Allow PEImageLayout to be loadable for R2R images loaded from streams. (

#25159)

* Allow PEImageLayout to be loadable for R2R images loaded from streams.

* Add regression test coverage

* Change CheckILOnly to return true for R2R images (similar to the ILOnly API)

* Early out for R2R images

* Remove R2R check

src/utilcode/pedecoder.cpp

@@ -34,7 +34,7 @@ CHECK PEDecoder::CheckFormat() const
         {
             CHECK(CheckCorHeader());
 
-            if (IsILOnly() && !HasReadyToRunHeader())
+            if (IsILOnly())
                 CHECK(CheckILOnly());
 
             if (HasNativeHeader())
@@ -1406,6 +1406,12 @@ CHECK PEDecoder::CheckILOnly() const
 
     CHECK(CheckCorHeader());
 
+    if (HasReadyToRunHeader())
+    {
+        // Pretend R2R images are IL-only 
+        const_cast<PEDecoder *>(this)->m_flags |= FLAG_IL_ONLY_CHECKED;
+        CHECK_OK;
+    }
 
     // Allow only verifiable directories.
 

tests/src/readytorun/tests/main.cs

@@ -425,6 +425,16 @@ static void RVAFieldTest()
             Assert.AreEqual(value[i], (byte)(9 - i));
     }
 
+    static void TestLoadR2RImageFromByteArray()
+    {
+        Assembly assembly1 = typeof(Program).Assembly;
+
+        byte[] array = File.ReadAllBytes(assembly1.Location);
+        Assembly assembly2 = Assembly.Load(array);
+
+        Assert.AreEqual(assembly2.FullName, assembly1.FullName);
+    }
+
     static void RunAllTests()
     {
         TestVirtualMethodCalls();
@@ -479,6 +489,8 @@ static void RunAllTests()
         GenericLdtokenFieldsTest();
 
         RVAFieldTest();
+
+        TestLoadR2RImageFromByteArray();
     }
 
     static int Main()