Issues decompiling fields and methods/ (rva=0xYYYY) could not be foundin any section!

[greenozon]

Input code

just browse the binary eg ns0/GClass3 etc

Erroneous output

 ---> System.BadImageFormatException: Field data (rva=0xa730) could not be foundin any section!
   at ICSharpCode.Decompiler.SRMExtensions.GetInitialValue(FieldDefinition field, MetadataFile pefile, ICompilation typeSystem) in SRMExtensions.cs:line 641
   at ICSharpCode.Decompiler.IL.Transforms.TransformArrayInitializers.HandleRuntimeHelpersInitializeArray(Block body, Int32 pos, ILVariable array, IType arrayType, Int32[] arrayLength, ILInstruction[]& values, Int32& foundPos) in TransformArrayInitializers.cs:line 851
   at ICSharpCode.Decompiler.IL.Transforms.TransformArrayInitializers.DoTransform(ILFunction function, Block body, Int32 pos) in TransformArrayInitializers.cs:line 67
   at ICSharpCode.Decompiler.IL.Transforms.TransformArrayInitializers.ICSharpCode.Decompiler.IL.Transforms.IStatementTransform.Run(Block block, Int32 pos, StatementTransformContext context) in TransformArrayInitializers.cs:line 45
   at ICSharpCode.Decompiler.IL.Transforms.StatementTransform.Run(Block block, BlockTransformContext context) in StatementTransform.cs:line 140
   at ICSharpCode.Decompiler.IL.Block.RunTransforms(IEnumerable`1 transforms, BlockTransformContext context) in Block.cs:line 333
   at ICSharpCode.Decompiler.IL.Transforms.BlockILTransform.VisitBlock(ControlFlowNode entryNode, BlockTransformContext context) in BlockTransform.cs:line 136
   at ICSharpCode.Decompiler.IL.Transforms.BlockILTransform.Run(ILFunction function, ILTransformContext context) in BlockTransform.cs:line 100
   at ICSharpCode.Decompiler.IL.ILFunction.RunTransforms(IEnumerable`1 transforms, ILTransformContext context) in ILFunction.cs:line 415
   at ICSharpCode.Decompiler.CSharp.RecordDecompiler.DecompileBody(IMethod method) in RecordDecompiler.cs:line 1161
   at ICSharpCode.Decompiler.CSharp.RecordDecompiler.<DetectPrimaryConstructor>g__IsPrimaryConstructor|16_0(IMethod method, IMethod unspecializedMethod) in RecordDecompiler.cs:line 194
   at ICSharpCode.Decompiler.CSharp.RecordDecompiler.DetectPrimaryConstructor() in RecordDecompiler.cs:line 183
   at ICSharpCode.Decompiler.CSharp.RecordDecompiler..ctor(IDecompilerTypeSystem dts, ITypeDefinition recordTypeDef, DecompilerSettings settings, CancellationToken cancellationToken) in RecordDecompiler.cs:line 61
   at ICSharpCode.Decompiler.CSharp.CSharpDecompiler.DoDecompile(ITypeDefinition typeDef, DecompileRun decompileRun, ITypeResolveContext decompilationContext) in CSharpDecompiler.cs:line 1320
-- continuing with outer exception (ICSharpCode.Decompiler.DecompilerException) --
   at ICSharpCode.Decompiler.CSharp.CSharpDecompiler.DoDecompile(ITypeDefinition typeDef, DecompileRun decompileRun, ITypeResolveContext decompilationContext) in CSharpDecompiler.cs:line 1478
   at ICSharpCode.Decompiler.CSharp.CSharpDecompiler.Decompile(IEnumerable`1 definitions) in CSharpDecompiler.cs:line 1041
   at ICSharpCode.Decompiler.CSharp.CSharpDecompiler.Decompile(EntityHandle[] definitions) in CSharpDecompiler.cs:line 1013
   at ICSharpCode.ILSpy.CSharpLanguage.DecompileType(ITypeDefinition type, ITextOutput output, DecompilationOptions options) in offset 93
   at ICSharpCode.ILSpy.TreeNodes.TypeTreeNode.Decompile(Language language, ITextOutput output, DecompilationOptions options) in offset 8
   at ICSharpCode.ILSpy.TextView.DecompilerTextView.DecompileNodes(DecompilationContext context, ITextOutput textOutput) in offset 122
   at ICSharpCode.ILSpy.TextView.DecompilerTextView.<>c__DisplayClass58_0.<DecompileAsync>b__0() in offset 20

