[build] Require using EnablePreviewFeatures=true when using preview r…

…eleases. Contributes towards dotnet#18343.

Detect if we're using a non-stable Xcode, and in that case produce packages
that show an error if they're used and the EnablePreviewFeatures flag isn't
enabled.

Also add logic to set this flag for our own build, otherwise all our tests
would fail.

This is the same as Android does.

Contributes towards dotnet#18343.

.gitignore

@@ -1,3 +1,4 @@
+Build.props
 Make.config.inc
 Make.config.local
 configure.inc

Directory.Build.props

@@ -3,4 +3,5 @@
 		<!-- Disables the transitive restore of packages like Microsoft.AspNetCore.App.Ref, Microsoft.WindowsDesktop.App.Ref -->
 		<DisableTransitiveFrameworkReferenceDownloads>true</DisableTransitiveFrameworkReferenceDownloads>
 	</PropertyGroup>
+	<Import Project="Build.props" Condition="Exists('Build.props')" />
 </Project>

Make.config

@@ -205,6 +205,21 @@ XCODE_URL=https://dl.internalx.com/internal-files/xcodes/Xcode_14.3.1.xip
 XCODE_DEVELOPER_ROOT=/Applications/Xcode_14.3.1.app/Contents/Developer
 XCODE_PRODUCT_BUILD_VERSION:=$(shell /usr/libexec/PlistBuddy -c 'Print :ProductBuildVersion' $(XCODE_DEVELOPER_ROOT)/../version.plist 2>/dev/null || echo "    $(shell tput setaf 1 2>/dev/null)The required Xcode ($(XCODE_VERSION)) is not installed in $(basename $(basename $(XCODE_DEVELOPER_ROOT)))$(shell tput sgr0 2>/dev/null)" >&2)
 
+# We define stable Xcode as the Xcode app being named like "Xcode_#.#[.#].app"
+# and any other naming is deemed to be a beta. This is the safer approach: any
+# errors are likely to be Xcode classified as a beta, when it's not, and in that
+# case we'll accidentally release a prerelease version. This is not a problem:
+# we fix it, and release the fixed version to stable. The opposite scenario is
+# worse: when we release something as stable when it shouldn't be, so let's
+# try to avoid that.
+ifeq (OK,$(shell echo $(notdir $(abspath $(dir $(abspath $(dir $(XCODE_DEVELOPER_ROOT)))))) | sed -e 's/^Xcode[_0-9.]*[.]app$$/OK/'))
+XCODE_IS_STABLE=true
+XCODE_IS_PREVIEW=false
+else
+XCODE_IS_STABLE=false
+XCODE_IS_PREVIEW=true
+endif
+
 # Tell both Xcode and our build logic which Xcode we're using.
 export DEVELOPER_DIR=$(XCODE_DEVELOPER_ROOT)
 export MD_APPLE_SDK_ROOT=$(abspath $(XCODE_DEVELOPER_ROOT)/../..)
@@ -597,13 +612,28 @@ ALL_PLATFORMS=iOS tvOS watchOS macOS
 ALL_DOTNET_PLATFORMS=iOS macOS tvOS MacCatalyst
 
 -include $(TOP)/dotnet.config
-$(TOP)/dotnet.config: $(TOP)/eng/Versions.props
+$(TOP)/dotnet.config: $(TOP)/eng/Versions.props $(TOP)/Build.props
 	$(Q) grep MicrosoftDotnetSdkInternalPackageVersion $(TOP)/eng/Versions.props | sed -e 's/<*\/*MicrosoftDotnetSdkInternalPackageVersion>//g' -e 's/[ \t]*/DOTNET_VERSION=/' >> $@.tmp
 	$(Q) grep MicrosoftNETCoreAppRefPackageVersion $(TOP)/eng/Versions.props | sed -e 's/<*\/*MicrosoftNETCoreAppRefPackageVersion>//g' -e 's/[ \t]*/BUNDLED_NETCORE_PLATFORMS_PACKAGE_VERSION=/' >> $@.tmp
 	$(Q) grep "<$$(grep EmscriptenWorkloadVersion $(TOP)/eng/Versions.props | sed -e 's_.*>$$[\(]\(.*\)[\)]<.*_\1_')>" $(TOP)/eng/Versions.props | sed -e 's/.*>\(.*\)<.*/EMSCRIPTEN_MANIFEST_PACKAGE_VERSION=\1/' >> $@.tmp
 	$(Q) $(foreach platform,$(ALL_DOTNET_PLATFORMS),grep Microsoft$(platform)SdkPackageVersion $(TOP)/eng/Versions.props | sed -e 's/<*\/*Microsoft$(platform)SdkPackageVersion>//g' -e 's/[ \t]*/NET7_$(shell echo $(platform) | tr '[:lower:]' '[:upper:]')_NUGET_VERSION_NO_METADATA=/' >> $@.tmp &&) true
 	$(Q) mv $@.tmp $@
 
