Nabble - Mono - Cecil

Re: Cecil v2.0 Status? (was: Re: Lazy loading of TypeDefinition)

2009-12-01T04:58:22Z

Hey Philip,

On 11/20/09, Philip Laureano <philip.laureano@...> wrote:
> Any news regarding the next version of Cecil?

The first bits were rolled to some users that are doing reading
specific stuff, and we're killing some bugs before making it more
widely available. It's currently still missing the IL manipulation
bits (Import and stuff to work on the IL stream), so it wouldn't be
really useful for LinFu right now.

--
Jb Evain <jb@...>

--
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mono-cecil

Finding overrides and implements

2009-11-21T09:18:23Z

Hi all -

If someone is interested, here (at the end of this posting) is the
code I plan to use in my call graph machine. It is a modification of
Mono.Linker.Steps.TypeMapStep, to which Jb pointed me.

The changes from the original code are:

(a) It's an abstract class that has an abstract OnFoundMatch(MethodDef
@base, MethodDef @override). Therefore, a bunch of methods is now non-
static.

(b) If there are more interfaces with a matching method,
TypeMapStep.GetBaseMethodInInterfaceHierarchy returns the method of
only the first interface. With a call graph, we need all matching
methods in all base interfaces. Example:

interface I1 { void M(); }
interface I2 { void M(); }
class C : I1, I2 { public void M() {} }

In this code, we want to know that C.M() implements I1.M() as well as
I2.M().
Therefore, GetBaseMethodInInterfaceHierarchy() now returns an
IEnumerable<MethodDefinition>; and calls to it now iterate over the
result.

(c) I also want to get all potential calls from "mixing in interface
method implementations", so I need also these "strange
implementations." Here is an example of valid C# code:

interface I1 { void M(); }
class C { public void M() {} }
class CDerived : C {}

Here, I1.M() is implemented by C.M() in CDerived, although I1 and C do
not have any direct knowledge of each other. To find all these cases,
I added the following code to MapVirtualMethods:

// Go to each base class ...
for (var @base = GetBaseType(type); @base != null; @base =
GetBaseType(@base)) {
foreach (MethodDefinition method in @base.Methods) {
if (!method.IsVirtual)
continue;
// ... and map its methods to the methods of all
the current(!) type's interfaces.
MapVirtualInterfaceMethod(type, method);
}
}

To do this, I gave MapVirtualInterfaceMethod an additional parameter,
namely the type from which it should take the implementation method;
the single-parameter version of GetBaseMethodInInterfaceHierarchy
became useless after this. In addition, the guard at the top of
MapVirtualMethods which returns immediately if no methods are present
is removed so that the new for loop runs also in this case (which is
e.g. necessary for the given example).

----------

The code below does not handle everything perfectly - and moreover, I
have not tested it except for some demo cases. Momentarily, the idea
is not to miss any potential overrides; but maybe accept a few wrong
ones. Here are two examples where the code gives a "false positive":

a.
interface I { void M(); }
abstract class C {
public virtual void M() { }
}
abstract class D : C { }
abstract class E : D {
public new virtual void M() { }
}
class F : E, I { }

Here, C.M() cannot implement I.M() if we make the "closed-world
assumption" that we know all classes in the universe (which I assume
with tools that look "downwards" in the inheritance tree). The
MethodMatcher, yet, says that (a) C.M() implements I.M(); and (b) that
E.M() overrides C.M(). Precise tracking of hidings is, I think,
necessary to find out which methods are NOT overrides or implements in
such cases.

b. An interesting piece of code in C#:

interface I<T> {
T M(T p);
}
abstract class C<T> : I<T> {
public abstract T M(T p);
}
abstract class D<T> : C<T>, I<int> {
public override T M(T p) { return p; }
public int M(int p) { return 10; }
}
class E : D<int> { }

Now, we can create an E and call M(5) on it. The interesting question
then is: Which M() is called? ;-) ...

... there is a general rule somewhere that spelt-out parameter types
are a better match than generic parameters. Therefore, the second
method (where int is spelt out) is called. I found no way to call the
first implementation of M in class D via an object of class E - is
there one?

On the other hand, the current MethodMatcher says that also the first
implementation implementents I<T>'s M() method - which is therefore
"somewhat true" (leaving it out gives a compile time error) and
"somewhat false" (a call to I<T> will never call that implementation
[it appears]).

