Permit comparing non-empty interfaces with empty interfaces.

From-SVN: r170385

diff --git a/gcc/go/gofrontend/expressions.cc b/gcc/go/gofrontend/expressions.cc
index 3d687a613d472b9f46be4571a3e8aa51651e9bc4..8b064e617f56d6773e1e47b46d92db6c621044e8 100644 (file)
--- a/gcc/go/gofrontend/expressions.cc
+++ b/gcc/go/gofrontend/expressions.cc
@@ -6270,9 +6270,9 @@ Expression::comparison_tree(Translate_context* context, Operator op,
   else if (left_type->interface_type() != NULL
           && right_type->interface_type() != NULL)
     {
-      if (left_type->interface_type()->is_empty())
+      if (left_type->interface_type()->is_empty()
+         && right_type->interface_type()->is_empty())
        {
-         gcc_assert(right_type->interface_type()->is_empty());
          static tree empty_interface_compare_decl;
          left_tree = Gogo::call_builtin(&empty_interface_compare_decl,
                                         location,
@@ -6288,9 +6288,9 @@ Expression::comparison_tree(Translate_context* context, Operator op,
          // This can panic if the type is uncomparable.
          TREE_NOTHROW(empty_interface_compare_decl) = 0;
        }
-      else
+      else if (!left_type->interface_type()->is_empty()
+              && !right_type->interface_type()->is_empty())
        {
-         gcc_assert(!right_type->interface_type()->is_empty());
          static tree interface_compare_decl;
          left_tree = Gogo::call_builtin(&interface_compare_decl,
                                         location,
@@ -6306,6 +6306,32 @@ Expression::comparison_tree(Translate_context* context, Operator op,
          // This can panic if the type is uncomparable.
          TREE_NOTHROW(interface_compare_decl) = 0;
        }
+      else
+       {
+         if (left_type->interface_type()->is_empty())
+           {
+             gcc_assert(op == OPERATOR_EQEQ || op == OPERATOR_NOTEQ);
+             std::swap(left_type, right_type);
+             std::swap(left_tree, right_tree);
+           }
+         gcc_assert(!left_type->interface_type()->is_empty());
+         gcc_assert(right_type->interface_type()->is_empty());
+         static tree interface_empty_compare_decl;
+         left_tree = Gogo::call_builtin(&interface_empty_compare_decl,
+                                        location,
+                                        "__go_interface_empty_compare",
+                                        2,
+                                        integer_type_node,
+                                        TREE_TYPE(left_tree),
+                                        left_tree,
+                                        TREE_TYPE(right_tree),
+                                        right_tree);
+         if (left_tree == error_mark_node)
+           return error_mark_node;
+         // This can panic if the type is uncomparable.
+         TREE_NOTHROW(interface_empty_compare_decl) = 0;
+       }
+
       right_tree = build_int_cst_type(integer_type_node, 0);
     }
 

diff --git a/libgo/Makefile.am b/libgo/Makefile.am
index 9274b36d52d355080159538fc0f6f4929eae4b93..814d7ed6132e4e611eadc37a7f0b8ead1a2290b6 100644 (file)
--- a/libgo/Makefile.am
+++ b/libgo/Makefile.am
@@ -352,6 +352,7 @@ runtime_files = \
        runtime/go-int-array-to-string.c \
        runtime/go-int-to-string.c \
        runtime/go-interface-compare.c \
+       runtime/go-interface-eface-compare.c \
        runtime/go-interface-val-compare.c \
        runtime/go-lock-os-thread.c \
        runtime/go-map-delete.c \

