cxx-qt-lib: keep headers split otherwise Windows fails to build

When cxx-qt-lib is a build dependency we have a failure with
a missing dll.

Author: ahayzen-kdab

Cargo.toml

@@ -9,6 +9,7 @@ members = [
     "crates/cxx-qt-build",
     "crates/cxx-qt-gen",
     "crates/cxx-qt-lib",
+    "crates/cxx-qt-lib-headers",
     "crates/qt-build-utils",
 
     "examples/cargo_without_cmake",
@@ -36,6 +37,7 @@ cxx-qt-macro = { path = "crates/cxx-qt-macro", version = "0.6.0" }
 cxx-qt-build = { path = "crates/cxx-qt-build" }
 cxx-qt-gen = { path = "crates/cxx-qt-gen", version = "0.6.0" }
 cxx-qt-lib = { path = "crates/cxx-qt-lib" }
+cxx-qt-lib-headers = { path = "crates/cxx-qt-lib-headers", version = "0.6.0" }
 qt-build-utils = { path = "crates/qt-build-utils", version = "0.6.0" }
 
 cc = { version = "1.0.86", features = ["parallel"] }

crates/cxx-qt-lib-headers/Cargo.toml

@@ -0,0 +1,20 @@
+# SPDX-FileCopyrightText: 2022 Klarälvdalens Datakonsult AB, a KDAB Group company <[email protected]>
+# SPDX-FileContributor: Be Wilson <[email protected]>
+#
+# SPDX-License-Identifier: MIT OR Apache-2.0
+[package]
+name = "cxx-qt-lib-headers"
+version.workspace = true
+authors = ["Andrew Hayzen <[email protected]>", "Be Wilson <[email protected]>"]
+edition.workspace = true
+license.workspace = true
+description = "A small crate for cxx-qt-lib and cxx-qt-build to share cxx-qt-lib's C++ headers"
+repository.workspace = true
+
+[features]
+default = []
+qt_gui = ["cxx-qt-build/qt_gui"]
+qt_qml = ["cxx-qt-build/qt_qml"]
+
+[dependencies]
+cxx-qt-build.workspace = true

crates/cxx-qt-lib/include/common.h renamed to crates/cxx-qt-lib-headers/include/common.h

