cxx-qt-build: return an Interface from CxxQtBuilder #1224

ahayzen-kdab · 2025-03-13T15:59:24Z

This is the first step towards #1125 towards a builder pattern with various stages.

codecov · 2025-03-13T16:02:03Z

Codecov Report

All modified and coverable lines are covered by tests ✅

Project coverage is 100.00%. Comparing base (a662b2e) to head (16f9f04).

Additional details and impacted files

@@            Coverage Diff            @@
##              main     #1224   +/-   ##
=========================================
  Coverage   100.00%   100.00%           
=========================================
  Files           73        73           
  Lines        12634     12634           
=========================================
  Hits         12634     12634

☔ View full report in Codecov by Sentry.
📢 Have feedback on the report? Share it here.

🚀 New features to boost your workflow:

❄️ Test Analytics: Detect flaky tests, report on failures, and find test suite problems.

ahayzen-kdab · 2025-03-13T16:03:05Z

crates/cxx-qt/build.rs

+    // TODO: should we even have this ? Instead pass in an include_directory to our
+    // builder that handles this?
+    // As they are first being copied to the OUT_DIR/include/<crate> and then
+    // to the target/cxx-qt-build/../include
+    //
+    // This then causes problems because we try to symlink this dir now after
+    // the CXX files are written already


@LeonMatthesKDAB lets discuss this and the general way that we should handle how we have include dirs that use files from the source directory + have generated files (so is not as simple as a symlink). And whether there should be a default include dir already or not 🤔

I note that in the CXX tutorials ( https://cxx.rs/tutorial.html ) they have the following

#include "cxx-demo/include/blobstore.h" #include "cxx-demo/src/main.rs.h"

For CXX the crate is already added as an include directory and the other folder is target/cxxbridge/cxx-demo/src/main.rs.h.

I wonder if we can do similar and use the fact that rust files are (always?) under src/ ? As we could instead have

my-crate/ include/ myheader.h src/ rustmod.rs

Then have in the export target folder

exporttarget/ my-crate/ include/ -- symlink to the my-crate/include/ (which avoids the current copy we always do) src/ -- where the generated files are written?

But probably needs more thought about how we can avoid collisions and if we can avoid a copy of the include like we do currently or not 🤔

Here's the notes from todays call:

include/ my_crate/ - include/ - my_header.hpp <-- copied over from crate source - src/ - my_bridge.rs // <-- actually a header file generated from the bridge - my_bridge.rs.h // <-- actually a header file generated from the bridge - my_bridge.rs.cxx.h // <-- actually a header file generated from the bridge upstream_crate/ <-- ??? // CXX-Qt behavior (OUT_DIR) include/ <--- include_dir cxx-qt-lib/ src/core/ - qobject.rs ---> .cxxqt.h - qobject.rs.cxxqt.h - qobject.rs.cxx.h include/ <-- copied from crate dir (same as CXX does see: best_effort_copy_headers)) ... include!(cxx-qt-lib/include/qstring.h); vvvvvvv include_dir crates/cxx-qt-lib/include/cxx-qt-lib/qstring.h crates-include/ <-- this is added as an include_dir - cxx-qt-lib -> source of cxx-qt-lib - cxx-qt -> Source of cxx-qt - my-crate -> source of my-crate

The important point was to separate the downstream dependencies header dirs from the header dirs provided by the current crate.
Then you can manually separately override which dependencies to re-export, and which of the include dirs to export for the current crate.

ahayzen-kdab · 2025-04-18T14:57:44Z

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

@@ -121,6 +121,10 @@ pub(crate) fn header_root() -> PathBuf {
    crate_target().join("include")
 }

+pub(crate) fn header_root_interface() -> PathBuf {
+    target().join("crates-include")


probably want a better name like export-include and sort out various naming across the codebase

This still needs more refactoring later but is a first step.

This allows export() to have no args meaning we can return an Interface from the compile command next.

LeonMatthesKDAB

This seems to be going in the right direction, but some concepts around where which include dir is defined still require working out.

LeonMatthesKDAB · 2025-04-22T14:50:05Z

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

+        .collect()
+}
+
+fn reexported_dependencies(interface: &Interface, dependencies: &[Dependency]) -> Vec<Dependency> {


This should be in impl Interface, no?
Same with all_include_prefix.

Could be, this has just moved the existing code :-)

LeonMatthesKDAB · 2025-04-22T14:53:56Z

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

+            .expect("Failed to convert Manifest to JSON!");
+        std::fs::write(&manifest_path, manifest_json).expect("Failed to write manifest.json!");
+        println!(
+            "cargo::metadata=CXX_QT_MANIFEST_PATH={}",


This assumes we have a links key set, right?
We should probably panic if it isn't the case here.
However, then we'd have to check whether we're currently exporting to CMake, as then it's not needed.

A few lines further up (at the start of this export() function) we panic if the link name is empty?

LeonMatthesKDAB · 2025-04-22T14:58:13Z

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

-        let mut this = Self::new();
-        this.public_interface = Some(interface_definition);
-
+    pub fn library() -> Self {


This method won't really be necessary here anymore, right?

The Interface in the end defines whether the project is re-exported or not, at which point it should also check whether the links key is set.

Right i'll see if this can be removed now...

