Simplify webassembly targets (dotnet#41869)

Add a subset for compiling only the wasm runtime: `mono.wasmruntime`
This allows us to rebuild the wasm runtime without building the full libraries subset.

Updated documentation with new guidance.

Updated how we build the dotnet.timezones.blat.

Directory.Build.props

@@ -44,20 +44,24 @@
 
     <DocsDir>$([MSBuild]::NormalizeDirectory('$(RepoRoot)', 'docs'))</DocsDir>
     <ManPagesDir>$([MSBuild]::NormalizeDirectory('$(DocsDir)', 'manpages'))</ManPagesDir>
+
+    <!-- System.Private.CoreLib -->
     <CoreLibSharedDir>$([MSBuild]::NormalizeDirectory('$(LibrariesProjectRoot)', 'System.Private.CoreLib', 'src'))</CoreLibSharedDir>
+    <CoreLibProject Condition="'$(RuntimeFlavor)' == 'CoreCLR'">$([MSBuild]::NormalizePath('$(CoreClrProjectRoot)', 'src', 'System.Private.CoreLib', 'System.Private.CoreLib.csproj'))</CoreLibProject>
+    <CoreLibProject Condition="'$(RuntimeFlavor)' == 'Mono'">$([MSBuild]::NormalizePath('$(MonoProjectRoot)', 'netcore', 'System.Private.CoreLib', 'System.Private.CoreLib.csproj'))</CoreLibProject>
   </PropertyGroup>
 
   <PropertyGroup Condition="'$(TargetsMobile)' == 'true'">
     <AppleAppBuilderDir>$([MSBuild]::NormalizeDirectory('$(ArtifactsBinDir)', 'AppleAppBuilder', 'Debug', '$(NetCoreAppCurrent)'))</AppleAppBuilderDir>
     <AndroidAppBuilderDir>$([MSBuild]::NormalizeDirectory('$(ArtifactsBinDir)', 'AndroidAppBuilder', 'Debug', '$(NetCoreAppCurrent)'))</AndroidAppBuilderDir>
     <WasmAppBuilderDir>$([MSBuild]::NormalizeDirectory('$(ArtifactsBinDir)', 'WasmAppBuilder', 'Debug', '$(NetCoreAppCurrent)', 'publish'))</WasmAppBuilderDir>
-    <GenerateWasmBundleDir>$([MSBuild]::NormalizeDirectory('$(ArtifactsBinDir)', 'GenerateWasmBundle', 'Debug', '$(NetCoreAppCurrent)', 'publish'))</GenerateWasmBundleDir>
+    <WasmBuildTasksDir>$([MSBuild]::NormalizeDirectory('$(ArtifactsBinDir)', 'WasmBuildTasks', 'Debug', '$(NetCoreAppCurrent)', 'publish'))</WasmBuildTasksDir>
     <MonoAOTCompilerDir>$([MSBuild]::NormalizeDirectory('$(ArtifactsBinDir)', 'MonoAOTCompiler', 'Debug', '$(NetCoreAppCurrent)'))</MonoAOTCompilerDir>
 
     <AppleAppBuilderTasksAssemblyPath>$([MSBuild]::NormalizePath('$(AppleAppBuilderDir)', 'AppleAppBuilder.dll'))</AppleAppBuilderTasksAssemblyPath>
     <AndroidAppBuilderTasksAssemblyPath>$([MSBuild]::NormalizePath('$(AndroidAppBuilderDir)', 'AndroidAppBuilder.dll'))</AndroidAppBuilderTasksAssemblyPath>
     <WasmAppBuilderTasksAssemblyPath>$([MSBuild]::NormalizePath('$(WasmAppBuilderDir)', 'WasmAppBuilder.dll'))</WasmAppBuilderTasksAssemblyPath>
-    <GenerateWasmBundlesAssemblyPath>$([MSBuild]::NormalizePath('$(GenerateWasmBundleDir)', 'GenerateWasmBundle.dll'))</GenerateWasmBundlesAssemblyPath>
+    <WasmBuildTasksAssemblyPath>$([MSBuild]::NormalizePath('$(WasmBuildTasksDir)', 'WasmBuildTasks.dll'))</WasmBuildTasksAssemblyPath>
     <MonoAOTCompilerTasksAssemblyPath>$([MSBuild]::NormalizePath('$(MonoAOTCompilerDir)', 'MonoAOTCompiler.dll'))</MonoAOTCompilerTasksAssemblyPath>
   </PropertyGroup>
 

docs/workflow/building/libraries/webassembly-instructions.md

@@ -4,102 +4,109 @@
 
 If you haven't already done so, please read [this document](../../README.md#Build_Requirements) to understand the build requirements for your operating system.
 