@@ -0,0 +1,116 @@
+// SPDX-FileCopyrightText: 2022 Klarälvdalens Datakonsult AB, a KDAB Group company <[email protected]>
+// SPDX-FileContributor: Be Wilson <[email protected]>
+//
+// SPDX-License-Identifier: MIT OR Apache-2.0
+
+#![deny(missing_docs)]
+
+//! The headers for cxx-qt-lib, when combined into cxx-qt-lib crate this fails to build on Windows.
+//! The issue occurs when cxx-qt-lib is a build-dependency of an example
+
+/// Retrieves the headers for cxx-qt-lib
+///
+/// These can be passed into [cxx_qt_build::CxxQtBuilder].
+pub fn build_opts() -> cxx_qt_build::CxxQtBuildersOpts {
+    let mut opts = cxx_qt_build::CxxQtBuildersOpts::default();
+
+    for (file_contents, file_name) in [
+        (include_str!("../include/core/qbytearray.h"), "qbytearray.h"),
+        (
+            include_str!("../include/core/qcoreapplication.h"),
+            "qcoreapplication.h",
+        ),
+        (include_str!("../include/core/qdate.h"), "qdate.h"),
+        (include_str!("../include/core/qdatetime.h"), "qdatetime.h"),
+        (include_str!("../include/core/qhash.h"), "qhash.h"),
+        (include_str!("../include/core/qline.h"), "qline.h"),
+        (include_str!("../include/core/qlinef.h"), "qlinef.h"),
+        (include_str!("../include/core/qlist.h"), "qlist.h"),
+        (
+            include_str!("../include/core/qlist_qvector.h"),
+            "qlist_qvector.h",
+        ),
+        (include_str!("../include/core/qmap.h"), "qmap.h"),
+        (include_str!("../include/core/qmargins.h"), "qmargins.h"),
+        (include_str!("../include/core/qmarginsf.h"), "qmarginsf.h"),
+        (
+            include_str!("../include/core/qmetaobjectconnection.h"),
+            "qmetaobjectconnection.h",
+        ),
+        (
+            include_str!("../include/core/qmodelindex.h"),
+            "qmodelindex.h",
+        ),
+        #[cfg(feature = "qt_gui")]
+        (include_str!("../include/gui/qpen.h"), "qpen.h"),
+        (
+            include_str!("../include/core/qpersistentmodelindex.h"),
+            "qpersistentmodelindex.h",
+        ),
+        (include_str!("../include/core/qpoint.h"), "qpoint.h"),
+        (include_str!("../include/core/qpointf.h"), "qpointf.h"),
+        (include_str!("../include/core/qrect.h"), "qrect.h"),
+        (include_str!("../include/core/qrectf.h"), "qrectf.h"),
+        (include_str!("../include/core/qset.h"), "qset.h"),
+        (include_str!("../include/core/qsize.h"), "qsize.h"),
+        (include_str!("../include/core/qsizef.h"), "qsizef.h"),
+        (include_str!("../include/core/qstring.h"), "qstring.h"),
+        (
+            include_str!("../include/core/qstringlist.h"),
+            "qstringlist.h",
+        ),
+        (include_str!("../include/core/qt.h"), "qt.h"),
+        (include_str!("../include/core/qtime.h"), "qtime.h"),
+        (include_str!("../include/core/qtimezone.h"), "qtimezone.h"),
+        (include_str!("../include/core/qurl.h"), "qurl.h"),
+        (include_str!("../include/core/qvariant.h"), "qvariant.h"),
+        (include_str!("../include/core/qvector.h"), "qvector.h"),
+        #[cfg(feature = "qt_gui")]
+        (include_str!("../include/gui/qcolor.h"), "qcolor.h"),
+        #[cfg(feature = "qt_gui")]
+        (include_str!("../include/gui/qfont.h"), "qfont.h"),
+        #[cfg(feature = "qt_gui")]
+        (
+            include_str!("../include/gui/qguiapplication.h"),
+            "qguiapplication.h",
+        ),
+        #[cfg(feature = "qt_gui")]
+        (include_str!("../include/gui/qimage.h"), "qimage.h"),
+        #[cfg(feature = "qt_gui")]
+        (include_str!("../include/gui/qpolygon.h"), "qpolygon.h"),
+        (include_str!("../include/gui/qpolygonf.h"), "qpolygonf.h"),
+        (
+            include_str!("../include/gui/qpainterpath.h"),
+            "qpainterpath.h",
+        ),
+        #[cfg(feature = "qt_gui")]
+        (include_str!("../include/gui/qpainter.h"), "qpainter.h"),
+        #[cfg(feature = "qt_gui")]
+        (include_str!("../include/gui/qvector2d.h"), "qvector2d.h"),
+        #[cfg(feature = "qt_gui")]
+        (include_str!("../include/gui/qvector3d.h"), "qvector3d.h"),
+        #[cfg(feature = "qt_gui")]
+        (include_str!("../include/gui/qvector4d.h"), "qvector4d.h"),
+        #[cfg(feature = "qt_qml")]
+        (
+            include_str!("../include/qml/qqmlapplicationengine.h"),
+            "qqmlapplicationengine.h",
+        ),
+        #[cfg(feature = "qt_qml")]
+        (include_str!("../include/qml/qqmlengine.h"), "qqmlengine.h"),
+        (include_str!("../include/common.h"), "common.h"),
+    ] {
+        opts.headers.push((
+            file_contents.to_owned(),
+            "cxx-qt-lib".to_owned(),
+            file_name.to_owned(),
+        ));
+    }
+
+    #[cfg(feature = "qt_gui")]
+    opts.defines.insert("CXX_QT_GUI_FEATURE".to_owned());
+    #[cfg(feature = "qt_qml")]
+    opts.defines.insert("CXX_QT_QML_FEATURE".to_owned());
+
+    opts
+}

crates/cxx-qt-lib/include/core/qbytearray.h renamed to crates/cxx-qt-lib-headers/include/core/qbytearray.h

