[vcpkg_paths] Add get_cmake/git/nuget_exe() functions

toolsrc/include/vcpkg_paths.h

@@ -3,6 +3,7 @@
 #include "expected.h"
 #include "package_spec.h"
 #include "BinaryParagraph.h"
+#include "lazy.h"
 
 namespace vcpkg
 {
@@ -35,5 +36,14 @@ namespace vcpkg
         fs::path vcpkg_dir_updates;
 
         fs::path ports_cmake;
+
+        const fs::path& get_cmake_exe() const;
+        const fs::path& get_git_exe() const;
+        const fs::path& get_nuget_exe() const;
+
+    private:
+        lazy<fs::path> cmake_exe;
+        lazy<fs::path> git_exe;
+        lazy<fs::path> nuget_exe;
     };
 }

toolsrc/src/vcpkg_paths.cpp

@@ -4,9 +4,153 @@
 #include "metrics.h"
 #include "vcpkg_System.h"
 #include "package_spec.h"
+#include "vcpkg_Environment.h"
 
 namespace vcpkg
 {
+    static bool exists_and_has_equal_or_greater_version(const std::wstring& version_cmd, const std::array<int, 3>& expected_version)
+    {
+        static const std::regex re(R"###((\d+)\.(\d+)\.(\d+))###");
+
+        auto rc = System::cmd_execute_and_capture_output(Strings::wformat(LR"(%s 2>&1)", version_cmd));
+        if (rc.exit_code != 0)
+        {
+            return false;
+        }
+
+        std::match_results<std::string::const_iterator> match;
+        auto found = std::regex_search(rc.output, match, re);
+        if (!found)
+        {
+            return false;
+        }
+
+        int d1 = atoi(match[1].str().c_str());
+        int d2 = atoi(match[2].str().c_str());
+        int d3 = atoi(match[3].str().c_str());
+        if (d1 > expected_version[0] || (d1 == expected_version[0] && d2 > expected_version[1]) || (d1 == expected_version[0] && d2 == expected_version[1] && d3 >= expected_version[2]))
+        {
+            // satisfactory version found
+            return true;
+        }
+
+        return false;
+    }
+
+    static optional<fs::path> find_if_has_equal_or_greater_version(const std::vector<fs::path>& candidate_paths, const std::wstring& version_check_arguments, const std::array<int, 3>& expected_version)
+    {
+        auto it = std::find_if(candidate_paths.cbegin(), candidate_paths.cend(), [&](const fs::path& p)
+        {
+            const std::wstring cmd = Strings::wformat(LR"("%s" %s)", p.native(), version_check_arguments);
+            return exists_and_has_equal_or_greater_version(cmd, expected_version);
+        });
+
+        if (it != candidate_paths.cend())
+        {
+            return std::make_unique<fs::path>(std::move(*it));
+        }
+
+        return nullptr;
+    }
+
+    static std::vector<fs::path> find_from_PATH(const std::wstring& name)
+    {
+        const std::wstring cmd = Strings::wformat(L"where.exe %s", name);
+        auto out = System::cmd_execute_and_capture_output(cmd);
+        if (out.exit_code != 0)
+        {
+            return {};
+        }
+
+        const std::vector<std::string> paths_to_add = Strings::split(out.output, "\n");
+        std::vector<fs::path> v;
+        v.insert(v.end(), paths_to_add.cbegin(), paths_to_add.cend());
+        return v;
+    }
+
+    static fs::path fetch_dependency(const fs::path scripts_folder, const std::wstring& tool_name, const fs::path& expected_downloaded_path)
+    {
+        const fs::path script = scripts_folder / "fetchDependency.ps1";
+        auto install_cmd = System::create_powershell_script_cmd(script, Strings::wformat(L"-Dependency %s", tool_name));
+        System::exit_code_and_output rc = System::cmd_execute_and_capture_output(install_cmd);
+        if (rc.exit_code)
+        {
+            System::println(System::color::error, "Launching powershell failed or was denied");
+            TrackProperty("error", "powershell install failed");
+            TrackProperty("installcmd", install_cmd);
+            exit(rc.exit_code);
+        }
+
+        const fs::path actual_downloaded_path = rc.output;
+        Checks::check_exit(expected_downloaded_path == actual_downloaded_path, "Expected dependency downloaded path to be %s, but was %s",
+            expected_downloaded_path.generic_string(), actual_downloaded_path.generic_string());
