| 1 | //===-- Implementation of a class for mapping signals to strings ----------===// |
|---|---|
| 2 | // |
| 3 | // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions. |
| 4 | // See https://llvm.org/LICENSE.txt for license information. |
| 5 | // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception |
| 6 | // |
| 7 | //===----------------------------------------------------------------------===// |
| 8 | |
| 9 | #include "signal_to_string.h" |
| 10 | #include "platform_signals.h" |
| 11 | |
| 12 | #include "src/__support/CPP/span.h" |
| 13 | #include "src/__support/CPP/string_view.h" |
| 14 | #include "src/__support/CPP/stringstream.h" |
| 15 | #include "src/__support/StringUtil/message_mapper.h" |
| 16 | #include "src/__support/integer_to_string.h" |
| 17 | #include "src/__support/macros/attributes.h" |
| 18 | |
| 19 | #include <signal.h> |
| 20 | #include <stddef.h> |
| 21 | |
| 22 | namespace LIBC_NAMESPACE { |
| 23 | namespace internal { |
| 24 | |
| 25 | constexpr size_t max_buff_size() { |
| 26 | constexpr size_t base_str_len = sizeof("Real-time signal"); |
| 27 | // the buffer should be able to hold "Real-time signal" + ' ' + num_str |
| 28 | return (base_str_len + 1 + IntegerToString<int>::buffer_size()) * |
| 29 | sizeof(char); |
| 30 | } |
| 31 | |
| 32 | // This is to hold signal strings that have to be custom built. It may be |
| 33 | // rewritten on every call to strsignal (or other signal to string function). |
| 34 | constexpr size_t SIG_BUFFER_SIZE = max_buff_size(); |
| 35 | LIBC_THREAD_LOCAL char signal_buffer[SIG_BUFFER_SIZE]; |
| 36 | |
| 37 | constexpr size_t TOTAL_STR_LEN = total_str_len(table: PLATFORM_SIGNALS); |
| 38 | |
| 39 | constexpr size_t SIG_ARRAY_SIZE = max_key_val(table: PLATFORM_SIGNALS) + 1; |
| 40 | |
| 41 | constexpr MessageMapper<SIG_ARRAY_SIZE, TOTAL_STR_LEN> |
| 42 | signal_mapper(PLATFORM_SIGNALS); |
| 43 | |
| 44 | cpp::string_view build_signal_string(int sig_num, cpp::span<char> buffer) { |
| 45 | cpp::string_view base_str; |
| 46 | if (sig_num >= SIGRTMIN && sig_num <= SIGRTMAX) { |
| 47 | base_str = cpp::string_view("Real-time signal"); |
| 48 | sig_num -= SIGRTMIN; |
| 49 | } else { |
| 50 | base_str = cpp::string_view("Unknown signal"); |
| 51 | } |
| 52 | |
| 53 | // if the buffer can't hold "Unknown signal" + ' ' + num_str, then just |
| 54 | // return "Unknown signal". |
| 55 | if (buffer.size() < |
| 56 | (base_str.size() + 1 + IntegerToString<int>::buffer_size())) |
| 57 | return base_str; |
| 58 | |
| 59 | cpp::StringStream buffer_stream( |
| 60 | {const_cast<char *>(buffer.data()), buffer.size()}); |
| 61 | buffer_stream << base_str << ' ' << sig_num << '\0'; |
| 62 | return buffer_stream.str(); |
| 63 | } |
| 64 | |
| 65 | } // namespace internal |
| 66 | |
| 67 | cpp::string_view get_signal_string(int sig_num) { |
| 68 | return get_signal_string( |
| 69 | err_num: sig_num, buffer: {internal::signal_buffer, internal::SIG_BUFFER_SIZE}); |
| 70 | } |
| 71 | |
| 72 | cpp::string_view get_signal_string(int sig_num, cpp::span<char> buffer) { |
| 73 | auto opt_str = internal::signal_mapper.get_str(num: sig_num); |
| 74 | if (opt_str) |
| 75 | return *opt_str; |
| 76 | else |
| 77 | return internal::build_signal_string(sig_num, buffer); |
| 78 | } |
| 79 | |
| 80 | } // namespace LIBC_NAMESPACE |
| 81 |