libdl: Refactor shared code in ARM and AArch64

rtl-mdreloc-arm.c was used as the basis for rtl-mdreloc-aarch64.c. This lead
to some code being shared by the two files. The code was consolidated into
rtl-unwind-arm.c.

Closes #4686

cpukit/libdl/rtl-mdreloc-aarch64.c

@@ -73,16 +73,12 @@ __RCSID("$NetBSD: mdreloc.c,v 1.14 2020/06/16 21:01:30 joerg Exp $");
 #include <inttypes.h>
 #include <sys/stat.h>
 #include <sys/endian.h>
-#include <unwind.h>
 
 #include <rtems/rtl/rtl.h>
 #include "rtl-elf.h"
 #include "rtl-error.h"
 #include <rtems/rtl/rtl-trace.h>
-#include "rtl-unwind.h"
-
-typedef unsigned _Unwind_Word __attribute__((__mode__(__word__)));
-typedef _Unwind_Word _uw;
+#include "rtl-unwind-arm.h"
 
 struct tls_data {
   size_t    td_tlsindex;
@@ -522,78 +518,3 @@ rtems_rtl_elf_relocate_rel (rtems_rtl_obj*            obj,
   rtems_rtl_set_error (EINVAL, "rela type record not supported");
   return rtems_rtl_elf_rel_failure;
 }
-
-bool
-rtems_rtl_elf_unwind_parse (const rtems_rtl_obj* obj,
-                            const char*          name,
-                            uint32_t             flags)
-{
-  /*
-   * We location the EH sections in section flags.
-   */
-  return false;
-}
-
-bool
-rtems_rtl_elf_unwind_register (rtems_rtl_obj* obj)
-{
-  return true;
-}
-
-bool
-rtems_rtl_elf_unwind_deregister (rtems_rtl_obj* obj)
-{
-  obj->loader = NULL;
-  return true;
-}
-
-/* An exception index table entry.  */
-typedef struct __EIT_entry
-{
-  _uw fnoffset;
-  _uw content;
-} __EIT_entry;
-
-/* The exception index table location in the base module */
-extern __EIT_entry __exidx_start;
-extern __EIT_entry __exidx_end;
-
-/*
- * A weak reference is in libgcc, provide a real version and provide a way to
- * manage loaded modules.
- *
- * Passed in the return address and a reference to the number of records
- * found. We set the start of the exidx data and the number of records.
- */
-_Unwind_Ptr __gnu_Unwind_Find_exidx (_Unwind_Ptr return_address,
-                                     int*        nrec) __attribute__ ((__noinline__,
-                                                                       __used__,
-                                                                       __noclone__));
-
-_Unwind_Ptr __gnu_Unwind_Find_exidx (_Unwind_Ptr return_address,
-                                     int*        nrec)
-{
-  rtems_rtl_data*   rtl;
-  rtems_chain_node* node;
-  __EIT_entry*      exidx_start = &__exidx_start;
-  __EIT_entry*      exidx_end = &__exidx_end;
-
-  rtl = rtems_rtl_lock ();
-
-  node = rtems_chain_first (&rtl->objects);
-  while (!rtems_chain_is_tail (&rtl->objects, node)) {
-    rtems_rtl_obj* obj = (rtems_rtl_obj*) node;
-    if (rtems_rtl_obj_text_inside (obj, (void*) return_address)) {
-      exidx_start = (__EIT_entry*) obj->eh_base;
-      exidx_end = (__EIT_entry*) (obj->eh_base + obj->eh_size);
-      break;
-    }
-    node = rtems_chain_next (node);
-  }
-
-  rtems_rtl_unlock ();
-
-  *nrec = exidx_end - exidx_start;
-
-  return (_Unwind_Ptr) exidx_start;
-}

cpukit/libdl/rtl-mdreloc-arm.c

@@ -12,14 +12,12 @@
 #include <string.h>
 #include <sys/types.h>
 #include <sys/stat.h>
-#include <unwind.h>
-#include <unwind-arm-common.h>
 
 #include <rtems/rtl/rtl.h>
 #include "rtl-elf.h"
 #include "rtl-error.h"
 #include <rtems/rtl/rtl-trace.h>
-#include "rtl-unwind.h"
+#include "rtl-unwind-arm.h"
 
 /*
  * Set to 1 to allow untested relocations. If you tested one and it
@@ -597,78 +595,3 @@ rtems_rtl_elf_relocate_rel (rtems_rtl_obj*            obj,
                                   symvalue,
                                   false);
 }
-
-bool
-rtems_rtl_elf_unwind_parse (const rtems_rtl_obj* obj,
-                            const char*          name,
-                            uint32_t             flags)
-{
-  /*
-   * We location the EH sections in section flags.
-   */
-  return false;
-}
-
-bool
-rtems_rtl_elf_unwind_register (rtems_rtl_obj* obj)
-{
-  return true;
-}
-
-bool
-rtems_rtl_elf_unwind_deregister (rtems_rtl_obj* obj)
-{
-  obj->loader = NULL;
-  return true;
-}
-
-/* An exception index table entry.  */
-typedef struct __EIT_entry
-{
-  _uw fnoffset;
-  _uw content;
-} __EIT_entry;
-
-/* The exception index table location in the base module */
-extern __EIT_entry __exidx_start;
-extern __EIT_entry __exidx_end;
-
-/*
- * A weak reference is in libgcc, provide a real version and provide a way to
- * manage loaded modules.
- *
- * Passed in the return address and a reference to the number of records
- * found. We set the start of the exidx data and the number of records.
- */
-_Unwind_Ptr __gnu_Unwind_Find_exidx (_Unwind_Ptr return_address,
-                                     int*        nrec) __attribute__ ((__noinline__,
-                                                                       __used__,
-                                                                       __noclone__));
-
-_Unwind_Ptr __gnu_Unwind_Find_exidx (_Unwind_Ptr return_address,
-                                     int*        nrec)
-{
-  rtems_rtl_data*   rtl;
-  rtems_chain_node* node;
-  __EIT_entry*      exidx_start = &__exidx_start;
-  __EIT_entry*      exidx_end = &__exidx_end;
-
-  rtl = rtems_rtl_lock ();
-
-  node = rtems_chain_first (&rtl->objects);
-  while (!rtems_chain_is_tail (&rtl->objects, node)) {
-    rtems_rtl_obj* obj = (rtems_rtl_obj*) node;
-    if (rtems_rtl_obj_text_inside (obj, (void*) return_address)) {
-      exidx_start = (__EIT_entry*) obj->eh_base;
-      exidx_end = (__EIT_entry*) (obj->eh_base + obj->eh_size);
-      break;
-    }
-    node = rtems_chain_next (node);
-  }
-
-  rtems_rtl_unlock ();
-
-  *nrec = exidx_end - exidx_start;
-
-  return (_Unwind_Ptr) exidx_start;
-}

