Help: Provide cross-references between compiler settings

Help/command/add_compile_options.rst

@@ -46,3 +46,6 @@ to use the more specific commands :command:`add_compile_definitions`
 and :command:`include_directories`.
 
 The command :command:`target_compile_options` adds target-specific options.
+
+The source file property :prop_sf:`COMPILE_OPTIONS` adds options to one
+source file.

Help/command/target_compile_options.rst

@@ -46,3 +46,5 @@ to use the more specific commands :command:`target_compile_definitions`
 and :command:`target_include_directories`.
 
 For directory-wide settings, there is the command :command:`add_compile_options`.
+
+For file-specific settings, there is the source file property :prop_sf:`COMPILE_OPTIONS`.

Help/prop_sf/COMPILE_OPTIONS.rst

@@ -25,3 +25,8 @@ Related properties:
 * Prefer this property over :prop_sf:`COMPILE_FLAGS`.
 * Use :prop_sf:`COMPILE_DEFINITIONS` to pass additional preprocessor definitions.
 * Use :prop_sf:`INCLUDE_DIRECTORIES` to pass additional include directories.
+
+Related commands:
+
+* :command:`add_compile_options` for directory-wide settings
+* :command:`target_compile_options` for target-specific settings