Preserve LargeAwareAddress image flag (#775)

jbevain · Jul 1, 2021 · d820a5b · d820a5b
1 parent b0b93f5
commit d820a5b
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Showing 6 changed files with 22 additions and 6 deletions.
diff --git a/Mono.Cecil.PE/Image.cs b/Mono.Cecil.PE/Image.cs
@@ -25,9 +25,10 @@ sealed class Image : IDisposable {
 		public string FileName;
 
 		public ModuleKind Kind;
+		public uint Characteristics;
 		public string RuntimeVersion;
 		public TargetArchitecture Architecture;
-		public ModuleCharacteristics Characteristics;
+		public ModuleCharacteristics DllCharacteristics;
 		public ushort LinkerVersion;
 		public ushort SubSystemMajor;
 		public ushort SubSystemMinor;

diff --git a/Mono.Cecil.PE/ImageReader.cs b/Mono.Cecil.PE/ImageReader.cs
@@ -88,8 +88,9 @@ void ReadImage ()
 			ReadMetadata ();
 			ReadDebugHeader ();
 
+			image.Characteristics = characteristics;
 			image.Kind = GetModuleKind (characteristics, subsystem);
-			image.Characteristics = (ModuleCharacteristics) dll_characteristics;
+			image.DllCharacteristics = (ModuleCharacteristics) dll_characteristics;
 		}
 
 		TargetArchitecture ReadArchitecture ()

diff --git a/Mono.Cecil.PE/ImageWriter.cs b/Mono.Cecil.PE/ImageWriter.cs
@@ -194,12 +194,18 @@ void WritePEFileHeader ()
 			WriteUInt32 (metadata.timestamp);
 			WriteUInt32 (0);	// PointerToSymbolTable
 			WriteUInt32 (0);	// NumberOfSymbols
-			WriteUInt16 (SizeOfOptionalHeader ());	// SizeOfOptionalHeader
+			WriteUInt16 (SizeOfOptionalHeader ());  // SizeOfOptionalHeader
 
-			// ExecutableImage | (pe64 ? 32BitsMachine : LargeAddressAware)
-			var characteristics = (ushort) (0x0002 | (!pe64 ? 0x0100 : 0x0020));
+			const ushort LargeAddressAware = 0x0020;
+
+			// ExecutableImage | (!pe64 ? 32BitsMachine : LargeAddressAware)
+			var characteristics = (ushort) (0x0002 | (!pe64 ? 0x0100 : LargeAddressAware));
 			if (module.Kind == ModuleKind.Dll || module.Kind == ModuleKind.NetModule)
 				characteristics |= 0x2000;
+
+			if (module.Image != null && (module.Image.Characteristics & LargeAddressAware) != 0)
+				characteristics |= LargeAddressAware;
+
 			WriteUInt16 (characteristics);	// Characteristics
 		}
 

diff --git a/Mono.Cecil/ModuleDefinition.cs b/Mono.Cecil/ModuleDefinition.cs
@@ -586,7 +586,7 @@ internal ModuleDefinition (Image image)
 			this.RuntimeVersion = image.RuntimeVersion;
 			this.architecture = image.Architecture;
 			this.attributes = image.Attributes;
-			this.characteristics = image.Characteristics;
+			this.characteristics = image.DllCharacteristics;
 			this.linker_version = image.LinkerVersion;
 			this.subsystem_major = image.SubSystemMajor;
 			this.subsystem_minor = image.SubSystemMinor;

diff --git a/Test/Mono.Cecil.Tests/ImageReadTests.cs b/Test/Mono.Cecil.Tests/ImageReadTests.cs
@@ -100,6 +100,14 @@ public void X64Module ()
 			}, verify: !Platform.OnMono);
 		}
 
+		[Test]
+		public void AnyCPU32BitPreferred ()
+		{
+			TestModule ("anycpu32bitpreferred.exe", module => {
+				Assert.AreNotEqual (0, module.Image.Characteristics & 0x0020);
+			});
+		}
+
 		[Test]
 		public void X64ModuleTextOnlySection ()
 		{

diff --git a/Test/Resources/assemblies/anycpu32bitpreferred.exe b/Test/Resources/assemblies/anycpu32bitpreferred.exe