Handle function aliases better (PR gdb/19487, errno printing)

[deliverable/binutils-gdb.git] / gdb / c-exp.y

diff --git a/gdb/c-exp.y b/gdb/c-exp.y
index 24a2fbd76e684e284bc32878068567d99fef4ec8..a1f9feee71795dc6d90ef6bb2aca5eb1784946c1 100644 (file)
--- a/gdb/c-exp.y
+++ b/gdb/c-exp.y
@@ -1038,18 +1038,38 @@ variable:       name_not_typename
                            }
                          else
                            {
-                             struct bound_minimal_symbol msymbol;
                              char *arg = copy_name ($1.stoken);
 
-                             msymbol =
-                               lookup_bound_minimal_symbol (arg);
-                             if (msymbol.minsym != NULL)
-                               write_exp_msymbol (pstate, msymbol);
-                             else if (!have_full_symbols () && !have_partial_symbols ())
-                               error (_("No symbol table is loaded.  Use the \"file\" command."));
+                             bound_minimal_symbol msymbol
+                               = lookup_bound_minimal_symbol (arg);
+                             if (msymbol.minsym == NULL)
+                               {
+                                 if (!have_full_symbols () && !have_partial_symbols ())
+                                   error (_("No symbol table is loaded.  Use the \"file\" command."));
+                                 else
+                                   error (_("No symbol \"%s\" in current context."),
+                                          copy_name ($1.stoken));
+                               }
+
+                             /* This minsym might be an alias for
+                                another function.  See if we can find
+                                the debug symbol for the target, and
+                                if so, use it instead, since it has
+                                return type / prototype info.  This
+                                is important for example for "p
+                                *__errno_location()".  */
+                             symbol *alias_target
+                               = find_function_alias_target (msymbol);
+                             if (alias_target != NULL)
+                               {
+                                 write_exp_elt_opcode (pstate, OP_VAR_VALUE);
+                                 write_exp_elt_block
+                                   (pstate, SYMBOL_BLOCK_VALUE (alias_target));
+                                 write_exp_elt_sym (pstate, alias_target);
+                                 write_exp_elt_opcode (pstate, OP_VAR_VALUE);
+                               }
                              else
-                               error (_("No symbol \"%s\" in current context."),
-                                      copy_name ($1.stoken));
+                               write_exp_msymbol (pstate, msymbol);
                            }
                        }
        ;