CMake: Use juce_add_modules to import modules from install tree

This change means that imported juce modules will be made available both
with and without a namespace prefix, e.g. `juce_core` and
`juce::juce_core` will both be created.

This change allows custom modules to specify dependencies without a
juce:: prefix, which allows the modules to be used with the Projucer, or
under CMake with JUCE in a subdirectory, or under CMake with JUCE
installed to the system.

CMakeLists.txt

@@ -88,20 +88,22 @@ set(JUCE_INSTALL_DESTINATION "lib/cmake/JUCE-${JUCE_VERSION}" CACHE STRING
 
 install(EXPORT JUCE NAMESPACE juce:: DESTINATION "${JUCE_INSTALL_DESTINATION}")
 set(JUCE_EXPORT_FILE_NAME "JUCE.cmake")
+set(JUCE_MODULE_PATH "include/JUCE-${JUCE_VERSION}/modules")
 set(UTILS_INSTALL_DIR "${JUCE_INSTALL_DESTINATION}")
 set(JUCEAIDE_PATH "${JUCE_TOOL_INSTALL_DIR}/${JUCE_JUCEAIDE_NAME}")
 configure_package_config_file("${JUCE_CMAKE_UTILS_DIR}/JUCEConfig.cmake.in"
     "${JUCE_BINARY_DIR}/JUCEConfig.cmake"
-    PATH_VARS UTILS_INSTALL_DIR JUCEAIDE_PATH
+    PATH_VARS UTILS_INSTALL_DIR JUCEAIDE_PATH JUCE_MODULE_PATH
     INSTALL_DESTINATION "${JUCE_INSTALL_DESTINATION}")
 
 set(JUCE_EXPORT_FILE_NAME "JUCEBuildTree.cmake")
+set(JUCE_MODULE_PATH "${CMAKE_CURRENT_SOURCE_DIR}/modules")
 export(EXPORT JUCE NAMESPACE juce:: FILE "${JUCE_EXPORT_FILE_NAME}")
 set(UTILS_INSTALL_DIR "${CMAKE_CURRENT_SOURCE_DIR}/extras/Build/CMake")
 get_target_property(JUCEAIDE_PATH juceaide IMPORTED_LOCATION)
 configure_package_config_file("${JUCE_CMAKE_UTILS_DIR}/JUCEConfig.cmake.in"
     "${JUCE_BINARY_DIR}/JUCEExportConfig.cmake"
-    PATH_VARS UTILS_INSTALL_DIR JUCEAIDE_PATH
+    PATH_VARS UTILS_INSTALL_DIR JUCEAIDE_PATH JUCE_MODULE_PATH
     INSTALL_PREFIX "${CMAKE_CURRENT_BINARY_DIR}"
     INSTALL_DESTINATION "${CMAKE_CURRENT_BINARY_DIR}")
 

examples/CMake/readme.md

@@ -491,15 +491,11 @@ both to the target's `SOURCES` and `INTERFACE_SOURCES`, which may result in many
 module being built into a single target, which would cause build failures in the best case and
 silent ODR violations in the worst case. Scary stuff!
 
-This command has a few optional arguments: `INSTALL_PATH` and `INSTALL_EXPORT` should be provided if
-you want the module to be installable through the CMake installation mechanism. `INSTALL_PATH` is a
-path, relative to the install prefix, to which the module sources will be copied. `INSTALL_EXPORT`
-specifies the CMake export group for the installed module. ALIAS_NAMESPACE will add an alias for the
-target(s) with the provided namespace. For example, the following invocation will add a module
-target named `my_module`, along with an alias named `company::my_module`.
-```
-juce_add_module(my_module ALIAS_NAMESPACE company)`
-```
+This command has a few optional arguments: `INSTALL_PATH` is a path, relative to the install prefix,
+to which the module sources will be copied during installation of the module. ALIAS_NAMESPACE will
+add an alias for the module target(s) with the provided namespace. For example, the following
+invocation will add a module target named `my_module`, along with an alias named
+`company::my_module`. ``` juce_add_module(my_module ALIAS_NAMESPACE company)` ```
 
 `juce_add_modules` is a convenience function that can be used to add multiple JUCE modules at once.
 This version accepts many module paths, rather than just one. For an example of usage, see the

extras/Build/CMake/JUCEConfig.cmake.in

@@ -31,3 +31,59 @@ endif()
 check_required_components("@PROJECT_NAME@")
 
 include("@PACKAGE_UTILS_INSTALL_DIR@/JUCEUtils.cmake")
+
+set(_juce_modules
+    juce_analytics
+    juce_audio_basics
+    juce_audio_devices
+    juce_audio_formats
+    juce_audio_plugin_client
+    juce_audio_processors
+    juce_audio_utils
+    juce_blocks_basics
+    juce_box2d
+    juce_core
+    juce_cryptography
+    juce_data_structures
+    juce_dsp
+    juce_events
+    juce_graphics
+    juce_gui_basics
+    juce_gui_extra
+    juce_opengl
+    juce_osc
+    juce_product_unlocking
+    juce_video)
+
+set(_targets_defined)
+set(_targets_expected)
+
+foreach(_juce_module IN LISTS _juce_modules)
+    list(APPEND _targets_expected ${_juce_module} juce::${_juce_modules})
+    if(TARGET ${_juce_module})
+        list(APPEND _targets_defined ${_juce_module})
+    endif()
+
+    if(TARGET juce::${_juce_module})
+        list(APPEND _targets_defined juce::${_juce_module})
+    endif()
+endforeach()
+
+if("${_targets_defined}" STREQUAL "${_targets_expected}")
+    unset(_targets_defined)
+    unset(_targets_expected)
+    return()
+endif()
+
+if(NOT "${_targets_defined}" STREQUAL "")
+    message(FATAL_ERROR "Some targets in this export set were already defined.")
+endif()
+
+unset(_targets_defined)
+unset(_targets_expected)
+
+foreach(_juce_module IN LISTS _juce_modules)
+    juce_add_module("@PACKAGE_JUCE_MODULE_PATH@/${_juce_module}" ALIAS_NAMESPACE juce)
+endforeach()
+
+unset(_juce_modules)

