sim/posix: Add APPLE to a build target for sim's configuration using CMake.

.codespellrc

@@ -41,6 +41,7 @@ ignore-words-list =
   infor,
   inport,
   ist,
+  lief,
   lod,
   mot,
   mis,

arch/sim/include/arch.h

@@ -27,4 +27,42 @@
 #ifndef __ARCH_SIM_INCLUDE_ARCH_H
 #define __ARCH_SIM_INCLUDE_ARCH_H
 
+/****************************************************************************
+ * Pre-processor Definitions
+ ****************************************************************************/
+
+#ifdef __cplusplus
+#define EXTERN extern "C"
+extern "C"
+{
+#else
+#define EXTERN extern
+#endif
+
+/****************************************************************************
+ * Public Data
+ ****************************************************************************/
+
+/* _sinit and _einit mark the beginning and end of the C++ constructor
+ * array.  They are mapped to platform-specific linker symbols:
+ *   macOS:  section$start$__DATA_CONST$__mod_init_func /
+ *           section$end$__DATA_CONST$__mod_init_func (Mach-O auto)
+ * On macOS, the section type flags are patched post-link to prevent
+ * dyld from auto-running constructors before NuttX is initialized.
+ */
+
+#ifdef CONFIG_HAVE_CXXINITIALIZE
+#  if defined(CONFIG_HOST_MACOS)
+extern void (*_sinit[])(void)
+  __asm("section$start$__DATA_CONST$__mod_init_func");
+extern void (*_einit[])(void)
+  __asm("section$end$__DATA_CONST$__mod_init_func");
+#  endif
+#endif
+
+#undef EXTERN
+#ifdef __cplusplus
+}
+#endif
+
 #endif /* __ARCH_SIM_INCLUDE_ARCH_H */

arch/sim/src/Makefile

@@ -139,24 +139,15 @@ sim_hostfs.c: hostfs.h
 
 STDLIBS += -lpthread
 ifeq ($(CONFIG_HOST_MACOS),y)
-ifeq ($(CONFIG_HAVE_CXXINITIALIZE),y)
-  # Note: sim_macho_init.c is not in CSRCS because it's picky about
-  # the place in the object list for linking. Namely, its constructor
-  # should be the first one in the executable.
-  HEADSRC = sim_macho_init.c
-
-  # sim_macho_init.c is not compatible with chained fixups.
-  # cf. https://github.com/apache/nuttx/issues/15208
-  ifeq ($(shell $(LD) -ld_classic -no_fixup_chains 2>&1 | grep "unknown option"),)
+  ifeq ($(CONFIG_HAVE_CXXINITIALIZE),y)
     LDLINKFLAGS += -ld_classic -no_fixup_chains
     LDFLAGS += -Wl,-ld_classic,-no_fixup_chains
   endif
-endif
 
-# Keep the simulator executable from exporting NuttX symbols. Otherwise dyld
-# may resolve host libc references against NuttX's internal libc implementation
-# during process initialization, which can crash before main() runs.
-LDFLAGS += -Wl,-exported_symbol,__mh_execute_header
+  # Keep the simulator executable from exporting NuttX symbols. Otherwise dyld
+  # may resolve host libc references against NuttX's internal libc implementation
+  # during process initialization, which can crash before main() runs.
+  LDFLAGS += -Wl,-exported_symbol,__mh_execute_header
 else
   STDLIBS += -lrt
 endif
@@ -517,6 +508,9 @@ else
 	$(Q) $(call LINK_ALLSYMS_KASAN)
 	$(Q) $(call LINK_ALLSYMS_KASAN)
 	$(Q) $(call LINK_ALLSYMS_KASAN)
+endif
+ifeq ($(CONFIG_HOST_MACOS)$(CONFIG_HAVE_CXXINITIALIZE),yy)
+	$(Q) python3 $(ARCH_SRCDIR)/patch_macho_initsection.py $(TOPDIR)/$@
 endif
 	$(Q) $(NM) $(TOPDIR)/$@ | \
 		grep -v '\(compiled\)\|\(\.o$$\)\|\( [aUw] \)\|\(\.\.ng$$\)\|\(LASH[RL]DI\)' | \

