var ss: set[int];
+
+ 	start state Init {
+ 		entry {
+ 			var iter: int;
+ 			var sum: int;
+ 			ss += (100);
+ 			ss += (123);
+ 			ss += (134);
+ 			ss += (245);
+
+ 			foreach(iter in ss)
+ 			{
+ 			    print format ("Iter = {0}, Sum = {1}", iter, sum);
+ 			    assert sum <= 100, "Incorrect sum inside loop";
+ 				sum = sum + iter;
+ 				if (iter == 123) {
+ 				    break;
+ 				}
+ 			}
+
+            print format ("Final Sum = {0}", sum);
+ 			assert sum == 223, "Incorrect sum outside loop";
+ 		}
+ 	}
+ } 
+
diff --git a/Tst/RegressionTests/Feature2Stmts/Correct/foreach4/foreach4.p b/Tst/RegressionTests/Feature2Stmts/Correct/foreach4/foreach4.p
@@ -0,0 +1,36 @@
+/********************
+ * This example explains the usage of foreach iterator with break and continue
+ * ******************/
+
+
+ machine Main {
+ 	var ss: set[int];
+
+ 	start state Init {
+ 		entry {
+ 			var iter: int;
+ 			var sum: int;
+ 			ss += (100);
+ 			ss += (134);
+ 			ss += (123);
+ 			ss += (245);
+
+ 			foreach(iter in ss)
+ 			{
+ 			    print format ("Iter = {0}, Sum = {1}", iter, sum);
+ 			    assert sum <= 100, "Incorrect sum inside loop";
+ 				if (iter == 134) {
+ 				    continue;
+ 				}
+ 				sum = sum + iter;
+ 				if (iter == 123) {
+ 				    break;
+ 				}
+ 			}
+
+            print format ("Final Sum = {0}", sum);
+ 			assert sum == 223, "Incorrect sum outside loop";
+ 		}
+ 	}
+ } 
+
diff --git a/Tst/RegressionTests/Feature2Stmts/DynamicError/foreach2/foreach2.p b/Tst/RegressionTests/Feature2Stmts/DynamicError/foreach2/foreach2.p
@@ -0,0 +1,32 @@
+/********************
+ * This example explains the usage of foreach iterator with continue
+ * ******************/
+
+
+ machine Main {
+ 	var ss: set[int];
+
+ 	start state Init {
+ 		entry {
+ 			var iter: int;
+ 			var sum: int;
+ 			ss += (100);
+ 			ss += (134);
+ 			ss += (245);
+
+ 			foreach(iter in ss)
+ 			{
+ 			    print format ("Iter = {0}, Sum = {1}", iter, sum);
+ 			    assert sum <= 345, "Incorrect sum inside loop";
+ 				if (iter == 134) {
+ 				    continue;
+ 				}
+ 				sum = sum + iter;
+ 			}
+
+            print format ("Final Sum = {0}", sum);
+ 			assert sum != 345, "Should get triggered";
+ 		}
+ 	}
+ } 
+
diff --git a/Tst/RegressionTests/Feature2Stmts/DynamicError/foreach3/foreach3.p b/Tst/RegressionTests/Feature2Stmts/DynamicError/foreach3/foreach3.p
@@ -0,0 +1,33 @@
+/********************
+ * This example explains the usage of foreach iterator with break
+ * ******************/
+
+
+ machine Main {
+ 	var ss: set[int];
+
+ 	start state Init {
+ 		entry {
+ 			var iter: int;
+ 			var sum: int;
+ 			ss += (100);
+ 			ss += (123);
+ 			ss += (134);
+ 			ss += (245);
+
+ 			foreach(iter in ss)
+ 			{
+ 			    print format ("Iter = {0}, Sum = {1}", iter, sum);
+ 			    assert sum <= 100, "Incorrect sum inside loop";
+ 				sum = sum + iter;
+ 				if (iter == 123) {
+ 				    break;
+ 				}
+ 			}
+
+            print format ("Final Sum = {0}", sum);
+ 			assert sum != 223, "Should get triggered";
+ 		}
+ 	}
+ } 
+
diff --git a/Tst/RegressionTests/Feature2Stmts/DynamicError/foreach4/foreach4.p b/Tst/RegressionTests/Feature2Stmts/DynamicError/foreach4/foreach4.p
@@ -0,0 +1,36 @@
+/********************
+ * This example explains the usage of foreach iterator with break and continue
+ * ******************/
+
+
+ machine Main {
+ 	var ss: set[int];
+
+ 	start state Init {
+ 		entry {
+ 			var iter: int;
+ 			var sum: int;
+ 			ss += (100);
+ 			ss += (134);
+ 			ss += (123);
+ 			ss += (245);
+
+ 			foreach(iter in ss)
+ 			{
+ 			    print format ("Iter = {0}, Sum = {1}", iter, sum);
+ 			    assert sum <= 100, "Incorrect sum inside loop";
+ 				if (iter == 134) {
+ 				    continue;
+ 				}
+ 				sum = sum + iter;
+ 				if (iter == 123) {
+ 				    break;
+ 				}
+ 			}
+
+            print format ("Final Sum = {0}", sum);
+ 			assert sum != 223, "Should get triggered";
+ 		}
+ 	}
+ } 
+