-An installation of the emsdk needs to be installed.  Follow the installation guide [here](https://emscripten.org/docs/getting_started/downloads.html#sdk-download-and-install).  Once installed the EMSDK_PATH needs to be set:
+The Emscripten SDK (emsdk) needs to be installed.  Follow the installation guide [here](https://emscripten.org/docs/getting_started/downloads.html#sdk-download-and-install) or run `make -C src/mono/wasm provision-wasm` to install emsdk into `src/mono/wasm/emsdk`.
 
-On Linux and MacOSX:
+Once installed the `EMSDK_PATH` environment variable needs to be set:
+
+On Linux and macOS:
 
 ```bash
-export EMSDK_PATH=PATH_TO_SDK_INSTALL/emsdk
+export EMSDK_PATH=<FULL_PATH_TO_SDK_INSTALL>/emsdk
 ```
 
 ## Building everything
 
-At this time no other build configurations are necessary to start building for WebAssembly.  The CoreLib for WebAssembly build configurations will be built by default using the WebAssembly configuration shown below.
+At this time no other build dependencies are necessary to start building for WebAssembly.
 
-This document explains how to work on libraries. In order to work on library projects or run library tests it is necessary to have built the runtime to give the libraries something to run on. If you haven't already done so, please read [this document](../../README.md#Configurations) to understand configurations.
+This document explains how to work on the runtime or libraries. If you haven't already done so, please read [this document](../../README.md#Configurations) to understand configurations.
 
+For Linux and macOS:
 
-For Linux and MacOSX:
 ```bash
-./build.sh --arch wasm --os Browser --configuration release
+./build.sh -os Browser -configuration Release
 ```
 
-Detailed information about building and testing runtimes and the libraries is in the documents linked below.
+Artifacts will be placed in `artifacts/bin/microsoft.netcore.app.runtime.browser-wasm/Release/`. When rebuilding with `build.sh` after a code change, you need to ensure that the `mono.wasmruntime` and `libs.pretest` subsets are included even for a Mono-only change or this directory will not be updated (details below).
 
-## How to build native components only
+## Building Mono's System.Private.CoreLib or runtime
 
-The libraries build contains some native code. This includes shims over libc, openssl, gssapi, and zlib. The build system uses CMake to generate Makefiles using clang. The build also uses git for generating some version information.
+If you are working on core parts of Mono you will probably need to build the Mono runtime and [System.Private.CoreLib](../../../design/coreclr/botr/corelib.md) which can be built with the following:
 
-**Examples**
+```bash
+./build.sh mono -os Browser -c Debug|Release
+```
+
+To build just System.Private.CoreLib without the Mono runtime you can use the `Mono.CoreLib` subset:
 
-- Building in debug mode for platform wasm and Browser operating system
 ```bash
-./build.sh libs.native --arch wasm --os Browser
+./build.sh mono.corelib -os Browser -c Debug|Release
 ```
 
-- Building in release mode for platform wasm and Browser operating system
+To build just the Mono runtime without System.Private.CoreLib use the `Mono.Runtime` subset:
+
 ```bash
-./build.sh libs.native --arch wasm --os Browser -c Release
+./build.sh mono.runtime -os Browser -c Debug|Release
 ```
 
-## How to build mono System.Private.CoreLib
+Building both Mono/System.Private.CoreLib and the managed libraries:
 
-If you are working on core parts of mono libraries you will probably need to build the [System.Private.CoreLib](../../../design/coreclr/botr/corelib.md) which can be built with the following:
+```bash
+./build.sh mono+libs -os Browser -c Debug|Release
+```
 
