Add macOS Apple Silicon (arm64) support

.github/workflows/make-test-multi-platform.yml

@@ -22,10 +22,10 @@ jobs:
             compiler: gcc
           - os: ubuntu-latest
             compiler: clang
-#         - os: macos-latest
-#           compiler: clang
-#         - os: macos-14
-#           compiler: clang            
+          - os: macos-13
+            compiler: clang
+          - os: macos-latest
+            compiler: clang
     steps:
     - uses: actions/checkout@v4
 
@@ -70,50 +70,32 @@ jobs:
           echo "--- done RUNNING $f ---"
         done
       working-directory: ${{ github.workspace }}/test
-    - name: Build and run tests (Macos)
-      if: ${{ matrix.os == 'macos-latest' }}
+    - name: Build and run tests (macOS)
+      if: ${{ startsWith(matrix.os, 'macos') }}
       run: |
-        sysctl hw
-        make -f Makefile.linux64.clang
-        compiler=clang
-        for f in $(find . -type f -name "*.cpp"); do
-          if [[ -z "${f##*win.cpp}" ]]; then
-            continue
-          fi
-
-          f=${f%.cpp}
-
-          if [ ${compiler}="clang" ] && [[ $f == *virtual* ]]; then
-            continue
-          fi
-
+        sysctl -n machdep.cpu.brand_string || true
+        uname -m
+        # Build + post-process (macos_enable_stub.sh is invoked automatically
+        # by the Makefile: it patches __TEXT maxprot to rwx and re-signs the
+        # binary ad-hoc so cpp-stub's Apple code path can create a writable
+        # alias of __TEXT at runtime).
+        make -f Makefile.darwin.clang
+        for f in $(find . -maxdepth 1 -type f -perm -u+x ! -name "Makefile*" ! -name "*.cpp" ! -name "*.md"); do
           echo "--- RUNNING $f ---"
-             printf '\x07' | dd of=${f} bs=1 seek=160 count=1 conv=notrunc
-            ${f}
+          "$f"
           echo "--- done RUNNING $f ---"
         done
       working-directory: ${{ github.workspace }}/test
-    - name: Build and run tests (Macos M1)
-      if: ${{ matrix.os == 'macos-14' }}
+      shell: bash
+
+    - name: CMake integration smoke test (macOS)
+      if: ${{ startsWith(matrix.os, 'macos') }}
       run: |
-        sysctl hw
-        make -f Makefile.linux64.clang
-        compiler=clang
-        for f in $(find . -type f -name "*.cpp"); do
-          if [[ -z "${f##*win.cpp}" ]]; then
-            continue
-          fi
-
-          f=${f%.cpp}
-
-          if [ ${compiler}="clang" ] && [[ $f == *virtual* ]]; then
-            continue
-          fi
-
-          echo "--- RUNNING $f ---"
-             printf '\x07' | dd of=${f} bs=1 seek=160 count=1 conv=notrunc
-            ${f}
-          echo "--- done RUNNING $f ---"
-        done
-      working-directory: ${{ github.workspace }}/test
+        # Verifies that downstream projects only need
+        #   target_link_libraries(my_test PRIVATE cpp-stub)
+        # and no manual post-build step — the root CMakeLists.txt
+        # defers and attaches macos_enable_stub.sh automatically.
+        cmake -S example/cmake_smoke -B example/cmake_smoke/build
+        cmake --build example/cmake_smoke/build
+        ./example/cmake_smoke/build/cmake_smoke
       shell: bash

