The recent change introducing ABSU_EXPR neglected to also handle this code in cxx_eval_constant_expression so this patch puts it there. Also two other spots for good measure. It's possible we'll find out that we need to fix other spots too.
Bootstrapped/regtested on x86_64-linux, ok for trunk? 2018-06-20 Marek Polacek <pola...@redhat.com> PR c++/86240 * constexpr.c (cxx_eval_constant_expression): Handle ABSU_EXPR. (fold_simple_1): Likewise. * error.c (dump_expr): Likewise. * g++.dg/pr86240.C: New test. diff --git gcc/cp/constexpr.c gcc/cp/constexpr.c index 216eecd4b06..44f3093ab47 100644 --- gcc/cp/constexpr.c +++ gcc/cp/constexpr.c @@ -4412,6 +4412,7 @@ cxx_eval_constant_expression (const constexpr_ctx *ctx, tree t, case FLOAT_EXPR: case NEGATE_EXPR: case ABS_EXPR: + case ABSU_EXPR: case BIT_NOT_EXPR: case TRUTH_NOT_EXPR: case FIXED_CONVERT_EXPR: @@ -5056,6 +5057,7 @@ fold_simple_1 (tree t) return fold_sizeof_expr (t); case ABS_EXPR: + case ABSU_EXPR: case CONJ_EXPR: case REALPART_EXPR: case IMAGPART_EXPR: diff --git gcc/cp/error.c gcc/cp/error.c index 6a261132afb..b0d8e322e65 100644 --- gcc/cp/error.c +++ gcc/cp/error.c @@ -2764,6 +2764,7 @@ dump_expr (cxx_pretty_printer *pp, tree t, int flags) case VEC_DELETE_EXPR: case MODOP_EXPR: case ABS_EXPR: + case ABSU_EXPR: case CONJ_EXPR: case VECTOR_CST: case FIXED_CST: diff --git gcc/testsuite/g++.dg/pr86240.C gcc/testsuite/g++.dg/pr86240.C index e69de29bb2d..16ae89cccd1 100644 --- gcc/testsuite/g++.dg/pr86240.C +++ gcc/testsuite/g++.dg/pr86240.C @@ -0,0 +1,12 @@ +// { dg-do compile } + +extern "C" int abs (int); +struct a { + short b; +} e; +short c; +bool +foo () +{ + return abs(c) >= e.b; +}