Add a simple size test (#81517)

The size of Hello World is currently 1.8 MB. This is achieved by avoiding any non-field reflection in the codepaths that are part of a hello world. If reflection comes into picture, the size jumps by several 100 kB because suddenly we need a lot of code to support that. This is a smoke test to detect those situations. We're getting proper size testing in the dotnet/performance repo with trend histories, etc., but the invariant for Hello World is easy to check for and nice to gate commits on.

src/tests/nativeaot/SmokeTests/HardwareIntrinsics/Program.cs

@@ -1,8 +1,9 @@
-// Licensed to the .NET Foundation under one or more agreements.
+// Licensed to the .NET Foundation under one or more agreements.
 // The .NET Foundation licenses this file to you under the MIT license.
 
 using System;
 using System.Numerics;
+using System.Runtime.InteropServices;
 using System.Runtime.Intrinsics;
 using System.Runtime.Intrinsics.X86;
 
@@ -12,6 +13,36 @@ static int Main()
     {
         s_success = true;
 
+#if !DEBUG
+        Console.WriteLine("****************************************************");
+        Console.WriteLine("* Size test                                        *");
+        long fileSize = new System.IO.FileInfo(Environment.ProcessPath).Length;
+        Console.WriteLine($"* Size of the executable is {fileSize / 1024,7:n0} kB             *");
+        Console.WriteLine("****************************************************");
+
+        const int Meg = 1024 * 1024;
+        const int HalfMeg = Meg / 2;
+        long lowerBound, upperBound;
+        if (RuntimeInformation.IsOSPlatform(OSPlatform.OSX))
+        {
+            lowerBound = 2 * Meg; // 2 MB
+            upperBound = 4 * Meg; // 4 MB
+        }
+        else
+        {
+            lowerBound = Meg + HalfMeg; // 1.5 MB
+            upperBound = 2 * Meg; // 2 MB
+        }
+
+        if (fileSize < lowerBound || fileSize > upperBound)
+        {
+            Console.WriteLine("BUG: File size is not in the expected range. Did a libraries change regress size of Hello World?");
+            return 1;
+        }
+
+        Console.WriteLine();
+#endif
+
         // We expect the AOT compiler generated HW intrinsics with the following characteristics:
         //
         // * TRUE = IsSupported assumed to be true, no runtime check

src/tests/nativeaot/SmokeTests/HardwareIntrinsics/X64Baseline.csproj

@@ -6,6 +6,10 @@
     <CLRTestTargetUnsupported Condition="'$(TargetArchitecture)' != 'x64'">true</CLRTestTargetUnsupported>
     <AllowUnsafeBlocks>true</AllowUnsafeBlocks>
     <DefineConstants>$(DefineConstants);BASELINE_INTRINSICS</DefineConstants>
+    <StripSymbols>true</StripSymbols>
+
+    <!-- We should be able to delete once CI machines no longer use ancient LLVM -->
+    <ObjCopyName>objcopy</ObjCopyName>
   </PropertyGroup>
   <ItemGroup>
     <Compile Include="Program.cs" />

src/tests/nativeaot/SmokeTests/HardwareIntrinsics/x64NonVex.csproj

@@ -6,6 +6,10 @@
     <CLRTestTargetUnsupported Condition="'$(TargetArchitecture)' != 'x64'">true</CLRTestTargetUnsupported>
     <AllowUnsafeBlocks>true</AllowUnsafeBlocks>
     <DefineConstants>$(DefineConstants);NON_VEX_INTRINSICS</DefineConstants>
+    <StripSymbols>true</StripSymbols>
+
+    <!-- We should be able to delete once CI machines no longer use ancient LLVM -->
+    <ObjCopyName>objcopy</ObjCopyName>
   </PropertyGroup>
 
   <ItemGroup>

src/tests/nativeaot/SmokeTests/HardwareIntrinsics/x64Vex.csproj

@@ -6,6 +6,10 @@
     <CLRTestTargetUnsupported Condition="'$(TargetArchitecture)' != 'x64'">true</CLRTestTargetUnsupported>
     <AllowUnsafeBlocks>true</AllowUnsafeBlocks>
     <DefineConstants>$(DefineConstants);VEX_INTRINSICS</DefineConstants>
+    <StripSymbols>true</StripSymbols>
+
+    <!-- We should be able to delete once CI machines no longer use ancient LLVM -->
+    <ObjCopyName>objcopy</ObjCopyName>
   </PropertyGroup>
 
   <ItemGroup>