public void FailsIfThereAreReferenceOrTypeErrors()
{
string program = "class Factorial {\n" +
" public static void main () {\n" +
" System.out.println (new Factor ().ComputeFac (10));\n" +
"} \n\n" +
"} \n" +
"class Fac { \n" +
" public int ComputeFac (int num) {\n" +
" assert (num > true || num == 0);\n" +
" int num_aux;\n" +
" if (num == 0)\n" +
" num_aux = 1;\n" +
" else \n" +
" aux = num * this.ComputeFac (num-1);\n" +
" return aux;\n" +
" }\n" +
"}\n";
var reader = new StringReader(program);
var frontend = new FrontEnd(reader);
Program syntaxTree;
Assert.False(frontend.TryProgramAnalysis(out syntaxTree));
Assert.NotNull(syntaxTree); // syntax analysis was ok
Assert.That(frontend.GetErrors(), Is.Not.Empty);
reader.Close();
}
public void CanContinueToTypeCheckIfNonFatalErrorsFound()
{
string program = "class Factorial {\n" +
" public static void main () {\n" +
" System.out.println (new Fac ().ComputeFac (10));\n" +
"} \n\n" +
"} \n" +
"class Fac { \n" +
" public int ComputeFac (int num) {\n" +
" assert (num > 0 || num == 0);\n" +
" void num_aux;\n" +
" if (num == 0)\n" +
" num_aux = 1;\n" +
" else \n" +
" num_aux = num * this.ComputeFac (num-1);\n" +
" return num_aux;\n" +
" }\n" +
" public int ComputeFac () { }\n" +
"}\n";
var reader = new StringReader(program);
var frontend = new FrontEnd(reader);
Program syntaxTree;
Assert.False(frontend.TryProgramAnalysis(out syntaxTree));
Assert.NotNull(syntaxTree); // syntax analysis was ok
Assert.That(frontend.GetErrors(), Is.Not.Empty);
Assert.That(frontend.GetErrors().Last().ToString(), Is.StringContaining("Missing return statement in method ComputeFac"));
reader.Close();
}
public void OnlyReportsTypeResolvingErrorsOnce()
{
string program = "class Factorial {\n" +
" public static void main () {\n" +
" System.out.println (new Fac ().ComputeFac (10));\n" +
"} \n\n" +
"} \n";
var reader = new StringReader(program);
var frontend = new FrontEnd(reader);
Program syntaxTree;
Assert.False(frontend.TryProgramAnalysis(out syntaxTree));
Assert.NotNull(syntaxTree); // syntax analysis was ok
var errors = frontend.GetErrors();
Assert.AreEqual(1, errors.Count);
Assert.That(errors[0].Content, Is.StringContaining("Unknown type Fac"));
reader.Close();
}
public void OrdersErrorsByCodeLocation()
{
string program = "class Foo {\n" +
" public static void main() {\n" +
" int foo;\n" +
" foo = 10 + new A().alwaysTrue();\n" +
" A foo2;\n" +
" foo2 = new C();\n" +
" int bar;\n" +
" bar = new A();\n" +
" bar = 99999999999999999;\n" +
" boolean baz; baz = 15 && new A().alwaysTrue(10) || new C() || foo;\n" +
" baz = zzz || foo;\n" +
" baz = foo && zzz;\n" +
" baz = zzz || new C();\n" +
" foo = zzz[zzz];\n" +
" assert(zzz);\n" +
" }\n" +
"}\n" +
"class A {\n" +
" public boolean alwaysTrue() {\n" +
" if (true) { }\n" +
" else { return true; }\n" +
" }\n" +
" public void foo() { return 10; }\n" +
" public boolean bar() { return true; }\n" +
"}\n" +
"class B extends A {" +
" public boolean alwaysTrue(int foo) { return true; }\n" +
"}\n";
var reader = new StringReader(program);
var frontend = new FrontEnd(reader);
Program syntaxTree;
Assert.False(frontend.TryProgramAnalysis(out syntaxTree));
Assert.NotNull(syntaxTree); // syntax analysis was ok
Assert.That(frontend.GetErrors(), Is.Not.Empty);
reader.Close();
var errors = frontend.GetErrors();
int[] locationValues = new int[errors.Count()];
for (int i = 0; i < locationValues.Length; i++)
{
locationValues[i] = errors[i].Row * 100 + errors[i].Col;
}
int[] expectedValues = new int[errors.Count()];
locationValues.CopyTo(expectedValues, 0);
System.Array.Sort(expectedValues);
CollectionAssert.AreEqual(expectedValues, locationValues);
}
public void ValidProgramGoesThroughWithoutProblems()
{
string program = "class Factorial {\n" +
" public static void main () {\n" +
" System.out.println (new Fac ().ComputeFac (10));\n" +
"} \n\n" +
"} \n" +
"class Fac { \n" +
" public int ComputeFac (int num) {\n" +
" assert (num > 0 || num == 0);\n" +
" int num_aux;\n" +
" if (num == 0)\n" +
" num_aux = 1;\n" +
" else \n" +
" num_aux = num * this.ComputeFac (num-1);\n" +
" return num_aux;\n" +
" }\n" +
"}\n";
var reader = new StringReader(program);
var frontend = new FrontEnd(reader);
Program syntaxTree;
Assert.True(frontend.TryProgramAnalysis(out syntaxTree));
Assert.NotNull(syntaxTree);
Assert.That(frontend.GetErrors(), Is.Empty);
