From c9be6f4e391211ab9c49f684bafb1bd77b126dd4 Mon Sep 17 00:00:00 2001
From: Linlccc <linlccc@163.com>
Date: Wed, 23 Jul 2025 16:04:53 +0800
Subject: [PATCH 1/2] Fix the issue of Mono.AotCross build errors Configure the
 DotNetBuildMonoCrossAOT property when building Mono.AotCross

Fixes dotnet#117970
---
 eng/Subsets.props | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/eng/Subsets.props b/eng/Subsets.props
index 3c854690a1c0a9..a3b38c487230ee 100644
--- a/eng/Subsets.props
+++ b/eng/Subsets.props
@@ -153,7 +153,7 @@
     <BootstrapSubsets Condition="'$(UseNativeAotForComponents)' == 'true'">$(BootstrapSubsets)+clr.nativeaotlibs+clr.nativeaotruntime+libs.native</BootstrapSubsets>
 
     <SwapNativeForIL Condition="$(_subset.Contains('+bootstrap+')) and '$(RuntimeFlavor)' == 'CoreCLR'">true</SwapNativeForIL>
-    
+
     <!-- Define AllSubsets to include all available subsets including OnDemand ones -->
     <AllSubsetsExpansion>clr.nativeprereqs+clr.iltools+clr.runtime+clr.native+clr.aot+clr.nativeaotlibs+clr.nativeaotruntime+clr.crossarchtools</AllSubsetsExpansion>
     <AllSubsetsExpansion>$(AllSubsetsExpansion)+clr.paltests+clr.paltestlist+clr.hosts+clr.jit+clr.alljits+clr.alljitscommunity+clr.spmi+clr.corelib+clr.nativecorelib+clr.tools+clr.toolstests+clr.packages</AllSubsetsExpansion>
@@ -558,7 +558,7 @@
   </ItemGroup>
 
   <ItemGroup Condition="$(_subset.Contains('+mono.aotcross+'))">
-    <ProjectToBuild Include="$(MonoProjectRoot)monoaotcross.proj" Category="mono" />
+    <ProjectToBuild Include="$(MonoProjectRoot)monoaotcross.proj" Category="mono" AdditionalProperties="%(AdditionalProperties);DotNetBuildMonoCrossAOT=true" />
   </ItemGroup>
 
   <ItemGroup Condition="$(_subset.Contains('+mono.corelib+'))">

From 05af31648cca762da4ad0c6b07beaf7112ba381c Mon Sep 17 00:00:00 2001
From: Linlccc <linlccc@163.com>
Date: Thu, 24 Jul 2025 00:28:27 +0800
Subject: [PATCH 2/2] Fix the issue of Mono.AotCross build errors Remove the
 DotNetBuildMonoCrossAOT default value when building Mono.AotCross Check
 MonoAotTarget before building and prompt

Fixes #117970
---
 eng/Subsets.props          | 2 +-
 src/mono/monoaotcross.proj | 9 +++++++++
 2 files changed, 10 insertions(+), 1 deletion(-)

diff --git a/eng/Subsets.props b/eng/Subsets.props
index a3b38c487230ee..4faf7526520e83 100644
--- a/eng/Subsets.props
+++ b/eng/Subsets.props
@@ -558,7 +558,7 @@
   </ItemGroup>
 
   <ItemGroup Condition="$(_subset.Contains('+mono.aotcross+'))">
-    <ProjectToBuild Include="$(MonoProjectRoot)monoaotcross.proj" Category="mono" AdditionalProperties="%(AdditionalProperties);DotNetBuildMonoCrossAOT=true" />
+    <ProjectToBuild Include="$(MonoProjectRoot)monoaotcross.proj" Category="mono" />
   </ItemGroup>
 
   <ItemGroup Condition="$(_subset.Contains('+mono.corelib+'))">
diff --git a/src/mono/monoaotcross.proj b/src/mono/monoaotcross.proj
index b31f88314f2ba0..0830b7c7892ec2 100644
--- a/src/mono/monoaotcross.proj
+++ b/src/mono/monoaotcross.proj
@@ -22,6 +22,15 @@
     <MonoAotTargetRids Include="$(MonoAotTargets.Split(';'))" />
   </ItemGroup>
 
+  <Target Name="CheckMonoAotTargets" BeforeTargets="BuildMonoCrossAllTargets">
+    <PropertyGroup>
+      <_SupportOS>android, browser, wasi</_SupportOS>
+      <_SupportOS Condition="$([MSBuild]::IsOSPlatform('OSX'))">$(_SupportOS), tvos, ios, maccatalyst</_SupportOS>
+    </PropertyGroup>
+
+    <Error Condition="'@(MonoAotTargetRids->Count())' == '0'" Text="MonoAotTargets is empty. Please configure MonoCrossAOTTargetOS with supported values: $(_SupportOS). Multiple values should be separated with '+' (e.g., /p:MonoCrossAOTTargetOS=android+browser)." />
+  </Target>
+
   <Target Name="BuildMonoCrossAllTargets" AfterTargets="Build">
     <MSBuild Targets="Restore"
              Projects="$(MSBuildThisFileDirectory)mono.proj"