[Bug c++/84726] [8 regression] Unnecessary lambda capture of constant variables

[jason at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=84726

--- Comment #2 from Jason Merrill <jason at gcc dot gnu.org> ---
Author: jason
Date: Fri Mar  9 21:40:55 2018
New Revision: 258398

URL: https://gcc.gnu.org/viewcvs?rev=258398&root=gcc&view=rev
Log:
        PR c++/84726 - unnecessary capture of constant vars.

        * cp-tree.h (LAMBDA_CAPTURE_EXPLICIT_P)
        (LAMBDA_EXPR_CAPTURE_OPTIMIZED): New.
        * expr.c (mark_use): Set LAMBDA_EXPR_CAPTURE_OPTIMIZED.
        * lambda.c (is_constant_capture_proxy)
        (current_lambda_expr, var_to_maybe_prune, mark_const_cap_r)
        (prune_lambda_captures): New.
        (finish_lambda_function): Call prune_lambda_captures.

Added:
    trunk/gcc/testsuite/g++.dg/abi/lambda-capture1.C
Modified:
    trunk/gcc/cp/ChangeLog
    trunk/gcc/cp/cp-tree.h
    trunk/gcc/cp/expr.c
    trunk/gcc/cp/lambda.c