(With two interfaces, that sort of thing is NOT allowed:

interface I<T> {
T M(T p);
}
abstract class D<T> : I<T>, I<int> {
public T M(T p) { return p; }
public int M(int p) { return 10; }
}
class E : D<int> { }

yields (in Visual Studio 2010 beta) Error: 'D<T>' cannot implement
both 'I<int>' and 'I<T>' because they may unify for some type
parameter substitutions. This does not even work if one specifies
"where T : class" which would guarantee that T can never be int.)

Ok - so much for the moment. Below is the code.

Regards
Harald M.

----------

using System.Collections.Generic;
using Mono.Cecil;

/// <summary>
/// Resolution of overrides and implements of methods.
/// Copied and modified from Mono's Mono.Linker.Steps.TypeMapStep
by Jb Evain (jbevain@...)
/// </summary>
public abstract class MethodMatcher {

protected abstract void OnFoundMatch(MethodDefinition @base,
MethodDefinition @override);

public void ProcessAssembly(AssemblyDefinition assembly) {
foreach (TypeDefinition type in assembly.MainModule.Types)
MapType(type);
}

void MapType(TypeDefinition type) {
MapVirtualMethods(type);
}

void MapVirtualMethods(TypeDefinition type) {
foreach (MethodDefinition method in type.Methods) {
if (!method.IsVirtual)
continue;

MapVirtualMethod(method);

if (method.HasOverrides)
MapOverrides(method);
}

// Go to each base class ...
for (var @base = GetBaseType(type); @base != null; @base =
GetBaseType(@base)) {
foreach (MethodDefinition method in @base.Methods) {
if (!method.IsVirtual)
continue;
// ... and map its methods to the methods of all
the current(!) type's interfaces.
MapVirtualInterfaceMethod(type, method);
}
}
}

void MapVirtualMethod(MethodDefinition method) {
MapVirtualBaseMethod(method);
MapVirtualInterfaceMethod(method.DeclaringType, method);
}

void MapVirtualBaseMethod(MethodDefinition method) {
MethodDefinition @base = GetBaseMethodInTypeHierarchy
(method);
if (@base == null)
return;

AnnotateMethods(@base, method);
}

void MapVirtualInterfaceMethod(TypeDefinition type,
MethodDefinition method) {
foreach (var @base in GetBaseMethodInInterfaceHierarchy
(type, method))
AnnotateMethods(@base, method);
}

void MapOverrides(MethodDefinition method) {
foreach (MethodReference overrideRef in method.Overrides)
{
MethodDefinition @override = overrideRef.Resolve();
if (@override == null)
continue;

AnnotateMethods(@override, method);
}
}

void AnnotateMethods(MethodDefinition @base, MethodDefinition
@override) {
OnFoundMatch(@base, @override);
}

static MethodDefinition GetBaseMethodInTypeHierarchy
(MethodDefinition method) {
TypeDefinition @base = GetBaseType(method.DeclaringType);
while (@base != null) {
MethodDefinition baseMethod = TryMatchMethod(@base,
method);
if (baseMethod != null)
return baseMethod;

@base = GetBaseType(@base);
}

return null;
}

static IEnumerable<MethodDefinition>
GetBaseMethodInInterfaceHierarchy(TypeDefinition type,
MethodDefinition method) {
foreach (TypeReference interfaceRef in type.Interfaces) {
TypeDefinition @interface = interfaceRef.Resolve();
if (@interface == null)
continue;

MethodDefinition baseMethod = TryMatchMethod
(@interface, method);
if (baseMethod != null)
yield return baseMethod;

foreach (var md in GetBaseMethodInInterfaceHierarchy
(@interface, method))
yield return md;
}
}

static MethodDefinition TryMatchMethod(TypeDefinition type,
MethodDefinition method) {
if (!type.HasMethods)
return null;

foreach (MethodDefinition candidate in type.Methods)
if (MethodMatch(candidate, method))
return candidate;

return null;
}

static bool MethodMatch(MethodDefinition candidate,
MethodDefinition method) {
if (!candidate.IsVirtual)
return false;

if (candidate.Name != method.Name)
return false;

if (!TypeMatch(candidate.ReturnType.ReturnType,
method.ReturnType.ReturnType))
return false;

if (candidate.Parameters.Count != method.Parameters.Count)
return false;

for (int i = 0; i < candidate.Parameters.Count; i++)
if (!TypeMatch(candidate.Parameters[i].ParameterType,
method.Parameters[i].ParameterType))
return false;

return true;
}

static bool TypeMatch(ModType a, ModType b) {
if (!TypeMatch(a.ModifierType, b.ModifierType))
return false;

