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Example of using the Roslyn Control Flow Analysis API
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using Microsoft.CodeAnalysis; | |
using Microsoft.CodeAnalysis.CSharp; | |
using Microsoft.CodeAnalysis.CSharp.Syntax; | |
using System; | |
using System.Linq; | |
namespace ConsoleRoslyn | |
{ | |
class Program | |
{ | |
static void ProcessExample(String rawCode) | |
{ | |
SyntaxTree code = CSharpSyntaxTree.ParseText(rawCode); | |
MetadataReference corLib = MetadataReference.CreateFromAssembly(typeof(object).Assembly); | |
CSharpCompilation compilation = CSharpCompilation.Create("TestCompilation", | |
new[] { code }, | |
new[] { corLib }); | |
SemanticModel semanticModel = compilation.GetSemanticModel(code); | |
CatchClauseSyntax theCatch = code.GetRoot().DescendantNodes().OfType<CatchClauseSyntax>().First(); | |
ControlFlowAnalysis result = semanticModel.AnalyzeControlFlow(theCatch.Block); | |
Console.WriteLine("======================================================================="); | |
Console.WriteLine("{0}", theCatch.Block.ToString()); | |
Console.WriteLine("Succeeded : {0}", result.Succeeded); | |
Console.WriteLine("Return statements : {0}", result?.ReturnStatements.Count() ?? 0); | |
Console.WriteLine("Endpoint reachable : {0}", result.EndPointIsReachable); | |
Console.WriteLine("Exit point count : {0}", result?.ExitPoints.Count() ?? 0); | |
} | |
static void Main(string[] args) | |
{ | |
String code = @" | |
using System; | |
using System.IO; | |
class SimpleThrow | |
{ | |
public void Example(Int32 i) | |
{ | |
try | |
{ | |
Console.WriteLine(""i = {0}"", i); | |
} | |
catch (FileNotFoundException) | |
{ | |
Console.WriteLine(""Got an exception""); | |
throw; | |
} | |
} | |
} | |
"; | |
ProcessExample(code); | |
code = @" | |
using System; | |
using System.IO; | |
class EatException | |
{ | |
public void Example(Int32 i) | |
{ | |
try | |
{ | |
Console.WriteLine(""i = {0}"", i); | |
} | |
catch (FileNotFoundException) | |
{ | |
} | |
} | |
} | |
"; | |
ProcessExample(code); | |
code = @" | |
using System; | |
using System.IO; | |
class EatExceptionInOneCase | |
{ | |
public void Example(Int32 i) | |
{ | |
try | |
{ | |
Console.WriteLine(""i = {0}"", i); | |
} | |
catch (FileNotFoundException) | |
{ | |
if (i < 5) | |
{ | |
throw; | |
} | |
} | |
} | |
} | |
"; | |
ProcessExample(code); | |
code = @" | |
class EatExceptionWithReturn | |
{ | |
public void Example(Int32 i) | |
{ | |
try | |
{ | |
Console.WriteLine(""i = {0}"", i); | |
} | |
catch (FileNotFoundException) | |
{ | |
if (i < 5) | |
{ | |
return; | |
} | |
else | |
{ | |
throw; | |
} | |
} | |
} | |
} | |
"; | |
ProcessExample(code); | |
code = @" | |
class EatExceptionWithReturn | |
{ | |
static void Main() | |
{ | |
try | |
{ | |
String s = null; | |
if (s.Length > 0) | |
{ | |
Console.WriteLine(""Too big""); | |
} | |
} | |
catch | |
{ | |
goto BailOut; | |
} | |
Console.WriteLine(""You should not see this!""); | |
BailOut: | |
Console.WriteLine(""Bailed!""); | |
} | |
} | |
"; | |
ProcessExample(code); | |
} | |
} | |
} |
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