[vcpkg] Environment Variable Passthrough (#7290)

* use additional env param

* remove partials

* remove change to linux triplet

* Fix some issues that vicroms pointed out

* whitespace change

2 files changed, 26 insertions, 0 deletions

diff --git a/toolsrc/include/vcpkg/build.h b/toolsrc/include/vcpkg/build.h
index 04cd7cf87..e26597376 100644
--- a/toolsrc/include/vcpkg/build.h
+++ b/toolsrc/include/vcpkg/build.h
@@ -117,6 +117,29 @@ namespace vcpkg::Build
     std::string create_error_message(const BuildResult build_result, const PackageSpec& spec);
     std::string create_user_troubleshooting_message(const PackageSpec& spec);
 
+   enum class VcpkgTripletVar
+   {
+       TARGET_ARCHITECTURE = 0,
+       CMAKE_SYSTEM_NAME,
+       CMAKE_SYSTEM_VERSION,
+       PLATFORM_TOOLSET,
+       VISUAL_STUDIO_PATH,
+       CHAINLOAD_TOOLCHAIN_FILE,
+       BUILD_TYPE,
+       ENV_PASSTHROUGH,
+   };
+
+   const std::unordered_map<std::string, VcpkgTripletVar> VCPKG_OPTIONS = {
+       {"VCPKG_TARGET_ARCHITECTURE", VcpkgTripletVar::TARGET_ARCHITECTURE},
+       {"VCPKG_CMAKE_SYSTEM_NAME", VcpkgTripletVar::CMAKE_SYSTEM_NAME},
+       {"VCPKG_CMAKE_SYSTEM_VERSION", VcpkgTripletVar::CMAKE_SYSTEM_VERSION},
+       {"VCPKG_PLATFORM_TOOLSET", VcpkgTripletVar::PLATFORM_TOOLSET},
+       {"VCPKG_VISUAL_STUDIO_PATH", VcpkgTripletVar::VISUAL_STUDIO_PATH},
+       {"VCPKG_CHAINLOAD_TOOLCHAIN_FILE", VcpkgTripletVar::CHAINLOAD_TOOLCHAIN_FILE},
+       {"VCPKG_BUILD_TYPE", VcpkgTripletVar::BUILD_TYPE},
+       {"VCPKG_ENV_PASSTHROUGH", VcpkgTripletVar::ENV_PASSTHROUGH},
+   };
+
     /// <summary>
     /// Settings from the triplet file which impact the build environment and post-build checks
     /// </summary>
@@ -135,6 +158,7 @@ namespace vcpkg::Build
         Optional<fs::path> visual_studio_path;
         Optional<std::string> external_toolchain_file;
         Optional<ConfigurationType> build_type;
+        std::vector<std::string> passthrough_env_vars;
     };
 
     std::string make_build_env_cmd(const PreBuildInfo& pre_build_info, const Toolset& toolset);
diff --git a/toolsrc/include/vcpkg/sourceparagraph.h b/toolsrc/include/vcpkg/sourceparagraph.h
index 6232a3fd2..9fbd83475 100644
--- a/toolsrc/include/vcpkg/sourceparagraph.h
+++ b/toolsrc/include/vcpkg/sourceparagraph.h
@@ -23,6 +23,8 @@ namespace vcpkg
 
     std::vector<std::string> filter_dependencies(const std::vector<Dependency>& deps, const Triplet& t);
     std::vector<FeatureSpec> filter_dependencies_to_specs(const std::vector<Dependency>& deps, const Triplet& t);
+    std::vector<Features> filter_dependencies_to_features(const std::vector<vcpkg::Dependency>& deps,
+                                                          const Triplet& t);
 
     // zlib[uwp] becomes Dependency{"zlib", "uwp"}
     std::vector<Dependency> expand_qualified_dependencies(const std::vector<std::string>& depends);