Some specific meta-programming (metadata access) questions...

[mgravell]

Blame @davidfowl - he told me to put them here ;p

1. the big one; is there an indirect equivalent to GetMethodBody() / GetILAsByteArray() (plus locals, params, exception clauses etc)? Basically, is there an API that exposes the raw underlying IL? If the answer to this one is "nope", then the rest is moot...
2. [UnverifiableCodeAttribute] - no longer exists; is there a way to determine if a member is unverifiable?
3. can volatile fields be detected? Sigil used to do this via GetRequiredCustomModifiers()
4. TypedReference - am I right in thinking this simply doesn't exist as a concept?
5. any mechanism to resolve string literal and fields from metadata tokens? (akin to ResolveString() / ResolveField())

Context: I'm converting Sigil/Jil; most stuff is working, but some low-level meta-programming stuff is missing. It would be nice to reinstate the original optimizations to Jil (and an entire chunk of Sigil).

[davidfowl]

/cc @nguerrera

[nguerrera]

cc @weshaggard

[nguerrera]

1. You can use GetMetadataToken() from System.Reflection.TypeExtensions and then drop down to System.Reflection.Metadata to get the IL. I'll post a gist later tonight. Keep in mind that tokens will not be available on .NET Native if you're also expecting this to work there.
2. I don't believe there's any easy way, but a method could be unverifiable and not have that attribute. Really, the actual verifier succeeding is the only thing you could trust. What do you need it for?
3. Could also be done via metadata token -> S.R.M, but messy. We should add GetRequiredModifiers to .NET Core.
4. Correct.
5. You can enumerate each member's token and put them in a dictionary for subsequent lookup.

[mgravell]

Awesome. Sounds very promising so far. The UWP stuff would be of no use
here anyway - requires fundamental re-architecture to support that, sadly.
Either pre-emptive (code-generation) meta-programming in the build chain,
or something like Expression-tree (runtime evaluated).
On 17 Nov 2015 8:41 pm, "Nick Guerrera" notifications@github.com wrote:

You can use GetMetadataToken() from System.Reflection.TypeExtensions
and then drop down to System.Reflection.Metadata to get the IL. I'll post a
gist later tonight. Keep in mind that tokens will not be available on .NET
Native if you're also expecting this to work there.
2.

I don't believe there's any easy way, but a method could be
unverifiable and not have that attribute. Really, the actual verifier
succeeding is the only thing you could trust. What do you need it for?
3.

Could also be done via metadata token -> S.R.M, but messy. We should
add GetRequiredModifiers to .NET Core.

dotnet/corefx#4 dotnet/corefx#4 Correct.

dotnet/corefx#5 dotnet/corefx#5 Can enumerate each member's
token and put them in a dictionary for subsequent lookup.

—
Reply to this email directly or view it on GitHub
https://github.com/dotnet/corefx/issues/4543#issuecomment-157491151.

[mgravell]

Sorry, I meant native when I said UWP. There may or may not be some
intersection there.
On 17 Nov 2015 8:44 pm, "Marc Gravell" marc.gravell@gmail.com wrote:

Awesome. Sounds very promising so far. The UWP stuff would be of no use
here anyway - requires fundamental re-architecture to support that, sadly.
Either pre-emptive (code-generation) meta-programming in the build chain,
or something like Expression-tree (runtime evaluated).
On 17 Nov 2015 8:41 pm, "Nick Guerrera" notifications@github.com wrote:

You can use GetMetadataToken() from System.Reflection.TypeExtensions
and then drop down to System.Reflection.Metadata to get the IL. I'll post a
gist later tonight. Keep in mind that tokens will not be available on .NET
Native if you're also expecting this to work there.
2.

I don't believe there's any easy way, but a method could be
unverifiable and not have that attribute. Really, the actual verifier
succeeding is the only thing you could trust. What do you need it for?
3.

Could also be done via metadata token -> S.R.M, but messy. We should
add GetRequiredModifiers to .NET Core.

dotnet/corefx#4 dotnet/corefx#4 Correct.

dotnet/corefx#5 dotnet/corefx#5 Can enumerate each member's
token and put them in a dictionary for subsequent lookup.

—
Reply to this email directly or view it on GitHub
https://github.com/dotnet/corefx/issues/4543#issuecomment-157491151.

[nguerrera]

Here's that gist for (1). Sorry for not posting sooner. I forgot all about it until now: https://gist.github.com/nguerrera/72444715c7ea0b40addb

Unfortunately, it doesn't quite work on DNX because I'm getting Assembly.Location = String.Empty. I'll follow up. We either need DNX to override Location somehow, or to add a TryGetRawPEImage alongside TryGetRawMetadata.

[davidfowl]

TryGetRawPEImage would be nice

[pallavit]

GetRequiredCustomModifiers() will be added to .NET Core as part of dotnet/corefx#5381.

@nguerrera , @mgravell Looking at the rest of the thread, the other request is to add a new API TryGetRawPEImage to System.Reflection.Metadata. Let me know if I missed something here.

[nguerrera]

TryGetRawPEImage needs to be implemented in mscorlib, just like TryGetRawMetadata. We used the System.Reflection.Metadata namespace for TryGetRawMetadata, but it cannot actually be implemented in System.Reflection.Metadata.dll.