LeonMatthesKDAB · 2025-04-22T15:02:40Z

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

@@ -1134,6 +1083,17 @@ extern "C" bool {init_fun}() {{
        // to the generated files without any namespacing.
        include_paths.push(header_root.join(&self.include_prefix));

+        // Automatically add any include/ directory from the cargo manifest dir


This will mean any directory named include/ will be available directly without prefix, right?

e.g. something like this:

include/test.h Cargo.toml

Will mean it'll be possible to do:

#include <test.h>

I think CXX behavior was to have this available as:

#include <my_crate/include/test.h>

I think to specify certain include directories we wanted to add an include function that sets up the right include path with the given prefix and is passed to the Interface, right?

We possibly need to

copy CXX and add any headers relative to the manifest dir to the header root (OUT/include) under crate name (so includes become crate/include/header.h)

one of the functions allows for copying things from header root to exported headers (OUT/crate-include)

Note that we currently rename to eg cxx-qt-lib/qstring.h instead of cxx-qt-lib/include/core/qstring.h, however we now have the problem of how do these headers include other the common.h as within the build they are at cxx-qt-lib/include/common.h but when exported they are now at cxx-qt-lib/common.h. Should we instead not perform our renaming and force the developer to create a clean input ? For cxx-qt-lib this would mean you copy/write the headers into the structure you want inside the OUT dir and then manually add that to CxxQtBuilder rather than using the automatic relative manifest include. For other crates that don't need this functionality they can use the automatic relative manifest include.

ahayzen-kdab commented Mar 13, 2025

View reviewed changes

ahayzen-kdab force-pushed the 1125-build-system-changes branch from dbe3464 to 08febd9 Compare March 13, 2025 17:14

ahayzen-kdab force-pushed the 1125-build-system-changes branch from 08febd9 to 5f8f83d Compare April 18, 2025 11:03

ahayzen-kdab commented Apr 18, 2025

View reviewed changes

ahayzen-kdab force-pushed the 1125-build-system-changes branch 2 times, most recently from e7141dd to d5ab884 Compare April 21, 2025 11:33

ahayzen-kdab added 5 commits April 22, 2025 08:39

cxx-qt-build: split interface into a separate file

e0a7d10

cxx-qt-build: move write_manifest to export of Interface

73462c9

This still needs more refactoring later but is a first step.

cxx-qt-build: move write of exported include directories to interface

08ae5f7

cxx-qt-build: store manifest and dependencies in Interface for now

e38866b

This allows export() to have no args meaning we can return an Interface from the compile command next.

cxx-qt-build: return an Interface rather than taking as input

b138245

ahayzen-kdab force-pushed the 1125-build-system-changes branch 2 times, most recently from e7ce493 to a690dc8 Compare April 22, 2025 08:09

ahayzen-kdab added 2 commits April 22, 2025 09:34

cxx-qt-build: check the links key when exporting

141be4c

cxx-qt-build: split include and exported include dirs

ba76e47

ahayzen-kdab force-pushed the 1125-build-system-changes branch from a690dc8 to 24e624b Compare April 22, 2025 09:44

WIP: cxx-qt-build: include headers directory manually

fb6ff0f

ahayzen-kdab force-pushed the 1125-build-system-changes branch from 24e624b to fb6ff0f Compare April 22, 2025 10:44

ahayzen-kdab marked this pull request as ready for review April 22, 2025 12:49

LeonMatthesKDAB reviewed Apr 22, 2025

View reviewed changes

cxx-qt-build: remove CxxQtBuilder::library instead use new and export

16f9f04

ahayzen-kdab force-pushed the 1125-build-system-changes branch from 4bdf78f to 16f9f04 Compare April 22, 2025 17:18

Provide feedback

Saved searches

Use saved searches to filter your results more quickly

cxx-qt-build: return an Interface from CxxQtBuilder #1224

cxx-qt-build: return an Interface from CxxQtBuilder #1224

ahayzen-kdab commented Mar 13, 2025

codecov bot commented Mar 13, 2025 •

edited

Loading

ahayzen-kdab Mar 13, 2025

ahayzen-kdab Mar 13, 2025

LeonMatthesKDAB Mar 20, 2025

ahayzen-kdab Apr 18, 2025

LeonMatthesKDAB left a comment

LeonMatthesKDAB Apr 22, 2025

ahayzen-kdab Apr 22, 2025

LeonMatthesKDAB Apr 22, 2025

ahayzen-kdab Apr 22, 2025

LeonMatthesKDAB Apr 22, 2025

ahayzen-kdab Apr 22, 2025

LeonMatthesKDAB Apr 22, 2025

LeonMatthesKDAB Apr 22, 2025

ahayzen-kdab Apr 22, 2025

cxx-qt-build: return an Interface from CxxQtBuilder #1224

Are you sure you want to change the base?

cxx-qt-build: return an Interface from CxxQtBuilder #1224

Conversation

ahayzen-kdab commented Mar 13, 2025

codecov bot commented Mar 13, 2025 • edited Loading

Codecov Report

Choose a reason for hiding this comment

Choose a reason for hiding this comment

Choose a reason for hiding this comment

Choose a reason for hiding this comment

LeonMatthesKDAB left a comment

Choose a reason for hiding this comment

Choose a reason for hiding this comment

Choose a reason for hiding this comment

Choose a reason for hiding this comment

Choose a reason for hiding this comment

Choose a reason for hiding this comment

Choose a reason for hiding this comment

Choose a reason for hiding this comment

Choose a reason for hiding this comment

Choose a reason for hiding this comment

codecov bot commented Mar 13, 2025 •

edited

Loading