arch/sim/src/cmake/Toolchain.cmake

@@ -135,6 +135,9 @@ endif()
 if(CONFIG_COVERAGE_ALL)
   if(CONFIG_ARCH_TOOLCHAIN_GCC)
     add_compile_options(-fprofile-arcs -ftest-coverage -fno-inline)
+    if(APPLE)
+      add_link_options(-fprofile-arcs -ftest-coverage)
+    endif()
   elseif(CONFIG_ARCH_TOOLCHAIN_CLANG)
     add_compile_options(-fprofile-instr-generate -fcoverage-mapping)
     add_link_options(-fprofile-instr-generate)

arch/sim/src/patch_macho_initsection.py

@@ -0,0 +1,83 @@
+#!/usr/bin/env python3
+############################################################################
+# arch/sim/src/patch_macho_initsection.py
+#
+# SPDX-License-Identifier: Apache-2.0
+#
+# Licensed to the Apache Software Foundation (ASF) under one or more
+# contributor license agreements.  See the NOTICE file distributed with
+# this work for additional information regarding copyright ownership.  The
+# ASF licenses this file to you under the Apache License, Version 2.0 (the
+# "License"); you may not use this file except in compliance with the
+# License.  You may obtain a copy of the License at
+#
+#   http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or
+# implied.  See the License for the specific language governing
+# permissions and limitations under the License.
+#
+############################################################################
+
+"""Patch Mach-O init section type flags to prevent dyld from
+auto-running C++ constructors.
+
+Changes MOD_INIT_FUNC_POINTERS (0x9) section types to REGULAR (0x0)
+so that dyld ignores them.  NuttX will invoke the constructors
+explicitly from lib_cxx_initialize().
+
+Requires: pip install lief
+"""
+
+import argparse
+import subprocess
+import sys
+
+try:
+    import lief
+except ImportError:
+    print(
+        "Error: lief is required. Install with: pip install lief",
+        file=sys.stderr,
+    )
+    sys.exit(1)
+
+
+def main():
+    parser = argparse.ArgumentParser(description="Patch Mach-O init section type flags")
+    parser.add_argument("binary", help="Path to the Mach-O binary")
+    args = parser.parse_args()
+
+    binary = lief.MachO.parse(args.binary)
+    if binary is None:
+        print(f"Error: failed to parse {args.binary}", file=sys.stderr)
+        sys.exit(1)
+
+    fat = binary.at(0)
+    T = lief.MachO.Section.TYPE
+    patched = 0
+    for section in fat.sections:
+        if section.type == T.MOD_INIT_FUNC_POINTERS:
+            section.type = T.REGULAR
+            patched += 1
+
+    if patched:
+        fat.write(args.binary)
+
+        # Re-sign the binary on macOS: writing the file invalidates the
+        # ad-hoc signature that ld attached at link time, which causes the
+        # kernel to SIGKILL the process at exec with
+        # "CODE SIGNING: rejecting invalid page ...".
+        if sys.platform == "darwin":
+            subprocess.run(
+                ["codesign", "--force", "--sign", "-", args.binary],
+                check=True,
+            )
+
+    return 0
+
+
+if __name__ == "__main__":
+    sys.exit(main())

arch/sim/src/sim/CMakeLists.txt

@@ -29,7 +29,9 @@ set(HOSTSRCS)
 set(HOST_INCLUDE_DIRS)
 set(STDLIBS pthread)
 
-if(CONFIG_COVERAGE_TOOLCHAIN)
+if(CONFIG_COVERAGE_TOOLCHAIN
+   AND CONFIG_ARCH_TOOLCHAIN_GCC
+   AND NOT APPLE)
   list(APPEND STDLIBS gcov)
 endif()
 
@@ -150,14 +152,30 @@ list(
   sim_hosttime.c
   sim_hostuart.c)
 
