[libc] move strerror and strsignal to OS msg maps

[michaelrj]

Summary

Other OSes may have different mappings from error number to message.
This creates a system to allow new platforms to define their own
mappings.

[sivachandra]

libc/src/__support/StringUtil/CMakeLists.txt

7

I don't think we should just return when a platform directory is missing. See below.

11

This should be conditional:

if(EXISTS ${CMAKE_CURRENT_SOURCE_DIR}/${LIBC_TARGET_OS})
  add_subdirectory(${LIBC_TARGET_OS})
endif()

21

This should be added conditionally I think:

list(APPEND error_to_string_deps 
  libc.src.errno.errno
  libc.src.__support.CPP.span
  libc.src.__support.CPP.string_view
  libc.src.__support.CPP.stringstream
  libc.src.__support.integer_to_string
)
if(TARGET libc.src.__support.StringUtil.${LIBC_TARGET_OS}.strerror_map)
  list(APPEND error_to_string_deps  libc.src.__support.StringUtil.${LIBC_TARGET_OS}.strerror_map)
else()
  list(APPEND error_to_string_deps  <target for the default error map - see below>)
endif()

37

Ditto.

libc/src/__support/StringUtil/error_to_string.cpp

20

s/__unix__/__linux__ ?

21

Instead of expecting everything to be listed in a platform specific table, we can have three kinds of tables:

1. Table of errors specified by the C standard - this will be the fallback table instead of the #error you have below.
2. Table of POSIX extension errors.
3. Table of Linux extension errors.

To get the full Linux table for example, you will have to merge all the above three tables. You likely have to use cpp::array for the tables to get this to work at compile-time.

[michaelrj]

Update the string mapping to support concatenating arrays at compile time.
Simplify the cmake.

[sivachandra]

Mostly LGTM but I suggested some rearrangement of what you already have to improve modularity.

libc/src/__support/StringUtil/error_to_string.cpp

21

I prefer an organization like this:

1. stdc_error_table.h contains:

inline constexpr ErrorTable<...> STDC_ERRORS = {
  ...
};

2. posix_error_table.h contains:

inline constexpr ErrorTable<...> POSIX_EXTENSION_ERRORS = {
  ...
};

3. linux/error_table.h contains:

#include "stdc_errors.h"
#include "posix_errros.h"

namespace __llvm_libc {
inline constexpr ErrorTable<...> LINUX_EXTENSION_ERRORS = {
  ...
};
} // namespace __llvm_libc

4. error_table.h contains:

#ifdef __linux__
#include "linux/error_table.h"
inline constexpr ErrorTable<...> PLATFORM_ERRORS = STDC_ERRORS + POSIX_EXTENSION_ERRORS + LINUX_EXTENSION_ERRORS;
#else
#include "stdc_error_table.h"
inline constexpr ErrorTable<...> PLATFORM_ERRORS = STDC_ERRORS;
#endif

In this file, all you have to do is include error_table.h and operate on PLATFORM_ERRORS.

libc/src/__support/StringUtil/message_mapper.h

32

Do we need a special class? Can this work:

template <size_t N>
using ErrorTable = cpp::array<MsgMapping, N>;

template <size_t N1, size_t N2>
constexpr ErrorTable<N1 + N2> operator+(const ErrorTable &t1, const ErrorTable &t2) {
  ErrorTable<N1 + N2> res{};
  for (std::size_t i = 0; i < N1; ++i)
    res[i] = t1[i];
  for (std::size_t i = 0; i < N2; ++i)
    res[N1 + i] = t2[i];
  return res;
}

[michaelrj]

subdivide the files more and remove unnecessary custom class.

libc/src/__support/StringUtil/error_to_string.cpp

21

I moved these files into a subdirectory for clarity, but otherwise this is laid out as described.

libc/src/__support/StringUtil/message_mapper.h

32

Interesting, this does work, but when I tried adding operator+ to cpp::array directly it complained about the result not being constexpr.

[sivachandra]

libc/src/__support/StringUtil/CMakeLists.txt

11

We are moving to giving directories also lower case names. So, may be just tables for the nested directory?

libc/src/__support/StringUtil/TableMappings/error_table.h

26 ↗

(On Diff #514742)

Lets not add POSIX_ERRORS for the default case.

libc/src/__support/StringUtil/TableMappings/linux/error_table.h

19 ↗

(On Diff #514742)

constexpr tables declared in header files should be inline constexpr ....

libc/src/__support/StringUtil/error_to_string.cpp

33

Remove?

