re PR c++/82541 (Wduplicated-branches triggers in template context)

	PR c++/82541
	* call.c (build_conditional_expr_1): Check complain before warning.
	* pt.c (tsubst_copy_and_build) <case COND_EXPR>: Suppress
	-Wduplicated-branches.

	* g++.dg/warn/Wduplicated-branches4.C: New test.

From-SVN: r256441

diff --git a/gcc/cp/ChangeLog b/gcc/cp/ChangeLog
index 3cce2120b5a1806be2119778495095dc53104626..d664bd26af93f1eedec5fb6ee79039b513960171 100644 (file)
--- a/gcc/cp/ChangeLog
+++ b/gcc/cp/ChangeLog
@@ -1,3 +1,10 @@
+2018-01-10  Marek Polacek  <polacek@redhat.com>
+
+       PR c++/82541
+       * call.c (build_conditional_expr_1): Check complain before warning.
+       * pt.c (tsubst_copy_and_build) <case COND_EXPR>: Suppress
+       -Wduplicated-branches.
+
 2018-01-10  Jakub Jelinek  <jakub@redhat.com>
 
        PR c++/81327

diff --git a/gcc/cp/call.c b/gcc/cp/call.c
index 515e4607de0db2f39cd1e7af4f056e1b6aed262e..87bbf3c7991812f763968474b53716d0ae700b0c 100644 (file)
--- a/gcc/cp/call.c
+++ b/gcc/cp/call.c
@@ -5345,6 +5345,7 @@ build_conditional_expr_1 (location_t loc, tree arg1, tree arg2, tree arg3,
   /* If the ARG2 and ARG3 are the same and don't have side-effects,
      warn here, because the COND_EXPR will be turned into ARG2.  */
   if (warn_duplicated_branches
+      && (complain & tf_warning)
       && (arg2 == arg3 || operand_equal_p (arg2, arg3, 0)))
     warning_at (EXPR_LOCATION (result), OPT_Wduplicated_branches,
                "this condition has identical branches");

diff --git a/gcc/cp/pt.c b/gcc/cp/pt.c
index 2fb327a3e28889faba605230cbc4783eb78d2186..2deccd822c26e6c9ed811dedca59e8f16aecbd21 100644 (file)
--- a/gcc/cp/pt.c
+++ b/gcc/cp/pt.c
@@ -17846,6 +17846,7 @@ tsubst_copy_and_build (tree t,
            exp2 = RECUR (TREE_OPERAND (t, 2));
          }
 
+       warning_sentinel s(warn_duplicated_branches);
        RETURN (build_x_conditional_expr (EXPR_LOCATION (t),
                                         cond, exp1, exp2, complain));
       }

diff --git a/gcc/testsuite/ChangeLog b/gcc/testsuite/ChangeLog
index 0bfacf0d0e608122232bea93787122a3ba557053..3936188e2f4945704396e05785f7143c0bb8fdee 100644 (file)
--- a/gcc/testsuite/ChangeLog
+++ b/gcc/testsuite/ChangeLog
@@ -1,3 +1,8 @@
+2018-01-10  Marek Polacek  <polacek@redhat.com>
+
+       PR c++/82541
+       * g++.dg/warn/Wduplicated-branches4.C: New test.
+
 2018-01-10  Jakub Jelinek  <jakub@redhat.com>
 
        PR c++/81327

diff --git a/gcc/testsuite/g++.dg/warn/Wduplicated-branches4.C b/gcc/testsuite/g++.dg/warn/Wduplicated-branches4.C
new file mode 100644 (file)
index 0000000..7963c9e
--- /dev/null
+++ b/gcc/testsuite/g++.dg/warn/Wduplicated-branches4.C
@@ -0,0 +1,16 @@
+// PR c++/82541
+// { dg-do compile }
+// { dg-options "-Wduplicated-branches" }
+
+template<int N>
+struct AR
+{
+    char a1[N > 0 ? N : 1]; // { dg-bogus "this condition has identical branches" }
+    char a2[N > 0 ? 1 : 1]; // { dg-warning "this condition has identical branches" }
+};
+
+int
+main ()
+{
+    AR<1> w;
+}