cxx-qt-lib: use +whole_archive for std_types so that cargo-only works

CHANGELOG.md

@@ -32,6 +32,10 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
 - `#[qinvokable]` is now defined as a signature in `extern "RustQt"`
 - `rust_mut` is now safe to call
 
+### Fixed
+
+- Do not use -bundle otherwise CMake builds are missing qt-static-initalizers (note this is broken in rustc 1.69)
+
 ### Removed
 
 - Removed support for `cxx_type` and `cxx_return_type` and related conversion methods.

crates/cxx-qt-build/Cargo.toml

@@ -22,6 +22,7 @@ proc-macro2.workspace = true
 quote.workspace = true
 qt-build-utils.workspace = true
 codespan-reporting = "0.11"
+version_check = "0.9"
 
 [features]
 default = ["qt_gui", "qt_qml"]

crates/cxx-qt-build/src/lib.rs

@@ -389,12 +389,11 @@ impl CxxQtBuilder {
         // Ensure that the linker is setup correctly for Cargo builds
         qt_build_utils::setup_linker();
 
-        let out_dir = env::var("OUT_DIR").unwrap();
         // The include directory needs to be namespaced by crate name when exporting for a C++ build system,
         // but for using cargo build without a C++ build system, OUT_DIR is already namespaced by crate name.
         let header_root = match env::var("CXXQT_EXPORT_DIR") {
             Ok(export_dir) => format!("{export_dir}/{}", env::var("CARGO_PKG_NAME").unwrap()),
-            Err(_) => out_dir,
+            Err(_) => env::var("OUT_DIR").unwrap(),
         };
         let generated_header_dir = format!("{header_root}/cxx-qt-gen");
 
@@ -424,11 +423,29 @@ impl CxxQtBuilder {
         // to avoid bloating the binary.
         let mut cc_builder_whole_archive = cc::Build::new();
         cc_builder_whole_archive.link_lib_modifier("+whole-archive");
-        // Workaround for spurious compiler error in Rust 1.69. The bug has been fixed, but keeping this
-        // workaround seems to be harmless.
-        // https://github.com/rust-lang/rust/issues/110912
-        cc_builder_whole_archive.link_lib_modifier("-bundle");
+
+        // Ensure we are not using rustc 1.69
+        if let Some(version) = version_check::Version::read() {
+            let (major, minor, _) = version.to_mmp();
+            if major == 1 && minor == 69 {
+                // rustc 1.69 had a regression where +whole-archive wouldn't
+                // work without specifying -bundle.
+                // https://github.com/rust-lang/rust/pull/110917
+                //
+                // However, we need to not have -bundle for qt-static-initializers to work
+                // with CMake builds, otherwise the statement below occurs where it's missing
+                // from the final binary.
+                //
+                // When building a staticlib -bundle means that the native static library
+                // is simply not included into the archive and some higher level build
+                // system will need to add it later during linking of the final binary.
+                // https://doc.rust-lang.org/rustc/command-line-arguments.html#option-l-link-lib
+                panic!("rustc 1.69.x is not supported with CXX-Qt due to a compiler bug.\nSee: https://github.com/rust-lang/rust/pull/110917\nPlease update your compiler using 'rustup update' or use an older compiler.");
+            }
+        }
+
         for builder in [&mut self.cc_builder, &mut cc_builder_whole_archive] {
+            // Note, ensure our settings stay in sync across cxx-qt-build and cxx-qt-lib
             builder.cpp(true);
             // MSVC
             builder.flag_if_supported("/std:c++17");
@@ -506,6 +523,36 @@ impl CxxQtBuilder {
             cc_builder_whole_archive.file(qtbuild.qrc(&qrc_file));
             cc_builder_whole_archive_files_added = true;
         }
+
+        // If we are using Qt 5 then write the std_types source
+        // This registers std numbers as a type for use in QML
+        //
+        // Note that we need this to be compiled into the whole_archive builder
+        // as they are stored in statics in the source.
+        //
+        // TODO: once +whole-archive and +bundle are allowed together in rlibs
+        // we should be able to move this into cxx-qt so that it's only built
+        // once rather than for every cxx-qt-build. When this happens also
+        // ensure that in a multi project that numbers work everywhere.
+        //
+        // Also then it should be possible to use CARGO_MANIFEST_DIR/src/std_types_qt5.cpp
+        // as path for cc::Build rather than copying the .cpp file
+        //
+        // https://github.com/rust-lang/rust/issues/108081
+        // https://github.com/KDAB/cxx-qt/pull/598
+        if qtbuild.version().major == 5 {
+            let std_types_contents = include_str!("std_types_qt5.cpp");
+            let std_types_path = format!(
+                "{out_dir}/std_types_qt5.cpp",
+                out_dir = env::var("OUT_DIR").unwrap()
+            );
+            let mut source =
+                File::create(&std_types_path).expect("Could not create std_types source");
+            write!(source, "{std_types_contents}").expect("Could not write std_types source");
+            cc_builder_whole_archive.file(&std_types_path);
+            cc_builder_whole_archive_files_added = true;
+        }
+
         if cc_builder_whole_archive_files_added {
             cc_builder_whole_archive.compile("qt-static-initializers");
         }

crates/cxx-qt-lib/build.rs

@@ -232,8 +232,6 @@ fn main() {
     }
     builder.file("src/qt_types.cpp");
     println!("cargo:rerun-if-changed=src/qt_types.cpp");
-    builder.file("src/std_types.cpp");
-    println!("cargo:rerun-if-changed=src/std_types.cpp");
     println!("cargo:rerun-if-changed=src/assertion_utils.h");
 
     // Write this library's manually written C++ headers to files and add them to include paths
@@ -251,11 +249,14 @@ fn main() {
         builder.define("CXX_QT_QML_FEATURE", None);
     }
 
+    // Note, ensure our settings stay in sync across cxx-qt-build and cxx-qt-lib
+    builder.cpp(true);
     // MSVC
     builder.flag_if_supported("/std:c++17");
     builder.flag_if_supported("/Zc:__cplusplus");
     builder.flag_if_supported("/permissive-");
     // GCC + Clang
     builder.flag_if_supported("-std=c++17");
+
     builder.compile("cxx-qt-lib");
 }