Created attachment 42116 [details] The test file. Trying to use a function pointer as predicate, e.g. in std::equal results in the following error: $ g++ test.cpp -std=c++1z -save-temps -v Using built-in specs. COLLECT_GCC=g++ COLLECT_LTO_WRAPPER=E:/MinGW64/bin/../libexec/gcc/x86_64-w64-mingw32/7.1.0/lto-wrapper.exe Target: x86_64-w64-mingw32 Configured with: ../../../src/gcc-7.1.0/configure --host=x86_64-w64-mingw32 --build=x86_64-w64-mingw32 --target=x86_64-w64-mingw32 --prefix=/mingw64 --with-sysroot=/c/mingw710/x86_64-710-posix-seh-rt_v5-rev2/mingw64 --enable-shared --enable-static --disable-multilib --enable-languages=c,c++,fortran,lto --enable-libstdcxx-time=yes --enable-threads=posix --enable-libgomp --enable-libatomic --enable-lto --enable-graphite --enable-checking=release --enable-fully-dynamic-string --enable-version-specific-runtime-libs --enable-libstdcxx-filesystem-ts=yes --disable-libstdcxx-pch --disable-libstdcxx-debug --enable-bootstrap --disable-rpath --disable-win32-registry --disable-nls --disable-werror --disable-symvers --with-gnu-as --with-gnu-ld --with-arch=nocona --with-tune=core2 --with-libiconv --with-system-zlib --with-gmp=/c/mingw710/prerequisites/x86_64-w64-mingw32-static --with-mpfr=/c/mingw710/prerequisites/x86_64-w64-mingw32-static --with-mpc=/c/mingw710/prerequisites/x86_64-w64-mingw32-static --with-isl=/c/mingw710/prerequisites/x86_64-w64-mingw32-static --with-pkgversion='x86_64-posix-seh-rev2, Built by MinGW-W64 project' --with-bugurl=https://sourceforge.net/projects/mingw-w64 CFLAGS='-O2 -pipe -fno-ident -I/c/mingw710/x86_64-710-posix-seh-rt_v5-rev2/mingw64/opt/include -I/c/mingw710/prerequisites/x86_64-zlib-static/include -I/c/mingw710/prerequisites/x86_64-w64-mingw32-static/include' CXXFLAGS='-O2 -pipe -fno-ident -I/c/mingw710/x86_64-710-posix-seh-rt_v5-rev2/mingw64/opt/include -I/c/mingw710/prerequisites/x86_64-zlib-static/include -I/c/mingw710/prerequisites/x86_64-w64-mingw32-static/include' CPPFLAGS=' -I/c/mingw710/x86_64-710-posix-seh-rt_v5-rev2/mingw64/opt/include -I/c/mingw710/prerequisites/x86_64-zlib-static/include -I/c/mingw710/prerequisites/x86_64-w64-mingw32-static/include' LDFLAGS='-pipe -fno-ident -L/c/mingw710/x86_64-710-posix-seh-rt_v5-rev2/mingw64/opt/lib -L/c/mingw710/prerequisites/x86_64-zlib-static/lib -L/c/mingw710/prerequisites/x86_64-w64-mingw32-static/lib ' Thread model: posix gcc version 7.1.0 (x86_64-posix-seh-rev2, Built by MinGW-W64 project) COLLECT_GCC_OPTIONS='-std=c++1z' '-save-temps' '-v' '-shared-libgcc' '-mtune=core2' '-march=nocona' E:/MinGW64/bin/../libexec/gcc/x86_64-w64-mingw32/7.1.0/cc1plus.exe -E -quiet -v -iprefix E:/MinGW64/bin/../lib/gcc/x86_64-w64-mingw32/7.1.0/ -D_REENTRANT test.cpp -mtune=core2 -march=nocona -std=c++1z -fpch-preprocess -o test.ii ignoring duplicate directory "E:/MinGW64/lib/gcc/../../lib/gcc/x86_64-w64-mingw32/7.1.0/include/c++" ignoring duplicate directory "E:/MinGW64/lib/gcc/../../lib/gcc/x86_64-w64-mingw32/7.1.0/include/c++/x86_64-w64-mingw32" ignoring duplicate directory "E:/MinGW64/lib/gcc/../../lib/gcc/x86_64-w64-mingw32/7.1.0/include/c++/backward" ignoring duplicate directory "E:/MinGW64/lib/gcc/../../lib/gcc/x86_64-w64-mingw32/7.1.0/include" ignoring