我目前正在尝试从IL字节码和PDB文件中检索源代码， 我已经到了可以从IL和反射生成源代码的地步 我知道本地变量名的名称包含在pdb文件中。 我的问题是我怎么能找到它？应该用什么库来处理pdb文件（如果有的话）或者我应该自己编写代码？我在哪里可以找到有关pdb文件格式的信息？ 目前在生成的源代码中我使用自动生成的局部变量值，但我想改变它，因为我相信如果您有pdb文件可以找回该信息。 我试图在谷歌上看，但我没有找到任何有用的信息。
提前感谢您的回复;）
答案 0 :(得分：3)
以下是如何使用System.Diagnostics.SymbolStore中的类型从MethodInfo中读取局部变量名：
public class LocalVariableNameReader
{
Dictionary<int, string> _names = new Dictionary<int, string> ();
public string this [int index]
{
get
{
if (!_names.ContainsKey (index)) return null;
return _names [index];
}
}
public LocalVariableNameReader (MethodInfo m)
{
ISymbolReader symReader = SymUtil.GetSymbolReaderForFile (m.DeclaringType.Assembly.Location, null);
ISymbolMethod met = symReader.GetMethod (new SymbolToken (m.MetadataToken));
VisitLocals (met.RootScope);
}
void VisitLocals (ISymbolScope iSymbolScope)
{
foreach (var s in iSymbolScope.GetLocals ()) _names [s.AddressField1] = s.Name;
foreach (var c in iSymbolScope.GetChildren ()) VisitLocals (c);
}
}
SymUtil课程来自this example。
修改：以上链接已损坏。来自谷歌缓存：
很久以前我一直在研究如何处理pdb文件 获得反射根本无法提供的其他信息。 现在我难过了一个5岁的Mike Stall职位 （here） 突然间一切都变得清晰了。我把一个小例子放在一起 使用.net 4.0来读取源代码中的方法体代码 汇编汇编的地方。请注意，为了这个 要工作，你必须有程序集的pdb可用。也 请确保为ISymWrapper和您的项目添加一个引用 目标是.Net 4.0框架，而不是.Net 4.0 Client。
using System;
using System.Diagnostics.SymbolStore;
using System.IO;
using System.Reflection;
using System.Runtime.InteropServices;
namespace PdbTest
{
class Program
{
static void Main(string[] args)
{
Assembly ass = Assembly.GetExecutingAssembly();
ISymbolReader symreader = SymUtil.GetSymbolReaderForFile(ass.Location, null);
MethodInfo m = ass.GetType("PdbTest.TestClass").GetMethod("GetStringRepresentation");
ISymbolMethod met = symreader.GetMethod(new SymbolToken(m.MetadataToken));
int count = met.SequencePointCount;
ISymbolDocument[] docs = new ISymbolDocument[count];
int[] offsets = new int[count];
int[] lines = new int[count];
int[] columns = new int[count];
int[] endlines = new int[count];
int[] endcolumns = new int[count];
met.GetSequencePoints(offsets, docs, lines, columns, endlines, endcolumns);
StreamReader reader = new StreamReader(docs[0].URL);
string[] linesOfCode = reader.ReadToEnd().Split('n');
reader.Close();
Console.WriteLine("The content of method PdbTest.TestClass.GetStringRepresentation");
for (int i = lines[0]; i < endlines[count - 1] - 1; i++)
{
Console.WriteLine(linesOfCode[i]);
}
}
}
#region test class
public enum MyEnum
{
Apples,
Oranges
}
public partial class TestClass
{
public string GetStringRepresentation(MyEnum e)
{
MyEnum e2 = MyEnum.Apples;
return e.ToString() + e2.ToString();
}
}
#endregion test class
#region Get a symbol reader for the given module
// Encapsulate a set of helper classes to get a symbol reader from a file.
// The symbol interfaces require an unmanaged metadata interface.
static class SymUtil
{
static class NativeMethods
{
[DllImport("ole32.dll")]
public static extern int CoCreateInstance(
[In] ref Guid rclsid,
[In, MarshalAs(UnmanagedType.IUnknown)] Object pUnkOuter,
[In] uint dwClsContext,
[In] ref Guid riid,
[Out, MarshalAs(UnmanagedType.Interface)] out Object ppv);
}
// Wrapper.
public static ISymbolReader GetSymbolReaderForFile(string pathModule, string searchPath)
{
return SymUtil.GetSymbolReaderForFile(
new System.Diagnostics.SymbolStore.SymBinder(), pathModule, searchPath);
}
// We demand Unmanaged code permissions because we're reading from the file
// system and calling out to the Symbol Reader
// @TODO - make this more specific.
[System.Security.Permissions.SecurityPermission(
System.Security.Permissions.SecurityAction.Demand,
Flags = System.Security.Permissions.SecurityPermissionFlag.UnmanagedCode)]
public static ISymbolReader GetSymbolReaderForFile(
System.Diagnostics.SymbolStore.SymBinder binder, string pathModule, string searchPath)
{
// Guids for imported metadata interfaces.