-# Note: sim_macho_init.c is picky about the place in the object list for
-# linking. Namely, its constructor should be the first one in the executable.
-# For now, we are just assuming no other files in HOSTSRCS provide constructors.
 if(CONFIG_HOST_MACOS)
-  if(CONFIG_HAVE_CXXINITIALIZE)
-    list(APPEND HOSTSRCS sim_macho_init.c)
-    target_link_options(nuttx PRIVATE -Wl,-ld_classic,-no_fixup_chains)
-  endif()
+  # Provide a sim/macOS specific override of clock_gettime() that translates
+  # Darwin clock IDs to NuttX's CLOCK_MONOTONIC.  Keep all macOS specific logic
+  # in arch/sim/ instead of polluting sched/clock/clock_gettime.c.
+  list(APPEND SRCS macos/sim_clock_gettime.c)
+endif()
+
+if(CONFIG_HOST_MACOS AND CONFIG_HAVE_CXXINITIALIZE)
+  # Keep classic __mod_init_func format so post-link lief patching works
+  target_link_options(nuttx PRIVATE -Wl,-ld_classic,-no_fixup_chains)
+
+  # NOTE: add_custom_command(TARGET ...) can only be used in the directory where
+  # the target was created. The `nuttx` executable is created in the top-level
+  # CMakeLists.txt, so we cannot attach a POST_BUILD command to it here. Use a
+  # custom target hooked into `nuttx_post` instead.
+  add_custom_target(
+    sim_patch_macho_initsection ALL
+    COMMAND
+      ${Python3_EXECUTABLE}
+      ${CMAKE_CURRENT_SOURCE_DIR}/../patch_macho_initsection.py
+      $<TARGET_FILE:nuttx>
+    DEPENDS nuttx
+    COMMENT "Patching Mach-O init section type flags")
+  add_dependencies(nuttx_post sim_patch_macho_initsection)
 endif()
 
 if(CONFIG_SIM_CAMERA_V4L2)

arch/sim/src/sim/macos/sim_clock_gettime.c

@@ -0,0 +1,94 @@
+/****************************************************************************
+ * arch/sim/src/sim/macos/sim_clock_gettime.c
+ *
+ * SPDX-License-Identifier: Apache-2.0
+ *
+ * Licensed to the Apache Software Foundation (ASF) under one or more
+ * contributor license agreements.  See the NOTICE file distributed with
+ * this work for additional information regarding copyright ownership.  The
+ * ASF licenses this file to you under the Apache License, Version 2.0 (the
+ * "License"); you may not use this file except in compliance with the
+ * License.  You may obtain a copy of the License at
+ *
+ *   http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
+ * WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.  See the
+ * License for the specific language governing permissions and limitations
+ * under the License.
+ *
+ ****************************************************************************/
+
+/****************************************************************************
+ * Included Files
+ ****************************************************************************/
+
+#include <nuttx/config.h>
+
+#include <time.h>
+#include <errno.h>
+
+#include <nuttx/clock.h>
+
+/****************************************************************************
+ * Pre-processor Definitions
+ ****************************************************************************/
+
+/* Rust code (and any other code) built for the macOS host uses Darwin's libc
+ * clock IDs.  When such code is linked into the NuttX simulator, those
+ * Darwin-specific values reach NuttX's clock_gettime() implementation
+ * instead of Darwin's one.  Translate them here so that the common
+ * sched/clock implementation does not need to know about Darwin clock IDs.
+ *
+ *   _CLOCK_MONOTONIC  == 6  (Darwin / XNU)
+ *   _CLOCK_UPTIME_RAW == 8  (Darwin / XNU)
+ */
+
+#define DARWIN_CLOCK_MONOTONIC  6
+#define DARWIN_CLOCK_UPTIME_RAW 8
+
+/****************************************************************************
+ * Public Functions
+ ****************************************************************************/
+
+/****************************************************************************
+ * Name: clock_gettime
+ *
+ * Description:
+ *   sim/macOS specific override of clock_gettime() that translates Darwin
+ *   clock IDs (CLOCK_MONOTONIC=6, CLOCK_UPTIME_RAW=8) into NuttX's
+ *   CLOCK_MONOTONIC before delegating to the common nxclock_gettime()
+ *   implementation.
+ *
+ *   This override is required because Rust crates built for the macOS host
+ *   call libc::clock_gettime() with Darwin's clock IDs.  When the resulting
+ *   object code is linked into the NuttX simulator, the call is resolved to
+ *   NuttX's clock_gettime() instead of Darwin's one.
+ *
+ *   The common POSIX clock_gettime() in sched/clock/clock_gettime.c is
+ *   declared as a weak symbol, so this strong definition takes precedence
+ *   when CONFIG_HOST_MACOS is enabled.
+ *
+ ****************************************************************************/
+
+__attribute__((visibility("hidden")))
+int clock_gettime(clockid_t clock_id, struct timespec *tp)
+{
+  int ret;
+
+  if (clock_id == DARWIN_CLOCK_MONOTONIC ||
+      clock_id == DARWIN_CLOCK_UPTIME_RAW)
+    {
+      clock_id = CLOCK_MONOTONIC;
+    }
+
+  ret = nxclock_gettime(clock_id, tp);
+  if (ret < 0)
+    {
+      set_errno(-ret);
+      return ERROR;
+    }
+
+  return OK;
+}