Enable partial Linux builds for Copilot support

.github/workflows/linux-build.yml

@@ -0,0 +1,29 @@
+# yamllint disable rule:line-length rule:document-start rule:truthy
+name: Linux Build Verification
+on:
+  pull_request:
+
+permissions:
+  contents: read
+
+jobs:
+  linux-build:
+    name: Verify Linux Build
+    runs-on: ubuntu-latest
+
+    steps:
+      - name: 'Checkout'
+        uses: actions/checkout@v4
+        with:
+          fetch-depth: 0
+          submodules: recursive
+
+      - name: Check system dependencies
+        run: |
+          set -ex
+          ./system-dependencies.sh
+
+      - name: Build on Linux
+        run: |
+          set -ex
+          make

Make.config

@@ -1,5 +1,11 @@
 include $(TOP)/mk/subdirs.mk
 
+# Detect if we're building on Linux
+UNAME_S:=$(shell uname -s)
+ifeq ($(UNAME_S),Linux)
+IS_LINUX=1
+endif
+
 # Common cURL command:
 # --fail: return an exit code if the connection succeeded, but returned an HTTP error code.
 # --location: follow redirects
@@ -203,6 +209,7 @@ MACCATALYST_NUGET_VERSION_FULL=$(MACCATALYST_NUGET_VERSION_NO_METADATA)$(NUGET_B
 # Xcode version should have both a major and a minor version (even if the minor version is 0)
 XCODE_VERSION=26.2
 XCODE_URL=https://dl.internalx.com/internal-files/xcodes/Xcode_26.2.xip
+ifndef IS_LINUX
 XCODE_DEVELOPER_ROOT=/Applications/Xcode_26.2.0.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)
 
@@ -224,6 +231,12 @@ 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)/../..)
+else
+# On Linux, set placeholder Xcode values
+XCODE_PRODUCT_BUILD_VERSION=
+XCODE_IS_STABLE=true
+XCODE_IS_PREVIEW=false
+endif
 
 # We don't need to be told there are workload updates
 export DOTNET_CLI_WORKLOAD_UPDATE_NOTIFY_DISABLE=true

Makefile

@@ -3,6 +3,11 @@ SUBDIRS=builds runtime src msbuild tools
 include $(TOP)/Make.config
 include $(TOP)/mk/versions.mk
 
+# On Linux, skip directories that require native compilation
+ifdef IS_LINUX
+SUBDIRS := $(filter-out runtime,$(SUBDIRS))
+endif
+
 SUBDIRS += dotnet
 
 #

builds/Makefile

@@ -25,7 +25,8 @@ downloads/$(DOTNET_INSTALL_NAME): dotnet-install.sh
 			tar -xzf $(DOTNET_CACHE_FILENAME) -C "$@.tmp"; \
 		else \
 			./dotnet-install.sh --install-dir "$@.tmp" --version "$(DOTNET_VERSION)" --architecture $(DOTNET_ARCH) --no-path --keep-zip --zip-path "downloads/$(DOTNET_FILENAME)" $$DOTNET_INSTALL_EXTRA_ARGS; \
-			cp -c downloads/$(DOTNET_FILENAME) $(DOTNET_CACHE_FILENAME); \
+			mkdir -p $$(dirname $(DOTNET_CACHE_FILENAME)); \
+			$(CP) downloads/$(DOTNET_FILENAME) $(DOTNET_CACHE_FILENAME); \
 			echo "Cached the download of $(DOTNET_FILENAME) in ~/Library/Caches/xamarin-macios"; \
 		fi
 	$(Q) rm -Rf "$@"

builds/create-csproj-for-all-packagereferences.sh

@@ -4,6 +4,13 @@ WHITE=$(tput setaf 7 || true)
 RED=$(tput setaf 9 || true)
 CLEAR=$(tput sgr0 || true)
 
+# Detect the OS to use the right sed syntax
+if [[ "$(uname -s)" == "Darwin" ]]; then
+	SED_INPLACE="sed -i ''"
+else
+	SED_INPLACE="sed -i"
+fi
+
 OUTPUTPATH=
 while [[ $# -gt 0 ]]; do
 	case $1 in
@@ -35,7 +42,7 @@ while [[ $# -gt 0 ]]; do
 	esac
 done
 
