fix recursively_compute_inclusions and add dwz test case

Doug pointed out a while ago that in the final dwz -m patch, nothing
ever set symtab::user.

This patch fixes this oversight and adds a test case showing why it is
important.

Built and regtested (both ways) on x86-64 Fedora 18.
The new test unconditionally tests the partial unit machinery, which I
think is an added plus.

	* dwarf2read.c (recursively_compute_inclusions): Add
	"immediate_parent" argument.  Set symtab's "user" field
	if not set.
	(compute_symtab_includes): Update.

	* gdb.dwarf2/dwz.exp: New file.

gdb/ChangeLog

@@ -1,3 +1,10 @@
+2013-08-07  Tom Tromey  <tromey@redhat.com>
+
+	* dwarf2read.c (recursively_compute_inclusions): Add
+	"immediate_parent" argument.  Set symtab's "user" field
+	if not set.
+	(compute_symtab_includes): Update.
+
 2013-08-07  Tom Tromey  <tromey@redhat.com>
 
 	* linespec.c (convert_linespec_to_sals): Use maybe_add_address

gdb/dwarf2read.c

@@ -7374,7 +7374,8 @@ get_symtab (struct dwarf2_per_cu_data *per_cu)
 static void
 recursively_compute_inclusions (VEC (symtab_ptr) **result,
 				htab_t all_children, htab_t all_type_symtabs,
-				struct dwarf2_per_cu_data *per_cu)
+				struct dwarf2_per_cu_data *per_cu,
+				struct symtab *immediate_parent)
 {
   void **slot;
   int ix;
@@ -7402,10 +7403,16 @@ recursively_compute_inclusions (VEC (symtab_ptr) **result,
 	    {
 	      *slot = symtab;
 	      VEC_safe_push (symtab_ptr, *result, symtab);
+	      if (symtab->user == NULL)
+		symtab->user = immediate_parent;
 	    }
 	}
       else
-	VEC_safe_push (symtab_ptr, *result, symtab);
+	{
+	  VEC_safe_push (symtab_ptr, *result, symtab);
+	  if (symtab->user == NULL)
+	    symtab->user = immediate_parent;
+	}
     }
 
   for (ix = 0;
@@ -7413,7 +7420,7 @@ recursively_compute_inclusions (VEC (symtab_ptr) **result,
        ++ix)
     {
       recursively_compute_inclusions (result, all_children,
-				      all_type_symtabs, iter);
+				      all_type_symtabs, iter, symtab);
     }
 }
 
@@ -7449,7 +7456,8 @@ compute_symtab_includes (struct dwarf2_per_cu_data *per_cu)
 	   ++ix)
 	{
 	  recursively_compute_inclusions (&result_symtabs, all_children,
-					  all_type_symtabs, per_cu_iter);
+					  all_type_symtabs, per_cu_iter,
+					  symtab);
 	}
 
       /* Now we have a transitive closure of all the included symtabs.  */

gdb/testsuite/ChangeLog

@@ -1,3 +1,7 @@
+2013-08-07  Tom Tromey  <tromey@redhat.com>
+
+	* gdb.dwarf2/dwz.exp: New file.
+
 2013-08-02  Tom Tromey  <tromey@redhat.com>
 
 	* gdb.base/watchpoint.c (struct foo5): New.

gdb/testsuite/gdb.dwarf2/dwz.exp

@@ -0,0 +1,106 @@
+# Copyright 2013 Free Software Foundation, Inc.
+
+# This program is free software; you can redistribute it and/or modify
+# it under the terms of the GNU General Public License as published by
+# the Free Software Foundation; either version 3 of the License, or
+# (at your option) any later version.
+#
+# This program is distributed in the hope that it will be useful,
+# but WITHOUT ANY WARRANTY; without even the implied warranty of
+# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+# GNU General Public License for more details.
+#
+# You should have received a copy of the GNU General Public License
+# along with this program.  If not, see <http://www.gnu.org/licenses/>.
+
+load_lib dwarf.exp
+
+# This test can only be run on targets which support DWARF-2 and use gas.
+if {![dwarf2_support]} {
+    return 0
+}
+
+standard_testfile main.c dwz.S
+
+# Create the DWARF.
+set asm_file [standard_output_file $srcfile2]
+Dwarf::assemble $asm_file {
+    declare_labels partial_label double_label int_label int_label2
+
+    extern main
+
+    cu {} {
+	partial_label: partial_unit {} {
+	    subprogram {
+		{name main}
+		{low_pc main addr}
+		{high_pc "main + 10" addr}
+	    }
+	}
+    }
+
+    cu {} {
+	compile_unit {{language @DW_LANG_C}} {
+	    int_label2: base_type {
+		{name int}
+		{byte_size 4 sdata}
+		{encoding @DW_ATE_signed}
+	    }
+
+	    constant {
+		{name the_int}
+		{type :$int_label2}
+		{const_value 99 data1}
+	    }
+
+	    constant {
+		{name other_int}
+		{type :$int_label2}
+		{const_value 99 data1}
+	    }
+	}
+    }
+
+    cu {} {
+	compile_unit {{language @DW_LANG_C}} {
+	    imported_unit {
+		{import $partial_label ref_addr}
+	    }
+
+	    int_label: base_type {
+		{name int}
+		{byte_size 4 sdata}
+		{encoding @DW_ATE_signed}
+	    }
+
+	    constant {
+		{name the_int}
+		{type :$int_label}
+		{const_value 23 data1}
+	    }
+	}
+    }
+}
+
+if  { [gdb_compile ${srcdir}/${subdir}/${srcfile} ${binfile}1.o \
+	   object {nodebug}] != "" } {
+    return -1
+}
+
+if  { [gdb_compile $asm_file ${binfile}2.o object {nodebug}] != "" } {
+    return -1
+}
+
+if  { [gdb_compile [list ${binfile}1.o ${binfile}2.o] \
+	   "${binfile}" executable {}] != "" } {
+    return -1
+}
+
+clean_restart ${testfile}
+
+if ![runto_main] {
+    return -1
+}
+
+gdb_test "p other_int" " = 99"
+gdb_test "p the_int" " = 23"