return TypeMatch(a.ElementType, b.ElementType);
}

static bool TypeMatch(TypeSpecification a, TypeSpecification
b) {
if (a is GenericInstanceType)
return TypeMatch((GenericInstanceType)a,
(GenericInstanceType)b);

if (a is ModType)
return TypeMatch((ModType)a, (ModType)b);

return TypeMatch(a.ElementType, b.ElementType);
}

static bool TypeMatch(GenericInstanceType a,
GenericInstanceType b) {
if (!TypeMatch(a.ElementType, b.ElementType))
return false;

if (a.GenericArguments.Count != b.GenericArguments.Count)
return false;

if (a.GenericArguments.Count == 0)
return true;

for (int i = 0; i < a.GenericArguments.Count; i++)
if (!TypeMatch(a.GenericArguments[i],
b.GenericArguments[i]))
return false;

return true;
}

static bool TypeMatch(TypeReference a, TypeReference b) {
if (a is GenericParameter)
return true;

if (a is TypeSpecification || b is TypeSpecification) {
if (a.GetType() != b.GetType())
return false;

return TypeMatch((TypeSpecification)a,
(TypeSpecification)b);
}

return a.FullName == b.FullName;
}

static TypeDefinition GetBaseType(TypeDefinition type) {
if (type == null || type.BaseType == null)
return null;

return type.BaseType.Resolve();
}
}

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mono-cecil

Cecil v2.0 Status? (was: Re: Lazy loading of TypeDefinition)

2009-11-20T14:53:22Z

Hi Jb,

Any news regarding the next version of Cecil?

On Thu, Nov 19, 2009 at 10:23 PM, Jb Evain <jb@...> wrote:

Hey Anatoly,

On 11/19/09, Anatoly <amspb1@...> wrote:
> For performace I'd like initially to load only type's names/fullnames.
> The other information (fields, properties,methods) I'd like to load
> later (when considering the given type). Is this scenario possible in
> Mono.Cecil?

Right now Cecil aggresively loads everything. Its next version is
allows you to load metadata lazily. I suggest you use the current
version of Cecil, and try the next version as soon as it's out.

--
Jb Evain <jb@...>

--
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mono-cecil

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mono-cecil

Re: Lazy loading of TypeDefinition

2009-11-19T06:23:57Z

Hey Anatoly,

On 11/19/09, Anatoly <amspb1@...> wrote:
> For performace I'd like initially to load only type's names/fullnames.
> The other information (fields, properties,methods) I'd like to load
> later (when considering the given type). Is this scenario possible in
> Mono.Cecil?

Right now Cecil aggresively loads everything. Its next version is
allows you to load metadata lazily. I suggest you use the current
version of Cecil, and try the next version as soon as it's out.

--
Jb Evain <jb@...>

--
--
mono-cecil

Re: Lazy loading of TypeDefinition

2009-11-19T06:22:11Z

Mono does not contain APIs for getting such information without loading the type hierarchy.
However, it uses lazy loading for other stuff like method bodies...

If performance is an absolute requirement, you may consider implementing your own optimized routines

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mono-cecil

Lazy loading of TypeDefinition

2009-11-19T06:04:53Z

Hello,
For performace I'd like initially to load only type's names/fullnames.
The other information (fields, properties,methods) I'd like to load
later (when considering the given type). Is this scenario possible in
Mono.Cecil?

--
--
mono-cecil

Re: Code or info to find overridden, implemented, and overriding methods

2009-11-17T12:28:04Z

Thanks - I'll dive into it ...
Regards
Harald

-------- Original-Nachricht --------
> Datum: Tue, 17 Nov 2009 18:08:30 +0100
> Von: Jb Evain <jb@...>
> An: mono-cecil@...
> Betreff: Re: [mono-cecil] Code or info to find overridden, implemented, and overriding methods

> Hey Harold,
>
> On 11/17/09, Harald M. <harald_m_mueller@...> wrote:
> > If someone could give me a pointer to such code (e.g. in Gendarme?),
> > I'd be happy ... and of course willing to post back any knowledge I
> > might gain :-)
>
> You can have a look at the code in the linker which creates a map of
> all methods that are base method or that override methods:
>
> http://anonsvn.mono-project.com/source/trunk/mcs/tools/linker/Mono.Linker.Steps/TypeMapStep.cs
>
> --
> Jb Evain <jb@...>
>
> --
> --
> mono-cecil

--
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Jetzt freischalten unter http://portal.gmx.net/de/go/maxdome01