at the same time no issues when using dnSpy(ex)

eg

Details

• ILSpy version 9.1.0.8004+82e461be8c74782943ad32210eb9559176cc5d41
• .NET version 8.0.15+50c4cb9fc31c47f03eac865d7bc518af173b74b7

https://www.sendspace.com/file/d21r6f

[siegfriedpammer]

The issue is not in the declaration of bool_3. When looking at a field or constructor of a type ILSpy will decompile all constructors and field declarations at the same time, in order to be able to show field initializers from constructor bodies when looking at fields.

dnSpy does not crash when looking at the ctor of ns0.GClass3. It displays some data when looking at the field with the Field RVA 0xA730:

// Token: 0x040003F1 RID: 1009 RVA: 0x0000A730 File Offset: 0x00000000
.field assembly static valuetype 'ns11.<PrivateImplementationDetails>{B6AB8E58-C4F4-4140-A4A8-39EE6DE7BB67}'/Struct1 struct1_0 at I_0000A730
.data cil I_0000A730 = bytearray (
	4d 5a 90 00 03 00 00 00 04 00 00 00 ff ff 00 00
	b8 00 00 00 00 00 00 00 40 00 00 00 00 00 00 00
	00 00 00 00 00 00 00 00 53 45 4e 53 00 00 00 00
	00 00 00 00 00 00 00 00 00 00 00 00 80 00 00 00
	0e 1f ba 0e 00 b4 09 cd 21 b8 01 4c cd 21 54 68
	69 73 20 70 72 6f 67 72 61 6d 20 63 61 6e 6e 6f
	74 20 62 65 20 72 75 6e 20 69 6e 20 44 4f 53 20
	6d 6f 64 65 2e 0d 0d 0a 24 00 00 00 00 00 00 00
	50 45 00 00 4c 01 0e 00 37 51 42 68 00 00 00 00
	00 00 00 00 e0 00 02 01 0b 01 08 00 00 f4 0f 01
	00 c2 00 00 00 00 00 00 4c c3 26 00 00 20 00 00
)

Now I tried to find where dnSpy found this data and looking for the bytes, it seems it's just showing the first 176 bytes of a PE file, the PE header and a bit more. I am not convinced that this is the correct output, when comparing the behavior of dnSpy with ECMA-335.

Looking at how ECMA335 defines the lookup of .data sections:

The PE format frequently uses the term RVA (Relative Virtual Address). An RVA is the address of an
item once loaded into memory, with the base address of the image file subtracted from it (i.e., the offset
from the base address where the file is loaded). The RVA of an item will almost always differ from its
position within the file on disk. To compute the file position of an item with RVA r, search all the
sections in the PE file to find the section with RVA s, length l and file position p in which the RVA
lies, ie s <= r < s+l. The file position of the item is then given by p+(r-s).

The assembly contains the following sections:

Following the above algorithm, we would pick the first section (RVA 0x2000 and size 0x1FE800) because that contains 0xA730. However, as you can see in the table it has a raw size of 0, so there is actually no data to be found and ILSpy throws, whereas dnSpy simply seems to fall back to file offset 0, which is not the correct thing to do IMHO.

Looking at the IL ILSpy shows the following output:

.field assembly static valuetype 'ns11.<PrivateImplementationDetails>{B6AB8E58-C4F4-4140-A4A8-39EE6DE7BB67}'/Struct1 struct1_0 at I_0000A730
// .data I_0000A730 = Field data (rva=0xa730) could not be found in any section!

I believe that the correct fix here is to handle the error and just abort the TransformArrayInitializers.HandleRuntimeHelpersInitializeArray step.