This bug is possibly related to Bug 79989 and/or Bug 82148, but presents itself in a slightly different manner than in either of those examples. The short version: The following command, given the preprocessed source file provided, produces an ICE: ``` $ g++ --verbose -c fd_array.ii -O Using built-in specs. COLLECT_GCC=g++ Target: x86_64-pc-linux-gnu Configured with: /build/gcc/src/gcc/configure --prefix=/usr --libdir=/usr/lib --libexecdir=/usr/lib --mandir=/usr/share/man --infodir=/usr/share/info --with-bugurl=https://bugs.archlinux.org/ --enable-languages=c,c++,ada,fortran,go,lto,objc,obj-c++ --enable-shared --enable-threads=posix --enable-libmpx --with-system-zlib --with-isl --enable-__cxa_atexit --disable-libunwind-exceptions --enable-clocale=gnu --disable-libstdcxx-pch --disable-libssp --enable-gnu-unique-object --enable-linker-build-id --enable-lto --enable-plugin --enable-install-libiberty --with-linker-hash-style=gnu --enable-gnu-indirect-function --disable-multilib --disable-werror --enable-checking=release --enable-default-pie --enable-default-ssp Thread model: posix gcc version 7.2.0 (GCC) COLLECT_GCC_OPTIONS='-v' '-c' '-O' '-shared-libgcc' '-mtune=generic' '-march=x86-64' /usr/lib/gcc/x86_64-pc-linux-gnu/7.2.0/cc1plus -fpreprocessed fd_array.ii -quiet -dumpbase fd_array.ii -mtune=generic -march=x86-64 -auxbase fd_array -O -version -o /tmp/ccOdsz5s.s GNU C++14 (GCC) version 7.2.0 (x86_64-pc-linux-gnu) compiled by GNU C version 7.2.0, GMP version 6.1.2, MPFR version 3.1.5-p2, MPC version 1.0.3, isl version isl-0.18-GMP GGC heuristics: --param ggc-min-expand=100 --param ggc-min-heapsize=131072 GNU C++14 (GCC) version 7.2.0 (x86_64-pc-linux-gnu) compiled by GNU C version 7.2.0, GMP version 6.1.2, MPFR version 3.1.5-p2, MPC version 1.0.3, isl version isl-0.18-GMP GGC heuristics: --param ggc-min-expand=100 --param ggc-min-heapsize=131072 Compiler executable checksum: 5931a2fe3d5a5365a85e56248f3f55d7 sim/fd_array.cc: In member function ‘void FDArray::restoreFileOffsets()’: sim/fd_array.cc:143:5: internal compiler error: in assign_temp, at function.c:968 }; ^ Please submit a full bug report, with preprocessed source if appropriate. See <https://bugs.archlinux.org/> for instructions. ``` Note, this report is from GCC 7.2.0 running on Arch Linux, but I also observed the same error message using GCC 7.2.1 running on OpenSUSE Tumbleweed. Additional information: This code does compile with no optimization flag or with '-O0', but any other '-O' flag triggers this bug (including '-Ofast' and '-Og'). I was unable to trigger the bug purely by adding optimization flags, even when specifying all flags listed under -O1 at: https://gcc.gnu.org/onlinedocs/gcc/Optimize-Options.html: $ g++ -c fd_array.ii -fauto-inc-dec -fbranch-count-reg -fcombine-stack-adjustments -fcompare-elim -fcprop-registers -fdce -fdefer-pop -fdelayed-branch -fdse -fforward-propagate -fguess-branch-probability -fif-conversion2 -fif-conversion -finline-functions-called-once -fipa-pure-const -fipa-profile -fipa-reference -fmerge-constants -fmove-loop-invariants -freorder-blocks -fshrink-wrap -fshrink-wrap-separate -fsplit-wide-types -fssa-backprop -fssa-phiopt -ftree-bit-ccp -ftree-ccp -ftree-ch -ftree-coalesce-vars -ftree-copy-prop -ftree-dce -ftree-dominator-opts -ftree-dse -ftree-forwprop -ftree-fre -ftree-phiprop -ftree-sink -ftree-slsr -ftree-sra -ftree-pta -ftree-ter -funit-at-a-time -fomit-frame-pointer This produces one warning on my machine due to the -fdelayed-branch flag which is unsupported by the target machine. In point of fact, I specified all flags from -O1, -O2, and -O3, and had no error. I was able to trigger the ICE using the flags from Bug 79989 ('$ g++ -c fd_array.ii -mmpx -fcheck-pointer-bounds '), but this produced additional output and is not listed as flags which are provided by the '-O' flag (namely, this treated the function as a static member function rather than simply a "member function"): sim/fd_array.cc: In static member function ‘static void FDArray::restoreFileOffsets()::<lambda(std::shared_ptr<FileFDEntry>)>::_FUN.chkp(std::shared_ptr<FileFDEntry>, \xe2\x80\x98pointer_bounds_typ\xe2\x80\x99 not supported by dump_type#<type error>, void, ...)’: sim/fd_array.cc:143:5: internal compiler error: in assign_temp, at function.c:968 }; ^ The original code compiles with g++-6 (though the g++-7 preprocessed file provided here does not complete compilation with g++-6) The source file is from the gem5 cpu simulator, BSD 3-clause licensed
