[dotnet] Port misc build/test logic to .NET. (#21497)

More steps towards removing our build-time Mono dependency.

src/Makefile.generator

@@ -71,5 +71,5 @@ $(RSP_DIR)/dotnet/%-defines-dotnet.rsp: frameworks.sources Makefile.generator ge
 	$(Q) mv $@.tmp $@
 
 $(DOTNET_BUILD_DIR)/Xamarin.Apple.BindingAttributes.dll: bgen/Attributes.cs bgen/PlatformName.cs Makefile.generator | $(DOTNET_BUILD_DIR)
-	$(Q_DOTNET_BUILD) $(SYSTEM_CSC) $(DOTNET_FLAGS) -out:$@ bgen/Attributes.cs bgen/PlatformName.cs
+	$(Q_DOTNET_BUILD) $(DOTNET_CSC) $(DOTNET_FLAGS) -out:$@ bgen/Attributes.cs bgen/PlatformName.cs
 

tests/Makefile

@@ -203,8 +203,10 @@ $(TOP)/tools/common/SdkVersions.cs: $(TOP)/tools/common/SdkVersions.in.cs
 $(XHARNESS_EXECUTABLE): MSBUILD_EXE_PATH=
 $(XHARNESS_EXECUTABLE): $(xharness_dependencies) test.config test-system.config .stamp-src-project-files $(TOP)/tools/common/SdkVersions.cs
 	$(Q_GEN) $(DOTNET) build "/bl:$@.binlog" $(MSBUILD_VERBOSITY_QUIET) xharness/xharness.csproj
-xharness/xharness.csproj.inc: export BUILD_VERBOSITY=$(XBUILD_VERBOSITY)
+xharness/xharness.csproj.inc: export BUILD_VERBOSITY=$(DOTNET_BUILD_VERBOSITY)
 xharness/xharness.csproj.inc: export ABSOLUTE_PATHS=1
+xharness/xharness.csproj.inc: export DOTNET:=$(DOTNET)
+xharness/xharness.csproj.inc: export MSBUILD_EXE_PATH=
 -include xharness/xharness.csproj.inc
 
 killall:

tests/dotnet/SimpleAppWithOldReferences/dotnet45assembly/Makefile

@@ -3,6 +3,6 @@ TOP=../../../..
 include $(TOP)/Make.config
 
 dotnet45assembly.dll: Library.cs
-	$(SYSTEM_CSC) -target:library -out:$@ $<
+	$(Q) $(DOTNET) build *.csproj $(DOTNET_BUILD_VERBOSITY)
 
 all-local:: dotnet45assembly.dll

tests/dotnet/SimpleAppWithOldReferences/dotnet45assembly/dotnet45assembly.csproj

@@ -0,0 +1,7 @@
+<Project Sdk="Microsoft.NET.Sdk">
+  <PropertyGroup>
+    <TargetFramework>net4.7.2</TargetFramework>
+    <OutputPath>.</OutputPath>
+    <AppendTargetFrameworkToOutputPath>false</AppendTargetFrameworkToOutputPath>
+  </PropertyGroup>
+</Project>

tools/common/create-makefile-fragment.sh

@@ -34,7 +34,11 @@ if test -z "$FRAGMENT_PATH"; then
 fi
 
 if test -z "$BUILD_EXECUTABLE"; then
-	BUILD_EXECUTABLE=msbuild
+	if test -z "$DOTNET"; then
+		echo "The DOTNET environment variable isn't set to the location of the 'dotnet' executable"
+		exit 1
+	fi
+	BUILD_EXECUTABLE="$DOTNET build"
 fi
 
 if test -z "$BUILD_VERBOSITY"; then

tools/mmp/Makefile

@@ -14,6 +14,7 @@ LOCAL_MMP_COMMAND=$(SYSTEM_MONO) --debug $(LOCAL_MMP)
 
 # mmp.csproj.inc contains the mmp_dependencies variable used to determine if mmp needs to be rebuilt or not.
 mmp.csproj.inc: export BUILD_VERBOSITY=$(MSBUILD_VERBOSITY)
+mmp.csproj.inc: export DOTNET:=$(DOTNET)
 -include mmp.csproj.inc
 
 $(MMP_DIR)/mmp.exe: $(mmp_dependencies)

tools/mtouch/Makefile

@@ -233,6 +233,7 @@ DOTNET_PLATFORMS_MTOUCH=$(filter-out macOS,$(DOTNET_PLATFORMS))
 
 # mtouch.csproj.inc contains the mtouch_dependencies variable used to determine if mtouch needs to be rebuilt or not.
 mtouch.csproj.inc: export BUILD_VERBOSITY=$(MSBUILD_VERBOSITY)
+mtouch.csproj.inc: export DOTNET:=$(DOTNET)
 -include mtouch.csproj.inc
 
 $(MTOUCH_DIR)/mtouch.exe: $(mtouch_dependencies)