fix: prev commit

Author: MarkusB

README.md

@@ -50,10 +50,9 @@ mb_pre_commit_setup()
 mb_pre_commit_setup_subdirectory(PRE_COMMIT_INSTALL_EXAMPLE_CONFIG OFF)
 ```
 
-That installs hooks and a sweep target named `mb-pre-commit-sweep-<id>` where `<id>` is
-this tree's `project()` name when it differs from the top-level project, otherwise the
-source directory name (e.g. `mb-pre-commit-sweep-devenv`) so it does not clash with the
-parent's `mb-pre-commit-sweep`.
+That installs hooks and a sweep target named `mb-pre-commit-sweep-<dir>` where `<dir>` is
+the basename of the directory containing the calling `CMakeLists.txt` (e.g.
+`mb-pre-commit-sweep-devenv`) so it does not clash with the parent's `mb-pre-commit-sweep`.
 
 Or without CMake:
 
@@ -193,9 +192,9 @@ This project’s CMake module uses APIs that require **CMake 3.21+** (`file(COPY
 Same options as `mb_pre_commit_setup`, but **`PROJECT_SOURCE_DIR`** / **`PROJECT_BINARY_DIR`** default to
 **`CMAKE_CURRENT_SOURCE_DIR`** / **`CMAKE_CURRENT_BINARY_DIR`** (the project whose `CMakeLists.txt`
 calls it), and **`PRE_COMMIT_INSTALL_EXAMPLE_CONFIG`** defaults to **`OFF`** unless you set it.
-**`PRE_COMMIT_SWEEP_TARGET`** defaults to `mb-pre-commit-sweep-<id>`: this tree's
-`PROJECT_NAME` when it is not the top-level `CMAKE_PROJECT_NAME`, otherwise the basename of
-`CMAKE_CURRENT_SOURCE_DIR`.
+**`PRE_COMMIT_SWEEP_TARGET`** defaults to `mb-pre-commit-sweep-<dir>` where `<dir>` is the
+basename of `CMAKE_CURRENT_LIST_DIR` at the call site (the folder that contains the calling
+`CMakeLists.txt`).
 
 Relative paths for `PROJECT_SOURCE_DIR` / `PROJECT_BINARY_DIR` / `PRE_COMMIT_VENV_DIR` are resolved against
 `CMAKE_SOURCE_DIR`, `CMAKE_BINARY_DIR`, and `PROJECT_SOURCE_DIR` respectively, matching CMake’s usual behavior.

cmake/mb-pre-commit.cmake

@@ -266,37 +266,42 @@ endfunction()
 # Uses CMAKE_CURRENT_SOURCE_DIR/BINARY_DIR instead of the top-level CMAKE_SOURCE_DIR so Git
 # hooks and .venv land in the submodule tree. Commits inside that submodule then run this
 # hook; the parent's mb_pre_commit_setup() does not apply there.
-function(mb_pre_commit_setup_subdirectory)
-    cmake_parse_arguments(
-        SUBPC
-        ""
-        "PRE_COMMIT_SWEEP_TARGET;PRE_COMMIT_INSTALL_EXAMPLE_CONFIG"
-        ""
-        ${ARGN}
+function(_mb_pre_commit_setup_subdirectory_impl)
+    set(options)
+    set(oneValueArgs
+        CALLER_LIST_DIR
+        CALLER_SOURCE_DIR
+        CALLER_BINARY_DIR
+        PRE_COMMIT_SWEEP_TARGET
+        PRE_COMMIT_INSTALL_EXAMPLE_CONFIG
     )
+    cmake_parse_arguments(SUBPC "${options}" "${oneValueArgs}" "" ${ARGN})
+
+    if(
+        NOT SUBPC_CALLER_LIST_DIR
+        OR NOT SUBPC_CALLER_SOURCE_DIR
+        OR NOT SUBPC_CALLER_BINARY_DIR
+    )
+        message(
+            FATAL_ERROR
+            "_mb_pre_commit_setup_subdirectory_impl: internal caller paths missing"
+        )
+    endif()
 
     if(NOT SUBPC_PRE_COMMIT_SWEEP_TARGET)
-        # CMAKE_PROJECT_NAME is always the top-level project(); nested add_subdirectory
-        # trees need PROJECT_NAME or the source dir leaf so targets do not collide.
-        if(PROJECT_NAME AND NOT PROJECT_NAME STREQUAL CMAKE_PROJECT_NAME)
-            set(_subpc_sweep_id "${PROJECT_NAME}")
-        else()
-            get_filename_component(
-                _subpc_sweep_id
-                "${CMAKE_CURRENT_SOURCE_DIR}"
-                NAME
-            )
-        endif()
+        # Do not use PROJECT_NAME or CMAKE_PROJECT_NAME: in a function they may not reflect
+        # the caller's directory scope (PROJECT_NAME inherits the top-level project() name).
+        get_filename_component(_subpc_sweep_id "${SUBPC_CALLER_LIST_DIR}" NAME)
         set(SUBPC_PRE_COMMIT_SWEEP_TARGET
             "mb-pre-commit-sweep-${_subpc_sweep_id}"
         )
     endif()
 
     set(_sub_setup_args
         PROJECT_SOURCE_DIR
-        "${CMAKE_CURRENT_SOURCE_DIR}"
+        "${SUBPC_CALLER_SOURCE_DIR}"
         PROJECT_BINARY_DIR
-        "${CMAKE_CURRENT_BINARY_DIR}"
+        "${SUBPC_CALLER_BINARY_DIR}"
         PRE_COMMIT_SWEEP_TARGET
         "${SUBPC_PRE_COMMIT_SWEEP_TARGET}"
     )
@@ -316,3 +321,17 @@ function(mb_pre_commit_setup_subdirectory)
 
     mb_pre_commit_setup(${_sub_setup_args})
 endfunction()
+
+# Macro so CMAKE_CURRENT_* are read at the call site (the submodule CMakeLists.txt), not
+# inside a function scope where PROJECT_NAME can still be the top-level project() name.
+macro(mb_pre_commit_setup_subdirectory)
+    _mb_pre_commit_setup_subdirectory_impl(
+        CALLER_LIST_DIR
+        "${CMAKE_CURRENT_LIST_DIR}"
+        CALLER_SOURCE_DIR
+        "${CMAKE_CURRENT_SOURCE_DIR}"
+        CALLER_BINARY_DIR
+        "${CMAKE_CURRENT_BINARY_DIR}"
+        ${ARGN}
+    )
+endmacro()