.gitignore

@@ -1,2 +1,3 @@
 .ccls-cache
 replit*
+*.dSYM/

CMakeLists.txt

@@ -0,0 +1,106 @@
+cmake_minimum_required(VERSION 3.19)
+project(cpp-stub CXX)
+
+# Header-only interface library. Downstream usage:
+#
+#   add_subdirectory(third_party/cpp-stub)
+#   add_executable(my_test test.cpp)
+#   target_link_libraries(my_test PRIVATE cpp-stub)
+#
+# On macOS the build system automatically patches the produced binary
+# after link so cpp-stub can rewrite __TEXT at runtime; no manual step
+# is required. On Linux/Windows the post-build hook is a no-op.
+
+add_library(cpp-stub INTERFACE)
+add_library(cpp-stub::cpp-stub ALIAS cpp-stub)
+
+target_include_directories(cpp-stub INTERFACE
+    "${CMAKE_CURRENT_SOURCE_DIR}/src")
+
+if(APPLE)
+    target_include_directories(cpp-stub INTERFACE
+        "${CMAKE_CURRENT_SOURCE_DIR}/src_darwin")
+endif()
+
+if(UNIX AND NOT APPLE)
+    target_include_directories(cpp-stub INTERFACE
+        "${CMAKE_CURRENT_SOURCE_DIR}/src_linux")
+endif()
+
+if(WIN32)
+    target_include_directories(cpp-stub INTERFACE
+        "${CMAKE_CURRENT_SOURCE_DIR}/src_win")
+endif()
+
+# -----------------------------------------------------------------------------
+# macOS post-build automation
+# -----------------------------------------------------------------------------
+if(APPLE)
+    set(_CPP_STUB_ENABLE_TOOL
+        "${CMAKE_CURRENT_SOURCE_DIR}/tool/macos_enable_stub.sh"
+        CACHE INTERNAL "")
+
+    # Explicit opt-in helper for cases where the auto-detect below cannot
+    # see a target (e.g. the executable only links cpp-stub transitively
+    # through an intermediate static library).
+    function(cpp_stub_enable target)
+        get_target_property(_already "${target}" _CPP_STUB_POSTBUILD_ADDED)
+        if(_already)
+            return()
+        endif()
+        add_custom_command(TARGET "${target}" POST_BUILD
+            COMMAND "${_CPP_STUB_ENABLE_TOOL}" "$<TARGET_FILE:${target}>"
+            COMMENT "cpp-stub: patching __TEXT maxprot and re-signing ${target}"
+            VERBATIM)
+        set_target_properties("${target}" PROPERTIES
+            _CPP_STUB_POSTBUILD_ADDED TRUE)
+    endfunction()
+
+    # Recursively collect all targets in the directory tree rooted at `dir`.
+    function(_cpp_stub_collect_targets dir out_var)
+        set(_acc "")
+        get_property(_here DIRECTORY "${dir}" PROPERTY BUILDSYSTEM_TARGETS)
+        if(_here)
+            list(APPEND _acc ${_here})
+        endif()
+        get_property(_subs DIRECTORY "${dir}" PROPERTY SUBDIRECTORIES)
+        foreach(_s IN LISTS _subs)
+            _cpp_stub_collect_targets("${_s}" _sub)
+            if(_sub)
+                list(APPEND _acc ${_sub})
+            endif()
+        endforeach()
+        set(${out_var} "${_acc}" PARENT_SCOPE)
+    endfunction()
+
+    # Deferred callback: invoked at end-of-config of the top-level directory,
+    # by which time every target has been declared. For each executable that
+    # (directly) links cpp-stub, attach the post-build patch step.
+    function(_cpp_stub_auto_enable_all)
+        _cpp_stub_collect_targets("${CMAKE_SOURCE_DIR}" _targets)
+        foreach(_t IN LISTS _targets)
+            if(NOT TARGET "${_t}")
+                continue()
+            endif()
+            get_target_property(_type "${_t}" TYPE)
+            if(NOT _type STREQUAL "EXECUTABLE")
+                continue()
+            endif()
+            set(_links "")
+            get_target_property(_l "${_t}" LINK_LIBRARIES)
+            if(_l)
+                list(APPEND _links ${_l})
+            endif()
+            get_target_property(_il "${_t}" INTERFACE_LINK_LIBRARIES)
+            if(_il)
+                list(APPEND _links ${_il})
+            endif()
+            if("cpp-stub" IN_LIST _links OR "cpp-stub::cpp-stub" IN_LIST _links)
+                cpp_stub_enable("${_t}")
+            endif()
+        endforeach()
+    endfunction()
+
+    cmake_language(DEFER DIRECTORY "${CMAKE_SOURCE_DIR}"
+        CALL _cpp_stub_auto_enable_all)
+endif()