cpukit/libdl/rtl-unwind-arm.c

@@ -0,0 +1,65 @@
+#include "rtl-unwind-arm.h"
+
+bool
+rtems_rtl_elf_unwind_parse (const rtems_rtl_obj* obj,
+                            const char*          name,
+                            uint32_t             flags)
+{
+  /*
+   * We location the EH sections in section flags.
+   */
+  return false;
+}
+
+bool
+rtems_rtl_elf_unwind_register (rtems_rtl_obj* obj)
+{
+  return true;
+}
+
+bool
+rtems_rtl_elf_unwind_deregister (rtems_rtl_obj* obj)
+{
+  obj->loader = NULL;
+  return true;
+}
+
+/*
+ * A weak reference is in libgcc, provide a real version and provide a way to
+ * manage loaded modules.
+ *
+ * Passed in the return address and a reference to the number of records
+ * found. We set the start of the exidx data and the number of records.
+ */
+_Unwind_Ptr __gnu_Unwind_Find_exidx (_Unwind_Ptr return_address,
+                                     int*        nrec) __attribute__ ((__noinline__,
+                                                                       __used__,
+                                                                       __noclone__));
+
+_Unwind_Ptr __gnu_Unwind_Find_exidx (_Unwind_Ptr return_address,
+                                     int*        nrec)
+{
+  rtems_rtl_data*   rtl;
+  rtems_chain_node* node;
+  __EIT_entry*      exidx_start = &__exidx_start;
+  __EIT_entry*      exidx_end = &__exidx_end;
+
+  rtl = rtems_rtl_lock ();
+
+  node = rtems_chain_first (&rtl->objects);
+  while (!rtems_chain_is_tail (&rtl->objects, node)) {
+    rtems_rtl_obj* obj = (rtems_rtl_obj*) node;
+    if (rtems_rtl_obj_text_inside (obj, (void*) return_address)) {
+      exidx_start = (__EIT_entry*) obj->eh_base;
+      exidx_end = (__EIT_entry*) (obj->eh_base + obj->eh_size);
+      break;
+    }
+    node = rtems_chain_next (node);
+  }
+
+  rtems_rtl_unlock ();
+
+  *nrec = exidx_end - exidx_start;
+
+  return (_Unwind_Ptr) exidx_start;
+}

cpukit/libdl/rtl-unwind-arm.h

@@ -0,0 +1,46 @@
+#include <unwind.h>
+
+#include <rtems/rtl/rtl.h>
+#include "rtl-unwind.h"
+
+typedef unsigned _Unwind_Word __attribute__((__mode__(__word__)));
+typedef _Unwind_Word _uw;
+
+bool
+rtems_rtl_elf_unwind_parse (const rtems_rtl_obj* obj,
+                            const char*          name,
+                            uint32_t             flags);
+
+bool
+rtems_rtl_elf_unwind_register (rtems_rtl_obj* obj);
+
+bool
+rtems_rtl_elf_unwind_deregister (rtems_rtl_obj* obj);
+
+/* An exception index table entry.  */
+typedef struct __EIT_entry
+{
+  _uw fnoffset;
+  _uw content;
+} __EIT_entry;
+
+/* The exception index table location in the base module */
+extern __EIT_entry __exidx_start;
+extern __EIT_entry __exidx_end;
+
+/*
+ * A weak reference is in libgcc, provide a real version and provide a way to
+ * manage loaded modules.
+ *
+ * Passed in the return address and a reference to the number of records
+ * found. We set the start of the exidx data and the number of records.
+ */
+_Unwind_Ptr
+__gnu_Unwind_Find_exidx (_Unwind_Ptr return_address,
+                         int*        nrec) __attribute__ ((__noinline__,
+                                                           __used__,
+                                                           __noclone__));
+
+_Unwind_Ptr
+__gnu_Unwind_Find_exidx (_Unwind_Ptr return_address,
+                         int*        nrec);

spec/build/cpukit/objdlaarch64.yml

@@ -12,4 +12,5 @@ install: []
 links: []
 source:
 - cpukit/libdl/rtl-mdreloc-aarch64.c
+- cpukit/libdl/rtl-unwind-arm.c
 type: build

spec/build/cpukit/objdlarm.yml

@@ -12,4 +12,5 @@ install: []
 links: []
 source:
 - cpukit/libdl/rtl-mdreloc-arm.c
+- cpukit/libdl/rtl-unwind-arm.c
 type: build