extras/Build/CMake/JUCEUtils.cmake

@@ -431,7 +431,7 @@ endfunction()
 # ==================================================================================================
 
 function(juce_add_module module_path)
-    set(one_value_args INSTALL_PATH INSTALL_EXPORT ALIAS_NAMESPACE)
+    set(one_value_args INSTALL_PATH ALIAS_NAMESPACE)
     cmake_parse_arguments(JUCE_ARG "" "${one_value_args}" "" ${ARGN})
 
     _juce_make_absolute(module_path)
@@ -455,20 +455,13 @@ function(juce_add_module module_path)
 
     list(APPEND all_module_sources "${base_path}/${module_name}/${module_header_name}")
 
-    set(install_export_args)
-
-    if(JUCE_ARG_INSTALL_EXPORT)
-        set(install_export_args INSTALL_EXPORT "${JUCE_ARG_INSTALL_EXPORT}")
-    endif()
-
     if(${module_name} STREQUAL "juce_audio_plugin_client")
         _juce_get_platform_plugin_kinds(plugin_kinds)
 
         foreach(kind IN LISTS plugin_kinds)
             _juce_add_plugin_wrapper_target(FORMAT ${kind}
                 PATH "${module_path}"
-                OUT_PATH "${base_path}"
-                ${install_export_args})
+                OUT_PATH "${base_path}")
         endforeach()
 
         list(APPEND all_module_sources "${base_path}/${module_name}/juce_audio_plugin_client_utils.cpp")
@@ -497,10 +490,6 @@ function(juce_add_module module_path)
             "${base_path}/juce_audio_processors/format_types/VST3_SDK")
         target_link_libraries(juce_audio_processors INTERFACE juce_vst3_headers)
 
-        if(JUCE_ARG_INSTALL_EXPORT)
-            install(TARGETS juce_vst3_headers EXPORT "${JUCE_ARG_INSTALL_EXPORT}")
-        endif()
-
         if(JUCE_ARG_ALIAS_NAMESPACE)
             add_library(${JUCE_ARG_ALIAS_NAMESPACE}::juce_vst3_headers ALIAS juce_vst3_headers)
         endif()
@@ -568,9 +557,8 @@ function(juce_add_module module_path)
     _juce_get_metadata("${metadata_dict}" dependencies module_dependencies)
     target_link_libraries(${module_name} INTERFACE ${module_dependencies})
 
-    if(JUCE_ARG_INSTALL_PATH OR JUCE_ARG_INSTALL_EXPORT)
+    if(installed_module_path)
         install(DIRECTORY "${module_path}" DESTINATION "${installed_module_path}")
-        install(TARGETS ${module_name} EXPORT "${JUCE_ARG_INSTALL_EXPORT}")
     endif()
 
     if(JUCE_ARG_ALIAS_NAMESPACE)
@@ -579,13 +567,12 @@ function(juce_add_module module_path)
 endfunction()
 
 function(juce_add_modules)
-    set(one_value_args INSTALL_PATH INSTALL_EXPORT ALIAS_NAMESPACE)
+    set(one_value_args INSTALL_PATH ALIAS_NAMESPACE)
     cmake_parse_arguments(JUCE_ARG "" "${one_value_args}" "" ${ARGN})
 
     foreach(path IN LISTS JUCE_ARG_UNPARSED_ARGUMENTS)
         juce_add_module(${path}
             INSTALL_PATH "${JUCE_ARG_INSTALL_PATH}"
-            INSTALL_EXPORT "${JUCE_ARG_INSTALL_EXPORT}"
             ALIAS_NAMESPACE "${JUCE_ARG_ALIAS_NAMESPACE}")
     endforeach()
 endfunction()
@@ -2063,13 +2050,8 @@ function(juce_add_pip header)
 
         set(discovered_module)
 
-        # If we're building a PIP from outside the current build tree, the JUCE modules
-        # might be namespaced, so we try adding a namespace if we can't find a target with
-        # the name given in the metadata block.
         if(TARGET "${module}")
             set(discovered_module "${module}")
-        elseif(TARGET "juce::${module}")
-            set(discovered_module "juce::${module}")
         else()
             message(FATAL_ERROR "No such module: ${module}")
         endif()

modules/CMakeLists.txt

@@ -16,7 +16,6 @@
 
 juce_add_modules(
     INSTALL_PATH "include/JUCE-${JUCE_VERSION}/modules"
-    INSTALL_EXPORT JUCE
     ALIAS_NAMESPACE juce
     juce_analytics
     juce_audio_basics