--
--
mono-cecil

Re: Code or info to find overridden, implemented, and overriding methods

2009-11-17T12:27:33Z

No problem :-) !!!
-------- Original-Nachricht --------
> Datum: Tue, 17 Nov 2009 18:09:02 +0100
> Von: Jb Evain <jb@...>
> An: mono-cecil@...
> Betreff: Re: [mono-cecil] Code or info to find overridden, implemented, and overriding methods

> On 11/17/09, Jb Evain <jb@...> wrote:
> > Hey Harold,
>
> Sorry, Harald, I hit send too fast.
>
> --
> Jb Evain <jb@...>
>
> --
> --
> mono-cecil

--
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sicherer, schneller und einfacher! http://portal.gmx.net/de/go/chbrowser

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mono-cecil

Re: Code or info to find overridden, implemented, and overriding methods

2009-11-17T09:09:02Z

On 11/17/09, Jb Evain <jb@...> wrote:
> Hey Harold,

Sorry, Harald, I hit send too fast.

--
Jb Evain <jb@...>

--
--
mono-cecil

Re: Code or info to find overridden, implemented, and overriding methods

2009-11-17T09:08:30Z

Hey Harold,

On 11/17/09, Harald M. <harald_m_mueller@...> wrote:
> If someone could give me a pointer to such code (e.g. in Gendarme?),
> I'd be happy ... and of course willing to post back any knowledge I
> might gain :-)

You can have a look at the code in the linker which creates a map of
all methods that are base method or that override methods:

http://anonsvn.mono-project.com/source/trunk/mcs/tools/linker/Mono.Linker.Steps/TypeMapStep.cs

--
Jb Evain <jb@...>

--
--
mono-cecil

Code or info to find overridden, implemented, and overriding methods

2009-11-17T07:48:04Z

Hello -

I'm writing a call graph detector. It will, in its first version, show
"potential calls" = calls to all overriding methods.
I'll have to write code to find those methods, also over assembly
boundaries.

I'd like to take a look at code that already does this, as it
obviously not that easy (e.g. the cases shown in
http://groups.google.com/group/mono-cecil/msg/5f69e80a2c7e7240 ).

If someone could give me a pointer to such code (e.g. in Gendarme?),
I'd be happy ... and of course willing to post back any knowledge I
might gain :-)

Thanks
Harald M.

--
--
mono-cecil

Re: Bug in reflection of IList?

2009-11-11T07:43:21Z

Hello,
Thanks! It helps!

Anatoly

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Re: Bug in reflection of IList?

2009-11-10T08:16:27Z

Hey,

On 11/10/09, Anatoly <amspb1@...> wrote:
> I've got TypeDefinition of IList<T>. Then I examine Interfaces
> property. There is ICollection<TKey> type reference there. It's
> strange because no TKey generic parameter presents in IList<T>.
>
> How to solve this problem?

That's not the case with Cecil from svn. Try with a fresh Cecil from
the Mono daily build.

--
Jb Evain <jb@...>

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Bug in reflection of IList?

2009-11-10T07:25:43Z

Hello
I've got TypeDefinition of IList<T>. Then I examine Interfaces
property. There is ICollection<TKey> type reference there. It's
strange because no TKey generic parameter presents in IList<T>.

How to solve this problem?

Regards,
Anatoly

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Re: Metadata schema in .NET 4.0

2009-11-09T05:09:31Z

Thanks, Jb.

On Mon, Nov 9, 2009 at 4:04 PM, Jb Evain <jb@...> wrote:

Hey Vladimir,

On 11/9/09, Vladimir Reshetnikov <v.reshetnikov@...> wrote:
> Does anybody know, are there any publicly announced changes in image format
> and metadata schema in .NET 4.0?

Nope, it's the same as .net 2.0. Only the metadata version changes to
a v4.X. Where X is not determined for the final build.

--
Jb Evain <jb@...>

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Re: Metadata schema in .NET 4.0

2009-11-09T05:04:25Z

Hey Vladimir,

On 11/9/09, Vladimir Reshetnikov <v.reshetnikov@...> wrote:
> Does anybody know, are there any publicly announced changes in image format
> and metadata schema in .NET 4.0?

Nope, it's the same as .net 2.0. Only the metadata version changes to
a v4.X. Where X is not determined for the final build.

--
Jb Evain <jb@...>

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Metadata schema in .NET 4.0

2009-11-09T04:55:57Z

Hi,

Does anybody know, are there any publicly announced changes in image format and metadata schema in .NET 4.0?

