Clean up linker architecture macros.

We don't need our own architecture macros; the standard ones will do.

This patch also fixes some __x86_64__ tests to be USE_RELA tests instead,
because they're not actually x86_64-specific.

I've cleaned up architecture-specific code slightly so where possible
all the code corresponding to a particular architecture is together.

This patch also fixes a bug in LP64 DT_PLTGOT handling, which should be
an error rather than falling through into DT_DEBUG! There was another #ifdef
bug where we'd only report unexpected DT_ entries on MIPS.

Change-Id: Id1d04e372611f641c1aa278a18e379f28af9eaf5

1 files changed, 18 insertions, 24 deletions

diff --git a/libthread_db/libthread_db.c b/libthread_db/libthread_db.c
index bd78ae6..d899045 100644
--- a/libthread_db/libthread_db.c
+++ b/libthread_db/libthread_db.c
@@ -79,29 +79,8 @@ static td_thrhandle_t gEventMsgHandle;
 static int
 _event_getmsg_helper(td_thrhandle_t const * handle, void * bkpt_addr)
 {
-    void * pc;
-
-#ifdef __i386__
-    /* Get the eip from offset 12*4 = 48 as defined in the struct
-     * user_regs_struct in user_32.h
-     */
-    pc = (void *)ptrace(PTRACE_PEEKUSR, handle->tid, (void *)48 /* eip */, NULL);
-    /* FIXME - pc is a non-decremented breakpoint address, hence the
-     * addition of 1 on test.  This seems to work for the thread hook
-     * function in libc.so but should be properly fixed.
-     */
-    if (pc == ((int)bkpt_addr + 1)) {
-        /* The hook function takes the id of the new thread as it's first
-         * param, so grab it from ecx at offset 4 in struct user_regs_struct
-         * (using fastcall convention for x86)
-         */
-        gEventMsgHandle.pid = ptrace(PTRACE_PEEKUSR, handle->tid, (void *)4 /* ecx */, NULL);
-        gEventMsgHandle.tid = gEventMsgHandle.pid;
-        return 0x42;
-    }
-#elif defined(__arm__)
-    pc = (void *)ptrace(PTRACE_PEEKUSR, handle->tid, (void *)60 /* r15/pc */, NULL);
-
+#if defined(__arm__)
+    void* pc = (void *)ptrace(PTRACE_PEEKUSR, handle->tid, (void *)60 /* r15/pc */, NULL);
     if (pc == bkpt_addr) {
         // The hook function takes the id of the new thread as it's first param,
         // so grab it from r0.
@@ -109,8 +88,23 @@ _event_getmsg_helper(td_thrhandle_t const * handle, void * bkpt_addr)
         gEventMsgHandle.tid = gEventMsgHandle.pid;
         return 0x42;
     }
+#elif defined(__i386__)
+    // Get the eip from offset 12*4 = 48 as defined in the struct
+    // user_regs_struct in user_32.h
+    void* pc = (void *)ptrace(PTRACE_PEEKUSR, handle->tid, (void *)48 /* eip */, NULL);
+    // FIXME - pc is a non-decremented breakpoint address, hence the
+    // addition of 1 on test.  This seems to work for the thread hook
+    // function in libc.so but should be properly fixed.
+    if (pc == ((int)bkpt_addr + 1)) {
+        // The hook function takes the id of the new thread as it's first
+        // param, so grab it from ecx at offset 4 in struct user_regs_struct
+        // (using fastcall convention for x86)
+        gEventMsgHandle.pid = ptrace(PTRACE_PEEKUSR, handle->tid, (void *)4 /* ecx */, NULL);
+        gEventMsgHandle.tid = gEventMsgHandle.pid;
+        return 0x42;
+    }
 #elif defined(__mips__)
-    pc = (void *)ptrace(PTRACE_PEEKUSR, handle->tid, (void *)(64*4) /* pc */, NULL);
+    void* pc = (void *)ptrace(PTRACE_PEEKUSR, handle->tid, (void *)(64*4) /* pc */, NULL);
     if (pc == bkpt_addr) {
         // The hook function takes the id of the new thread as it's first param,
         // so grab it from a0