@@ -19,7 +19,6 @@ exclude = [ "**/generate.sh" ]
 [dependencies]
 cxx.workspace = true
 cxx-qt.workspace = true
-cxx-qt-build.workspace = true
 bytes = { version = "1.4", optional = true }
 chrono = { version = "0.4.27", optional = true }
 http = { version = "1.0", optional = true }
@@ -29,6 +28,7 @@ url = { version = "2.3", optional = true }
 
 [build-dependencies]
 cxx-build.workspace = true
+cxx-qt-lib-headers.workspace = true
 qt-build-utils.workspace = true
 
 [features]
@@ -37,8 +37,8 @@ bytes = ["dep:bytes"]
 chrono = ["dep:chrono"]
 http = ["dep:http"]
 rgb = ["dep:rgb"]
-qt_gui = ["cxx-qt-build/qt_gui"]
-qt_qml = ["cxx-qt-build/qt_qml"]
+qt_gui = ["cxx-qt-lib-headers/qt_gui"]
+qt_qml = ["cxx-qt-lib-headers/qt_qml"]
 time = ["dep:time"]
 url = ["dep:url"]
 link_qt_object_files = ["qt-build-utils/link_qt_object_files"]

crates/cxx-qt-lib/include/core/qcoreapplication.h renamed to crates/cxx-qt-lib-headers/include/core/qcoreapplication.h

@@ -3,6 +3,8 @@
 //
 // SPDX-License-Identifier: MIT OR Apache-2.0
 
+use std::{fs::File, io::Write};
+
 fn main() {
     let feature_qt_gui_enabled = std::env::var("CARGO_FEATURE_QT_GUI").is_ok();
     let feature_qt_qml_enabled = std::env::var("CARGO_FEATURE_QT_QML").is_ok();
@@ -263,38 +265,22 @@ fn main() {
     println!("cargo:rerun-if-changed=src/qt_types.cpp");
     println!("cargo:rerun-if-changed=src/assertion_utils.h");
 
-    fn copy_dir(src: impl AsRef<std::path::Path>, dest: impl AsRef<std::path::Path>) {
-        let dest = dest.as_ref();
-        let src = src.as_ref();
-        if src.is_dir() {
-            std::fs::create_dir_all(dest).expect("could not create directory {dest}");
-            for entry in std::fs::read_dir(src).expect("could not read dir {src}") {
-                let entry = entry.expect("could not retrieve entry for dir {src}");
-                let path = entry.path();
-                let file_name = entry
-                    .file_name()
-                    .into_string()
-                    .expect("cannot convert OsString to String");
-                let dest = dest.display();
-                if path.is_file() {
-                    std::fs::copy(path, format!("{dest}/{file_name}"))
-                        .expect("could not copy {path}");
-                }
-            }
-        }
-    }
-
     // Write this library's manually written C++ headers to files and add them to include paths
-    let include_out_dir = format!("{}/include", std::env::var("OUT_DIR").unwrap());
-    copy_dir("include/core", format!("{include_out_dir}/cxx-qt-lib"));
-    copy_dir("include/gui", format!("{include_out_dir}/cxx-qt-lib"));
-    copy_dir("include/qml", format!("{include_out_dir}/cxx-qt-lib"));
-    std::fs::copy(
-        "include/common.h",
-        format!("{include_out_dir}/cxx-qt-lib/common.h"),
-    )
-    .expect("could not copy common.h");
-    builder.include(include_out_dir);
+    let header_root = format!("{}/include", std::env::var("OUT_DIR").unwrap());
+    for (file_contents, dir_name, file_name) in cxx_qt_lib_headers::build_opts().headers {
+        let directory = if dir_name.is_empty() {
+            header_root.clone()
+        } else {
+            format!("{header_root}/{dir_name}")
+        };
+        std::fs::create_dir_all(directory.clone())
+            .expect("Could not create {directory} header directory");
+
+        let h_path = format!("{directory}/{file_name}");
+        let mut header = File::create(h_path).expect("Could not create header: {h_path}");
+        write!(header, "{file_contents}").expect("Could not write header: {h_path}");
+    }
+    builder.include(header_root);
 
