Added glibc_wrap to provide Linux OS backwards compatibility

CMakeLists.txt

@@ -19,6 +19,11 @@ set(CPACK_PACKAGE_VERSION_PATCH "0")
 set(CPACK_PACKAGE_DESCRIPTION_FILE "${CMAKE_CURRENT_SOURCE_DIR}/README.md")
 set(CPACK_RESOURCE_FILE_LICENSE "${CMAKE_CURRENT_SOURCE_DIR}/LICENSE")
 
+if (NOT WIN32)
+    set(GLIBC_WRAP_FUNCTIONS
+        -Wl,--wrap=gettid
+        -Wl,--wrap=log2)
+endif()
 # Enforce keeping the source directory clean by building in a separate
 # directory. This avoids unnecessary corner cases, e.g., copying files
 # from source to binary directory with identical relative paths.
@@ -333,7 +338,10 @@ target_link_libraries(acl PRIVATE
 if(UNIX)
   # we need this flag to expose symbols, otherwise linking will fail with:
   # "relocation against protected symbol X can not be used when making a shared object"
+  add_subdirectory(glibc_wrap)
   set_target_properties(acl PROPERTIES LINK_FLAGS "-Wl,-Bsymbolic")
+  target_include_directories(acl PRIVATE ${CMAKE_SOURCE_DIR}/glibc_wrap)
+  target_link_libraries(acl PRIVATE glibc_wrap)
 endif()
 
 set_property(TARGET acl PROPERTY PUBLIC_HEADER

cmake/manifests/linux/install_manifest.txt

@@ -36,4 +36,5 @@
 /fpga-runtime-for-opencl/include/CL/opencl.h
 /fpga-runtime-for-opencl/include/CL/opencl.hpp
 /fpga-runtime-for-opencl/include/MMD/aocl_mmd.h
-/fpga-runtime-for-opencl/include/MMD/aocl_mmd_deprecated.h
+/fpga-runtime-for-opencl/include/MMD/aocl_mmd_deprecated.h
+/__w/fpga-runtime-for-opencl/fpga-runtime-for-opencl/glibc_wrap/libglibc_wrap.a

glibc_wrap/CMakeLists.txt

@@ -0,0 +1,16 @@
+if (NOT WIN32)
+    add_library(glibc_wrap STATIC glibc_wrap.c)
+    # Ensure position-independent code is generated
+    set_target_properties(glibc_wrap PROPERTIES POSITION_INDEPENDENT_CODE ON)
+    target_include_directories(glibc_wrap PRIVATE ${CMAKE_SOURCE_DIR}/src)
+    # Specify the wrapped functions on the interface link options.
+    # This causes libraries linking against this one to use the wrapped 
+    # functions rather than those in a potentially too new glibc for
+    # our minimum supported OS. See glibc_wrap.c for details.
+    target_link_libraries(glibc_wrap INTERFACE ${GLIBC_WRAP_FUNCTIONS})
+
+    # Link the math library for debian-11-arm-dev
+    target_link_libraries(glibc_wrap INTERFACE m)
+
+    install(TARGETS glibc_wrap DESTINATION ${CMAKE_SOURCE_DIR}/glibc_wrap)
+endif()

glibc_wrap/glibc_wrap.c

@@ -0,0 +1,30 @@
+// These functions are only called by our code when built on newer distros. We
+// add '-Wl,--wrap={funcname}' to the link line which changes all calls to
+// '{funcname}' to '__wrap_{funcname}'
+
+// For all the gritty details:
+// https://www.win.tue.nl/~aeb/linux/misc/gcc-semibug.html
+// https://stackoverflow.com/questions/4032373/linking-against-an-old-version-of-libc-to-provide-greater-application-coverage
+
+#include <linux/unistd.h>
+#include <math.h>
+#include <sys/syscall.h>
+#include <unistd.h>
+
+#ifndef __arm__
+// Use GLIBC 2.2.5 versioning only if not on ARM
+asm(".symver log2_glibc_225, log2@GLIBC_2.2.5");
+extern double log2_glibc_225(double num);
+#endif
+
+double __wrap_log2(double num) {
+#ifdef __arm__
+  // If compiling for ARM, just call the system-native log2 function
+  return log2(num);
+#else
+  // Call the GLIBC 2.2.5 version of log2 if not on ARM
+  return log2_glibc_225(num);
+#endif
+}
+
+pid_t __wrap_gettid(void) { return (pid_t)syscall(SYS_gettid); }