-TMPPATH=$(PWD)/packagereferences.tmp.csproj
+TMPPATH="$PWD/packagereferences.tmp.csproj"
 
 # Go to the root directory
 cd "$(git rev-parse --show-toplevel)"
@@ -44,16 +51,16 @@ cd "$(git rev-parse --show-toplevel)"
 git grep -e '<PackageReference.*Include="[a-zA-Z0-9._-]*".*Version="[a-zA-Z0-9._-]*".*>' -h > "$TMPPATH"
 
 # Replace double double quotes with a single double quote. This happens in source code that generates project files (for tests).
-sed -i '' 's/""/"/g' "$TMPPATH"
+$SED_INPLACE 's/""/"/g' "$TMPPATH"
 
 # Remove packages that we build locally
-sed -i '' '/Xamarin.Tests.FrameworksInRuntimesNativeDirectory/d' "$TMPPATH"
-sed -i '' '/Xamarin.Tests.DynamicLibrariesInRuntimesNativeDirectory/d' "$TMPPATH"
-sed -i '' '/Xamarin.Tests.XCFrameworkWithStaticLibraryInRuntimesNativeDirectory/d' "$TMPPATH"
-sed -i '' '/Xamarin.Tests.XCFrameworkWithSymlinks/d' "$TMPPATH"
+$SED_INPLACE '/Xamarin.Tests.FrameworksInRuntimesNativeDirectory/d' "$TMPPATH"
+$SED_INPLACE '/Xamarin.Tests.DynamicLibrariesInRuntimesNativeDirectory/d' "$TMPPATH"
+$SED_INPLACE '/Xamarin.Tests.XCFrameworkWithStaticLibraryInRuntimesNativeDirectory/d' "$TMPPATH"
+$SED_INPLACE '/Xamarin.Tests.XCFrameworkWithSymlinks/d' "$TMPPATH"
 
 # Get only the name and version of each package, and write that back in a PackageDownload item
-sed -i '' 's@.*<PackageReference.*Include="\([a-zA-Z0-9._-]*\)".*Version="\([a-zA-Z0-9._-]*\)".*>.*@\t\t<PackageDownload Include="\1" Version="[\2]" />@g' "$TMPPATH"
+$SED_INPLACE 's@.*<PackageReference.*Include="\([a-zA-Z0-9._-]*\)".*Version="\([a-zA-Z0-9._-]*\)".*>.*@\t\t<PackageDownload Include="\1" Version="[\2]" />@g' "$TMPPATH"
 
 # Sort the references and only list each once.
 sort -u -o "$TMPPATH" "$TMPPATH"

msbuild/Makefile

@@ -115,15 +115,20 @@ DOTNET_IOS_WINDOWS_FILES += Messaging/Xamarin.Messaging.Build/obj/$(CONFIG)/Buil
 
 .dotnet-windows: .build-stamp .copy-windows-files
 
+ifndef IS_LINUX
 all-local:: .dotnet-windows
 dotnet:: .dotnet-windows
+endif
 
 ##
 ## Common targets ##
 ##
 
 # we must install locally during 'make all', because the F# build depends on the msbuild targets/assemblies.
-all-local:: $(MSBUILD_PRODUCTS) .stamp-test-xml
+all-local:: $(MSBUILD_PRODUCTS)
+ifndef IS_LINUX
+all-local:: .stamp-test-xml
+endif
 
 # I haven't found a way to execute ilrepack.exe on .NET (it will probably have to be built for .NET), so run it using Mono.
 

src/Makefile

@@ -346,13 +346,21 @@ $(DOTNET_DESTDIR)/$($(2)_NUGET_REF_NAME)/ref/$(DOTNET_TFM)/Microsoft.$(1).dll: $
 $(DOTNET_DESTDIR)/$($(2)_NUGET_REF_NAME)/ref/$(DOTNET_TFM)/Microsoft.$(1).xml: $($(2)_DOTNET_BUILD_DIR)/doc/Microsoft.$(1).xml | $(DOTNET_DESTDIR)/$($(2)_NUGET_REF_NAME)/ref/$(DOTNET_TFM)
 	$$(Q) $(CP) $$< $$@
 
