[vcpkg] add x86-wasm.cmake to community triplets (microsoft#11323)

* add x86-wasm.cmake to community triplets

The EMSDK enviroment variable is normally defined when first installing Emscripten.

* Rename x86-wasm.cmake to wasm32-emscripten.cmake

* Update wasm32-emscripten.cmake

* Update wasm32-emscripten.cmake

* Add wasm32 and wasm64 arch to docs

* Create wasm64-emscripten.cmake

* remove wasm64

* Delete wasm64-emscripten.cmake

* Add wasm32 to list of identifiers

* add emscripten VCPKG_CMAKE_SYSTEM_NAME support

* add path check to EMSDK cmake toolchain

.gitignore

@@ -313,6 +313,7 @@ __pycache__/
 !triplets/community/arm-ios.cmake
 !triplets/community/x64-ios.cmake
 !triplets/community/x86-ios.cmake
+!triplets/community/wasm32-emscripten.cmake
 !triplets/arm-uwp.cmake
 !triplets/x64-uwp.cmake
 !triplets/x64-windows.cmake

docs/maintainers/control-files.md

@@ -138,6 +138,8 @@ The predefined expressions are computed from standard triplet settings:
 - `osx` - `VCPKG_CMAKE_SYSTEM_NAME` == `"Darwin"`
 - `android` - `VCPKG_CMAKE_SYSTEM_NAME` == `"Android"`
 - `static` - `VCPKG_LIBRARY_LINKAGE` == `"static"`
+- `wasm32` - `VCPKG_TARGET_ARCHITECTURE` == `"wasm32"`
+- `emscripten` - `VCPKG_CMAKE_SYSTEM_NAME` == `"Emscripten"`
 
 These predefined expressions can be overridden in the triplet file via the [`VCPKG_DEP_INFO_OVERRIDE_VARS`](../users/triplets.md) option.
 

docs/users/triplets.md

@@ -29,7 +29,7 @@ Community Triplets are enabled by default, when using a community triplet a mess
 ### VCPKG_TARGET_ARCHITECTURE
 Specifies the target machine architecture.
 
-Valid options are `x86`, `x64`, `arm`, and `arm64`.
+Valid options are `x86`, `x64`, `arm`, `arm64` and `wasm32`.
 
 ### VCPKG_CRT_LINKAGE
 Specifies the desired CRT linkage (for MSVC).
@@ -49,6 +49,7 @@ Valid options include any CMake system name, such as:
 - `WindowsStore` (Universal Windows Platform)
 - `Darwin` (Mac OSX)
 - `Linux` (Linux)
+- `Emscripten` (WebAssembly)
 
 ### VCPKG_CMAKE_SYSTEM_VERSION
 Specifies the target platform system version.

toolsrc/src/vcpkg/logicexpression.cpp

@@ -25,6 +25,8 @@ namespace vcpkg
         osx,
         uwp,
         android,
+        emscripten,
+        wasm32,
 
         static_link,
     };
@@ -113,6 +115,8 @@ namespace vcpkg
                 {"osx", Identifier::osx},
                 {"uwp", Identifier::uwp},
                 {"android", Identifier::android},
+                {"emscripten", Identifier::emscripten},
+                {"wasm32", Identifier::wasm32},
                 {"static", Identifier::static_link},
             };
 
@@ -165,6 +169,8 @@ namespace vcpkg
                 case Identifier::osx: return true_if_exists_and_equal("VCPKG_CMAKE_SYSTEM_NAME", "Darwin");
                 case Identifier::uwp: return true_if_exists_and_equal("VCPKG_CMAKE_SYSTEM_NAME", "WindowsStore");
                 case Identifier::android: return true_if_exists_and_equal("VCPKG_CMAKE_SYSTEM_NAME", "Android");
+                case Identifier::emscripten: return true_if_exists_and_equal("VCPKG_CMAKE_SYSTEM_NAME", "Emscripten");
+                case Identifier::wasm32: return true_if_exists_and_equal("VCPKG_TARGET_ARCHITECTURE", "wasm32");
                 case Identifier::static_link: return true_if_exists_and_equal("VCPKG_LIBRARY_LINKAGE", "static");
             }
 

triplets/community/wasm32-emscripten.cmake

@@ -0,0 +1,15 @@
+set(VCPKG_ENV_PASSTHROUGH EMSDK PATH)
+
+if(NOT DEFINED ENV{EMSDK})
+   message(FATAL_ERROR "The EMSDK environment variable must be defined")
+endif()
+
+if(NOT EXISTS $ENV{EMSDK}/upstream/emscripten/cmake/Modules/Platform/Emscripten.cmake)
+   message(FATAL_ERROR "Emscripten.cmake toolchain file not found")
+endif()
+
+set(VCPKG_TARGET_ARCHITECTURE wasm32)
+set(VCPKG_CRT_LINKAGE dynamic)
+set(VCPKG_LIBRARY_LINKAGE static)
+set(VCPKG_CMAKE_SYSTEM_NAME Emscripten)
+set(VCPKG_CHAINLOAD_TOOLCHAIN_FILE $ENV{EMSDK}/upstream/emscripten/cmake/Modules/Platform/Emscripten.cmake)