Thanks,

Vladimir

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more performance issues

2009-10-30T10:13:12Z

Hi

Sorry to bother you again about performance, but I just did a profile on our assembly generator and a lot of time goes into getting the properties values and calling methods of the Type object using reflection. Examples are in ReflectionHelper:

        public static bool IsGenericType (Type t)
        {
            return GetProperty (t, "IsGenericType");
        }

What is the reason for calling members of Type using Invoke? The library could be faster if a direct call is made. I did a test by changing all the reflected calls in ReflectionHelper.cs and our generator got 20% faster (after the change saving the assembly takes now takes most of the time: 65%).

regards
Dirk

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performance problems when Import

2009-10-30T09:33:26Z

Hi

When Importing symbols (FieldReference, MethodReference, etc..) cecil gets very slow when the number of references already in the Module is great. Cecil searches the MemberReferences list linear to see if that reference was already added. This is very slow. I made a test when generation a largish assembly:
* 48 seconds with a plain cecil
* 6 seconds when I add a HashTable to the MethodReferences class for a fast lookup of the signature.
(note: In this test I already optimized the calling of Import so I only call it once for every MethodReference)

Is there interest in getting the Import method faster?

I used an additional HashTable, but more memory efficient would be to only use a HashTable and not a list anymore, but in that case the order of the references won't be preserved. Is this important? And do the maintainers of cecil have an interest in me providing a patch?

regards,
Dirk

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bug: creating a reference to a constructor of a instantiated generic type

2009-10-29T08:59:51Z

Hi,

I have come across a bug that has been on the mailing list before but no solution was put forward:

public class Y {}
public class X<T> {
    public X(T x)
    {
    }
}

    var assDef = AssemblyFactory.DefineAssembly("test", "test", TargetRuntime.NET_2_0, AssemblyKind.Dll);
    var module = assDef.MainModule;
    var ci = module.Import(typeof(X<Y>).GetConstructors()[0]);


Will return a MethodReference like this:

System.Void X`1<Y>::.ctor(Y)

But what should be emitted is:

System.Void X`1<Y>::.ctor(!0)

I think the bug is in ReflectionHelper.ImportMethodBase wioth the for loop

              SR.ParameterInfo[] parameters = mb.GetParameters();
              for(int i = 0; i < parameters.Length; i++)
                meth.Parameters.Add(new ParameterDefinition(
                    ImportSystemType(parameters[i].ParameterType, context)));
            }

To get around this I made a quickfix

            if(mb.DeclaringType.IsGenericType) {
              bool isConstructor = mb is SR.ConstructorInfo;
              SR.MethodBase[] mbList = isConstructor ? (SR.MethodBase[])mb.DeclaringType.GetConstructors() : mb.DeclaringType.GetMethods();
              int pos = Array.IndexOf(mbList, mb);
              Type openType = mb.DeclaringType.GetGenericTypeDefinition();
              SR.MethodBase openMb = (isConstructor ? (SR.MethodBase[])openType.GetConstructors() : openType.GetMethods())[pos];
              SR.ParameterInfo[] parameters = openMb.GetParameters();
              GenericInstanceType git = (GenericInstanceType)meth.DeclaringType;
              // this is not correct - what if the method is generic, what if it is generic in a generic in a generic etc..
              foreach(SR.ParameterInfo pi in parameters) {
                Type pType = pi.ParameterType;
                if(pType.IsGenericParameter) {
                  meth.Parameters.Add(new ParameterDefinition(git.ElementType.GenericParameters[pType.GenericParameterPosition]));
                } else {
                  meth.Parameters.Add(new ParameterDefinition(ImportSystemType(pType, context)));
                }
              }
            } else {
              SR.ParameterInfo[] parameters = mb.GetParameters();
              for(int i = 0; i < parameters.Length; i++)
                meth.Parameters.Add(new ParameterDefinition(
                    ImportSystemType(parameters[i].ParameterType, context)));
            }

Is there a way to improve this? Include a better version in cecil?

regards,
Dirk

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Saving symbols causes invalid metadata header

2009-10-27T15:25:42Z

I'm using Mono.Cecil to add some generated types to an assembly. I would like to preserve the debug information. However when I load and store symbols using Mono.Cecil.Pdb, the assembly's metadata header gets messed up. Reflector produces this message - "Common.Test, Invalid 'BSJB' signature in Metadata header." I generated one assembly with symbols and one without and compared the two and noticed a slight difference in the headers.

Any idea why they're being written differently?

