[bug#70031] [core-updates PATCH 02/19] build-system/cmake: Parameterize build system generator.

[Greg Hogan <code@greghogan.com>]

* guix/build-system/cmake.scm (cmake-build): Add generator parameter
defaulted to the default CMake build system generator.
* guix/build/cmake-build-system.scm (configure): Add and use generator
parameter to configure the build system.
* doc/guix.texi (Build Systems): Document #:generator for
cmake-build-system.
---
 doc/guix.texi                     | 4 ++++
 guix/build-system/cmake.scm       | 4 ++++
 guix/build/cmake-build-system.scm | 5 ++++-
 3 files changed, 12 insertions(+), 1 deletion(-)

diff --git a/doc/guix.texi b/doc/guix.texi
index ddd98a5fd46..782893b4f23 100644
--- a/doc/guix.texi
+++ b/doc/guix.texi
@@ -9623,6 +9623,10 @@ Build Systems
 it defaults to @code{"RelWithDebInfo"} (short for ``release mode with
 debugging information''), which roughly means that code is compiled with
 @code{-O2 -g}, as is the case for Autoconf-based packages by default.
+The @code{#:generator} parameter configures the native build system; it
+defaults to @code{"Unix Makefiles"} and can be changed to an alternative
+such as @code{Ninja} (the alternative generator must be available as
+both a module and native input).
 @end defvar
 
 @defvar composer-build-system
diff --git a/guix/build-system/cmake.scm b/guix/build-system/cmake.scm
index aa187c9844b..a4d69276748 100644
--- a/guix/build-system/cmake.scm
+++ b/guix/build-system/cmake.scm
@@ -101,6 +101,7 @@ (define* (cmake-build name inputs
                       (search-paths '())
                       (make-flags ''())
                       (out-of-source? #t)
+                      (generator "Unix Makefiles")
                       (build-type "RelWithDebInfo")
                       (tests? #t)
                       (test-target "test")
@@ -140,6 +141,7 @@ (define* (cmake-build name inputs
                                                      configure-flags)
                              #:make-flags #$make-flags
                              #:out-of-source? #$out-of-source?
+                             #:generator #$generator
                              #:build-type #$build-type
                              #:tests? #$tests?
                              #:test-target #$test-target
@@ -177,6 +179,7 @@ (define* (cmake-cross-build name
                             (native-search-paths '())
                             (make-flags ''())
                             (out-of-source? #t)
+                            (generator "Unix Makefiles")
                             (build-type "RelWithDebInfo")
                             (tests? #f) ; nothing can be done
                             (test-target "test")
@@ -231,6 +234,7 @@ (define* (cmake-cross-build name
                        #:configure-flags #$configure-flags
                        #:make-flags #$make-flags
                        #:out-of-source? #$out-of-source?
+                       #:generator #$generator
                        #:build-type #$build-type
                        #:tests? #$tests?
                        #:test-target #$test-target
diff --git a/guix/build/cmake-build-system.scm b/guix/build/cmake-build-system.scm
index ea342ff2ac9..1775f7a7509 100644
--- a/guix/build/cmake-build-system.scm
+++ b/guix/build/cmake-build-system.scm
@@ -34,7 +34,7 @@ (define-module (guix build cmake-build-system)
 ;; Code:
 
 (define* (configure #:key outputs (configure-flags '()) (out-of-source? #t)
-                    build-type target
+                    build-type target generator
                     #:allow-other-keys)
   "Configure the given package."
   (let* ((out        (assoc-ref outputs "out"))
@@ -50,6 +50,9 @@ (define* (configure #:key outputs (configure-flags '()) (out-of-source? #t)
     (format #t "build directory: ~s~%" (getcwd))
 
     (let ((args `(,srcdir
+                  ,@(if generator
+                        (list (string-append "-G" generator))
+                        '())
                   ,@(if build-type
                         (list (string-append "-DCMAKE_BUILD_TYPE="
                                              build-type))
-- 
2.44.0