+        return actual_downloaded_path;
+    }
+
+    static fs::path get_cmake_path(const fs::path& downloads_folder, const fs::path scripts_folder)
+    {
+        static constexpr std::array<int, 3> expected_version = { 3,8,0 };
+        static const std::wstring version_check_arguments = L"--version";
+
+        const fs::path downloaded_copy = downloads_folder / "cmake-3.8.0-rc1-win32-x86" / "bin" / "cmake.exe";
+        const std::vector<fs::path> from_path = find_from_PATH(L"cmake");
+
+        std::vector<fs::path> candidate_paths;
+        candidate_paths.push_back(downloaded_copy);
+        candidate_paths.insert(candidate_paths.end(), from_path.cbegin(), from_path.cend());
+        candidate_paths.push_back(Environment::get_ProgramFiles_platform_bitness() / "CMake" / "bin" / "cmake.exe");
+        candidate_paths.push_back(Environment::get_ProgramFiles_32_bit() / "CMake" / "bin");
+
+        if (auto ret = find_if_has_equal_or_greater_version(candidate_paths, version_check_arguments, expected_version))
+        {
+            return *ret;
+        }
+
+        return fetch_dependency(scripts_folder, L"cmake", downloaded_copy);
+    }
+
+    fs::path get_nuget_path(const fs::path& downloads_folder, const fs::path scripts_folder)
+    {
+        static constexpr std::array<int, 3> expected_version = { 3,3,0 };
+        static const std::wstring version_check_arguments = L"";
+
+        const fs::path downloaded_copy = downloads_folder / "nuget-3.5.0" / "nuget.exe";
+        const std::vector<fs::path> from_path = find_from_PATH(L"nuget");
+
+        std::vector<fs::path> candidate_paths;
+        candidate_paths.push_back(downloaded_copy);
+        candidate_paths.insert(candidate_paths.end(), from_path.cbegin(), from_path.cend());
+
+        if (auto ret = find_if_has_equal_or_greater_version(candidate_paths, version_check_arguments, expected_version))
+        {
+            return *ret;
+        }
+
+        return fetch_dependency(scripts_folder, L"nuget", downloaded_copy);
+    }
+
+    fs::path get_git_path(const fs::path& downloads_folder, const fs::path scripts_folder)
+    {
+        static constexpr std::array<int, 3> expected_version = { 2,0,0 };
+        static const std::wstring version_check_arguments = L"--version";
+
+        const fs::path downloaded_copy = downloads_folder / "MinGit-2.11.1-32-bit" / "cmd" / "git.exe";
+        const std::vector<fs::path> from_path = find_from_PATH(L"git");
+
+        std::vector<fs::path> candidate_paths;
+        candidate_paths.push_back(downloaded_copy);
+        candidate_paths.insert(candidate_paths.end(), from_path.cbegin(), from_path.cend());
+        candidate_paths.push_back(Environment::get_ProgramFiles_platform_bitness() / "git" / "cmd" / "git.exe");
+        candidate_paths.push_back(Environment::get_ProgramFiles_32_bit() / "git" / "cmd" / "git.exe");
+
+        if (auto ret = find_if_has_equal_or_greater_version(candidate_paths, version_check_arguments, expected_version))
+        {
+            return *ret;
+        }
+
+        return fetch_dependency(scripts_folder, L"git", downloaded_copy);
+    }
+
     expected<vcpkg_paths> vcpkg_paths::create(const fs::path& vcpkg_root_dir)
     {
         std::error_code ec;
@@ -43,6 +187,7 @@ namespace vcpkg
         paths.vcpkg_dir_updates = paths.vcpkg_dir / "updates";
 
         paths.ports_cmake = paths.scripts / "ports.cmake";
+
         return paths;
     }
 
@@ -80,4 +225,19 @@ namespace vcpkg
         }
         return false;
     }
+
+    const fs::path& vcpkg_paths::get_cmake_exe() const
+    {
+        return this->cmake_exe.get_lazy([this]() { return get_cmake_path(this->downloads, this->scripts); });
+    }
+
+    const fs::path& vcpkg_paths::get_git_exe() const
+    {
+        return this->git_exe.get_lazy([this]() { return get_git_path(this->downloads, this->scripts); });
+    }
+
+    const fs::path& vcpkg_paths::get_nuget_exe() const
+    {
+        return this->nuget_exe.get_lazy([this]() { return get_nuget_path(this->downloads, this->scripts); });
+    }
 }