MemberRef Signatures in VB.NET

Draw PDF-417 2d barcode in VB.NET MemberRef Signatures

MemberRef Signatures
PDF417 Maker In VB.NET
Using Barcode encoder for Visual Studio .NET Control to generate, create PDF-417 2d barcode image in .NET applications.
www.OnBarcode.com
Reading PDF417 In VB.NET
Using Barcode decoder for Visual Studio .NET Control to read, scan read, scan image in .NET framework applications.
www.OnBarcode.com
Member references, which are kept in the MemberRef metadata table, are the references to fields and methods, usually those defined outside the current module. There are no specific MethodRefs and FieldRefs, so you must look at the calling convention of a MemberRef signature to tell a field reference from a method reference, which is not exactly convenient or fast. On the flip side, this design solution saves 17 bytes per image loaded in memory (8 bytes for table descriptor and 3 * 3 bytes for column descriptors of a separate FieldRef table; see 5), which is undoubtedly a significant gain. MemberRef signatures for field references are the same as the field declaration signatures discussed earlier; see Field Signatures. MemberRef signatures for method references are structurally similar to method declaration signatures, although in the argument list of a vararg method reference, a sentinel can precede the optional arguments. The sentinel itself does not count as an additional argument, so if you call a vararg method with one mandatory argument and two optional arguments, the MemberRef signature will have an argument count of three and an argument list structure that looks like this: <mandatory_arg><sentinel><opt_arg1><opt_arg2>
Barcode Printer In VB.NET
Using Barcode creator for .NET Control to generate, create Barcode image in VS .NET applications.
www.OnBarcode.com
Create Barcode In Visual Basic .NET
Using Barcode creator for VS .NET Control to generate, create Barcode image in Visual Studio .NET applications.
www.OnBarcode.com
CHAPTER 8 PRIMITIVE TYPES AND SIGNATURES
PDF 417 Generator In VB.NET
Using Barcode creator for .NET framework Control to generate, create PDF417 image in Visual Studio .NET applications.
www.OnBarcode.com
Create Code 128 Code Set C In Visual Basic .NET
Using Barcode drawer for .NET framework Control to generate, create Code 128B image in VS .NET applications.
www.OnBarcode.com
Indirect Call Signatures
Matrix Barcode Maker In VB.NET
Using Barcode generator for .NET framework Control to generate, create 2D Barcode image in .NET applications.
www.OnBarcode.com
Creating ISSN In VB.NET
Using Barcode generation for .NET Control to generate, create ISSN - 13 image in VS .NET applications.
www.OnBarcode.com
To call methods indirectly, IL has the special instruction calli. This instruction takes argument values plus a function pointer from the stack and uses the StandAloneSig token as a parameter. The signature indexed by the token is the signature by which the call is made. Effectively, calli takes a function pointer and a signature and presumes that the signature is the correct one to use in calling this function: ldc.i4.0 // Load first argument ldc.i4.1 // Load second argument ldftn void Foo::Bar(int32, int32) // Load function pointer calli void(int32, int32) // Call Foo::Bar indirectly Indirect call signatures are similar to the method signatures of MemberRefs, but the calling convention can contain the modifier explicit, which indicates that the instance pointer of the parent object (this) is explicitly specified in the method signature as the first parameter. Also, the calling convention of indirect call signature might be one of the unmanaged calling conventions, if the method called indirectly is in fact unmanaged. Unmanaged calling conventions are defined in CorHdr.h in the CorUnmanagedCallingConvention enumeration as follows: IMAGE_CEE_UNMANAGED_CALLCONV_C (0x1). C/C++-style calling convention. The call stack is cleaned up by the caller. The ILAsm notation is unmanaged cdecl. IMAGE_CEE_UNMANAGED_CALLCONV_STDCALL (0x2). Win32 API calling convention. The call stack is cleaned up by the callee. The ILAsm notation is unmanaged stdcall. IMAGE_CEE_UNMANAGED_CALLCONV_THISCALL (0x3). C++ member method (non-vararg) calling convention. The callee cleans the stack, and the this pointer is passed through the ECX register. The ILAsm notation is unmanaged thiscall. IMAGE_CEE_UNMANAGED_CALLCONV_FASTCALL (0x4). Arguments are passed in registers when possible. The ILAsm notation is unmanaged fastcall. This calling convention is not supported in the first release of the runtime.
