re PR c++/28385 (templated function call goes awry)

        PR c++/28385
        * pt.c (tsubst) [TEMPLATE_TYPE_PARM]: Ignore quals from template
        if arg is a function.

From-SVN: r116203

diff --git a/gcc/cp/ChangeLog b/gcc/cp/ChangeLog
index 7b08dd7..f69c4ff 100644 (file)
--- a/gcc/cp/ChangeLog
+++ b/gcc/cp/ChangeLog
@@ -1,3 +1,9 @@
+2006-08-16  Jason Merrill  <jason@redhat.com>
+
+       PR c++/28385
+       * pt.c (tsubst) [TEMPLATE_TYPE_PARM]: Ignore quals from template
+       if arg is a function.
+
 2006-08-16  Volker Reichelt  <reichelt@igpm.rwth-aachen.de>
 
        PR c++/28593

diff --git a/gcc/cp/pt.c b/gcc/cp/pt.c
index 4c2b45a..27b6d11 100644 (file)
--- a/gcc/cp/pt.c
+++ b/gcc/cp/pt.c
@@ -7238,10 +7238,20 @@ tsubst (tree t, tree args, tsubst_flags_t complain, tree in_decl)
          {
            if (TREE_CODE (t) == TEMPLATE_TYPE_PARM)
              {
+               int quals;
                gcc_assert (TYPE_P (arg));
+
+               /* cv-quals from the template are discarded when
+                  substituting in a function or reference type.  */
+               if (TREE_CODE (arg) == FUNCTION_TYPE
+                   || TREE_CODE (arg) == METHOD_TYPE
+                   || TREE_CODE (arg) == REFERENCE_TYPE)
+                 quals = cp_type_quals (arg);
+               else
+                 quals = cp_type_quals (arg) | cp_type_quals (t);
+                 
                return cp_build_qualified_type_real
-                 (arg, cp_type_quals (arg) | cp_type_quals (t),
-                  complain | tf_ignore_bad_quals);
+                 (arg, quals, complain | tf_ignore_bad_quals);
              }
            else if (TREE_CODE (t) == BOUND_TEMPLATE_TEMPLATE_PARM)
              {

diff --git a/gcc/testsuite/g++.dg/template/const1.C b/gcc/testsuite/g++.dg/template/const1.C
new file mode 100644 (file)
index 0000000..629c4d4
--- /dev/null
+++ b/gcc/testsuite/g++.dg/template/const1.C
@@ -0,0 +1,30 @@
+// PR c++/28385
+// instantiating op() with void()() was making the compiler think that 'fcn'
+// was const, so it could eliminate the call.
+
+// { dg-do run }
+
+extern "C" void abort (void);
+
+int barcnt = 0;
+
+class Foo {
+  public:
+    template<typename T>
+    void operator()(const T& fcn) {
+      fcn();
+    }
+};
+
+void bar() {
+  barcnt++;
+}
+
+int main() {
+  Foo myFoo;
+  myFoo(bar);
+  myFoo(&bar);
+  if (barcnt != 2)
+    abort ();
+  return 0;
+}