+$(TOP)/Build.props: Make.config
+	$(Q) rm -f $@.tmp
+	$(Q) printf "<Project>\n" >> $@.tmp
+	$(Q) printf "\t<PropertyGroup>\n" >> $@.tmp
+ifeq ($(XCODE_IS_STABLE),true)
+	# do nothing
+else ifeq ($(XCODE_IS_STABLE),false)
+	$(Q) printf "\t\t<EnablePreviewFeatures>true</EnablePreviewFeatures>\n" >> $@.tmp
+else
+	$(error "The variable XCODE_IS_STABLE is not set!")
+endif
+	$(Q) printf "\t</PropertyGroup>\n" >> $@.tmp
+	$(Q) printf "</Project>\n" >> $@.tmp
+	$(Q) mv $@.tmp $@
+
 DOTNET_DESTDIR ?= $(TOP)/_build
 DOTNET_NUPKG_DIR ?= $(DOTNET_DESTDIR)/nupkgs
 DOTNET_PKG_DIR ?= $(DOTNET_DESTDIR)/pkgs

dotnet/Makefile

@@ -102,6 +102,7 @@ targets/Microsoft.$(1).Sdk.Versions.props: targets/Microsoft.Sdk.Versions.templa
 		-e 's*@VALID_RUNTIME_IDENTIFIERS@*$(foreach rid,$(3),\n\t\t<_XamarinValidRuntimeIdentifier Include="$(rid)" Platform="$(1)" />)*' \
 		-e 's/@DOTNET_TFM@/$(DOTNET_TFM)/g' \
 		-e 's/@RUNTIME_PACK_RUNTIME_IDENTIFIERS@/$(4)/g' \
+		-e 's/@XCODE_IS_PREVIEW@/$(XCODE_IS_PREVIEW)/g' \
 		$$< > $$@.tmp
 	$$(Q) mv $$@.tmp $$@
 

dotnet/targets/Microsoft.Sdk.Versions.template.props

@@ -7,6 +7,7 @@
 		<_ShortPackageVersion>@NUGET_VERSION_NO_METADATA@</_ShortPackageVersion>
 		<_PackageVersion>@NUGET_VERSION_FULL@</_PackageVersion>
 		<_DefaultTargetPlatformVersion>@DEFAULT_TARGET_PLATFORM_VERSION@</_DefaultTargetPlatformVersion>
+		<_XamarinIsPreviewRelease>@XCODE_IS_PREVIEW@</_XamarinIsPreviewRelease>
 	</PropertyGroup>
 
 	<ItemGroup>@VALID_RUNTIME_IDENTIFIERS@

dotnet/targets/Xamarin.Shared.Sdk.targets

@@ -889,8 +889,16 @@
 		<Error Text="Only CoreCLR is supported on macOS. Set 'UseMonoRuntime=false' to use CoreCLR." Condition="'$(_PlatformName)' == 'macOS' And '$(UseMonoRuntime)' != 'false'" />
 	</Target>
 
+	<Target Name="_VerifyPreviewFeaturesIfUnstableXcode">
+		<Error
+			Text="These are preview bindings for an unstable version of Xcode. Opt into preview features by adding &lt;EnablePreviewFeatures&gt;True&lt;/EnablePreviewFeatures&gt; to your project file."
+			Condition="'$(_XamarinIsPreviewRelease)' == 'true' And '$(EnablePreviewFeatures)' != 'true'"
+			/>
+	</Target>
+
 	<PropertyGroup>
 		<_ComputeVariablesDependsOn>
+			_VerifyPreviewFeaturesIfUnstableXcode;
 			_VerifyValidRuntime;
 			_GenerateBundleName;
 			_ComputeFrameworkVariables;

msbuild/Directory.Build.props

@@ -3,4 +3,5 @@
 		<MessagingVersion>1.10.37</MessagingVersion>
 		<HotRestartVersion>1.0.119</HotRestartVersion>
 	</PropertyGroup>
+	<Import Project="$(MSBuildThisFileDirectory)../Directory.Build.props" />
 </Project>