[Bug c++/56973] [DR 696] crash when capturing variables in nested lambdas

[jason at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=56973

--- Comment #6 from Jason Merrill <jason at gcc dot gnu.org> ---
Author: jason
Date: Thu Sep 28 19:39:45 2017
New Revision: 253266

URL: https://gcc.gnu.org/viewcvs?rev=253266&root=gcc&view=rev
Log:
        PR c++/56973, DR 696 - capture constant variables only as needed.

        * expr.c (mark_use): Split out from mark_rvalue_use and
        mark_lvalue_use.  Handle lambda capture of constant variables.
        (mark_lvalue_use_nonread): New.
        * semantics.c (process_outer_var_ref): Don't capture a constant
        variable until forced.
        * pt.c (processing_nonlambda_template): New.
        * call.c (build_this): Check it.
        * decl2.c (grok_array_decl): Call mark_rvalue_use and
        mark_lvalue_use_nonread.
        * init.c (constant_value_1): Don't call mark_rvalue_use.
        * typeck.c (build_static_cast): Handle lambda capture.

Added:
    trunk/gcc/testsuite/g++.dg/cpp0x/lambda/lambda-const6.C
    trunk/gcc/testsuite/g++.dg/cpp0x/lambda/lambda-const7.C
Modified:
    trunk/gcc/cp/ChangeLog
    trunk/gcc/cp/call.c
    trunk/gcc/cp/cp-tree.h
    trunk/gcc/cp/decl2.c
    trunk/gcc/cp/expr.c
    trunk/gcc/cp/init.c
    trunk/gcc/cp/pt.c
    trunk/gcc/cp/semantics.c
    trunk/gcc/cp/typeck.c
    trunk/gcc/testsuite/g++.dg/cpp0x/constexpr-64462.C
    trunk/gcc/testsuite/g++.dg/cpp1y/lambda-generic-const4.C