README.md

@@ -10,7 +10,14 @@
 - Supported operating systems:
   * [x] Windows
   * [x] Linux
-  * [x] MacOS(x86-64, printf '\x07' | dd of=test_function bs=1 seek=160 count=1 conv=notrunc)
+  * [x] MacOS — both Intel (x86-64) and Apple Silicon (arm64). Because macOS
+    enforces W^X on `__TEXT` and caps `mprotect` at each segment's `maxprot`,
+    every binary that uses cpp-stub needs a tiny post-link adjustment
+    (lift `__TEXT.maxprot` to `rwx` and ad-hoc re-sign; see
+    [issue #49](https://github.com/coolxv/cpp-stub/issues/49)).
+    cpp-stub ships build-system helpers that do this automatically, so
+    downstream users normally do **not** have to call anything by hand.
+    See [the macOS integration section](#macos-integration) below.
 - Supported hardware platform: 
   * [x] x86
   * [x] x86-64
@@ -68,6 +75,64 @@
 - -fprofile-arcs
 - -ftest-coverage
 
+## macOS integration
+
+macOS requires every binary that uses cpp-stub to have its `__TEXT`
+segment's `maxprot` lifted to `rwx` and be ad-hoc re-signed once, after
+link. The library ships helpers that wire this up for you; on Linux and
+Windows the same helpers do nothing.
+
+### CMake (zero manual steps)
+
+```cmake
+add_subdirectory(third_party/cpp-stub)
+add_executable(my_test test.cpp)
+target_link_libraries(my_test PRIVATE cpp-stub)
+```
+
+The root `CMakeLists.txt` installs a deferred hook that finds every
+executable that links `cpp-stub` and automatically attaches the
+post-build patch step on Apple platforms. For the rare case where an
+executable only links cpp-stub *transitively* through a static library,
+call it explicitly:
+
+```cmake
+cpp_stub_enable(my_test)
+```
+
+### Makefile
+
+```make
+CPP_STUB_DIR := third_party/cpp-stub
+include $(CPP_STUB_DIR)/mk/cpp-stub.mk
+
+my_test: my_test.cpp
+	$(CXX) $(addprefix -I,$(CPP_STUB_INCLUDE)) ... -o $@ $<
+	@$(CPP_STUB_POSTLINK)
+```
+
+`$(CPP_STUB_POSTLINK)` expands to the enable-stub command on macOS and
+to a no-op (`:`) on Linux/Windows, so the same rule works cross-platform.
+
+### Xcode / Bazel / other
+
+Add a run-script / `genrule` that invokes the helper once per built
+executable:
+
+```bash
+third_party/cpp-stub/tool/macos_enable_stub.sh "$TARGET_BUILD_DIR/$EXECUTABLE_PATH"
+```
+
+### Why this step exists
+
+See [issue #49](https://github.com/coolxv/cpp-stub/issues/49) and the
+`__APPLE__` branch of [src/stub.h](src/stub.h) for the full story: the
+kernel will not let `mprotect`/`mach_vm_protect` raise `__TEXT` above
+its Mach-O `maxprot`, and Apple Silicon further enforces W^X at the
+page-table level even when `maxprot=rwx`. `tool/macos_enable_stub.sh`