Guid dispenserClassID = new Guid(0xe5cb7a31, 0x7512, 0x11d2, 0x89,
0xce, 0x00, 0x80, 0xc7, 0x92, 0xe5, 0xd8); // CLSID_CorMetaDataDispenser
Guid dispenserIID = new Guid(0x809c652e, 0x7396, 0x11d2, 0x97, 0x71,
0x00, 0xa0, 0xc9, 0xb4, 0xd5, 0x0c); // IID_IMetaDataDispenser
Guid importerIID = new Guid(0x7dac8207, 0xd3ae, 0x4c75, 0x9b, 0x67,
0x92, 0x80, 0x1a, 0x49, 0x7d, 0x44); // IID_IMetaDataImport
// First create the Metadata dispenser.
object objDispenser;
NativeMethods.CoCreateInstance(ref dispenserClassID, null, 1,
ref dispenserIID, out objDispenser);
// Now open an Importer on the given filename. We'll end up passing this importer
// straight through to the Binder.
object objImporter;
IMetaDataDispenser dispenser = (IMetaDataDispenser)objDispenser;
dispenser.OpenScope(pathModule, 0, ref importerIID, out objImporter);
IntPtr importerPtr = IntPtr.Zero;
ISymbolReader reader;
try
{
// This will manually AddRef the underlying object, so we need to
// be very careful to Release it.
importerPtr = Marshal.GetComInterfaceForObject(objImporter,
typeof(IMetadataImport));
reader = binder.GetReader(importerPtr, pathModule, searchPath);
}
finally
{
if (importerPtr != IntPtr.Zero)
{
Marshal.Release(importerPtr);
}
}
return reader;
}
}
#region Metadata Imports
// We can use reflection-only load context to use reflection to query for
// metadata information rather
// than painfully import the com-classic metadata interfaces.
[Guid("809c652e-7396-11d2-9771-00a0c9b4d50c"),
InterfaceType(ComInterfaceType.InterfaceIsIUnknown)]
[ComVisible(true)]
interface IMetaDataDispenser
{
// We need to be able to call OpenScope, which is the 2nd vtable slot.
// Thus we need this one placeholder here to occupy the first slot..
void DefineScope_Placeholder();
//STDMETHOD(OpenScope)( // Return code.
//LPCWSTR szScope, // [in] The scope to open.
// DWORD dwOpenFlags, // [in] Open mode flags.
// REFIID riid, // [in] The interface desired.
// IUnknown **ppIUnk) PURE; // [out] Return interface on success.
void OpenScope([In, MarshalAs(UnmanagedType.LPWStr)] String szScope,
[In] Int32 dwOpenFlags, [In] ref Guid riid,
[Out, MarshalAs(UnmanagedType.IUnknown)] out Object punk);
// Don't need any other methods.
}
// Since we're just blindly passing this interface through managed code to the Symbinder,
// we don't care about actually importing the specific methods.
// This needs to be public so that we can call Marshal.GetComInterfaceForObject() on
// it to get the underlying metadata pointer.
[Guid("7DAC8207-D3AE-4c75-9B67-92801A497D44"),
InterfaceType(ComInterfaceType.InterfaceIsIUnknown)]
[ComVisible(true)]
[CLSCompliant(true)]
public interface IMetadataImport
{
// Just need a single placeholder method so that it doesn't complain
// about an empty interface.
void Placeholder();
}
#endregion
#endregion Get a symbol reader for the given module
}
答案 1 :(得分：1)
我看到在 2011 中提出了此问题。现在是 2019 ，有2个选项可以从方法中检索局部变量。
首先让我们定义VariableInfo以保留局部变量参数：
public class VariableInfo : IEquatable<VariableInfo>
{
public int Index { get; }
public string Name { get; }
public Type Type { get; }
public VariableInfo(int index, Type type, string name) =>
(Index, Type, Name) = (index, type, name);
public override bool Equals(object obj) =>
Equals(obj as VariableInfo);
public bool Equals(VariableInfo info) =>
info != null &&
Index.Equals(info.Index) &&
Name.Equals(info.Name) &&
Type.Equals(info.Type);
public override int GetHashCode()
{
unchecked
{
var hash = 17;
hash = 23 * hash + Index.GetHashCode();
hash = 23 * hash + Name.GetHashCode();
hash = 23 * hash + Type.GetHashCode();
return hash;
}
}
public override string ToString() =>
$"Index {Index}, Type {Type}, Name {Name}";
}
然后将ILocalsReader界面定义为以下内容：
public interface ILocalsReader
{
VariableInfo[] Read(MethodBase info);
}
现在可以像这样用Microsoft.Samples.Debugging.CorApi来实现它：
public class MicrosoftDebuggingReader : ILocalsReader
{
public VariableInfo[] Read(MethodBase info)
{
var il = info.GetMethodBody().LocalVariables.ToArray();
return SymbolAccess
