This PR complains about a bogus -Wduplicated-branches warning with a non-type
template argument. That can be easily fixed with a new sentinel. I also
noticed a missing tf_warning warning check, so I added it for good measure.
Bootstrapped/regtested on x86_64-linux, ok for trunk?
2018-01-02 Marek Polacek <pola...@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.
* g++.dg/warn/Wduplicated-branches4.C: New test.
diff --git gcc/cp/call.c gcc/cp/call.c
index bd7666d72bb..c23a733978e 100644
--- gcc/cp/call.c
+++ gcc/cp/call.c
@@ -5343,6 +5343,7 @@ 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 gcc/cp/pt.c gcc/cp/pt.c
index a8144e85a39..2c216eaebbe 100644
--- gcc/cp/pt.c
+++ 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 gcc/testsuite/g++.dg/warn/Wduplicated-branches4.C
gcc/testsuite/g++.dg/warn/Wduplicated-branches4.C
index e69de29bb2d..7963c9e8ab5 100644
--- gcc/testsuite/g++.dg/warn/Wduplicated-branches4.C
+++ 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;
+}
Marek