+raises `maxprot` so that cpp-stub can obtain a writable alias of
+`__TEXT` at runtime via `mach_vm_remap`.
+
 ## Code coverage statistics for linux g++
 ```
 lcov -d build/ -z

README_zh.md

@@ -9,7 +9,12 @@
 - 支持的操作系统 :
   * [x] Windows
   * [x] Linux
-  * [x] MacOS(x86-64, printf '\x07' | dd of=test_function bs=1 seek=160 count=1 conv=notrunc)
+  * [x] MacOS —— 同时支持 Intel (x86-64) 与 Apple Silicon (arm64)。由于 macOS
+    对 `__TEXT` 段施加 W^X 限制，并且 `mprotect` 不能超过段的 `maxprot`，
+    使用 cpp-stub 的每个可执行文件都需要在链接后做一次小处理（把 `__TEXT.maxprot`
+    抬到 `rwx` 并 ad-hoc 重新签名，见 [issue #49](https://github.com/coolxv/cpp-stub/issues/49)）。
+    本仓库提供了构建系统集成助手，下游通常**不需要手动调用**任何脚本。
+    详见下文的 [macOS 集成说明](#macos-集成说明)。
 
 - 支持的硬件平台 :
   * [x] x86
@@ -69,6 +74,60 @@
 - -fprofile-arcs
 - -ftest-coverage
 
+## macOS 集成说明
+
+macOS 下每个使用 cpp-stub 的可执行文件都需要在链接完成后做一次小处理：
+把 `__TEXT.maxprot` 抬到 `rwx`，并用 ad-hoc 重新签名。本仓库自带构建系统
+助手帮你自动做这件事；Linux / Windows 下这些助手是空操作。
+
+### CMake（零手动步骤）
+
+```cmake
+add_subdirectory(third_party/cpp-stub)
+add_executable(my_test test.cpp)
+target_link_libraries(my_test PRIVATE cpp-stub)
+```
+
+仓库根部的 `CMakeLists.txt` 会注册一个 deferred hook：在配置阶段结束时
+遍历所有 executable，对每个直接链接 `cpp-stub` 的目标自动挂 POST_BUILD
+步骤。只有当可执行文件通过中间静态库**间接**链接 cpp-stub 时，才需要
+显式调用：
+
+```cmake
+cpp_stub_enable(my_test)
+```
+
+### Makefile
+
+```make
+CPP_STUB_DIR := third_party/cpp-stub
+include $(CPP_STUB_DIR)/mk/cpp-stub.mk
+
+my_test: my_test.cpp
+	$(CXX) $(addprefix -I,$(CPP_STUB_INCLUDE)) ... -o $@ $<
+	@$(CPP_STUB_POSTLINK)
+```
+
+`$(CPP_STUB_POSTLINK)` 在 macOS 上展开为 enable-stub 命令，
+在 Linux/Windows 上展开为空操作 (`:`)，同一份 Makefile 跨平台可用。
+
+### Xcode / Bazel / 其它
+
+加一条 run-script / `genrule`，对每个可执行文件调一次：
+
+```bash
+third_party/cpp-stub/tool/macos_enable_stub.sh "$TARGET_BUILD_DIR/$EXECUTABLE_PATH"
+```
+
+### 为什么需要这一步
+
+参见 [issue #49](https://github.com/coolxv/cpp-stub/issues/49) 以及
+[src/stub.h](src/stub.h) 的 `__APPLE__` 分支：内核不允许
+`mprotect`/`mach_vm_protect` 把 `__TEXT` 的权限提升到 Mach-O 里
+`maxprot` 之上，而 Apple Silicon 还在页表层面强制 W^X。
+`tool/macos_enable_stub.sh` 负责把 `maxprot` 抬到 `rwx`，这样
+cpp-stub 运行时才能通过 `mach_vm_remap` 拿到 `__TEXT` 的可写别名。
+
 
 ## 代码覆盖率, linux g++使用方法
 ```

example/cmake_smoke/CMakeLists.txt

@@ -0,0 +1,13 @@
+cmake_minimum_required(VERSION 3.19)
+project(cpp_stub_cmake_smoke CXX)
+
+set(CMAKE_CXX_STANDARD 11)
+
+# Points at repository root (two levels up from this file).
+add_subdirectory(../.. cpp-stub-build)
+
+add_executable(cmake_smoke smoke.cpp)
+target_link_libraries(cmake_smoke PRIVATE cpp-stub)
+
+# Deliberately no cpp_stub_enable() call here: verifies that merely
+# linking the interface target is enough on macOS.