     // Enable Qt Gui in C++ if the feature is enabled
     if feature_qt_gui_enabled {

crates/cxx-qt-lib/include/core/qdate.h renamed to crates/cxx-qt-lib-headers/include/core/qdate.h

@@ -20,110 +20,3 @@ pub use crate::gui::*;
 mod qml;
 #[cfg(feature = "qt_qml")]
 pub use crate::qml::*;
-
-/// Retrieves the headers for cxx-qt-lib
-///
-/// These can be passed into [cxx_qt_build::CxxQtBuilder].
-pub fn build_opts() -> cxx_qt_build::CxxQtBuildersOpts {
-    let mut opts = cxx_qt_build::CxxQtBuildersOpts::default();
-
-    for (file_contents, file_name) in [
-        (include_str!("../include/core/qbytearray.h"), "qbytearray.h"),
-        (
-            include_str!("../include/core/qcoreapplication.h"),
-            "qcoreapplication.h",
-        ),
-        (include_str!("../include/core/qdate.h"), "qdate.h"),
-        (include_str!("../include/core/qdatetime.h"), "qdatetime.h"),
-        (include_str!("../include/core/qhash.h"), "qhash.h"),
-        (include_str!("../include/core/qline.h"), "qline.h"),
-        (include_str!("../include/core/qlinef.h"), "qlinef.h"),
-        (include_str!("../include/core/qlist.h"), "qlist.h"),
-        (
-            include_str!("../include/core/qlist_qvector.h"),
-            "qlist_qvector.h",
-        ),
-        (include_str!("../include/core/qmap.h"), "qmap.h"),
-        (include_str!("../include/core/qmargins.h"), "qmargins.h"),
-        (include_str!("../include/core/qmarginsf.h"), "qmarginsf.h"),
-        (
-            include_str!("../include/core/qmetaobjectconnection.h"),
-            "qmetaobjectconnection.h",
-        ),
-        (
-            include_str!("../include/core/qmodelindex.h"),
-            "qmodelindex.h",
-        ),
-        #[cfg(feature = "qt_gui")]
-        (include_str!("../include/gui/qpen.h"), "qpen.h"),
-        (
-            include_str!("../include/core/qpersistentmodelindex.h"),
-            "qpersistentmodelindex.h",
-        ),
-        (include_str!("../include/core/qpoint.h"), "qpoint.h"),
-        (include_str!("../include/core/qpointf.h"), "qpointf.h"),
-        (include_str!("../include/core/qrect.h"), "qrect.h"),
-        (include_str!("../include/core/qrectf.h"), "qrectf.h"),
-        (include_str!("../include/core/qset.h"), "qset.h"),
-        (include_str!("../include/core/qsize.h"), "qsize.h"),
-        (include_str!("../include/core/qsizef.h"), "qsizef.h"),
-        (include_str!("../include/core/qstring.h"), "qstring.h"),
-        (
-            include_str!("../include/core/qstringlist.h"),
-            "qstringlist.h",
-        ),
-        (include_str!("../include/core/qt.h"), "qt.h"),
-        (include_str!("../include/core/qtime.h"), "qtime.h"),
-        (include_str!("../include/core/qtimezone.h"), "qtimezone.h"),
-        (include_str!("../include/core/qurl.h"), "qurl.h"),
-        (include_str!("../include/core/qvariant.h"), "qvariant.h"),
-        (include_str!("../include/core/qvector.h"), "qvector.h"),
-        #[cfg(feature = "qt_gui")]
-        (include_str!("../include/gui/qcolor.h"), "qcolor.h"),
-        #[cfg(feature = "qt_gui")]
-        (include_str!("../include/gui/qfont.h"), "qfont.h"),
-        #[cfg(feature = "qt_gui")]
-        (
-            include_str!("../include/gui/qguiapplication.h"),
-            "qguiapplication.h",
-        ),
-        #[cfg(feature = "qt_gui")]
-        (include_str!("../include/gui/qimage.h"), "qimage.h"),
-        #[cfg(feature = "qt_gui")]
-        (include_str!("../include/gui/qpolygon.h"), "qpolygon.h"),
-        (include_str!("../include/gui/qpolygonf.h"), "qpolygonf.h"),
-        (
-            include_str!("../include/gui/qpainterpath.h"),
-            "qpainterpath.h",
-        ),
-        #[cfg(feature = "qt_gui")]
-        (include_str!("../include/gui/qpainter.h"), "qpainter.h"),
-        #[cfg(feature = "qt_gui")]
-        (include_str!("../include/gui/qvector2d.h"), "qvector2d.h"),
-        #[cfg(feature = "qt_gui")]
-        (include_str!("../include/gui/qvector3d.h"), "qvector3d.h"),
-        #[cfg(feature = "qt_gui")]
-        (include_str!("../include/gui/qvector4d.h"), "qvector4d.h"),
-        #[cfg(feature = "qt_qml")]
-        (
-            include_str!("../include/qml/qqmlapplicationengine.h"),
-            "qqmlapplicationengine.h",
-        ),
-        #[cfg(feature = "qt_qml")]
-        (include_str!("../include/qml/qqmlengine.h"), "qqmlengine.h"),
-        (include_str!("../include/common.h"), "common.h"),
-    ] {
-        opts.headers.push((
-            file_contents.to_owned(),
-            "cxx-qt-lib".to_owned(),
-            file_name.to_owned(),
-        ));
-    }
-
-    #[cfg(feature = "qt_gui")]
-    opts.defines.insert("CXX_QT_GUI_FEATURE".to_owned());
-    #[cfg(feature = "qt_qml")]
-    opts.defines.insert("CXX_QT_QML_FEATURE".to_owned());
-
-    opts
-}

