[PATCH 0/3] Automatically add compile_commands.json to ${S}

[PATCH 0/3] Automatically add compile_commands.json to ${S}

[Anakin Childerhose]

To better take advantage of Meson and Cmake's automatic generation of a
compile_commands.json file for the clangd language server, link the
${B}/compile_commands.json to ${S}/compile_commands.json.

I accidentally missed the initial commit which provided the
compile_commands.bbclass. This corrects the previous submission.

Anakin Childerhose (3):
  clangd: add compile_commands.bbclass
  cmake.bbclass: inherit compile_commands.bbclass
  meson.bbclass: inherit compile_commands.bbclass

 meta/classes-recipe/cmake.bbclass            |  2 ++
 meta/classes-recipe/compile_commands.bbclass | 18 ++++++++++++++++++
 meta/classes-recipe/meson.bbclass            |  2 +-
 3 files changed, 21 insertions(+), 1 deletion(-)
 create mode 100644 meta/classes-recipe/compile_commands.bbclass

--
2.50.1

[PATCH 1/3] clangd: add compile_commands.bbclass

[Anakin Childerhose]

Add a class to link the ${B}/compile_commands.json file to
${S}/compile_commands.json to automatically configure the clangd
language server for build systems that generate a compile_commands.json
file.

Signed-off-by: Anakin Childerhose <anakin@childerhose.ca>
---
 meta/classes-recipe/compile_commands.bbclass | 18 ++++++++++++++++++
 1 file changed, 18 insertions(+)
 create mode 100644 meta/classes-recipe/compile_commands.bbclass

diff --git a/meta/classes-recipe/compile_commands.bbclass b/meta/classes-recipe/compile_commands.bbclass
new file mode 100644
index 0000000000..da8795647c
--- /dev/null
+++ b/meta/classes-recipe/compile_commands.bbclass
@@ -0,0 +1,18 @@
+#
+# Copyright Anakin Childerhose
+#
+# SPDX-License-Identifier: MIT
+#
+
+do_generate_compile_commands[doc] = "Add compile_commands.json to S for clangd language server"
+do_generate_compile_commands() {
+    if ! [ -f "${B}/compile_commands.json" ]; then
+        bbwarn "no compile_commands.json found"
+        return
+    fi
+
+    ln -sf ${B}/compile_commands.json ${S}/compile_commands.json || {
+        bbwarn "failed to link compile_commands.json to \${S}"
+    }
+}
+addtask generate_compile_commands after do_compile
-- 
2.50.1

Re: [OE-core] [PATCH 1/3] clangd: add compile_commands.bbclass

[Alexander Kanavin]

On Sun, 3 Aug 2025 at 03:04, Anakin Childerhose via
lists.openembedded.org <anakin=childerhose.ca@lists.openembedded.org>
wrote:
> Add a class to link the ${B}/compile_commands.json file to
> ${S}/compile_commands.json to automatically configure the clangd
> language server for build systems that generate a compile_commands.json
> file.

I don't understand this description. What does this json file do, what
does clangd language server do, why can't it find the original file in
${S} and should that be fixed instead? Having different directories
for source and build artefacts is common, and we shouldn't be fixing
it up for others.

Alex

Re: [OE-core] [PATCH 1/3] clangd: add compile_commands.bbclass

[Khem Raj]

On 8/4/25 3:42 AM, Alexander Kanavin via lists.openembedded.org wrote:
> On Sun, 3 Aug 2025 at 03:04, Anakin Childerhose via
> lists.openembedded.org <anakin=childerhose.ca@lists.openembedded.org>
> wrote:
>> Add a class to link the ${B}/compile_commands.json file to
>> ${S}/compile_commands.json to automatically configure the clangd
>> language server for build systems that generate a compile_commands.json
>> file.
> 
> I don't understand this description. What does this json file do, what
> does clangd language server do,

It will be good to summarize that it implements LSP for C/C++ and 
reference to https://microsoft.github.io/language-server-protocol/

  why can't it find the original file in
> ${S} and should that be fixed instead? Having different directories
> for source and build artefacts is common, and we shouldn't be fixing
> it up for others.
> 

Clangd tries several search paths in S and B as well, but perhaps
something is unique about OE build structure that it is not able to
find it ?

clangd has --compile-commands-dir=<...> option which might be of 
interest here

Aside from this, I think it will be good to add 
-DCMAKE_EXPORT_COMPILE_COMMANDS=ON via cmake.bbclass if someone wants
LSP at distro level.

> Alex
> 
> 
> 
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[PATCH 2/3] cmake.bbclass: inherit compile_commands.bbclass

[Anakin Childerhose]

cmake.bbclass generates a compile_commands.json file by default in ${B}.
To automatically configure the clangd language server, link the
compile_commands.json file to ${S} via compile_commands.bbclass.

Signed-off-by: Anakin Childerhose <anakin@childerhose.ca>
---
 meta/classes-recipe/cmake.bbclass | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/meta/classes-recipe/cmake.bbclass b/meta/classes-recipe/cmake.bbclass
index 1488d744d4..2da4a9a6c5 100644
--- a/meta/classes-recipe/cmake.bbclass
+++ b/meta/classes-recipe/cmake.bbclass
@@ -4,6 +4,8 @@
 # SPDX-License-Identifier: MIT
 #
 
+inherit compile_commands
+
 # Path to the CMake file to process.
 OECMAKE_SOURCEPATH ??= "${S}"
 
-- 
2.50.1

[PATCH 3/3] meson.bbclass: inherit compile_commands.bbclass

[Anakin Childerhose]

meson.bbclass generates a compile_commands.json file by default in ${B}.
To automatically configure the clangd language server, link the
compile_commands.json file to ${S} via compile_commands.bbclass.

Signed-off-by: Anakin Childerhose <anakin@childerhose.ca>
---
 meta/classes-recipe/meson.bbclass | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/meta/classes-recipe/meson.bbclass b/meta/classes-recipe/meson.bbclass
index c8b3e1ec29..4f5d7b9e5e 100644
--- a/meta/classes-recipe/meson.bbclass
+++ b/meta/classes-recipe/meson.bbclass
@@ -4,7 +4,7 @@
 # SPDX-License-Identifier: MIT
 #
 
-inherit python3native meson-routines qemu
+inherit python3native meson-routines qemu compile_commands
 
 DEPENDS:append = " meson-native ninja-native"
 
-- 
2.50.1