fix: use -fno-trampolines to replace stack trampolines with register-based ones

The previous approach (-Wl,-z,noexecstack only) caused SIGSEGV during FT8 decode
because the WSJT-X Fortran code uses internal procedure pointers at runtime which
require trampolines. With the stack non-executable, those trampolines segfaulted.

This commit uses a two-part fix:
1. -fno-trampolines (Fortran compile flag): instructs gfortran to use register-based
   trampolines instead of stack-based ones. GCC 9+ / aarch64 supports this natively.
2. -Wl,-z,noexecstack (linker flag): marks the SO as not requiring executable stack,
   which is now safe since trampolines no longer live on the stack.

If the Fortran code has nested procedure arguments that cannot use register trampolines,
CI will fail at compile or test time, indicating code restructuring is needed.

Author: boybook

CMakeLists.txt

@@ -38,6 +38,13 @@ if(UNIX AND NOT APPLE)
     add_compile_options(-fPIC -fvisibility=hidden)
     set(CMAKE_CXX_FLAGS "${CMAKE_CXX_FLAGS} -Wno-stringop-overflow -Wno-deprecated-declarations")
     set(CMAKE_C_FLAGS "${CMAKE_C_FLAGS} -Wno-stringop-overflow -Wno-deprecated-declarations")
+    # Disable stack-based trampolines in Fortran code.
+    # Required together with -Wl,-z,noexecstack: modern kernels (OrbStack 6.17+) reject
+    # dlopen of .so with PT_GNU_STACK RWE. -fno-trampolines tells gfortran to use
+    # register-based (non-stack) trampolines for internal procedure pointers.
+    # If this causes a compile error, the Fortran code has nested procedure arguments
+    # that require restructuring. GCC 9+ on aarch64 supports this without libffi.
+    add_compile_options($<$<COMPILE_LANGUAGE:Fortran>:-fno-trampolines>)
 elseif(APPLE)
     set(CMAKE_CXX_FLAGS "${CMAKE_CXX_FLAGS} -fvisibility=hidden -Wno-deprecated-declarations -Wno-unqualified-std-cast-call")
 elseif(WIN32 AND CMAKE_CXX_COMPILER_ID MATCHES "GNU")

package-lock.json

@@ -1,6 +1,6 @@
 {
   "name": "wsjtx-lib",
-  "version": "1.2.2",
+  "version": "1.2.3",
   "description": "Node.js C++ extension for WSJTX digital radio protocol library",
   "type": "module",
   "main": "dist/src/index.js",