From def1bdd693046fc40ada9e9f004f1001adf0160b Mon Sep 17 00:00:00 2001
From: Leonard Hecker <lhecker@microsoft.com>
Date: Tue, 26 Oct 2021 21:08:49 +0200
Subject: [PATCH] Compile OpenConsoleProxy without CRT (#11610)

After this commit OpenConsoleProxy will be built without a CRT.
This cuts down its binary size and DLL dependency bloat.
We hope that this fixes a COM server activation bug if the
user doesn't have a CRT installed globally on their system.

Fixes #11529
---
 .github/actions/spelling/expect/expect.txt |  3 +++
 src/common.build.pre.props                 |  3 ++-
 src/cppwinrt.build.pre.props               |  2 +-
 src/host/proxy/Host.Proxy.vcxproj          | 19 +++++++++++++++----
 src/host/proxy/Host.Proxy.vcxproj.filters  |  3 +++
 src/host/proxy/nodefaultlib_shim.h         | 18 ++++++++++++++++++
 6 files changed, 42 insertions(+), 6 deletions(-)
 create mode 100644 src/host/proxy/nodefaultlib_shim.h

diff --git a/.github/actions/spelling/expect/expect.txt b/.github/actions/spelling/expect/expect.txt
index dccd6d740..c18d880e4 100644
--- a/.github/actions/spelling/expect/expect.txt
+++ b/.github/actions/spelling/expect/expect.txt
@@ -938,6 +938,7 @@ GTP
 guc
 gui
 guidatom
+guiddef
 GValue
 GWL
 GWLP
@@ -1535,6 +1536,7 @@ NOCOLOR
 NOCOMM
 NOCONTEXTHELP
 NOCOPYBITS
+nodefaultlib
 nodiscard
 NODUP
 noexcept
@@ -2232,6 +2234,7 @@ STARTWPARMSW
 Statusline
 stdafx
 STDAPI
+stdc
 stdcall
 stdcpp
 stderr
diff --git a/src/common.build.pre.props b/src/common.build.pre.props
index ca15b0a04..1ec821e3f 100644
--- a/src/common.build.pre.props
+++ b/src/common.build.pre.props
@@ -107,7 +107,7 @@
         C4467: usage of ATL attributes is deprecated
           Conhost code still uses ATL.
       -->
-      <DisableSpecificWarnings>4103;4201;4312;4467;%(DisableSpecificWarnings)</DisableSpecificWarnings>
+      <DisableSpecificWarnings>4103;4201;4312;4467;5105;%(DisableSpecificWarnings)</DisableSpecificWarnings>
       <PreprocessorDefinitions>_WINDOWS;EXTERNAL_BUILD;%(PreprocessorDefinitions)</PreprocessorDefinitions>
       <SDLCheck>true</SDLCheck>
       <PrecompiledHeaderFile>precomp.h</PrecompiledHeaderFile>
@@ -117,6 +117,7 @@
       <MinimalRebuild>false</MinimalRebuild>
       <RuntimeTypeInfo>false</RuntimeTypeInfo>
       <LanguageStandard>stdcpp17</LanguageStandard>
+      <LanguageStandard_C>stdc17</LanguageStandard_C>
       <AdditionalOptions>/utf-8 %(AdditionalOptions)</AdditionalOptions>
       <ControlFlowGuard>Guard</ControlFlowGuard>
       <FloatingPointModel>Fast</FloatingPointModel>
diff --git a/src/cppwinrt.build.pre.props b/src/cppwinrt.build.pre.props
index 4587ab3ea..2022dbc7f 100644
--- a/src/cppwinrt.build.pre.props
+++ b/src/cppwinrt.build.pre.props
@@ -75,7 +75,7 @@
       <ConformanceMode>true</ConformanceMode>
       <UseStandardPreprocessor>true</UseStandardPreprocessor>
       <AdditionalOptions>%(AdditionalOptions) /bigobj /Zc:twoPhase-</AdditionalOptions>
-      <DisableSpecificWarnings>5104;5105;28204;%(DisableSpecificWarnings)</DisableSpecificWarnings>
+      <DisableSpecificWarnings>5104;28204;%(DisableSpecificWarnings)</DisableSpecificWarnings>
 
