You should use Hg for this instead of Hc. Hc is used for step/continue, while Hg is used for everything else.
> -----Original Message----- > From: lldb-dev <lldb-dev-boun...@lists.llvm.org> On Behalf Of Michal Górny > via lldb-dev > Sent: Tuesday, January 11, 2022 6:38 AM > To: lldb-dev@lists.llvm.org > Subject: [lldb-dev] RFC: siginfo reading/writing support > > Hello, > > TL;DR: I'd like to implement at least partial support for reading/writing > siginfo > via LLDB. I can't think of a better approach than copying the GDB's idea of > "magical" $_siginfo variable that works through the expression evaluator. I'd > like to know your opinion/ideas. > > > POSIX defines a siginfo_t structure that is used to pass additional signal > information -- such as more detailed signal code, faulting memory address in > case of SIGSEGV or PID of the child process in case of SIGCHLD. LLDB already > uses ptrace(2) to obtain this information and use it internally but it doesn't > expose it to the user. > > The GDB Remote Serial protocol provides the ability to read/write siginfo via > qXfer:siginfo:... packets [1]. GDB exposes this information to the user via a > special $_siginfo variable [2]. > > A few things to note: > > 1. Some targets (e.g. Linux, NetBSD) support overwriting siginfo, some (e.g. > FreeBSD) only reading. > > 2. Siginfo is generally associated with a single thread, so the packets should > be combined with respective thread selection (Hg or Hc?). > > 3. The exact type of siginfo_t differs per platform (POSIX specifies a minimal > subset). > > > My rough idea right now is to follow GDB here. While using "$_siginfo" > may seem hacky, it has the nice advantage that it can easily support all > different siginfo_t structures used by various platforms. > > The plan would be to: > > 1. Implement the qXfer:siginfo:... packets in lldb-server, and add tests to > them. > > 2. Implement support for "$_siginfo" in the client (I suppose this means > hacking on expression evaluator). > > 3. (Optionally) implement hardcoded siginfo_t definitions for common > platforms to make things work without debug info. > > WDYT? > > > [1] > https://www.sourceware.org/gdb/onlinedocs/gdb/General-Query- > Packets.html#qXfer-siginfo-read > [2] https://sourceware.org/gdb/current/onlinedocs/gdb.html#Signals > > > -- > Best regards, > Michał Górny > > > _______________________________________________ > lldb-dev mailing list > lldb-dev@lists.llvm.org > https://lists.llvm.org/cgi-bin/mailman/listinfo/lldb-dev _______________________________________________ lldb-dev mailing list lldb-dev@lists.llvm.org https://lists.llvm.org/cgi-bin/mailman/listinfo/lldb-dev
