Simplify in-source disabling

- This prevents in-source builds to not bloat .gitignore file, but still
  allows adding this project via add_subdirectory(), or
  FetchContent/ExternalProject modules. Added before the project() call
  to have less configure steps done in this case.
- Added installation step to CI.
- Added missing BUILD_INTERFACE for sapi/embed.

Author: petk

.github/workflows/ci.yaml

@@ -136,5 +136,7 @@ jobs:
           sudo systemctl restart dovecot
 
       - name: Run tests
-        run: |
-          ctest --preset all-enabled
+        run: ctest --preset all-enabled
+
+      - name: Install PHP
+        run: cmake --install php-build/all-enabled

CMakeLists.txt

@@ -57,15 +57,7 @@ further information.
 
 cmake_minimum_required(VERSION 3.25...3.31)
 
-project(
-  PhpBuildSystem
-  VERSION 8.3
-  DESCRIPTION "CMake-based PHP build system"
-  HOMEPAGE_URL "https://github.com/petk/php-build-system"
-  LANGUAGES NONE
-)
-
-if(PROJECT_IS_TOP_LEVEL AND CMAKE_SOURCE_DIR PATH_EQUAL CMAKE_BINARY_DIR)
+if(CMAKE_BINARY_DIR PATH_EQUAL CMAKE_CURRENT_LIST_DIR)
   message(
     FATAL_ERROR
     "In-source builds are disabled. Please, set the build directory.\n"
@@ -75,6 +67,14 @@ if(PROJECT_IS_TOP_LEVEL AND CMAKE_SOURCE_DIR PATH_EQUAL CMAKE_BINARY_DIR)
   )
 endif()
 
+project(
+  PhpBuildSystem
+  VERSION 8.3
+  DESCRIPTION "CMake-based PHP build system"
+  HOMEPAGE_URL "https://github.com/petk/php-build-system"
+  LANGUAGES NONE
+)
+
 # Configuration.
 block(PROPAGATE phpUrl)
   set(

cmake/sapi/embed/CMakeLists.txt

@@ -47,7 +47,7 @@ target_sources(
 target_link_libraries(
   php_sapi_embed
   PRIVATE
-    PHP::sapi
+    $<BUILD_INTERFACE:PHP::sapi>
 )
 
 target_compile_definitions(php_sapi_embed PRIVATE ZEND_ENABLE_STATIC_TSRMLS_CACHE)