Thanks,
- Brandon

Re: is ModuleDefinition.Import on nullable bool correct?

2009-10-20T06:12:52Z

Ok forget it, I just tried the SVN version and there it works. Sorry to
bother you all :(

regards,
Dirk

Dirk Bonné wrote:

> Hi
>
> I noticed a problem when trying importing a nullable bool:
>
> [Test]
> public void ImportNullable()
> {
> var assDef = AssemblyFactory.DefineAssembly("test", "test",
> TargetRuntime.NET_2_0, AssemblyKind.Dll);
> var tr = assDef.MainModule.Import(typeof(bool?));
> Assert.IsTrue(tr.IsValueType);
> }
>
> I would expect IsValueType to return true for "bool?".
>
> Is this a bug?
>
> I fell over that when generating properties/fields with nullable
> types, and it may be the cause of a type loader exception.
>
> Any ideas to get around this?
>
> regards
> Dirk
>
>
>
>

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is ModuleDefinition.Import on nullable bool correct?

2009-10-20T05:48:57Z

Hi

I noticed a problem when trying importing a nullable bool:

[Test]
public void ImportNullable()
{
var assDef = AssemblyFactory.DefineAssembly("test", "test",
TargetRuntime.NET_2_0, AssemblyKind.Dll);
var tr = assDef.MainModule.Import(typeof(bool?));
Assert.IsTrue(tr.IsValueType);
}

I would expect IsValueType to return true for "bool?".

Is this a bug?

I fell over that when generating properties/fields with nullable
types, and it may be the cause of a type loader exception.

Any ideas to get around this?

regards
Dirk

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Re: type of Exception thrown

2009-10-12T00:50:52Z

May I how do u use this option (can u provide an example)? After the exception is found, how do u print it out?

Thanks.

From: jonpryor@...

Sent: Saturday, October 10, 2009 10:50 PM

To: mono-cecil@...

Cc: mono-cecil@...

Subject: [mono-cecil] Re: type of Exception thrown

On Oct 10, 2009, at 5:52 AM, Wee Li Yen <weeliyen@...> wrote:

Is there anyway I can detect what type of Exception I have thrown?

Yes, but it's not easy. You meed to track which type is on the top of the call stack at the point of the throw, and since that could be the result of a method call you'll need to follow all method calls. Furthermore, due to runtime conditionals you may find more than one potential type

mdoc[0, 1] provides vaguely similar functionality through the 'mdoc update --exceptions' option, but does this by instead tracking which exception types are created (which is an easier though incorrect algorithm).

- Jon

[0] http://go-mono.com/docs/monodoc.ashx?link=man:mdoc-update(1)

[1] http://anonsvn.mono-project.com/viewvc/trunk/mcs/tools/mdoc/

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Re: type of Exception thrown

2009-10-10T07:50:14Z

On Oct 10, 2009, at 5:52 AM, Wee Li Yen <weeliyen@...> wrote:

Is there anyway I can detect what type of Exception I have thrown?

- Jon

[0] http://go-mono.com/docs/monodoc.ashx?link=man:mdoc-update(1)

[1] http://anonsvn.mono-project.com/viewvc/trunk/mcs/tools/mdoc/

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type of Exception thrown

2009-10-10T02:52:29Z

Is there anyway I can detect what type of Exception I have thrown?

Currently I am only able to detect that I have thrown an Exception, but checking if the opcode of the instruction is "throw" or "rethrow", but I can't detect the type of Exception I have thrown. I can get info from some other instruction through its operand, but throw/rethrow don't hv operand.

Thanks.

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Re: What are the following constructs in Mono.Cecil referring to in C#?

2009-10-05T22:41:25Z

>> I suggest you have a look at the ECMA-335 document. Cecil is basically
>> mapping the metadata layout that is decribed is the document into an
>> objet model.
>
> Can u tell me more specifically where should I look at? I search for
> "metadata" but still can't find the info I want.

Partition II ( Metadata definition and semantics); most notably
chapter 22 (Metadata logical format: tables). (That's from the 4th
edition from June 2006.)

