Constify chain_candidate

While investigating this bug, I wasn't sure if chain_candidate might
update 'chain'.  I changed it to accept a const reference, making it
clear that it cannot.  This simplifies the code a tiny bit as well.

diff --git a/gdb/dwarf2/loc.c b/gdb/dwarf2/loc.c
index acb7b863145bb02f24a67611b67f7d77a1a829df..addf611d8f892d76777b243340659eb1ba140d18 100644 (file)
--- a/gdb/dwarf2/loc.c
+++ b/gdb/dwarf2/loc.c
@@ -835,9 +835,9 @@ tailcall_dump (struct gdbarch *gdbarch, const struct call_site *call_site)
 static void
 chain_candidate (struct gdbarch *gdbarch,
                 gdb::unique_xmalloc_ptr<struct call_site_chain> *resultp,
-                std::vector<struct call_site *> *chain)
+                const std::vector<struct call_site *> &chain)
 {
-  long length = chain->size ();
+  long length = chain.size ();
   int callers, callees, idx;
 
   if (*resultp == NULL)
@@ -850,8 +850,8 @@ chain_candidate (struct gdbarch *gdbarch,
                    + sizeof (*result->call_site) * (length - 1)));
       result->length = length;
       result->callers = result->callees = length;
-      if (!chain->empty ())
-       memcpy (result->call_site, chain->data (),
+      if (!chain.empty ())
+       memcpy (result->call_site, chain.data (),
                sizeof (*result->call_site) * length);
       resultp->reset (result);
 
@@ -870,7 +870,7 @@ chain_candidate (struct gdbarch *gdbarch,
     {
       fprintf_unfiltered (gdb_stdlog, "tailcall: compare:");
       for (idx = 0; idx < length; idx++)
-       tailcall_dump (gdbarch, chain->at (idx));
+       tailcall_dump (gdbarch, chain[idx]);
       fputc_unfiltered ('\n', gdb_stdlog);
     }
 
@@ -878,7 +878,7 @@ chain_candidate (struct gdbarch *gdbarch,
 
   callers = std::min ((long) (*resultp)->callers, length);
   for (idx = 0; idx < callers; idx++)
-    if ((*resultp)->call_site[idx] != chain->at (idx))
+    if ((*resultp)->call_site[idx] != chain[idx])
       {
        (*resultp)->callers = idx;
        break;
@@ -889,7 +889,7 @@ chain_candidate (struct gdbarch *gdbarch,
   callees = std::min ((long) (*resultp)->callees, length);
   for (idx = 0; idx < callees; idx++)
     if ((*resultp)->call_site[(*resultp)->length - 1 - idx]
-       != chain->at (length - 1 - idx))
+       != chain[length - 1 - idx])
       {
        (*resultp)->callees = idx;
        break;
@@ -970,7 +970,7 @@ call_site_find_chain_1 (struct gdbarch *gdbarch, CORE_ADDR caller_pc,
 
       if (target_func_addr == callee_pc)
        {
-         chain_candidate (gdbarch, &retval, &chain);
+         chain_candidate (gdbarch, &retval, chain);
          if (retval == NULL)
            break;