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Fix RVA field alignment #55

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Merged
merged 2 commits into from
Dec 27, 2022
Merged

Fix RVA field alignment #55

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06f6d0a
Fix RVA field alignment
sbomer Dec 21, 2022
b407ed5
Merge branch 'main' into fixAlignment
sbomer Dec 27, 2022
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25 changes: 23 additions & 2 deletions Mono.Cecil.PE/TextMap.cs
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Original file line number Diff line number Diff line change
Expand Up @@ -9,6 +9,7 @@
//

using System;
using System.Diagnostics;

using RVA = System.UInt32;

Expand Down Expand Up @@ -47,11 +48,31 @@ public void AddMap (TextSegment segment, int length)
map [(int) segment] = new Range (GetStart (segment), (uint) length);
}

public void AddMap (TextSegment segment, int length, int align)
uint AlignUp (uint value, uint align)
{
align--;
return (value + align) & ~align;
}

AddMap (segment, (length + align) & ~align);
public void AddMap (TextSegment segment, int length, int align)
{
var index = (int) segment;
uint start;
if (index != 0) {
// Align up the previous segment's length so that the new
// segment's start will be aligned.
index--;
Range previous = map [index];
start = AlignUp (previous.Start + previous.Length, (uint) align);
map [index].Length = start - previous.Start;
} else {
start = ImageWriter.text_rva;
// Should already be aligned.
Debug.Assert (start == AlignUp (start, (uint) align));
}
Debug.Assert (start == GetStart (segment));

map [(int) segment] = new Range (start, (uint) length);
}

public void AddMap (TextSegment segment, Range range)
Expand Down
5 changes: 3 additions & 2 deletions Test/Mono.Cecil.Tests/FieldTests.cs
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Original file line number Diff line number Diff line change
Expand Up @@ -160,7 +160,7 @@ public void FieldRVAAlignment ()
var priv_impl = GetPrivateImplementationType (module);
Assert.IsNotNull (priv_impl);

Assert.AreEqual (6, priv_impl.Fields.Count);
Assert.AreEqual (8, priv_impl.Fields.Count);

foreach (var field in priv_impl.Fields)
{
Expand All @@ -170,7 +170,8 @@ public void FieldRVAAlignment ()
Assert.IsNotNull (field.InitialValue);

int rvaAlignment = AlignmentOfInteger (field.RVA);
int desiredAlignment = Math.Min(8, AlignmentOfInteger (field.InitialValue.Length));
var fieldType = field.FieldType.Resolve ();
int desiredAlignment = fieldType.PackingSize;
Assert.GreaterOrEqual (rvaAlignment, desiredAlignment);
}
}
Expand Down
14 changes: 14 additions & 0 deletions Test/Resources/il/FieldRVAAlignment.il
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Original file line number Diff line number Diff line change
Expand Up @@ -46,12 +46,22 @@
.size 6
} // end of class '__StaticArrayInitTypeSize=6'

.class explicit ansi sealed nested private '__StaticArrayInitTypeSize=4Align=32'
extends [mscorlib]System.ValueType
{
.pack 32
.size 4
}

.field static assembly valuetype '<PrivateImplementationDetails>{9B33BB20-87EF-4094-9948-34882DB2F001}'/'__StaticArrayInitTypeSize=3' '$$method0x6000001-1' at I_000020F0
.field static assembly valuetype '<PrivateImplementationDetails>{9B33BB20-87EF-4094-9948-34882DB2F001}'/'__StaticArrayInitTypeSize=20' '$$method0x6000001-2' at I_000020F8
.field static assembly valuetype '<PrivateImplementationDetails>{9B33BB20-87EF-4094-9948-34882DB2F001}'/'__StaticArrayInitTypeSize=5' '$$method0x6000001-3' at I_00002108
.field static assembly valuetype '<PrivateImplementationDetails>{9B33BB20-87EF-4094-9948-34882DB2F001}'/'__StaticArrayInitTypeSize=20' '$$method0x6000001-4' at I_00002110
.field static assembly valuetype '<PrivateImplementationDetails>{9B33BB20-87EF-4094-9948-34882DB2F001}'/'__StaticArrayInitTypeSize=6' '$$method0x6000001-5' at I_00002120
.field static assembly valuetype '<PrivateImplementationDetails>{9B33BB20-87EF-4094-9948-34882DB2F001}'/'__StaticArrayInitTypeSize=16' '$$method0x6000001-6' at I_00002130
.field static assembly valuetype '<PrivateImplementationDetails>{9B33BB20-87EF-4094-9948-34882DB2F001}'/'__StaticArrayInitTypeSize=3' 'separator' at I_00002140
.field static assembly valuetype '<PrivateImplementationDetails>{9B33BB20-87EF-4094-9948-34882DB2F001}'/'__StaticArrayInitTypeSize=4Align=32' '32_align' at I_00002150

} // end of class '<PrivateImplementationDetails>{9B33BB20-87EF-4094-9948-34882DB2F001}'


Expand All @@ -69,3 +79,7 @@
08 00 0C 00 0D 00)
.data cil I_00002130 = bytearray (
01 00 00 00 02 00 00 00 03 00 00 00 05 00 00 00)
.data cil I_00002140 = bytearray (
01 02 03)
.data cil I_00002150 = bytearray (
01 02 03 04)