diff --git a/libgo/Makefile.in b/libgo/Makefile.in
index e4ec14901c6c922b168f4b23a285625e04d3d448..11352cf93d91eea410190df742e59e62206c7738 100644 (file)
--- a/libgo/Makefile.in
+++ b/libgo/Makefile.in
@@ -179,6 +179,7 @@ am__libgo_la_SOURCES_DIST = runtime/go-append.c runtime/go-assert.c \
        runtime/go-getgoroot.c runtime/go-go.c runtime/go-gomaxprocs.c \
        runtime/go-int-array-to-string.c runtime/go-int-to-string.c \
        runtime/go-interface-compare.c \
+       runtime/go-interface-eface-compare.c \
        runtime/go-interface-val-compare.c runtime/go-lock-os-thread.c \
        runtime/go-map-delete.c runtime/go-map-index.c \
        runtime/go-map-len.c runtime/go-map-range.c \
@@ -222,16 +223,17 @@ am__objects_3 = go-append.lo go-assert.lo go-assert-interface.lo \
        go-defer.lo go-deferred-recover.lo go-eface-compare.lo \
        go-eface-val-compare.lo go-getgoroot.lo go-go.lo \
        go-gomaxprocs.lo go-int-array-to-string.lo go-int-to-string.lo \
-       go-interface-compare.lo go-interface-val-compare.lo \
-       go-lock-os-thread.lo go-map-delete.lo go-map-index.lo \
-       go-map-len.lo go-map-range.lo go-nanotime.lo go-new-channel.lo \
-       go-new-map.lo go-new.lo go-note.lo go-panic.lo \
-       go-panic-defer.lo go-print.lo go-rec-big.lo go-rec-nb-big.lo \
-       go-rec-nb-small.lo go-rec-small.lo go-recover.lo go-reflect.lo \
-       go-reflect-call.lo go-reflect-chan.lo go-reflect-map.lo \
-       go-rune.lo go-runtime-error.lo go-sched.lo go-select.lo \
-       go-semacquire.lo go-send-big.lo go-send-nb-big.lo \
-       go-send-nb-small.lo go-send-small.lo go-signal.lo go-strcmp.lo \
+       go-interface-compare.lo go-interface-eface-compare.lo \
+       go-interface-val-compare.lo go-lock-os-thread.lo \
+       go-map-delete.lo go-map-index.lo go-map-len.lo go-map-range.lo \
+       go-nanotime.lo go-new-channel.lo go-new-map.lo go-new.lo \
+       go-note.lo go-panic.lo go-panic-defer.lo go-print.lo \
+       go-rec-big.lo go-rec-nb-big.lo go-rec-nb-small.lo \
+       go-rec-small.lo go-recover.lo go-reflect.lo go-reflect-call.lo \
+       go-reflect-chan.lo go-reflect-map.lo go-rune.lo \
+       go-runtime-error.lo go-sched.lo go-select.lo go-semacquire.lo \
+       go-send-big.lo go-send-nb-big.lo go-send-nb-small.lo \
+       go-send-small.lo go-signal.lo go-strcmp.lo \
        go-string-to-byte-array.lo go-string-to-int-array.lo \
        go-strplus.lo go-strslice.lo go-trampoline.lo go-type-eface.lo \
        go-type-error.lo go-type-identity.lo go-type-interface.lo \
@@ -764,6 +766,7 @@ runtime_files = \
        runtime/go-int-array-to-string.c \
        runtime/go-int-to-string.c \
        runtime/go-interface-compare.c \
+       runtime/go-interface-eface-compare.c \
        runtime/go-interface-val-compare.c \
        runtime/go-lock-os-thread.c \
        runtime/go-map-delete.c \
@@ -2067,6 +2070,7 @@ distclean-compile:
 @AMDEP_TRUE@@am__include@ @am__quote@./$(DEPDIR)/go-int-array-to-string.Plo@am__quote@
 @AMDEP_TRUE@@am__include@ @am__quote@./$(DEPDIR)/go-int-to-string.Plo@am__quote@
 @AMDEP_TRUE@@am__include@ @am__quote@./$(DEPDIR)/go-interface-compare.Plo@am__quote@
+@AMDEP_TRUE@@am__include@ @am__quote@./$(DEPDIR)/go-interface-eface-compare.Plo@am__quote@
 @AMDEP_TRUE@@am__include@ @am__quote@./$(DEPDIR)/go-interface-val-compare.Plo@am__quote@
 @AMDEP_TRUE@@am__include@ @am__quote@./$(DEPDIR)/go-lock-os-thread.Plo@am__quote@
 @AMDEP_TRUE@@am__include@ @am__quote@./$(DEPDIR)/go-main.Po@am__quote@
@@ -2358,6 +2362,13 @@ go-interface-compare.lo: runtime/go-interface-compare.c
 @AMDEP_TRUE@@am__fastdepCC_FALSE@      DEPDIR=$(DEPDIR) $(CCDEPMODE) $(depcomp) @AMDEPBACKSLASH@
 @am__fastdepCC_FALSE@  $(LIBTOOL)  --tag=CC $(AM_LIBTOOLFLAGS) $(LIBTOOLFLAGS) --mode=compile $(CC) $(DEFS) $(DEFAULT_INCLUDES) $(INCLUDES) $(AM_CPPFLAGS) $(CPPFLAGS) $(AM_CFLAGS) $(CFLAGS) -c -o go-interface-compare.lo `test -f 'runtime/go-interface-compare.c' || echo '$(srcdir)/'`runtime/go-interface-compare.c
 