Regards,
Fabian

> --------------------------------------------------
> From: "Jb Evain" <jb@...>
> Sent: Sunday, October 04, 2009 11:25 PM
> To: <mono-cecil@...>
> Subject: [mono-cecil] Re: What are the following constructs in Mono.Cecil
> referring to in C#?
>
>>
>> Hey,
>>
>> On 10/4/09, Wee Li Yen <weeliyen@...> wrote:
>>> Can someone explain what are these referring to in Mono.Cecil?
>>> TypeReference, ExternType, Override, NestedType, PInvokeInfo,
>>> SecurityDeclaration and CustomAttribute and MarshalSpec
>>> Best if can illustrate with examples.
>>
>> I suggest you have a look at the ECMA-335 document. Cecil is basically
>> mapping the metadata layout that is decribed is the document into an
>> objet model.
>>
>>> What is TerminateModuleDefinition doing in BaseReflectionVisitor? What is
>>> the use and how to call it?
>>
>> The visitor pattern implemented in Cecil is kind of broken. I strongly
>> suggest you avoid using it, and implement your own visit mechanism. In
>> this particular case, it's just a method called after a module
>> definition has been completely visited.
>>
>> --
>> Jb Evain <jb@...>
>>
>> >
>>
>
> >
>

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Re: Difference btn MethodReference and MethodDefinition?

2009-10-05T17:42:15Z

Thanks for ur reply.

I don't quite understand "A MethodDefinition is the actual method itself, thus allowing access to the method's IL, etc.".

Cos I did more printings of the instructions' opcodes and operands of those method calls today and realised that MethodDefintion seems to be in the same assembly, just opp of what MethodReference is.

Li Yen

From: jonpryor@...

Sent: Monday, October 05, 2009 8:49 PM

To: mono-cecil@...

Cc: mono-cecil@...

Subject: [mono-cecil] Re: Difference btn MethodReference and MethodDefinition?

On Oct 5, 2009, at 8:11 AM, Wee Li Yen <weeliyen@...> wrote:

What is the difference btn a MethodReference and MethodDefinition?

A MethodReference is a reference to a method, which may be defined in another assembly (e.g. a call to Console.WriteLine() from yor app).

A MethodDefinition is the actual method itself, thus allowing access to the method's IL, etc.

- Jon

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Re: What are the following constructs in Mono.Cecil referring to in C#?

2009-10-05T06:13:05Z

On Sun, 2009-10-04 at 15:49 +0800, Wee Li Yen wrote:
> Can someone explain what are these referring to in Mono.Cecil?
> TypeReference,

A reference to a type (which may be present within another assembly).

For example, if you compile the code:

Console.WriteLine();

the IL will be:

call void class [mscorlib]System.Console::WriteLine()

which in Mono.Cecil will be a MethodReference to
System.Console.WriteLine(), and MethodReference.DeclaringType will be a
TypeReference to System.Console.

> ExternType, Override,

In this class:

class Demo {
public override string ToString() {return "demo";}
}

The virtual method System.Object.ToString() is overridden. All
overridden methods are present within an Overrides table for a type.

> NestedType,

A type declared within another type, e.g.:

class List<T> {
public struct Enumerator {}
}

List<T>.Enumerator is a nested type.

> PInvokeInfo,

When you use the [DllImport] attribute on a method.

> SecurityDeclaration

Many System.Security attributes aren't saved as normal custom attributes
in IL, but instead are stored "specially". Thus, there is a specific
table to store these "attributes".

(i.e. they only look like custom attributes within C# source, much like
[Serializable], but they're not really custom attributes.)

> and CustomAttribute

Used to store custom attributes:

[AttributeUsage(AttributeTargets.All)]
class FooAttribute : Attribute {
public FooAttribute(string foo) {}
}

[Foo ("this is a custom attribute!")]
class Bar {}

> and MarshalSpec

Used for custom marshaling. Usually used only for P/Invoke marshaling.

- Jon

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Re: Difference btn MethodReference and MethodDefinition?

2009-10-05T05:49:12Z

On Oct 5, 2009, at 8:11 AM, Wee Li Yen <weeliyen@...> wrote:

What is the difference btn a MethodReference and MethodDefinition?

A MethodReference is a reference to a method, which may be defined in another assembly (e.g. a call to Console.WriteLine() from yor app).

A MethodDefinition is the actual method itself, thus allowing access to the method's IL, etc.

- Jon

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Re: What are the following constructs in Mono.Cecil referring to in C#?

2009-10-05T05:46:24Z

> I suggest you have a look at the ECMA-335 document. Cecil is basically
> mapping the metadata layout that is decribed is the document into an
> objet model.

Can u tell me more specifically where should I look at? I search for
"metadata" but still can't find the info I want.
So I choose "PInvokeInfo" and try to search for it. I still can't it in the
file.

--------------------------------------------------
From: "Jb Evain" <jb@...>
Sent: Sunday, October 04, 2009 11:25 PM
To: <mono-cecil@...>
Subject: [mono-cecil] Re: What are the following constructs in Mono.Cecil
referring to in C#?

