[PATCH v2 8/8] Fix regression due to Pragma Import series

[Tom Tromey <tromey@adacore.com>]

A co-worker here at AdaCore discovered that the Pragma Import series
caused a rgression.  When debugging gnat1, gdb started asking for
overload resolution like:

(gdb) call pp(n)
Multiple matches for pp
[0] cancel
[1] pp (types.union_id) at ../../gcc/gcc/ada/treepr.adb:511
[2] treepr.pp (types.union_id) at ../../gcc/gcc/ada/treepr.adb:511

This worked before the series, and is strange anyway, because the
matches refer to the same function.

This patch adds a test case for this situation and fixes the bug by
pruning identical functions in remove_extra_symbols.
---
 gdb/ada-lang.c                       | 14 ++++++++++++++
 gdb/testsuite/gdb.ada/import.exp     |  2 ++
 gdb/testsuite/gdb.ada/import/pkg.adb |  7 +++++++
 gdb/testsuite/gdb.ada/import/pkg.ads |  5 +++++
 4 files changed, 28 insertions(+)

diff --git a/gdb/ada-lang.c b/gdb/ada-lang.c
index 091faba3037..224850b7a69 100644
--- a/gdb/ada-lang.c
+++ b/gdb/ada-lang.c
@@ -5080,6 +5080,20 @@ remove_extra_symbols (std::vector<struct block_symbol> &syms)
 	    }
 	}
       
+      /* Two functions with the same block are identical.  */
+
+      else if (syms[i].symbol->aclass () == LOC_BLOCK)
+	{
+	  for (j = 0; !remove_p && j < syms.size (); j += 1)
+	    {
+	      if (i != j
+		  && syms[j].symbol->aclass () == LOC_BLOCK
+		  && (syms[i].symbol->value_block ()
+		      == syms[j].symbol->value_block ()))
+		remove_p = true;
+	    }
+	}
+
       if (remove_p)
 	syms.erase (syms.begin () + i);
       else
diff --git a/gdb/testsuite/gdb.ada/import.exp b/gdb/testsuite/gdb.ada/import.exp
index 866b431aac5..90cffa48e9c 100644
--- a/gdb/testsuite/gdb.ada/import.exp
+++ b/gdb/testsuite/gdb.ada/import.exp
@@ -56,3 +56,5 @@ gdb_breakpoint "local_imported_func" message
 gdb_breakpoint "pkg.exported_func_ada" message
 gdb_breakpoint "exported_func_ada" message
 gdb_breakpoint "exported_func" message
+
+gdb_test "print copy" " = 42"
diff --git a/gdb/testsuite/gdb.ada/import/pkg.adb b/gdb/testsuite/gdb.ada/import/pkg.adb
index e4f1c1a88b7..1c706188c69 100644
--- a/gdb/testsuite/gdb.ada/import/pkg.adb
+++ b/gdb/testsuite/gdb.ada/import/pkg.adb
@@ -20,6 +20,13 @@ package body Pkg is
       return Imported_Var_Ada;
    end Exported_Func_Ada;
 
+   function base return Integer is
+   begin
+      return Imported_Var_Ada;
+   end base;
+
+   function copy return Integer renames base;
+
    procedure Do_Nothing (A : System.Address) is
    begin
       null;
diff --git a/gdb/testsuite/gdb.ada/import/pkg.ads b/gdb/testsuite/gdb.ada/import/pkg.ads
index 5576d1b92d7..e30781a436e 100644
--- a/gdb/testsuite/gdb.ada/import/pkg.ads
+++ b/gdb/testsuite/gdb.ada/import/pkg.ads
@@ -28,6 +28,11 @@ package Pkg is
    function Exported_Func_Ada return Integer;
    pragma Export (C, Exported_Func_Ada, "exported_func");
 
+   function base return Integer;
+   pragma Export (Ada, base);
+   function copy return Integer;
+   pragma Export (Ada, copy);
+
    procedure Do_Nothing (A : System.Address);
 
 end Pkg;

-- 
2.39.1