Created attachment 42554 [details] Preprocessed source file Needed to compress because the plain text is too large to submit. Did not realize it did not attach on my original comment
% cat fd_array.ii struct __shared_count { ~__shared_count(); }; struct A { operator int(); __shared_count _M_refcount; }; void fn1() { void (*seek)(A) = [](A) { fn1(); }; A fdp; if (auto ffd = fdp) seek(ffd); } % g++ -c fd_array.ii -O during RTL pass: expand fd_array.ii: In function ‘void fn1()’: fd_array.ii:9:36: internal compiler error: in assign_temp, at function.c:970 void (*seek)(A) = [](A) { fn1(); }; ^ 0xac2b3e assign_temp(tree_node*, int, int) /home/markus/gcc/gcc/function.c:970 0x9272bb initialize_argument_information /home/markus/gcc/gcc/calls.c:1820 0x92839a expand_call(tree_node*, rtx_def*, int) /home/markus/gcc/gcc/calls.c:3261 0xa5839d expand_expr_real_1(tree_node*, rtx_def*, machine_mode, expand_modifier, rtx_def**, bool) /home/markus/gcc/gcc/expr.c:10853 0x93f19b expand_expr /home/markus/gcc/gcc/expr.h:276 0x93f19b expand_call_stmt /home/markus/gcc/gcc/cfgexpand.c:2674 0x93f19b expand_gimple_stmt_1 /home/markus/gcc/gcc/cfgexpand.c:3608 0x93f19b expand_gimple_stmt /home/markus/gcc/gcc/cfgexpand.c:3774 0x9409b7 expand_gimple_basic_block /home/markus/gcc/gcc/cfgexpand.c:5779 0x946ed6 execute /home/markus/gcc/gcc/cfgexpand.c:6385
Started with r244728.
Started with r244728. Slightly adjusted testcase: struct S { ~S (); }; struct A { operator int (); S a; }; void bar () { void (*foo)(A) = [](A) { bar (); }; A b; if (auto c = b) foo (c); }
Author: nathan Date: Mon Nov 20 14:39:00 2017 New Revision: 254958 URL: https://gcc.gnu.org/viewcvs?rev=254958&root=gcc&view=rev Log: [PR c++/82878] pass-by-invisiref in lambda https://gcc.gnu.org/ml/gcc-patches/2017-11/msg01115.html PR c++/82878 PR c++/78495 * call.c (build_call_a): Don't set CALL_FROM_THUNK_P for inherited ctor. * cp-gimplify.c (cp_genericize_r): Restore THUNK dereference inhibibition check removed in previous c++/78495 change. PR c++/82878 * g++.dg/cpp0x/pr82878.C: New. * g++.dg/cpp1z/inh-ctor38.C: Check moves too. Added: trunk/gcc/testsuite/g++.dg/cpp0x/pr82878.C Modified: trunk/gcc/cp/ChangeLog trunk/gcc/cp/call.c trunk/gcc/cp/cp-gimplify.c trunk/gcc/cp/lambda.c trunk/gcc/testsuite/ChangeLog trunk/gcc/testsuite/g++.dg/cpp0x/lambda/lambda-switch.C trunk/gcc/testsuite/g++.dg/cpp1z/inh-ctor38.C
Fixed on the trunk so far.
Fixed r254958.
Well, not fixed on the 7 branch, right?
*** Bug 79989 has been marked as a duplicate of this bug. ***
Author: nathan Date: Fri Jan 26 13:48:37 2018 New Revision: 257089 URL: https://gcc.gnu.org/viewcvs?rev=257089&root=gcc&view=rev Log: [C++/82878] backport fix https://gcc.gnu.org/ml/gcc-patches/2018-01/msg02170.html PR c++/82878 PR c++/78495 * call.c (build_call_a): Don't set CALL_FROM_THUNK_P for inherited ctor. * cp-gimplify.c (cp_genericize_r): Restore THUNK dereference inhibibition check removed in previous c++/78495 change. PR c++/82878 * g++.dg/cpp0x/pr82878.C: New. * g++.dg/cpp1z/inh-ctor38.C: Check moves too. Added: branches/gcc-7-branch/gcc/testsuite/g++.dg/cpp0x/pr82878.C Modified: branches/gcc-7-branch/gcc/cp/ChangeLog branches/gcc-7-branch/gcc/cp/call.c branches/gcc-7-branch/gcc/cp/cp-gimplify.c branches/gcc-7-branch/gcc/cp/lambda.c branches/gcc-7-branch/gcc/testsuite/ChangeLog branches/gcc-7-branch/gcc/testsuite/g++.dg/cpp1z/inh-ctor38.C
fixed on gcc-7 branch r257089.