+ifndef IS_LINUX
 $($(2)_DOTNET_BUILD_DIR)/doc/Microsoft.$(1).xml: $($(2)_DOTNET_BUILD_DIR)/ref/Microsoft.$(1).xml $($(2)_DOTNET_BUILD_DIR)/ref/Microsoft.$(1).dll build/.build-adr-stamp | $($(2)_DOTNET_BUILD_DIR)/doc
 	$$(Q_GEN) $(TOP)/packages/appledocreader.$(ADR_RUNTIME_IDENTIFIER)/$(ADR_NUGET_VERSION)/tools/any/$(ADR_RUNTIME_IDENTIFIER)/AppleDocReader inject docs --assembly="$(abspath $($(2)_DOTNET_BUILD_DIR)/ref/Microsoft.$(1).dll)" --input="$(abspath $($(2)_DOTNET_BUILD_DIR)/ref/Microsoft.$(1).xml)" --output="$(abspath $$@)" --xcode="$(DEVELOPER_DIR)/../.." --runtimeDll="$(DOTNET_BCL_DIR)/System.Runtime.dll" -f
+else
+# On Linux, skip AppleDocReader (macOS-only tool) and just copy the XML
+$($(2)_DOTNET_BUILD_DIR)/doc/Microsoft.$(1).xml: $($(2)_DOTNET_BUILD_DIR)/ref/Microsoft.$(1).xml | $($(2)_DOTNET_BUILD_DIR)/doc
+	$(Q) $(CP) $$< $$@
+endif
 endef
 
+ifndef IS_LINUX
 build/.build-adr-stamp:
 	$(MAKE) -C $(TOP)/tools/adr
 	$(Q) touch $@
+endif
 
 # Template variables:
 # 1: Platform (correct case)

src/Makefile.generator

@@ -71,6 +71,6 @@ $(RSP_DIR)/dotnet/%-defines-dotnet.rsp: frameworks.sources Makefile.generator $(
 	$(Q) $(GENERATE_DEFINES_EXEC) $@.tmp '$(filter-out $(DOTNET_REMOVED_$(shell echo $* | tr a-z A-Z)_FRAMEWORKS),$($(shell echo $* | tr a-z A-Z)_FRAMEWORKS))'
 	$(Q) mv $@.tmp $@
 
-$(DOTNET_BUILD_DIR)/Xamarin.Apple.BindingAttributes.dll: bgen/Attributes.cs bgen/PlatformName.cs bgen/DotnetGlobals.cs Makefile.generator | $(DOTNET_BUILD_DIR)
-	$(Q_DOTNET_BUILD) $(DOTNET_CSC) $(DOTNET_FLAGS) -d:BINDING_ATTRIBUTES_DLL -out:$@ bgen/Attributes.cs bgen/PlatformName.cs bgen/DotnetGlobals.cs
+$(DOTNET_BUILD_DIR)/Xamarin.Apple.BindingAttributes.dll: bgen/Attributes.cs bgen/PlatformName.cs bgen/DotNetGlobals.cs Makefile.generator | $(DOTNET_BUILD_DIR)
+	$(Q_DOTNET_BUILD) $(DOTNET_CSC) $(DOTNET_FLAGS) -d:BINDING_ATTRIBUTES_DLL -out:$@ bgen/Attributes.cs bgen/PlatformName.cs bgen/DotNetGlobals.cs
 

system-dependencies.sh

@@ -4,6 +4,27 @@ set -o pipefail
 
 cd $(dirname $0)
 
+# Detect if we're running on Linux
+if [[ "$(uname -s)" == "Linux" ]]; then
+	IS_LINUX=1
+	# On Linux, ignore all macOS-specific dependencies
+	IGNORE_OSX=1
+	IGNORE_XCODE=1
+	IGNORE_XCODE_COMPONENTS=1
+	IGNORE_MONO=1
+	IGNORE_VISUAL_STUDIO=1
+	IGNORE_SHARPIE=1
+	IGNORE_SIMULATORS=1
+	IGNORE_OLD_SIMULATORS=1
+	IGNORE_7Z=1
+	IGNORE_HOMEBREW=1
+	IGNORE_SHELLCHECK=1
+	IGNORE_YAMLLINT=1
+	IGNORE_PYTHON3=1
+else
+	IS_LINUX=
+fi
+
 FAIL=
 PROVISION_DOWNLOAD_DIR=/tmp/x-provisioning
 SUDO=sudo
@@ -924,6 +945,11 @@ function check_osx_version () {
 }
 
 function check_checkout_dir () {
+	# Skip on Linux - this check is macOS-specific
+	if test -n "$IS_LINUX"; then
+		return
+	fi
+
 	# use apple script to get the possibly translated special folders and check that we are not a subdir
 	for special in documents downloads desktop; do
 		path=$(osascript -e "set result to POSIX path of (path to $special folder as string)")
@@ -1116,6 +1142,11 @@ function check_old_simulators ()
 
 echo "Checking system..."
 