.GetReaderForFile(info.DeclaringType.Assembly.Location)
.GetMethod(new SymbolToken(info.MetadataToken))
.RootScope
.GetInnerScopesRecursive()
.SelectMany(scope => scope.GetLocals())
.Select(local =>
new VariableInfo(local.AddressField1,
il[local.AddressField1].LocalType,
local.Name))
.ToArray();
}
}
GetInnerScopesRecursive是扩展方法：
internal static class SymbolScopeExtensions
{
public static IEnumerable<ISymbolScope> GetInnerScopesRecursive(this ISymbolScope scope)
{
yield return scope;
foreach (var innerScope in scope.GetChildren()
.SelectMany(innerScope => innerScope.GetInnerScopesRecursive()))
yield return innerScope;
}
}
记住要针对x64构建。
另一个选择是像这样使用Mono.Cecil：
public class MonoCecilReader : ILocalsReader
{
public VariableInfo[] Read(MethodBase info)
{
var method = info.GetMethodDefinition();
method.Module.ReadSymbols();
var pdb = Path.ChangeExtension(info.DeclaringType.Assembly.Location, "pdb");
new PdbReaderProvider().GetSymbolReader(method.Module, pdb)
.Read(method);
var il = info.GetMethodBody().LocalVariables;
return Read(method, il);
}
public VariableInfo[] Read(MethodDefinition method, IList<LocalVariableInfo> il)
{
return method
.DebugInformation
.Scope
.GetInnerScopesRecursive()
.SelectMany(scope => scope.Variables)
.Select(local =>
new VariableInfo(local.Index,
il[local.Index].LocalType,
local.Name))
.ToArray();
}
}
GetMethodDefinition是扩展方法：
public static class MethodDefinitionExtensions
{
public static MethodDefinition GetMethodDefinition(this MethodBase info) =>
AssemblyDefinition
.ReadAssembly(info.DeclaringType.Assembly.Location)
.Modules
.SelectMany(module => module.GetTypes())
.Single(type => type.FullNameMatches(info.DeclaringType))
.Methods
.FirstOrDefault(method =>
method.Name.Equals(info.Name) &&
method.ReturnType.FullName.Equals(info.GetReturnType().FullName) &&
method.Parameters.Select(parameter => parameter.ParameterType.FullName)
.SequenceEqual(info.GetParameters().Select(parameter => parameter.ParameterType.FullName)));
}
GetReturnType是扩展方法：
public static class MethodBaseExtensions
{
public static Type GetReturnType(this MethodBase method)
{
if (method is MethodInfo info)
return info.ReturnType;
if (method is ConstructorInfo ctor)
return typeof(void);
throw new ArgumentException($"Argument {nameof(method)} has unsupported type {method.GetType()}.");
}
}
FullNameMatches是扩展方法：
internal static class TypeDefinitionExtensions
{
public static bool FullNameMatches(this TypeDefinition typeDefinition, Type type) =>
typeDefinition.FullName.Replace("/", "").Equals(type.FullName.Replace("+", ""));
}
GetInnerScopesRecursive是扩展方法：
internal static class ScopeDebugInformationExtensions
{
public static IEnumerable<ScopeDebugInformation> GetInnerScopesRecursive(this ScopeDebugInformation scope)
{
yield return scope;
foreach (var innerScope in scope.Scopes
.SelectMany(innerScope => innerScope.GetInnerScopesRecursive()))
yield return innerScope;
}
}
用法：
class Program
{
static void Main(string[] args)
{
var info = new Action<string>(Foo).GetMethodInfo();
Console.WriteLine("\tMicrosoft.Samples.Debugging.CorSymbolStore");
foreach (var v in new MicrosoftDebuggingReader().Read(info))
Console.WriteLine(v);
Console.WriteLine("\tMono.Cecil");
foreach (var v in new MonoCecilReader().Read(info))
Console.WriteLine(v);
}
public static void Foo(string s)
{
for (int i; ;)
for (double j; ;)
for (bool k; ;)
for (object m = 0; ;)
for (DateTime n; ;) { }
}
}
礼物：
Microsoft.Samples.Debugging.CorSymbolStore
Index 0, Type System.Int32, Name i
Index 1, Type System.Double, Name j
Index 2, Type System.Boolean, Name k
Index 3, Type System.Object, Name m
Index 4, Type System.DateTime, Name n
Mono.Cecil
Index 0, Type System.Int32, Name i
Index 1, Type System.Double, Name j
Index 2, Type System.Boolean, Name k
Index 3, Type System.Object, Name m
Index 4, Type System.DateTime, Name n
注意：
Microsoft.Samples.Debugging.CorApi的下载量约为9000，最近一次更新是在2011年10月10日。Mono.Cecil的下载量约为34.1万，最新提交时间为05.08.2019 答案 2 :(得分：0)
查看Codeplex上的CCI项目。它有一个PDBReader项目。