reader.Close();
}
public void StopsBeforeTypeCheckIfCyclicDependenciesFound()
{
string program = "class Factorial {\n" +
" public static void main () {\n" +
" System.out.println (new Fac ().ComputeFac (10));\n" +
"} \n\n" +
"} \n" +
"class A extends B { }\n" +
"class B extends A {\n" +
" public int foo() { }\n" + // missing return statement is not detected
"}\n";
var reader = new StringReader(program);
var frontend = new FrontEnd(reader);
Program syntaxTree;
Assert.False(frontend.TryProgramAnalysis(out syntaxTree));
Assert.NotNull(syntaxTree); // syntax analysis was ok
Assert.That(frontend.GetErrors(), Is.Not.Empty);
Assert.That(frontend.GetErrors().Last().ToString(), Is.StringContaining("Cyclic inheritance involving B"));
reader.Close();
}
public void StopsAfterSyntaxAnalysisWhenThereAreSyntacticErrors()
{
string program = "class Factorial {\n" +
" public static void main () \n" +
" System.out.println (new Fac.ComputeFac 0));\n" +
"} \n\n" +
"} \n" +
"class Fac { \n" +
" public int ComputeFac (int num) {\n" +
" assert (num > 0 || num == 0\n" +
" int num_aux;\n" +
" if (num == 0)\n" +
" num" +
" else \n" +
" num_aux this.ComputeFac (num-1);\n" +
" return num_aux;\n" +
" }\n" +
"}\n";
var reader = new StringReader(program);
var frontend = new FrontEnd(reader);
Program syntaxTree;
Assert.False(frontend.TryProgramAnalysis(out syntaxTree));
Assert.IsNull(syntaxTree);
Assert.That(frontend.GetErrors(), Is.Not.Empty);
reader.Close();
}
public void StopsAfterBuildingTheTypeSetIfErrorsFound()
{
string program = "class Factorial {\n" +
" public static void main () {\n" +
" System.out.println (new Factorial ().ComputeFac (10));\n" +
"} \n\n" +
"} \n" +
"class Factorial { \n" +
" public int ComputeFac (int num) {\n" +
" assert (num > 0 || num == 0);\n" +
" int num_aux;\n" +
" if (num == 0)\n" +
" num_aux = 1;\n" +
" else \n" +
" num_aux = num * this.ComputeFac (num-1);\n" +
" return num_aux;\n" +
" }\n" +
"}\n";
var reader = new StringReader(program);
var frontend = new FrontEnd(reader);
Program syntaxTree;
Assert.False(frontend.TryProgramAnalysis(out syntaxTree));
Assert.NotNull(syntaxTree); // syntax analysis was ok
Assert.That(frontend.GetErrors(), Is.Not.Empty);
Assert.That(frontend.GetErrors().Last().ToString(), Is.StringContaining("Conflicting definitions for Factorial"));
reader.Close();
}
public void SemanticChecksCanHandleMethodSymbolDefinitionError()
{
string program = "class Test {\n" +
" public static void main () {\n" +
" int i;\n" +
" i = new Class().get();\n" +
"} \n\n" +
"} \n" +
"class Class { \n" +
" public boolean get() { return true; }" +
" public Class getClass() { return new Class(); }\n" +
" public int get () {\n" +
" OtherClass x;\n" +
" x = this.getClass();\n" +
" if (true) {\n" +
" if (this.get()) { return false; }\n" +
" } else { return 0; }\n" +
" }\n" +
"}\n";
var reader = new StringReader(program);
var frontend = new FrontEnd(reader);
Program syntaxTree;
Assert.False(frontend.TryProgramAnalysis(out syntaxTree));
Assert.NotNull(syntaxTree); // syntax analysis was ok
var errors = frontend.GetErrors();
Assert.AreEqual(5, errors.Count);
Assert.That(errors[0].ToString(), Is.StringContaining("Incompatible types")
.And.StringContaining("int").And.StringContaining("boolean"));
Assert.That(errors[1].ToString(), Is.StringContaining("already defined"));
Assert.That(errors[2].ToString(), Is.StringContaining("Missing return statement in method get"));
Assert.That(errors[3].ToString(), Is.StringContaining("Cannot convert expression of type boolean to int"));
Assert.That(errors[4].ToString(), Is.StringContaining("Unknown type OtherClass"));
reader.Close();
}
private static bool RunFrontEnd(string fileName, StreamReader fileStream, out Program abstractSyntaxTree)
{
var frontend = new FrontEnd.FrontEnd(fileStream);
if (frontend.TryProgramAnalysis(out abstractSyntaxTree))
{
return true;
}
else
{
Console.WriteLine("Compilation failed.");
var sourceCode = File.ReadAllLines(fileName);
var sourceLines = sourceCode.Count();
string errorCodeDecl = "Code near error source: ";
var errors = frontend.GetErrors();
foreach (var error in errors)
{
Console.WriteLine(error.ToString());
if (error.Row > 0 && error.Row <= sourceLines)
{
var sourceLine = sourceCode[error.Row - 1];
PrintError(errorCodeDecl, sourceLine, error.Col);
}
}
return false;
}
}