ProjectX: Ensure stable name uniqueness for read-only data blobs

The current naming scheme for data blobs is not deterministic. This is fixed in this change by using the sha256 hasher to ensure a high degree of stable uniqueness. However, this might be a chance the uniqueness is violated. Debug code is added to detect this.

[tfs-changeset: 1677971]

1 files changed, 15 insertions, 0 deletions

diff --git a/src/ILCompiler.Compiler/src/Compiler/UtcNameMangler.cs b/src/ILCompiler.Compiler/src/Compiler/UtcNameMangler.cs
index 0388e3860..2ff113ac8 100644
--- a/src/ILCompiler.Compiler/src/Compiler/UtcNameMangler.cs
+++ b/src/ILCompiler.Compiler/src/Compiler/UtcNameMangler.cs
@@ -611,6 +611,21 @@ namespace ILCompiler
             return mangledName;
         }
 
+        public string GetMangledDataBlobName(byte[] blob)
+        {
+            if (_sha256 == null)
+            {
+                // Use SHA256 hash here to provide a high degree of uniqueness to symbol names without requiring them to be long
+                // This hash function provides an exceedingly high likelihood that no two strings will be given equal symbol names
+                // This is not considered used for security purpose; however collisions would be highly unfortunate as they will cause compilation
+                // failure.
+                _sha256 = SHA256.Create();
+            }
+
+            var hash = _sha256.ComputeHash(blob);
+            return "__Data_" + BitConverter.ToString(hash).Replace("-", "");
+        }
+
         public string GetImportedTlsIndexPrefix()
         {
             uint ordinal;