>
> Hey,
>
> On 10/4/09, Wee Li Yen <weeliyen@...> wrote:
>> Can someone explain what are these referring to in Mono.Cecil?
>> TypeReference, ExternType, Override, NestedType, PInvokeInfo,
>> SecurityDeclaration and CustomAttribute and MarshalSpec
>> Best if can illustrate with examples.
>
> I suggest you have a look at the ECMA-335 document. Cecil is basically
> mapping the metadata layout that is decribed is the document into an
> objet model.
>
>> What is TerminateModuleDefinition doing in BaseReflectionVisitor? What is
>> the use and how to call it?
>
> The visitor pattern implemented in Cecil is kind of broken. I strongly
> suggest you avoid using it, and implement your own visit mechanism. In
> this particular case, it's just a method called after a module
> definition has been completely visited.
>
> --
> Jb Evain <jb@...>
>
> >
>

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Difference btn MethodReference and MethodDefinition?

2009-10-05T05:11:16Z

What is the difference btn a MethodReference and MethodDefinition?

It seems like methods under the same file as main or calling the constructors are MethodDefinitions, others are MethodReferences?

Thanks!

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Cecil Decompiler -- can i pass in a file from a different solution?

2009-10-04T10:36:46Z

Regarding Cecil.Decompiler:

            var method = GetProgramMethod(file, name);
            var cfg = ControlFlowGraph.Create(method);
            FormatControlFlowGraph(Console.Out, cfg);
            var language = CSharp.GetLanguage(CSharpVersion.V3);
            var writer = language.GetWriter(new PlainTextFormatter(Console.Out));
            writer.Write(method);

Can I call a method from another solution instead, replacing the variable "file"?

I tried putting in the path of the file, but it doesn't work...

Thanks!

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Re: What are the following constructs in Mono.Cecil referring to in C#?

2009-10-04T10:10:05Z

But I realised there are a lot of Visitors inside Cecil...
Which do I use if I want to accomplish sth like
http://help.eclipse.org/help33/index.jsp?topic=/org.eclipse.cdt.doc.isv/reference/api/org/eclipse/cdt/core/dom/ast/ASTVisitor.html
in eclipse?

If really there is no visitor pattern suitable for me...
Would implementing my own visitor without any existing visitor to extend be
difficult?

--------------------------------------------------
From: "Jb Evain" <jb@...>
Sent: Sunday, October 04, 2009 11:25 PM
To: <mono-cecil@...>
Subject: [mono-cecil] Re: What are the following constructs in Mono.Cecil
referring to in C#?

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Re: System.NotSupportedException due to LoadSymbols();

2009-10-04T10:02:44Z

I found a mono.snk in /gtk-sharp, so I compiled to mcs/class. I think it
works now, thank you so much!

The thread I found earlier
(http://www.mail-archive.com/mono-cecil@.../msg00943.html) says
"You need to either get Mono.Cecil.Pdb from /cecil/pdb in Mono' svn.
Mono.Cecil.Mdb is in /mcs/class/Mono.Cecil.Mdb, and of course,Mono.Cecil is
in /mcs/class/Mono.Cecil."
But Mdb doesn't seem to hv any effect on the variable names?

I still have variables with default names (starting with CS$) assigned, so I
guess it is cos they are just anonymous variables.

However why does "Console.WriteLine(a + " " + b + " " + c);" gives me an
additional variable with the name CS$0000?

--------------------------------------------------
From: "Jb Evain" <jb@...>
Sent: Sunday, October 04, 2009 11:27 PM
To: <mono-cecil@...>
Subject: [mono-cecil] Re: System.NotSupportedException due to LoadSymbols();

>
> Hey,
>
> On 10/4/09, Wee Li Yen <weeliyen@...> wrote:
>> There is no Mono.Cecil.Pdb.dll in /cecil/pdb, I also can't compile the
>> Mono.Cecil.Pdb solution due to "........\Visual Studio
>> 2008\Projects\Mono.CompilerServices.SymbolStore\mcs\class\mono.snk'
>> -- The system cannot find the file specified".
>
> Just change whatever path specified to the .snk to pick the one that
> is in the Mono svn (mcs/class/mono.snk). And make sure you have a
> Mono.Cecil.Pdb.dll near Mono.Cecil.dll when you call LoadSymbols, and
> that the assembly you're reading has a pdb symbol file.
>
> --
> Jb Evain <jb@...>
>
> >
>

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