       <AdditionalUsingDirectories>$(WindowsSDK_WindowsMetadata);$(AdditionalUsingDirectories)</AdditionalUsingDirectories>
     </ClCompile>
diff --git a/src/host/proxy/Host.Proxy.vcxproj b/src/host/proxy/Host.Proxy.vcxproj
index 45fc697f2..5888ce0c3 100644
--- a/src/host/proxy/Host.Proxy.vcxproj
+++ b/src/host/proxy/Host.Proxy.vcxproj
@@ -11,7 +11,7 @@
   <Import Project="$(SolutionDir)src\common.build.pre.props" />
   <ItemGroup>
     <Midl Include="IConsoleHandoff.idl">
-      <!-- 
+      <!--
         In Razzle, IDL files generate %FileName%.h
         In Visual Studio, IDL files generate %FileName%_h.h
         Visual Studio is easier to override than Razzle.
@@ -31,6 +31,7 @@
   <ItemGroup>
     <ClInclude Include="$(IntDir)\IConsoleHandoff.h" />
     <ClInclude Include="$(IntDir)\ITerminalHandoff.h" />
+    <ClInclude Include="nodefaultlib_shim.h" />
   </ItemGroup>
   <ItemGroup>
     <ClCompile Include="$(IntDir)\dlldata.c" />
@@ -56,16 +57,26 @@
   </ItemDefinitionGroup>
   <ItemDefinitionGroup>
     <ClCompile>
-      <AdditionalIncludeDirectories>..;%(AdditionalIncludeDirectories)</AdditionalIncludeDirectories>
-      <CallingConvention>StdCall</CallingConvention>
+      <AdditionalIncludeDirectories>.;..;%(AdditionalIncludeDirectories)</AdditionalIncludeDirectories>
+      <CallingConvention Condition="'$(Platform)'!='ARM64'">StdCall</CallingConvention>
       <!-- Must be Stdcall on all platforms to resolve _ObjectStublessClient3 -->
       <PreprocessorDefinitions>REGISTER_PROXY_DLL;WIN32;%(PreprocessorDefinitions)</PreprocessorDefinitions>
       <PrecompiledHeader>NotUsing</PrecompiledHeader>
+      <BufferSecurityCheck>false</BufferSecurityCheck>
+      <SDLCheck>false</SDLCheck>
+      <ForcedIncludeFiles>nodefaultlib_shim.h;%(ForcedIncludeFiles)</ForcedIncludeFiles>
     </ClCompile>
     <Link>
       <ModuleDefinitionFile>OpenConsoleProxy.def</ModuleDefinitionFile>
+      <!--
+        Not depending on the CRT cuts binary size by half and prevents issues if this DLL
+        is copied elsewhere and executed outside of our app package without our bundled CRT present.
+      -->
+      <AdditionalDependencies />
+      <IgnoreAllDefaultLibraries>true</IgnoreAllDefaultLibraries>
+      <EntryPointSymbol>DllMain</EntryPointSymbol>
     </Link>
   </ItemDefinitionGroup>
   <!-- Careful reordering these. Some default props (contained in these files) are order sensitive. -->
   <Import Project="$(SolutionDir)src\common.build.post.props" />
-</Project>
\ No newline at end of file
+</Project>
diff --git a/src/host/proxy/Host.Proxy.vcxproj.filters b/src/host/proxy/Host.Proxy.vcxproj.filters
index df6bcbd10..1cdf7ca25 100644
--- a/src/host/proxy/Host.Proxy.vcxproj.filters
+++ b/src/host/proxy/Host.Proxy.vcxproj.filters
@@ -41,6 +41,9 @@
     <ClInclude Include="$(IntDir)\ITerminalHandoff.h">
       <Filter>Header Files</Filter>
     </ClInclude>
+    <ClInclude Include="nodefaultlib_shim.h">
+      <Filter>Header Files</Filter>
+    </ClInclude>
   </ItemGroup>
   <ItemGroup>
     <Midl Include="IConsoleHandoff.idl">
diff --git a/src/host/proxy/nodefaultlib_shim.h b/src/host/proxy/nodefaultlib_shim.h
new file mode 100644
index 000000000..09c0ad53c
--- /dev/null
+++ b/src/host/proxy/nodefaultlib_shim.h
@@ -0,0 +1,18 @@
+// Copyright (c) Microsoft Corporation.
+// Licensed under the MIT license.
+
+#include <guiddef.h>
+
+#if !defined(_M_IX86) && !defined(_M_X64)
+
+// ARM64 doesn't define a (__builtin_)memcmp function without CRT,
+// but we need one to compile IID_GENERIC_CHECK_IID.
+// Luckily we only ever use memcmp for IIDs.
+#pragma function(memcmp)
+inline int memcmp(const IID* a, const IID* b, size_t count)
+{
+    (void)(count);
+    return 1 - InlineIsEqualGUID(a, b);
+}
+
+#endif