+go-interface-eface-compare.lo: runtime/go-interface-eface-compare.c
+@am__fastdepCC_TRUE@   $(LIBTOOL)  --tag=CC $(AM_LIBTOOLFLAGS) $(LIBTOOLFLAGS) --mode=compile $(CC) $(DEFS) $(DEFAULT_INCLUDES) $(INCLUDES) $(AM_CPPFLAGS) $(CPPFLAGS) $(AM_CFLAGS) $(CFLAGS) -MT go-interface-eface-compare.lo -MD -MP -MF $(DEPDIR)/go-interface-eface-compare.Tpo -c -o go-interface-eface-compare.lo `test -f 'runtime/go-interface-eface-compare.c' || echo '$(srcdir)/'`runtime/go-interface-eface-compare.c
+@am__fastdepCC_TRUE@   $(am__mv) $(DEPDIR)/go-interface-eface-compare.Tpo $(DEPDIR)/go-interface-eface-compare.Plo
+@AMDEP_TRUE@@am__fastdepCC_FALSE@      source='runtime/go-interface-eface-compare.c' object='go-interface-eface-compare.lo' libtool=yes @AMDEPBACKSLASH@
+@AMDEP_TRUE@@am__fastdepCC_FALSE@      DEPDIR=$(DEPDIR) $(CCDEPMODE) $(depcomp) @AMDEPBACKSLASH@
+@am__fastdepCC_FALSE@  $(LIBTOOL)  --tag=CC $(AM_LIBTOOLFLAGS) $(LIBTOOLFLAGS) --mode=compile $(CC) $(DEFS) $(DEFAULT_INCLUDES) $(INCLUDES) $(AM_CPPFLAGS) $(CPPFLAGS) $(AM_CFLAGS) $(CFLAGS) -c -o go-interface-eface-compare.lo `test -f 'runtime/go-interface-eface-compare.c' || echo '$(srcdir)/'`runtime/go-interface-eface-compare.c
+
 go-interface-val-compare.lo: runtime/go-interface-val-compare.c
 @am__fastdepCC_TRUE@   $(LIBTOOL)  --tag=CC $(AM_LIBTOOLFLAGS) $(LIBTOOLFLAGS) --mode=compile $(CC) $(DEFS) $(DEFAULT_INCLUDES) $(INCLUDES) $(AM_CPPFLAGS) $(CPPFLAGS) $(AM_CFLAGS) $(CFLAGS) -MT go-interface-val-compare.lo -MD -MP -MF $(DEPDIR)/go-interface-val-compare.Tpo -c -o go-interface-val-compare.lo `test -f 'runtime/go-interface-val-compare.c' || echo '$(srcdir)/'`runtime/go-interface-val-compare.c
 @am__fastdepCC_TRUE@   $(am__mv) $(DEPDIR)/go-interface-val-compare.Tpo $(DEPDIR)/go-interface-val-compare.Plo

diff --git a/libgo/runtime/go-interface-eface-compare.c b/libgo/runtime/go-interface-eface-compare.c
new file mode 100644 (file)
index 0000000..9de8424
--- /dev/null
+++ b/libgo/runtime/go-interface-eface-compare.c
@@ -0,0 +1,32 @@
+/* go-interface-eface-compare.c -- compare non-empty and empty interface.
+
+   Copyright 2011 The Go Authors. All rights reserved.
+   Use of this source code is governed by a BSD-style
+   license that can be found in the LICENSE file.  */
+
+#include "interface.h"
+
+/* Compare a non-empty interface value with an empty interface value.
+   Return 0 for equal, not zero for not equal (return value is like
+   strcmp).  */
+
+int
+__go_interface_empty_compare (struct __go_interface left,
+                             struct __go_empty_interface right)
+{
+  const struct __go_type_descriptor *left_descriptor;
+
+  if (left.__methods == NULL && right.__type_descriptor == NULL)
+    return 0;
+  if (left.__methods == NULL || right.__type_descriptor == NULL)
+    return 1;
+  left_descriptor = left.__methods[0];
+  if (!__go_type_descriptors_equal (left_descriptor, right.__type_descriptor))
+    return 1;
+  if (__go_is_pointer_type (left_descriptor))
+    return left.__object == right.__object ? 0 : 1;
+  if (!left_descriptor->__equalfn (left.__object, right.__object,
+                                  left_descriptor->__size))
+    return 1;
+  return 0;
+}