nonexistent directory "C:/mingw710/x86_64-710-posix-seh-rt_v5-rev2/mingw64C:/msys64/mingw64/lib/gcc/x86_64-w64-mingw32/7.1.0/../../../../include" ignoring duplicate directory "E:/MinGW64/lib/gcc/../../lib/gcc/x86_64-w64-mingw32/7.1.0/include-fixed" ignoring duplicate directory "E:/MinGW64/lib/gcc/../../lib/gcc/x86_64-w64-mingw32/7.1.0/../../../../x86_64-w64-mingw32/include" ignoring nonexistent directory "C:/mingw710/x86_64-710-posix-seh-rt_v5-rev2/mingw64/mingw/include" #include "..." search starts here: #include <...> search starts here: E:/MinGW64/bin/../lib/gcc/x86_64-w64-mingw32/7.1.0/include/c++ E:/MinGW64/bin/../lib/gcc/x86_64-w64-mingw32/7.1.0/include/c++/x86_64-w64-mingw32 E:/MinGW64/bin/../lib/gcc/x86_64-w64-mingw32/7.1.0/include/c++/backward E:/MinGW64/bin/../lib/gcc/x86_64-w64-mingw32/7.1.0/include E:/MinGW64/bin/../lib/gcc/x86_64-w64-mingw32/7.1.0/include-fixed E:/MinGW64/bin/../lib/gcc/x86_64-w64-mingw32/7.1.0/../../../../x86_64-w64-mingw32/include End of search list. COLLECT_GCC_OPTIONS='-std=c++1z' '-save-temps' '-v' '-shared-libgcc' '-mtune=core2' '-march=nocona' E:/MinGW64/bin/../libexec/gcc/x86_64-w64-mingw32/7.1.0/cc1plus.exe -fpreprocessed test.ii -quiet -dumpbase test.cpp -mtune=core2 -march=nocona -auxbase test -std=c++1z -version -o test.s GNU C++14 (x86_64-posix-seh-rev2, Built by MinGW-W64 project) version 7.1.0 (x86_64-w64-mingw32) compiled by GNU C version 7.1.0, GMP version 6.1.0, MPFR version 3.1.4, MPC version 1.0.3, isl version isl-0.16.1-GMP GGC heuristics: --param ggc-min-expand=100 --param ggc-min-heapsize=131072 GNU C++14 (x86_64-posix-seh-rev2, Built by MinGW-W64 project) version 7.1.0 (x86_64-w64-mingw32) compiled by GNU C version 7.1.0, GMP version 6.1.0, MPFR version 3.1.4, MPC version 1.0.3, isl version isl-0.16.1-GMP GGC heuristics: --param ggc-min-expand=100 --param ggc-min-heapsize=131072 Compiler executable checksum: c3bcadf019df782eccf0dceb06ec4054 test.cpp: In function 'int main()': test.cpp:14:69: internal compiler error: in type_throw_all_p, at cp/except.c:1186 return std::equal(a.begin(), a.end(), a.begin(), equal<int, int>); //Also fails ^ libbacktrace could not find executable to open Please submit a full bug report, with preprocessed source if appropriate. See <https://sourceforge.net/projects/mingw-w64> for instructions. Tested on MinGW 7.1, and 7.1 and 7.2 on http://gcc.godbolt.org see https://godbolt.org/g/M6FHp1
Created attachment 42117 [details] The preprocessed test file.
Reduced testcase (fails with all of -std=c++{11,14,17}, just the ICE is different with c++17): template <typename T, typename U> void bar (T x, U u) { u (x); } template <typename T> void baz (T t) noexcept (noexcept (t)); void foo (int x) { bar (x, baz<int>); }
Started to ICE with r160298 or so (when noexcept has been implemented).
Slightly adjusted testcase that better matches what the original had: template <typename T, typename U> void bar (T &x, T &y, U u) { u (x, y); } template <typename T> void baz (T &x, T &y) noexcept (noexcept (x == y)); void foo (int x, int y) { bar (x, y, baz<int>); } The ICE is always because there is a deferred throw/noexcept spec when we assert that it is not deferred.