[michaelrj]

address comments before landing

libc/src/__support/StringUtil/CMakeLists.txt

 add_header_library(
   message_mapper
   HDRS
     message_mapper.h
   DEPENDS
     libc.src.__support.CPP.string_view
     libc.src.__support.CPP.optional
 )
 
+# The table maps depend on message_mapper.
+add_subdirectory(tables)
+
 add_object_library(
   error_to_string
   HDRS
     error_to_string.h
   SRCS
     error_to_string.cpp
   DEPENDS
     .message_mapper
     libc.src.errno.errno
     libc.src.__support.CPP.span
     libc.src.__support.CPP.string_view
     libc.src.__support.CPP.stringstream
     libc.src.__support.integer_to_string
+    libc.src.__support.StringUtil.tables.error_table
 )
 
-
 add_object_library(
   signal_to_string
   HDRS
     signal_to_string.h
   SRCS
     signal_to_string.cpp
   DEPENDS
     .message_mapper
     libc.include.signal
     libc.src.__support.CPP.span
     libc.src.__support.CPP.string_view
     libc.src.__support.CPP.stringstream
     libc.src.__support.integer_to_string
+    libc.src.__support.StringUtil.tables.signal_table
 )

libc/src/__support/StringUtil/error_to_string.h

 //===-- Definition of a class for mapping errors to strings -----*- C++ -*-===//
 //
 // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
 // See https://llvm.org/LICENSE.txt for license information.
 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
 //
 //===----------------------------------------------------------------------===//
 
-#include "src/__support/CPP/span.h"
-#include "src/__support/CPP/string_view.h"
-
 #ifndef LLVM_LIBC_SRC_SUPPORT_ERROR_TO_STRING_H
 #define LLVM_LIBC_SRC_SUPPORT_ERROR_TO_STRING_H
 
+#include "src/__support/CPP/span.h"
+#include "src/__support/CPP/string_view.h"
+
 namespace __llvm_libc {
 
 cpp::string_view get_error_string(int err_num);
 
 cpp::string_view get_error_string(int err_num, cpp::span<char> buffer);
 
 } // namespace __llvm_libc
 
 #endif // LLVM_LIBC_SRC_SUPPORT_ERROR_TO_STRING_H

libc/src/__support/StringUtil/error_to_string.cpp

 //===-- Implementation of a class for mapping errors to strings -----------===//
 //
 // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
 // See https://llvm.org/LICENSE.txt for license information.
 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
 //
 //===----------------------------------------------------------------------===//
 
 #include "src/__support/StringUtil/error_to_string.h"
 
+#include "src/errno/libc_errno.h" // For error macros
+
+#include "src/__support/CPP/array.h"
 #include "src/__support/CPP/span.h"
 #include "src/__support/CPP/string_view.h"
 #include "src/__support/CPP/stringstream.h"
 #include "src/__support/StringUtil/message_mapper.h"
 #include "src/__support/integer_to_string.h"
-#include "src/errno/libc_errno.h" // For error macros
+
+#include "src/__support/StringUtil/tables/error_table.h"
 
 #include <stddef.h>
 
 namespace __llvm_libc {
 namespace internal {
 
 constexpr size_t max_buff_size() {
   constexpr size_t unknown_str_len = sizeof("Unknown error");
   constexpr size_t max_num_len =
       __llvm_libc::IntegerToString::dec_bufsize<int>();
   // the buffer should be able to hold "Unknown error" + ' ' + num_str
   return (unknown_str_len + 1 + max_num_len) * sizeof(char);
 }
 
 // This is to hold error strings that have to be custom built. It may be
 // rewritten on every call to strerror (or other error to string function).
 constexpr size_t ERR_BUFFER_SIZE = max_buff_size();
 thread_local char error_buffer[ERR_BUFFER_SIZE];
 