+if test -n "$IS_LINUX"; then
+	ok "Running on ${COLOR_BLUE}Linux${COLOR_CLEAR} - skipping macOS-specific checks"
+	ok "Only .NET download and managed code builds will be available"
+fi
+
 check_osx_version
 check_checkout_dir
 check_xcode

tools/common/create-makefile-fragment.sh

@@ -15,6 +15,13 @@
 
 cd "$(dirname "$0")"
 
+# Detect OS for sed syntax
+if [[ "$OSTYPE" == "darwin"* ]]; then
+	SED_INPLACE="sed -i ''"
+else
+	SED_INPLACE="sed -i"
+fi
+
 if test -z "$1"; then
 	echo "Must specify the project file to process."
 	exit 1
@@ -104,12 +111,12 @@ for proj in $(sort "$REFERENCES_PATH" | uniq); do
 
 	# The output contains relative paths, relative to the csproj directory
 	# Change those to full paths by prepending the csproj directory.
-	sed -i '' "s@^@$proj_dir/@" "$inputs_path"
+	$SED_INPLACE "s@^@$proj_dir/@" "$inputs_path"
 
 	# Change to Make syntax. This is horrifically difficult in MSBuild,
 	# because MSBuild blindly replaces backslashes with forward slashes (i.e.
 	# windows paths to unix paths...)
-	sed -i '' "s_^\\(.*\\)\$_    \\1 \\\\_" "$inputs_path"
+	$SED_INPLACE "s_^\\(.*\\)\$_    \\1 \\\\_" "$inputs_path"
 
 	# Clean up
 	rm -f "$TMPPROJ"
@@ -125,7 +132,7 @@ sort "${INPUT_PATHS[@]}" | uniq >> "$FRAGMENT_PATH"
 
 # Simplify paths somewhat by removing the current directory
 if test -z "$ABSOLUTE_PATHS"; then
-	sed -i '' "s@$PROJECT_DIR/@@" "$FRAGMENT_PATH"
+	$SED_INPLACE "s@$PROJECT_DIR/@@" "$FRAGMENT_PATH"
 fi
 
 # Cleanup

tools/mmp/Makefile

@@ -74,11 +74,13 @@ Microsoft.macOS.registrar.coreclr.arm64.m: $(TOP)/src/build/dotnet/macos/64/Micr
 %.arm64.a: %.arm64.m
 	$(Q_CC) $(CLANG) -isysroot $(macos_SDK) -DDEBUG -g -gdwarf-2 -x objective-c++ -std=c++14 -o $@ -c -arch arm64 $< -Wall -Wno-unguarded-availability-new -I$(TOP)/runtime -mmacosx-version-min=$(DOTNET_MIN_MACOS_SDK_VERSION) -fobjc-runtime=macosx $(EXTRA_DEFINES)
 
+ifndef IS_LINUX
 dotnet: $(MMP_TARGETS_DOTNET)
 ifdef INCLUDE_MAC
 install-local:: $(MMP_TARGETS_DOTNET)
 all-local:: $(MMP_TARGETS_DOTNET)
 endif
+endif
 
 clean-local::
 	rm -rf bin obj

tools/mtouch/Makefile

@@ -85,9 +85,11 @@ endef
 
 $(foreach platform,$(DOTNET_PLATFORMS_MTOUCH),$(foreach rid,$(DOTNET_$(platform)_RUNTIME_IDENTIFIERS),$(eval $(call InstallRegistrar,$(platform),$(rid)))))
 
+ifndef IS_LINUX
 dotnet: $(TARGETS_DOTNET)
 install-local:: $(TARGETS_DOTNET)
 all-local:: $(TARGETS_DOTNET)
+endif
 
 clean-local::
 	rm -Rf bin obj