libcamera/base: Validate internal headers as private

Headers which must not be exposed as part of the public libcamera API
should include base/private.h.

Any interface which includes the private.h header will only be able to
build if the libcamera_private dependency is used (or the
libcamera_base_private dependency directly).

Build targets which are intended to use the private API's will use the
libcamera_private to handle the automatic definition of the inclusion
guard.

Reviewed-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Signed-off-by: Kieran Bingham <kieran.bingham@ideasonboard.com>

10 files changed, 24 insertions, 9 deletions

diff --git a/src/android/meson.build b/src/android/meson.build
index bd58ef96..7d1e7e85 100644
--- a/src/android/meson.build
+++ b/src/android/meson.build
@@ -4,7 +4,7 @@ android_deps = [
     dependency('libexif', required : get_option('android')),
     dependency('libjpeg', required : get_option('android')),
     dependency('yaml-0.1', required : get_option('android')),
-    libcamera_dep,
+    libcamera_private,
 ]
 
 android_enabled = true
diff --git a/src/ipa/ipu3/meson.build b/src/ipa/ipu3/meson.build
index 0d843846..b6364190 100644
--- a/src/ipa/ipu3/meson.build
+++ b/src/ipa/ipu3/meson.build
@@ -12,7 +12,7 @@ mod = shared_module(ipa_name,
                     [ipu3_ipa_sources, libcamera_generated_ipa_headers],
                     name_prefix : '',
                     include_directories : [ipa_includes, libipa_includes],
-                    dependencies : libcamera_dep,
+                    dependencies : libcamera_private,
                     link_with : libipa,
                     install : true,
                     install_dir : ipa_install_dir)
diff --git a/src/ipa/libipa/meson.build b/src/ipa/libipa/meson.build
index 038fc490..ca541a5a 100644
--- a/src/ipa/libipa/meson.build
+++ b/src/ipa/libipa/meson.build
@@ -14,4 +14,4 @@ libipa_includes = include_directories('..')
 
 libipa = static_library('ipa', [libipa_sources, libipa_headers],
                         include_directories : ipa_includes,
-                        dependencies : libcamera_dep)
+                        dependencies : libcamera_private)
diff --git a/src/ipa/raspberrypi/meson.build b/src/ipa/raspberrypi/meson.build
index 230356d3..d7203aa0 100644
--- a/src/ipa/raspberrypi/meson.build
+++ b/src/ipa/raspberrypi/meson.build
@@ -3,7 +3,7 @@
 ipa_name = 'ipa_rpi'
 
 rpi_ipa_deps = [
-    libcamera_dep,
+    libcamera_private,
     dependency('boost'),
     libatomic,
 ]
diff --git a/src/ipa/rkisp1/meson.build b/src/ipa/rkisp1/meson.build
index 1a1c7159..f76b37f5 100644
--- a/src/ipa/rkisp1/meson.build
+++ b/src/ipa/rkisp1/meson.build
@@ -6,7 +6,7 @@ mod = shared_module(ipa_name,
                     ['rkisp1.cpp', libcamera_generated_ipa_headers],
                     name_prefix : '',
                     include_directories : [ipa_includes, libipa_includes],
-                    dependencies : libcamera_dep,
+                    dependencies : libcamera_private,
                     link_with : libipa,
                     install : true,
                     install_dir : ipa_install_dir)
diff --git a/src/ipa/vimc/meson.build b/src/ipa/vimc/meson.build
index a35825ae..ecbeee13 100644
--- a/src/ipa/vimc/meson.build
+++ b/src/ipa/vimc/meson.build
@@ -6,7 +6,7 @@ mod = shared_module(ipa_name,
                     ['vimc.cpp', libcamera_generated_ipa_headers],
                     name_prefix : '',
                     include_directories : [ipa_includes, libipa_includes],
-                    dependencies : libcamera_dep,
+                    dependencies : libcamera_private,
                     link_with : libipa,
                     install : true,
                     install_dir : ipa_install_dir)
diff --git a/src/libcamera/base/meson.build b/src/libcamera/base/meson.build
index a8b04cfc..87172157 100644
--- a/src/libcamera/base/meson.build
+++ b/src/libcamera/base/meson.build
@@ -21,10 +21,15 @@ libcamera_base_deps = [
     dependency('threads'),
 ]
 
+# Internal components must use the libcamera_base_private dependency to enable
+# the use of headers which must not be exposed to the libcamera public api.
+libcamera_base_args = [ '-DLIBCAMERA_BASE_PRIVATE' ]
+
 libcamera_base_lib = shared_library('libcamera-base',
                                     [libcamera_base_sources, libcamera_base_headers],
                                     name_prefix : '',
                                     install : true,
+                                    cpp_args : libcamera_base_args,
                                     include_directories : libcamera_includes,
                                     dependencies : libcamera_base_deps)
 
@@ -39,3 +44,6 @@ pkg_mod.generate(libcamera_base_lib,
                  version : '1.0',
                  description : 'Camera support base utility library',
                  subdirs : 'libcamera')
+
+libcamera_base_private = declare_dependency(dependencies : libcamera_base,
+                                            compile_args : libcamera_base_args)
diff --git a/src/libcamera/meson.build b/src/libcamera/meson.build
index e0c47352..ebd37e06 100644
--- a/src/libcamera/meson.build
+++ b/src/libcamera/meson.build
@@ -112,6 +112,7 @@ endif
 libcamera_deps = [
     libatomic,
     libcamera_base,
+    libcamera_base_private,
     libdl,
     libgnutls,
     liblttng,
@@ -143,9 +144,15 @@ libcamera_dep = declare_dependency(sources : [
                                        libcamera_generated_ipa_headers,
                                    ],
                                    include_directories : libcamera_includes,
-                                   dependencies: libcamera_base,
+                                   dependencies : libcamera_base,
                                    link_with : libcamera)
 
+# Internal dependency for components and plugins which can use private APIs
+libcamera_private = declare_dependency(dependencies : [
+                                           libcamera_dep,
+                                           libcamera_base_private,
+                                       ])
+
 pkg_mod = import('pkgconfig')
 pkg_mod.generate(libcamera,
                  libraries : libcamera_base_lib,
diff --git a/src/libcamera/proxy/worker/meson.build b/src/libcamera/proxy/worker/meson.build
index 28fe5f1f..70c8760a 100644
--- a/src/libcamera/proxy/worker/meson.build
+++ b/src/libcamera/proxy/worker/meson.build
@@ -21,7 +21,7 @@ foreach mojom : ipa_mojoms
                        [worker, libcamera_generated_ipa_headers],
                        install : true,
                        install_dir : proxy_install_dir,
-                       dependencies : libcamera_dep)
+                       dependencies : libcamera_private)
 endforeach
 
 config_h.set('IPA_PROXY_DIR',
diff --git a/src/v4l2/meson.build b/src/v4l2/meson.build
index 0accac19..f78497b6 100644
--- a/src/v4l2/meson.build
+++ b/src/v4l2/meson.build
@@ -31,5 +31,5 @@ v4l2_compat = shared_library('v4l2-compat',
                              v4l2_compat_sources,
                              name_prefix : '',
                              install : true,
-                             dependencies : [libcamera_dep, libdl],
+                             dependencies : [libcamera_private, libdl],
                              cpp_args : v4l2_compat_cpp_args)