+## Building the WebAssembly runtime files
+
+The WebAssembly implementation files are built after the libraries source build and made available in the artifacts folder.  If you are working on the code base and need to compile just these modules then building the `Mono.WasmRuntime` subset will allow one to do that:
 
 ```bash
-./build.sh mono --arch wasm --os Browser -c Release
+./build.sh mono.wasmruntime -os Browser -c Debug|Release
 ```
 
-To build just SPC without mono you can use the Mono.CoreLib subset.
+## Updating in-tree runtime pack
+
+If you don't run the full `Libs` subset then you can use the `Libs.PreTest` subset to copy updated runtime/corelib binaries to the runtime pack which is used for running tests:
 
 ```bash
-./build.sh mono.corelib --arch wasm --os Browser -c Release
+./build.sh libs.pretest -os Browser -c Debug|Release
 ```
 
-Building the managed libraries as well:
+## Building libraries native components only
+
+The libraries build contains some native code. This includes shims over libc, openssl, gssapi, and zlib. The build system uses CMake to generate Makefiles using clang. The build also uses git for generating some version information.
 
 ```bash
-./build.sh mono+libs --arch wasm --os Browser -c Release
+./build.sh libs.native -os Browser -c Debug|Release
 ```
 
 ## Building individual libraries
 
 Individual projects and libraries can be build by specifying the build configuration.
 
-Building individual libraries
 **Examples**
 
 - Build all projects for a given library (e.g.: System.Net.Http) including the tests
 
 ```bash
- ./build.sh --arch wasm --os Browser -c Release --projects src/libraries/System.Net.Http/System.Net.Http.sln
+./build.sh -os Browser -c Release --projects <full-repository-path>/src/libraries/System.Net.Http/System.Net.Http.sln
 ```
 
 - Build only the source project of a given library (e.g.: System.Net.Http)
 
 ```bash
- ./build.sh --arch wasm --os Browser -c Release --projects src/libraries/System.Net.Http/src/System.Net.Http.csproj
+ ./build.sh -os Browser -c Release --projects <full-repository-path>/src/libraries/System.Net.Http/src/System.Net.Http.csproj
 ```
 
 More information and examples can be found in the [libraries](./README.md#building-individual-libraries) document.
 
-## Building the WebAssembly runtime files
-
-The WebAssembly implementation files are built and made available in the artifacts folder.  If you are working on the code base and need to compile just these modules then the following will allow one to do that.
-
-For Linux and MacOSX:
-```bash
-./dotnet.sh build /p:Configuration=Debug|Release /p:TargetArchitecture=wasm /p:TargetOS=Browser src/libraries/src.proj /t:BuildWasmRuntimes
-```
+## Notes
 
-__Note__: A `Debug` build sets the following environment variables by default.  When built from the command line this way the `Configuration` value is case sensitive.
+A `Debug` build sets the following environment variables by default:
 
 - debugging and logging which will log garbage collection information to the console.
 
 ```
-   monoeg_g_setenv ("MONO_LOG_LEVEL", "debug", 0);
-   monoeg_g_setenv ("MONO_LOG_MASK", "gc", 0);
+MONO_LOG_LEVEL=debug
+MONO_LOG_MASK=gc
 ```
 
   #### Example:

docs/workflow/building/mono/README.md

@@ -51,31 +51,7 @@ The build has a number of options that you can learn about using build -?.
 
