cmake: create and link compile_commands.json file

CMake has support to create a json file which contains exact information
how each file in the project is compiled. This file can be consumed by
clangd, which in turn provides precise symbol information to IDEs for
better code navigation and contextual information.

I use it with vscode to be able to quickly switch between native Linux and
mingw builds and have the symbols info change dynamically with it. So
handy that I think it is useful for others as well.

Bump required CMake version for CREATE_LINK.

Change-Id: Ib14c1161b4b0c9df797b9932ad14739e202cea64
Signed-off-by: Heiko Hund <heiko@ist.eigentlich.net>
Acked-by: Frank Lichtenheld <frank@lichtenheld.com>
Message-Id: <20231220123659.55542-1-frank@lichtenheld.com>
URL: https://www.mail-archive.com/openvpn-devel@lists.sourceforge.net/msg27840.html
Signed-off-by: Gert Doering <gert@greenie.muc.de>

diff --git a/.gitignore b/.gitignore
index a1da3667223dd06e18289ab68a6c5371fd22c963..4153a3ed7d2441e16c314e825affe1744db70b30 100644 (file)
--- a/.gitignore
+++ b/.gitignore
@@ -40,6 +40,7 @@ m4/ltsugar.m4
 m4/ltversion.m4
 m4/lt~obsolete.m4
 
+compile_commands.json
 doc/openvpn-examples.5
 doc/openvpn-examples.5.html
 doc/openvpn.8

diff --git a/CMakeLists.txt b/CMakeLists.txt
index d40b213cab46f5cd579393fe1287a3cc2c2e8f86..bc46c276edf9b48842853cc649b78cc55451d928 100644 (file)
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -1,4 +1,4 @@
-cmake_minimum_required(VERSION 3.12)
+cmake_minimum_required(VERSION 3.14)
 set(CMAKE_CONFIGURATION_TYPES "Release;Debug;ASAN")
 project(openvpn)
 
@@ -42,6 +42,11 @@ option(USE_WERROR "Treat compiler warnings as errors (-Werror)" ON)
 
 set(PLUGIN_DIR /usr/local/lib/openvpn/plugins CACHE FILEPATH "Location of the plugin directory")
 
+# Create machine readable compile commands
+set(CMAKE_EXPORT_COMPILE_COMMANDS 1)
+file(CREATE_LINK ${CMAKE_CURRENT_BINARY_DIR}/compile_commands.json
+                 ${CMAKE_CURRENT_SOURCE_DIR}/compile_commands.json SYMBOLIC)
+
 # AddressSanitize - use CXX=clang++ CC=clang cmake -DCMAKE_BUILD_TYPE=asan to build with ASAN
 set(CMAKE_C_FLAGS_ASAN
     "-fsanitize=address,undefined -fno-sanitize-recover=all -fno-optimize-sibling-calls -fsanitize-address-use-after-scope -fno-omit-frame-pointer -g -O1"