PDF-417 2d Barcode Creator In .NET
Using Barcode creation for Reporting Service Control to generate, create PDF-417 2d barcode image in Reporting Service applications.
www.OnBarcode.com
PDF417 Reader In Visual Basic .NET
Using Barcode decoder for .NET Control to read, scan read, scan image in VS .NET applications.
www.OnBarcode.com
Local Variables Signatures
EAN13 Maker In Objective-C
Using Barcode generator for iPad Control to generate, create EAN / UCC - 13 image in iPad applications.
www.OnBarcode.com
European Article Number 13 Generation In None
Using Barcode printer for Online Control to generate, create UPC - 13 image in Online applications.
www.OnBarcode.com
Local variables signatures are the second type of signatures referenced by the StandAloneSig metadata table. Each such signature contains type encodings for all local variables used in a method. The method header can contain the StandAloneSig token, which identifies the local variables signature. This signature is retrieved by the loader when it prepares the method for JIT compilation. Local variables signatures are to some extent similar to method declaration signatures, with three differences: The calling convention is IMAGE_CEE_CS_CALLCONV_LOCAL_SIG. Local variables signatures have no return type. The local variable count is immediately followed by the sequence of encoded local variable types: <locals_sig> ::= <callconv_locals> <num_of_vars> <var_type>[,<var_type>*] ]
Scanning QR Code JIS X 0510 In None
Using Barcode recognizer for Software Control to read, scan read, scan image in Software applications.
www.OnBarcode.com
Decode Barcode In VB.NET
Using Barcode Control SDK for .NET framework Control to generate, create, read, scan barcode image in Visual Studio .NET applications.
www.OnBarcode.com
CHAPTER 8 PRIMITIVE TYPES AND SIGNATURES
UPC-A Supplement 5 Creator In Visual Studio .NET
Using Barcode creator for .NET framework Control to generate, create UPC-A Supplement 5 image in VS .NET applications.
www.OnBarcode.com
Decode Barcode In VB.NET
Using Barcode reader for .NET framework Control to read, scan read, scan image in .NET applications.
www.OnBarcode.com
where <var_type> is the same SET as <arg_type> in method declaration signatures it can be anything except void. The SETs may have the pinned modifier.
Barcode Drawer In Java
Using Barcode creation for Java Control to generate, create Barcode image in Java applications.
www.OnBarcode.com
Creating Barcode In Java
Using Barcode generator for Java Control to generate, create Barcode image in Java applications.
www.OnBarcode.com
Type Specifications
Encoding EAN / UCC - 13 In None
Using Barcode creator for Software Control to generate, create European Article Number 13 image in Software applications.
www.OnBarcode.com
PDF-417 2d Barcode Drawer In None
Using Barcode encoder for Microsoft Word Control to generate, create PDF-417 2d barcode image in Microsoft Word applications.
www.OnBarcode.com
Type specifications are special metadata items residing in the TypeSpec table and representing constructed types (pointers, arrays, function types, and so on) as opposed to TypeDefs and TypeRefs, which represent types (classes, interfaces, and value types). A common example of a constructed type is a vector or an array of classes or value types. Consider the following code snippet: .locals init(int32[0...,0...] iArr) // Declare 2-dim array reference ldc.i4 5 // Load size of first dimension ldc.i4 10 // Load size of second dimension // Create array by calling array constructor: newobj instance void int32[0...,0...]::.ctor(int32,int32) stloc iArr // Store reference to new array in iArr In the newobj instruction, we specified a MemberRef of the constructor method, parented not by a type but by a constructed type, int32[0...,0...]. The question is, Whose .ctor is it, anyway The arrays and vectors are generic types and can be instantiated only in conjunction with some nongeneric type, producing a new class in this case, a two-dimensional array of 4-byte integers with zero lower bounds. So the constructor we called was the constructor of this class. And, of course, about the only possible way to represent a constructed type is by a signature. That s why TypeSpec records have only one entry, containing an offset in the #Blob stream, pointing at the signature. Personally, I think it s a pity the TypeSpec record contains only one entry; a Name entry could be of some use. We could go pretty far with named TypeSpecs. Most obvious possibilities include type aliasing and type forwarding. The TypeSpec signature has no calling convention and consists of one SET, which, however, can be fairly long. Consider, for example, a multidimensional array of function pointers that have function pointers among their arguments. TypeSpec tokens can be used with all IL instructions that accept TypeDef or TypeRef tokens. In addition, as you ve seen, MemberRefs can be scoped to TypeSpecs as well as TypeRefs. The only places where TypeSpecs could not replace TypeDefs or TypeRefs in versions 1.0 and 1.1 were the extends and implements clauses of the class declaration, but in version 2.0 the TypeSpecs can be used there as well, because the generic type instantiations are represented by TypeSpecs (more about generic types and instantiations in 11). Two additional kinds of TypeSpecs, other than vectors and arrays, are unmanaged pointers and function pointers, which are not true generics, in that no abstract class exists from which all pointers inherit. Of course, both types of pointers can be cast to the value type int ([mscorlib]System.IntPtr), but this can hardly help the int value type is oblivious to the type being pointed at, so such casting results only in loss of information. Pointer kinds of TypeSpecs are rarely used, compared to array kinds, and have limited application.
Copyright © OnBarcode.com . All rights reserved.