crates/cxx-qt-lib/include/core/qdatetime.h renamed to crates/cxx-qt-lib-headers/include/core/qdatetime.h

@@ -31,5 +31,5 @@ cxx-qt-lib.workspace = true
 # Use `cxx-qt-build = "0.6"` here instead!
 # The link_qt_object_files feature is required for statically linking Qt 6.
 cxx-qt-build = { workspace = true, features = [ "link_qt_object_files" ] }
-# Use `cxx-qt-lib = "0.6"` here instead!
-cxx-qt-lib.workspace = true
+# Use `cxx-qt-lib-headers = "0.6"` here instead!
+cxx-qt-lib-headers.workspace = true

crates/cxx-qt-lib/include/core/qhash.h renamed to crates/cxx-qt-lib-headers/include/core/qhash.h

@@ -20,7 +20,7 @@ fn main() {
             qml_files: &["qml/main.qml"],
             ..Default::default()
         })
-        .with_opts(cxx_qt_lib::build_opts())
+        .with_opts(cxx_qt_lib_headers::build_opts())
         .build();
 }
 // ANCHOR_END: book_cargo_executable_build_rs

crates/cxx-qt-lib/include/core/qline.h renamed to crates/cxx-qt-lib-headers/include/core/qline.h

@@ -25,7 +25,7 @@ uuid = { version = "1.2", features = ["serde", "v4"] }
 
 [build-dependencies]
 cxx-qt-build.workspace = true
-cxx-qt-lib.workspace = true
+cxx-qt-lib-headers.workspace = true
 
 [features]
 link_qt_object_files = [ "cxx-qt-build/link_qt_object_files" ]

crates/cxx-qt-lib/include/core/qlinef.h renamed to crates/cxx-qt-lib-headers/include/core/qlinef.h

@@ -46,6 +46,6 @@ fn main() {
             ],
             ..Default::default()
         })
-        .with_opts(cxx_qt_lib::build_opts())
+        .with_opts(cxx_qt_lib_headers::build_opts())
         .build();
 }

crates/cxx-qt-lib/include/core/qlist.h renamed to crates/cxx-qt-lib-headers/include/core/qlist.h

@@ -22,7 +22,7 @@ serde_json.workspace = true
 
 [build-dependencies]
 cxx-qt-build.workspace = true
-cxx-qt-lib.workspace = true
+cxx-qt-lib-headers.workspace = true
 
 [features]
 link_qt_object_files = [ "cxx-qt-build/link_qt_object_files" ]