automatically parallelize C/C++ cmake builds

.emacs

@@ -126,6 +126,10 @@
 
 	;; Enable recursive minibuffers
 	(setq enable-recursive-minibuffers t)
+
+	(defconst atu/numprocs
+		(string-to-number (shell-command-to-string "nproc"))
+		"The number of processor on the system")
 	)
 
 
@@ -630,8 +634,8 @@
 	(projectile-register-project-type 'cmake-cc #'atu/cmake-cc-inference
 		:project-file "CMakeLists.txt"
 		:configure "cmake -S . -B build -DCMAKE_EXPORT_COMPILE_COMMANDS=On"
-		:compile "cmake --build build"
-		:test "cmake --build build --target check"
+		:compile (format "cmake --build build -j %d" atu/numprocs)
+		:test (format "cmake --build build -j %d --target check" atu/numprocs)
 		:related-files-fn
 		(list
 			#'atu/cc-related-files