On 13.10.2020 16:17, Pedro Alves wrote: > On 10/13/20 2:43 PM, Kamil Rytarowski wrote: > >> This patch applied on trunk gives me: >> >> gmake[2]: Wejście do katalogu '/public/binutils-gdb-netbsd/build/gdbserver' >> CXX netbsd-low.o >> ../../gdbserver/netbsd-low.cc: In function ‘bool elf_64_file_p(const >> char*)’: >> ../../gdbserver/netbsd-low.cc:1152:57: error: no matching function for >> call to ‘handle_eintr(int, int (&)(const char*, int, ...), const char*&, >> int)’ >> 1152 | int fd = gdb::handle_eintr (-1, ::open, file, O_RDONLY); >> | ^ >> In file included from ../../gdbserver/netbsd-low.cc:37: >> ../../gdbserver/../gdbsupport/eintr.h:58:1: note: candidate: >> ‘template typename >> gdb::return_type::type gdb::handle_eintr(ErrorValType, const Fun&, >> const Args& ...)’ >> 58 | handle_eintr (ErrorValType errval, const Fun &f, const Args &... >> args) >> | ^~~~~~~~~~~~ >> ../../gdbserver/../gdbsupport/eintr.h:58:1: note: template argument >> deduction/substitution failed: >> ../../gdbserver/../gdbsupport/eintr.h: In substitution of >> ‘template typename >> gdb::return_type::type gdb::handle_eintr(ErrorValType, const Fun&, >> const Args& ...) [with ErrorValType = int; Fun = int(const char*, int, >> ...); Args = {const char*, int}]’: >> ../../gdbserver/netbsd-low.cc:1152:57: required from here >> ../../gdbserver/../gdbsupport/eintr.h:58:1: error: invalid use of >> incomplete type ‘struct gdb::return_type’ >> In file included from ../../gdbserver/../gdbsupport/poison.h:23, >> from ../../gdbserver/../gdbsupport/common-utils.h:26, >> from ../../gdbserver/../gdbsupport/common-defs.h:125, >> from ../../gdbserver/server.h:22, >> from ../../gdbserver/netbsd-low.cc:18: >> ../../gdbserver/../gdbsupport/traits.h:49:8: note: declaration of >> ‘struct gdb::return_type’ >> 49 | struct return_type; >> | ^~~~~~~~~~~ > > Huh, Fun is clearly a function, yet the compiler doesn't pick > the partial specialization. > > I could reproduce it here, seems to be related to open being varargs. > > Anyhow, we don't really need the new trait. We can just > use decltype and a trailing return. I don't know why I didn't > think of it in the first place. > > Here's an updated patch. I believe this one should work for you too. > This version works for me. > > From 37d06f47a379e44a895f68a22cbb0f745da33ec5 Mon Sep 17 00:00:00 2001 > From: Pedro Alves > Date: Tue, 8 Sep 2020 17:34:41 +0100 > Subject: [PATCH v2] gdb::handle_eintr, remove need to specify return type > > This eliminates the need to specify the return type when using > handle_eintr. We let the compiler deduce it for us. > > Also, use lowercase for function parameter names. Uppercase should > only be used on template parameters. > > gdb/ChangeLog: > > * nat/linux-waitpid.c: Include "gdbsupport/eintr.h". > (my_waitpid): Use gdb::handle_eintr. > > gdbserver/ChangeLog: > > * netbsd-low.cc (netbsd_waitpid, netbsd_process_target::kill) > (netbsd_qxfer_libraries_svr4): Use gdb::handle_eintr without > explicit type. > > gdbsupport/ChangeLog: > > * eintr.h (handle_eintr): Replace Ret template parameter with > ErrorValType. Use it as type of the failure value. Deduce the > function's return type using decltype. Use lowercase for function > parameter names. > --- > gdb/nat/linux-waitpid.c | 11 ++--------- > gdbserver/netbsd-low.cc | 10 +++++----- > gdbsupport/eintr.h | 32 +++++++++++++++++++------------- > 3 files changed, 26 insertions(+), 27 deletions(-) > > diff --git a/gdb/nat/linux-waitpid.c b/gdb/nat/linux-waitpid.c > index f50e0c7bcff..d066239220a 100644 > --- a/gdb/nat/linux-waitpid.c > +++ b/gdb/nat/linux-waitpid.c > @@ -22,6 +22,7 @@ > #include "linux-nat.h" > #include "linux-waitpid.h" > #include "gdbsupport/gdb_wait.h" > +#include "gdbsupport/eintr.h" > > /* Convert wait status STATUS to a string. Used for printing debug > messages only. */ > @@ -54,13 +55,5 @@ status_to_str (int status) > int > my_waitpid (int pid, int *status, int flags) > { > - int ret; > - > - do > - { > - ret = waitpid (pid, status, flags); > - } > - while (ret == -1 && errno == EINTR); > - > - return ret; > + return gdb::handle_eintr (-1, ::waitpid, pid, status, flags); > } > diff --git a/gdbserver/netbsd-low.cc b/gdbserver/netbsd-low.cc > index 30028d3a384..519614d0473 100644 > --- a/gdbserver/netbsd-low.cc > +++ b/gdbserver/netbsd-low.cc > @@ -245,7 +245,7 @@ netbsd_waitpid (ptid_t ptid, struct target_waitstatus *ourstatus, > int options = (target_options & TARGET_WNOHANG) ? WNOHANG : 0; > > pid_t pid > - = gdb::handle_eintr (-1, ::waitpid, ptid.pid (), &status, options); > + = gdb::handle_eintr (-1, ::waitpid, ptid.pid (), &status, options); > > if (pid == -1) > perror_with_name (_("Child process unexpectedly missing")); > @@ -456,7 +456,7 @@ netbsd_process_target::kill (process_info *process) > return -1; > > int status; > - if (gdb::handle_eintr (-1, ::waitpid, pid, &status, 0) == -1) > + if (gdb::handle_eintr (-1, ::waitpid, pid, &status, 0) == -1) > return -1; > mourn (process); > return 0; > @@ -1149,15 +1149,15 @@ netbsd_qxfer_libraries_svr4 (const pid_t pid, const char *annex, > static bool > elf_64_file_p (const char *file) > { > - int fd = gdb::handle_eintr (-1, ::open, file, O_RDONLY); > + int fd = gdb::handle_eintr (-1, ::open, file, O_RDONLY); > if (fd < 0) > perror_with_name (("open")); > > Elf64_Ehdr header; > - ssize_t ret = gdb::handle_eintr (-1, ::read, fd, &header, sizeof (header)); > + ssize_t ret = gdb::handle_eintr (-1, ::read, fd, &header, sizeof (header)); > if (ret == -1) > perror_with_name (("read")); > - gdb::handle_eintr (-1, ::close, fd); > + gdb::handle_eintr (-1, ::close, fd); > if (ret != sizeof (header)) > error ("Cannot read ELF file header: %s", file); > > diff --git a/gdbsupport/eintr.h b/gdbsupport/eintr.h > index 64ff5940b75..02c26e4def1 100644 > --- a/gdbsupport/eintr.h > +++ b/gdbsupport/eintr.h > @@ -43,25 +43,31 @@ namespace gdb > > You could wrap it by writing the wrapped form: > > - ssize_t ret = gdb::handle_eintr (-1, ::write, pipe[1], "+", 1); > - > - The RET typename specifies the return type of the wrapped system call, which > - is typically int or ssize_t. The R argument specifies the failure value > - indicating the interrupted syscall when calling the F function with > - the A... arguments. */ > - > -template > -inline Ret handle_eintr (const Ret &R, const Fun &F, const Args &... A) > + ssize_t ret = gdb::handle_eintr (-1, ::write, pipe[1], "+", 1); > + > + ERRVAL specifies the failure value indicating that the call to the > + F function with ARGS... arguments was possibly interrupted with a > + signal. */ > + > +template + typename Fun, > + typename... Args> > +inline auto > +handle_eintr (ErrorValType errval, const Fun &f, const Args &... args) > + -> decltype (f(args...)) > { > - Ret ret; > + decltype (f(args...)) ret; > + > do > { > errno = 0; > - ret = F (A...); > + ret = f (args...); > } > - while (ret == R && errno == EINTR); > + while (ret == errval && errno == EINTR); > + > return ret; > } > -} > + > +} /* namespace gdb */ > > #endif /* GDBSUPPORT_EINTR_H */ > > base-commit: 87a37e5e078f506fa9905b74e9238593c537fcd5 >