Fix subtle CMake Install bugs (#7103)

* Update CMakeLists.txt

* Update CMakeLists.txt

CMakeLists.txt

@@ -90,6 +90,28 @@ option(TARGET_SPIRV "Include SPIR-V target" OFF)
 
 add_subdirectory(dependencies)
 
+##
+# Declare options
+##
+
+# Declare these options after we include dependencies (since it declares Halide_ENABLE_RTTI etc)
+# but before we add any subdirectories, since any option you test before it is defined is
+# implicitly false the *first* time that the build file is processed, and there are some
+# out-of-order dependencies here (e.g, code in src/ eventually checks WITH_UTILS).
+# This is especially subtle since it means that some options can end up with different
+# values if you build a target as part of the initial CMake run, so (e.g.) a `make install`
+# from as totally clean build might neglect to install some pieces.
+
+option(WITH_TESTS "Build tests" "${PROJECT_IS_TOP_LEVEL}")
+option(WITH_TUTORIALS "Build tutorials" "${PROJECT_IS_TOP_LEVEL}")
+option(WITH_DOCS "Build documentation" OFF)
+option(WITH_UTILS "Build utils" "${PROJECT_IS_TOP_LEVEL}")
+cmake_dependent_option(
+    WITH_PYTHON_BINDINGS "Build Python bindings" "${PROJECT_IS_TOP_LEVEL}"
+    "Halide_ENABLE_RTTI AND Halide_ENABLE_EXCEPTIONS" OFF
+)
+
+
 ##
 # Add source directories
 ##
@@ -101,42 +123,34 @@ add_subdirectory(tools)
 # Add tests, tutorials, etc. if we're not being imported into another CMake project.
 ##
 
-option(WITH_TESTS "Build tests" "${PROJECT_IS_TOP_LEVEL}")
 if (WITH_TESTS)
     message(STATUS "Building tests enabled")
     add_subdirectory(test)
 else ()
     message(STATUS "Building tests disabled")
 endif ()
 
-cmake_dependent_option(
-    WITH_PYTHON_BINDINGS "Build Python bindings" "${PROJECT_IS_TOP_LEVEL}"
-    "Halide_ENABLE_RTTI AND Halide_ENABLE_EXCEPTIONS" OFF
-)
 if (WITH_PYTHON_BINDINGS)
     message(STATUS "Building Python bindings enabled")
     add_subdirectory(python_bindings)
 else ()
     message(STATUS "Building Python bindings disabled")
 endif ()
 
-option(WITH_TUTORIALS "Build tutorials" "${PROJECT_IS_TOP_LEVEL}")
 if (WITH_TUTORIALS)
     message(STATUS "Building tutorials enabled")
     add_subdirectory(tutorial)
 else ()
     message(STATUS "Building tutorials disabled")
 endif ()
 
-option(WITH_DOCS "Build documentation" OFF)
 if (WITH_DOCS)
     message(STATUS "Building docs enabled")
     add_subdirectory(doc)
 else ()
     message(STATUS "Building docs disabled")
 endif ()
 
-option(WITH_UTILS "Build utils" "${PROJECT_IS_TOP_LEVEL}")
 if (WITH_UTILS)
     message(STATUS "Building utils enabled")
     add_subdirectory(util)