On trunk (GCC 8) the testcases of comment #2 and comment #4 only crash with -std=c++17, but don't crash with -std=c++11 or -std=c++14.
Workaround: force computation of noexcept of predicate before it is required: noexcept(+baz<int>); or simply baz<int>;
*** Bug 94525 has been marked as a duplicate of this bug. ***
*** Bug 97773 has been marked as a duplicate of this bug. ***
I have a patch.
The master branch has been updated by Marek Polacek <mpolacek@gcc.gnu.org>: https://gcc.gnu.org/g:af362af18f405c34840d820143aa3a94f72fce4d commit r11-6476-gaf362af18f405c34840d820143aa3a94f72fce4d Author: Marek Polacek <polacek@redhat.com> Date: Thu Dec 10 15:00:58 2020 -0500 c++: ICE with deferred noexcept when deducing targs [PR82099] In this test we ICE in type_throw_all_p because it got a deferred noexcept which it shouldn't. Here's the story: In noexcept61.C, we call bar, so we perform overload resolution. When adding the (only) candidate, we need to deduce template arguments, so call fn_type_unification as usually. That deduces U to void (*) (int &, int &) which is correct, but its noexcept-spec is deferred_noexcept. Then we call add_function_candidate (bar), wherein we try to create an implicit conversion sequence for every argument. Since baz<int> is of unknown type, we instantiate_type it; it is a TEMPLATE_ID_EXPR so that calls resolve_address_of_overloaded_function. But we crash there, because target_type contains the deferred_noexcept. So we need to maybe_instantiate_noexcept before we can compare types. resolve_overloaded_unification seemed like the appropriate spot, now fn_type_unification produces the function type with its noexcept-spec instantiated. This shouldn't go against CWG 1330 because here we really need to instantiate the noexcept-spec. This also fixes class-deduction76.C, a dg-ice test I recently added, therefore this fix also fixes c++/90799, yay. gcc/cp/ChangeLog: PR c++/82099 * pt.c (resolve_overloaded_unification): Call maybe_instantiate_noexcept after instantiating the function decl. gcc/testsuite/ChangeLog: PR c++/82099 * g++.dg/cpp1z/class-deduction76.C: Remove dg-ice. * g++.dg/cpp0x/noexcept61.C: New test.
The releases/gcc-10 branch has been updated by Marek Polacek <mpolacek@gcc.gnu.org>: https://gcc.gnu.org/g:ff22b4e8d0613170601d28eec9462ea31147c7c7 commit r10-9209-gff22b4e8d0613170601d28eec9462ea31147c7c7 Author: Marek Polacek <polacek@redhat.com> Date: Tue Jan 5 16:33:07 2021 -0500 c++: ICE with deferred noexcept when deducing targs [PR82099] In this test we ICE in type_throw_all_p because it got a deferred noexcept which it shouldn't. Here's the story: In noexcept61.C, we call bar, so we perform overload resolution. When adding the (only) candidate, we need to deduce template arguments, so call fn_type_unification as usually. That deduces U to void (*) (int &, int &) which is correct, but its noexcept-spec is deferred_noexcept. Then we call add_function_candidate (bar), wherein we try to create an implicit conversion sequence for every argument. Since baz<int> is of unknown type, we instantiate_type it; it is a TEMPLATE_ID_EXPR so that calls resolve_address_of_overloaded_function. But we crash there, because target_type contains the deferred_noexcept. So we need to maybe_instantiate_noexcept before we can compare types. resolve_overloaded_unification seemed like the appropriate spot, now fn_type_unification produces the function type with its noexcept-spec instantiated. This shouldn't go against CWG 1330 because here we really need to instantiate the noexcept-spec. This also fixes class-deduction76.C, a dg-ice test I recently added, therefore this fix also fixes c++/90799, yay. gcc/cp/ChangeLog: PR c++/82099 * pt.c (resolve_overloaded_unification): Call maybe_instantiate_noexcept after instantiating the function decl. gcc/testsuite/ChangeLog: PR c++/82099 * g++.dg/cpp0x/noexcept61.C: New test.
Fixed.