 ### WebAssembly
 
-In addition to the normal build requirements, WebAssembly builds require a local emsdk to be downloaded. This can either be external or acquired via a make target.
-
-To acquire it externally, move to a directory outside of the runtime repository and run:
-```bash
-git clone https://github.com/emscripten-core/emsdk.git
-```
-
-To use the make target, from the root of the runtime repo:
-```bash
-cd src/mono/wasm
-make provision-wasm
-cd ../../..
-```
-
-When building for WebAssembly, regardless of the machine architecture, you must set the `EMSDK_PATH` environmental variable and architecture/os, calling build.sh like so:
-```bash
-EMSDK_PATH={path to emsdk repo} ./build.sh --subset mono+libs --arch wasm --os browser -c release
-```
-
-If using the locally provisioned emsdk, this will be:
-```bash
-EMSDK_PATH={path to runtime repo}/src/mono/wasm/emsdk ./build.sh --subset mono+libs --arch wasm --os browser -c release
-```
-
-Artifacts will be placed in `artifacts/bin/microsoft.netcore.app.runtime.browser-wasm/Release/`. When rebuilding with `build.sh`, you _must_ rebuild with `mono+libs` even for mono-only changes, or this directory will not be updated. Alternative, you can rebuild just the runtime-specific bits from the `src/mono/wasm` directory by running either `make runtime` or `make corlib` when modifying Mono or System.Private.CoreLib respectively.
+See the instructions in [../libraries/webassembly-instructions.md].
 
 ## Packages
 

docs/workflow/testing/libraries/testing-wasm.md

@@ -25,11 +25,11 @@ PATH=/Users/<your_user>/.jsvu/:$PATH V8
 
 Now we're ready to build everything for WebAssembly (for more details, please read [this document](../../building/libraries/webassembly-instructions.md#building-everything)):
 ```bash
-./build.sh --arch wasm --os Browser -c release
+./build.sh -os Browser -c Release
 ```
 and even run tests one by one for each library:
 ```
-./build.sh --subset libs.tests -t --arch wasm --os Browser -c release
+./build.sh libs.tests -test -os Browser -c Release
 ```
 
 ### Running individual test suites

eng/Subsets.props

@@ -57,6 +57,7 @@
     <DefaultCoreClrSubsets>clr.runtime+linuxdac+clr.corelib+clr.nativecorelib+clr.tools+clr.packages</DefaultCoreClrSubsets>
 
     <DefaultMonoSubsets Condition="'$(MonoEnableLLVM)' == 'true' and '$(MonoLLVMDir)' == ''">mono.llvm+</DefaultMonoSubsets>
+    <DefaultMonoSubsets Condition="'$(TargetOS)' == 'Browser'">$(DefaultMonoSubsets)mono.wasmruntime+</DefaultMonoSubsets>
     <DefaultMonoSubsets>$(DefaultMonoSubsets)mono.runtime+mono.corelib+mono.packages</DefaultMonoSubsets>
 
     <DefaultLibrariesSubsets>libs.native+libs.ref+libs.src+libs.pretest+libs.packages</DefaultLibrariesSubsets>
@@ -94,6 +95,7 @@
     <SubsetName Include="Mono.Runtime" Description="The Mono .NET runtime." />
     <SubsetName Include="Mono.CoreLib" Description="The managed System.Private.CoreLib library for Mono." />
     <SubsetName Include="Mono.Packages" Description="The projects that produce NuGet packages for the Mono runtime." />
+    <SubsetName Include="Mono.WasmRuntime" Description="The WebAssembly runtime." />
 
     <!-- Libs -->
     <SubsetName Include="Libs" Description="The libraries native part, refs and source assemblies, test infra and packages, but NOT the tests (use Libs.Tests to request those explicitly)" />
@@ -195,6 +197,10 @@
     <ProjectToBuild Include="$(LibrariesProjectRoot)src.proj" Category="libs" />
   </ItemGroup>
 
+  <ItemGroup Condition="$(_subset.Contains('+mono.wasmruntime+'))">
+    <ProjectToBuild Include="$(MonoProjectRoot)wasm\wasm.proj" Category="mono" />
+  </ItemGroup>
+
   <ItemGroup Condition="$(_subset.Contains('+libs.pretest+'))">
     <ProjectToBuild Include="$(LibrariesProjectRoot)pretest.proj" Category="libs"  />
   </ItemGroup>

eng/build.sh

@@ -391,6 +391,11 @@ if [ ${#actInt[@]} -eq 0 ]; then
     arguments="-restore -build $arguments"
 fi
 
+if [ "$os" = "Browser" ] && [ "$arch" != "wasm" ]; then
+    # override default arch for Browser, we only support wasm
+    arch=wasm
+fi
+
 initDistroRid $os $arch $crossBuild $portableBuild
 
