[RFA] Make gdb.lookup_typename work for Rust types

[Tom Tromey <tom@tromey.com>]

PR rust/21763 points out that gdb.lookup_typename does not work properly
for (some) Rust types.  I tracked this down to a missing case in
symbol_matches_domain.

Tested by the buildbot.

2017-07-14  Tom Tromey  <tom@tromey.com>

	PR rust/21763:
	* symtab.c (symbol_matches_domain): Add language_rust to special
	case.
	* rust-exp.y (convert_ast_to_expression) <OP_VAR_VALUE>: Don't
	treat LOC_TYPEDEF symbols as variables.

2017-07-14  Tom Tromey  <tom@tromey.com>

	* gdb.rust/simple.exp: Add regression test for PR rust/21763.
---
 gdb/ChangeLog                     |  8 ++++++++
 gdb/rust-exp.y                    | 12 +++++++++---
 gdb/symtab.c                      |  3 ++-
 gdb/testsuite/ChangeLog           |  4 ++++
 gdb/testsuite/gdb.rust/simple.exp |  8 ++++++++
 5 files changed, 31 insertions(+), 4 deletions(-)

diff --git a/gdb/ChangeLog b/gdb/ChangeLog
index 550a7a8..5c36fb1 100644
--- a/gdb/ChangeLog
+++ b/gdb/ChangeLog
@@ -1,3 +1,11 @@
+2017-07-14  Tom Tromey  <tom@tromey.com>
+
+	PR rust/21763:
+	* symtab.c (symbol_matches_domain): Add language_rust to special
+	case.
+	* rust-exp.y (convert_ast_to_expression) <OP_VAR_VALUE>: Don't
+	treat LOC_TYPEDEF symbols as variables.
+
 2017-07-14  Simon Marchi  <simon.marchi@ericsson.com>
 
 	* ax-gdb.c (gen_aggregate_elt_ref): Remove operand_name and
diff --git a/gdb/rust-exp.y b/gdb/rust-exp.y
index c7361bc..821abcd 100644
--- a/gdb/rust-exp.y
+++ b/gdb/rust-exp.y
@@ -2316,7 +2316,7 @@ convert_ast_to_expression (struct parser_state *state,
 	varname = convert_name (state, operation);
 	sym = rust_lookup_symbol (varname, expression_context_block,
 				  VAR_DOMAIN);
-	if (sym.symbol != NULL)
+	if (sym.symbol != NULL && SYMBOL_CLASS (sym.symbol) != LOC_TYPEDEF)
 	  {
 	    write_exp_elt_opcode (state, OP_VAR_VALUE);
 	    write_exp_elt_block (state, sym.block);
@@ -2325,9 +2325,15 @@ convert_ast_to_expression (struct parser_state *state,
 	  }
 	else
 	  {
-	    struct type *type;
+	    struct type *type = NULL;
 
-	    type = rust_lookup_type (varname, expression_context_block);
+	    if (sym.symbol != NULL)
+	      {
+		gdb_assert (SYMBOL_CLASS (sym.symbol) == LOC_TYPEDEF);
+		type = SYMBOL_TYPE (sym.symbol);
+	      }
+	    if (type == NULL)
+	      type = rust_lookup_type (varname, expression_context_block);
 	    if (type == NULL)
 	      error (_("No symbol '%s' in current context"), varname);
 
diff --git a/gdb/symtab.c b/gdb/symtab.c
index 497d520..89cc338 100644
--- a/gdb/symtab.c
+++ b/gdb/symtab.c
@@ -2625,7 +2625,8 @@ symbol_matches_domain (enum language symbol_language,
      Similarly, any Ada type declaration implicitly defines a typedef.  */
   if (symbol_language == language_cplus
       || symbol_language == language_d
-      || symbol_language == language_ada)
+      || symbol_language == language_ada
+      || symbol_language == language_rust)
     {
       if ((domain == VAR_DOMAIN || domain == STRUCT_DOMAIN)
 	  && symbol_domain == STRUCT_DOMAIN)
diff --git a/gdb/testsuite/ChangeLog b/gdb/testsuite/ChangeLog
index c29f6e5..1807fb6 100644
--- a/gdb/testsuite/ChangeLog
+++ b/gdb/testsuite/ChangeLog
@@ -1,3 +1,7 @@
+2017-07-14  Tom Tromey  <tom@tromey.com>
+
+	* gdb.rust/simple.exp: Add regression test for PR rust/21763.
+
 2017-07-13  Andrew Burgess  <andrew.burgess@embecosm.com>
 
 	* gdb.mi/mi-vla-fortran.exp: Correct even more parameter passing
diff --git a/gdb/testsuite/gdb.rust/simple.exp b/gdb/testsuite/gdb.rust/simple.exp
index 872b22c..db23162 100644
--- a/gdb/testsuite/gdb.rust/simple.exp
+++ b/gdb/testsuite/gdb.rust/simple.exp
@@ -246,3 +246,11 @@ gdb_test "print parametrized.next.val" \
     " = \\(simple::ParametrizedStruct<i32> \\*\\) $hex"
 gdb_test "print parametrized" \
     " = simple::ParametrizedStruct<i32> \\{next: simple::ParametrizedEnum<\[a-z:\]*Box<simple::ParametrizedStruct<i32>>>::Val\\{val: $hex\\}, value: 0\\}"
+
+
+load_lib gdb-python.exp
+if {[skip_python_tests]} {
+    continue
+}
+
+gdb_test "python print(gdb.lookup_type('simple::HiBob'))" "simple::HiBob"
-- 
2.9.4