Update docs to use top-level CMake targets

ghstack-source-id: 4da6ffe
ghstack-comment-id: 3111967018
Pull-Request: #12807

Author: GregoryComer

docs/source/kernel-library-selective-build.md

@@ -34,9 +34,25 @@ The basic flow looks like this:
 3. A _kernel resolver _takes in the linked kernel libraries as well as the merged op info yaml file, then makes a decision on which kernels to be registered into ExecuTorch runtime.
 
 
+## Selective Build CMake Options
+
+To enable selective build when building the executorch kernel libraries as part of a CMake build, the following CMake options are exposed. These options affect the `executorch_kernels` CMake target. Make sure to link this target when using selective build.
+
+ * `EXECUTORCH_SELECT_OPS_YAML`: A path to a YAML file specifying the operators to include.
+ * `EXECUTORCH_SELECT_OPS_LIST`: A string containing the operators to include.
+ * `EXECUTORCH_SELECT_OPS_MODEL`: A path to a PTE file. Only operators used in this model will be included.
+ * `EXECUTORCH_ENABLE_DTYPE_SELECTIVE_BUILD`: If enabled, operators will be further specialized to only operator on the data types specified in the operator selection.
+
+Note that `EXECUTORCH_SELECT_OPS_YAML`, `EXECUTORCH_SELECT_OPS_LIST`, and `EXECUTORCH_SELECT_OPS_MODEL` are mutually exclusive. Only one operator specifier directive is allowed.
+
+As an example, to build with only operators used in mv2_xnnpack_fp32.pte, the CMake build can be configured as follows.
+```
+cmake .. -DEXECUTORCH_SELECT_OPS_MODEL=mv2_xnnpack_fp32.pte
+```
+
 ## APIs
 
-We expose a CMake macro [gen_selected_ops](https://github.com/pytorch/executorch/blob/main/tools/cmake/Codegen.cmake#L12), to allow users specifying op info:
+For fine-grained control, we expose a CMake macro [gen_selected_ops](https://github.com/pytorch/executorch/blob/main/tools/cmake/Codegen.cmake#L12) to allow users to specify op info:
 
 ```
 gen_selected_ops(
@@ -75,7 +91,7 @@ Beyond pruning the binary to remove unused operators, the binary size can furthe
 
 ## Example Walkthrough
 
-In [CMakeLists.txt](https://github.com/BujSet/executorch/blob/main/examples/selective_build/CMakeLists.txt#L48-L72), we have the following cmake config options:
+In [examples/selective_build/CMakeLists.txt](https://github.com/BujSet/executorch/blob/main/examples/selective_build/CMakeLists.txt#L48-L72), we have the following cmake config options:
 
 1. `EXECUTORCH_SELECT_OPS_YAML`
 2. `EXECUTORCH_SELECT_OPS_LIST`

docs/source/using-executorch-building-from-source.md

@@ -252,6 +252,17 @@ I 00:00:00.000764 executorch:executor_runner.cpp:180] Model executed successfull
 I 00:00:00.000770 executorch:executor_runner.cpp:184] 1 outputs:
 Output 0: tensor(sizes=[1], [2.])
 ```
+
+### CMake Targets
+
+To link against the ExecuTorch framework from CMake, the following top-level targets are exposed:
+
+ * `executorch::backends`: Contains all configured backends.
+ * `executorch::extensions`: Contains all configured extensions.
+ * `executorch::kernels`: Contains all configured kernel libraries.
+
+The backends, extensions, and kernels included in these targets are controlled by the various `EXECUTORCH_` CMake options specified by the build.
+
 ## Build ExecuTorch for Windows
 
 This document outlines the current known working build instructions for building and validating ExecuTorch on a Windows machine.

docs/source/using-executorch-cpp.md

@@ -40,7 +40,7 @@ Running a model using the low-level runtime APIs allows for a high-degree of con
 
 ## Building with CMake
 
-ExecuTorch uses CMake as the primary build system. Inclusion of the module and tensor APIs are controlled by the `EXECUTORCH_BUILD_EXTENSION_MODULE` and `EXECUTORCH_BUILD_EXTENSION_TENSOR` CMake options. As these APIs may not be supported on embedded systems, they are disabled by default when building from source. The low-level API surface is always included. To link, add the `executorch` target as a CMake dependency, along with `extension_module_static` and `extension_tensor`, if desired.
+ExecuTorch uses CMake as the primary build system. Inclusion of the module and tensor APIs are controlled by the `EXECUTORCH_BUILD_EXTENSION_MODULE` and `EXECUTORCH_BUILD_EXTENSION_TENSOR` CMake options. As these APIs may not be supported on embedded systems, they are disabled by default when building from source. The low-level API surface is always included. To link, add the `executorch` target as a CMake dependency, along with `executorch_backends`, `executorch_extensions`, and `extension_kernels`, to link all configured backends, extensions, and kernels.
 
 ```
 # CMakeLists.txt
@@ -49,10 +49,9 @@ add_subdirectory("executorch")
 target_link_libraries(
     my_target
     PRIVATE executorch
-    extension_module_static
-    extension_tensor
-    optimized_native_cpu_ops_lib
-    xnnpack_backend)
+    executorch::backends
+    executorch::extensions
+    executorch::kernels)
 ```
 
 See [Building from Source](using-executorch-building-from-source.md) for more information on the CMake build process.