Use FetchContent_MakeAvailable for vcpkg in case they add CMakeLists.txt

Author: mrexodia

docs/cmake-toml.md

@@ -105,6 +105,8 @@ The vcpkg `version` will automatically generate the `url` from the [official rep
 
 To specify package features you can use the following syntax: `imgui[docking-experimental,freetype,sdl2-binding,opengl3-binding]`.
 
+The `crt-linkage` specifies the MSVC runtime library variant to use while compiling packages. `library-linkage` is whether libraries built are dynamic (default) or static.
+
 ## Packages
 
 ```toml
@@ -116,8 +118,6 @@ config = true
 components = ["mycomponent"]
 ```
 
-The `crt-linkage` specifies the MSVC runtime library variant to use while compiling packages. `library-linkage` is whether libraries built are dynamic (default) or static.
-
 ## FetchContent
 
 **Note**: The `[fetch-content]` feature is unpolished and will likely change in a future release.

src/cmake_generator.cpp

@@ -634,14 +634,18 @@ void generate_cmake(const char *path, const parser::Project *parent_project) {
             cmd("include")("FetchContent");
             cmd("message")("STATUS", "Fetching vcpkg (" + version_name + ")...");
             cmd("FetchContent_Declare")("vcpkg", "URL", url);
-            cmd("FetchContent_MakeAvailable")("vcpkg");
-            if (!project.vcpkg.crt_linkage.empty()) {
-                cmd("set")("VCPKG_CRT_LINKAGE", project.vcpkg.crt_linkage);
-            }
-            if (!project.vcpkg.library_linkage.empty()) {
-                cmd("set")("VCPKG_LIBRARY_LINKAGE", project.vcpkg.library_linkage);
-            }
-            cmd("include")("${vcpkg_SOURCE_DIR}/scripts/buildsystems/vcpkg.cmake");
+            // Not using FetchContent_MakeAvailable here in case vcpkg adds CMakeLists.txt
+            cmd("FetchContent_GetProperties")("vcpkg");
+            cmd("if")("NOT", "vcpkg_POPULATED");
+                cmd("FetchContent_Populate")("vcpkg");
+                if (!project.vcpkg.crt_linkage.empty()) {
+                    cmd("set")("VCPKG_CRT_LINKAGE", project.vcpkg.crt_linkage);
+                }
+                if (!project.vcpkg.library_linkage.empty()) {
+                    cmd("set")("VCPKG_LIBRARY_LINKAGE", project.vcpkg.library_linkage);
+                }
+                cmd("include")("${vcpkg_SOURCE_DIR}/scripts/buildsystems/vcpkg.cmake");
+            cmd("endif")();
         cmd("endif")();
         endl();
         // clang-format on