 # URL-encode space (%20) to avoid quoting issues until the msbuild call in /eng/common/tools.sh.

eng/testing/tests.mobile.targets

@@ -151,24 +151,6 @@
       AssemblySearchPaths="@(AssemblySearchPaths)" />
   </Target>
 
-  <Import Project="$(MonoProjectRoot)wasm\timezones.props" Condition="'$(TargetOS)' == 'Browser'" />
-  <UsingTask TaskName="CompileTimeZoneData"
-             AssemblyFile="$(GenerateWasmBundlesAssemblyPath)" />
-  <Target Condition="'$(TargetOS)' == 'Browser'" Name="LoadTimeZone" >
-    <CompileTimeZoneData 
-      TimeZones="@(TimeZoneToBundle)"
-      InputDirectory="$([MSBuild]::NormalizePath('$(GenerateWasmBundleDir)', '..', 'data'))"
-      OutputDirectory="$(BundleDir)obj/data/output"/>
-  </Target>
-
-  <UsingTask TaskName="GenerateWasmBundle"
-             AssemblyFile="$(GenerateWasmBundlesAssemblyPath)" />
-  <Target Condition="'$(TargetOS)' == 'Browser'" Name="BundleWasmTestData" DependsOnTargets="LoadTimeZone">
-    <GenerateWasmBundle
-      InputDirectory="$(BundleDir)obj/data/output"
-      OutputFileName="$(MicrosoftNetCoreAppRuntimePackRidDir)dotnet.timezones.blat" />
-  </Target>
-
   <Target Name="AddTestRunnersToPublishedFiles"
           AfterTargets="ComputeResolvedFilesToPublishList">
     <ItemGroup>
@@ -184,5 +166,5 @@
   <Target Name="PublishTestAsSelfContained"
           Condition="'$(IsCrossTargetingBuild)' != 'true'"
           AfterTargets="Build"
-          DependsOnTargets="Publish;BundleTestAppleApp;BundleTestAndroidApp;BundleTestWasmApp;BundleWasmTestData;ArchiveTests" />
+          DependsOnTargets="Publish;BundleTestAppleApp;BundleTestAndroidApp;BundleTestWasmApp;ArchiveTests" />
 </Project>

src/libraries/Directory.Build.props

@@ -245,10 +245,6 @@
     <NetCoreAppCurrentRefPath>$([MSBuild]::NormalizeDirectory('$(RefRootPath)', '$(NetCoreAppCurrent)'))</NetCoreAppCurrentRefPath>
     <NetCoreAppCurrentRuntimePath>$([MSBuild]::NormalizeDirectory('$(ArtifactsBinDir)', 'runtime', '$(NetCoreAppCurrent)-$(TargetOS)-$(Configuration)-$(TargetArchitecture)'))</NetCoreAppCurrentRuntimePath>
 
-    <!-- System.Private.CoreLib -->
-    <CoreLibProject Condition="'$(RuntimeFlavor)' == 'CoreCLR'">$([MSBuild]::NormalizePath('$(CoreClrProjectRoot)', 'src', 'System.Private.CoreLib', 'System.Private.CoreLib.csproj'))</CoreLibProject>
-    <CoreLibProject Condition="'$(RuntimeFlavor)' == 'Mono'">$([MSBuild]::NormalizePath('$(MonoProjectRoot)', 'netcore', 'System.Private.CoreLib', 'System.Private.CoreLib.csproj'))</CoreLibProject>
-
     <!-- Helix properties -->
     <OSPlatformConfig>$(TargetOS).$(Platform).$(Configuration)</OSPlatformConfig>
     <AnyOSPlatformConfig>AnyOS.AnyCPU.$(Configuration)</AnyOSPlatformConfig>

src/libraries/src.proj

@@ -39,8 +39,6 @@
              Properties="$(TraversalGlobalProperties)" />
   </Target>
 
-  <Import Condition="'$(TargetOS)' == 'Browser'" Project="$(MonoProjectRoot)wasm\wasm.targets" />
-
   <Target Name="BuildManualShims"
           AfterTargets="BuildNonNetCoreAppProjects"
           Condition="'@(ManualShimProject)' != ''">