+constexpr size_t RAW_ARRAY_LEN = PLATFORM_ERRORS.size();
+constexpr size_t TOTAL_STR_LEN =
+    total_str_len(PLATFORM_ERRORS.data(), RAW_ARRAY_LEN);
+
 // Since the StringMappings array is a map from error numbers to their
 // corresponding strings, we have to have an array large enough we can use the
-// error numbers as indexes. Thankfully there are 132 errors in the above list
-// (41 and 58 are skipped) and the highest number is 133. If other platforms use
-// different error numbers, then this number may need to be adjusted.
-// Also if negative numbers or particularly large numbers are used, then the
-// array should be turned into a proper hashmap.
-constexpr size_t ERR_ARRAY_SIZE = 134;
-
-constexpr MsgMapping raw_err_array[] = {
-    MsgMapping(0, "Success"),
-    MsgMapping(EPERM, "Operation not permitted"),
-    MsgMapping(ENOENT, "No such file or directory"),
-    MsgMapping(ESRCH, "No such process"),
-    MsgMapping(EINTR, "Interrupted system call"),
-    MsgMapping(EIO, "Input/output error"),
-    MsgMapping(ENXIO, "No such device or address"),
-    MsgMapping(E2BIG, "Argument list too long"),
-    MsgMapping(ENOEXEC, "Exec format error"),
-    MsgMapping(EBADF, "Bad file descriptor"),
-    MsgMapping(ECHILD, "No child processes"),
-    MsgMapping(EAGAIN, "Resource temporarily unavailable"),
-    MsgMapping(ENOMEM, "Cannot allocate memory"),
-    MsgMapping(EACCES, "Permission denied"),
-    MsgMapping(EFAULT, "Bad address"),
-    MsgMapping(ENOTBLK, "Block device required"),
-    MsgMapping(EBUSY, "Device or resource busy"),
-    MsgMapping(EEXIST, "File exists"),
-    MsgMapping(EXDEV, "Invalid cross-device link"),
-    MsgMapping(ENODEV, "No such device"),
-    MsgMapping(ENOTDIR, "Not a directory"),
-    MsgMapping(EISDIR, "Is a directory"),
-    MsgMapping(EINVAL, "Invalid argument"),
-    MsgMapping(ENFILE, "Too many open files in system"),
-    MsgMapping(EMFILE, "Too many open files"),
-    MsgMapping(ENOTTY, "Inappropriate ioctl for device"),
-    MsgMapping(ETXTBSY, "Text file busy"),
-    MsgMapping(EFBIG, "File too large"),
-    MsgMapping(ENOSPC, "No space left on device"),
-    MsgMapping(ESPIPE, "Illegal seek"),
-    MsgMapping(EROFS, "Read-only file system"),
-    MsgMapping(EMLINK, "Too many links"),
-    MsgMapping(EPIPE, "Broken pipe"),
-    MsgMapping(EDOM, "Numerical argument out of domain"),
-    MsgMapping(ERANGE, "Numerical result out of range"),
-    MsgMapping(EDEADLK, "Resource deadlock avoided"),
-    MsgMapping(ENAMETOOLONG, "File name too long"),
-    MsgMapping(ENOLCK, "No locks available"),
-    MsgMapping(ENOSYS, "Function not implemented"),
-    MsgMapping(ENOTEMPTY, "Directory not empty"),
-    MsgMapping(ELOOP, "Too many levels of symbolic links"),
-    // No error for 41. Would be EWOULDBLOCK
-    MsgMapping(ENOMSG, "No message of desired type"),
-    MsgMapping(EIDRM, "Identifier removed"),
-    MsgMapping(ECHRNG, "Channel number out of range"),
-    MsgMapping(EL2NSYNC, "Level 2 not synchronized"),
-    MsgMapping(EL3HLT, "Level 3 halted"),
-    MsgMapping(EL3RST, "Level 3 reset"),
-    MsgMapping(ELNRNG, "Link number out of range"),
-    MsgMapping(EUNATCH, "Protocol driver not attached"),
-    MsgMapping(ENOCSI, "No CSI structure available"),
-    MsgMapping(EL2HLT, "Level 2 halted"),
-    MsgMapping(EBADE, "Invalid exchange"),
-    MsgMapping(EBADR, "Invalid request descriptor"),
-    MsgMapping(EXFULL, "Exchange full"),
-    MsgMapping(ENOANO, "No anode"),
-    MsgMapping(EBADRQC, "Invalid request code"),
-    MsgMapping(EBADSLT, "Invalid slot"),
-    // No error for 58. Would be EDEADLOCK.
-    MsgMapping(EBFONT, "Bad font file format"),
-    MsgMapping(ENOSTR, "Device not a stream"),
-    MsgMapping(ENODATA, "No data available"),
-    MsgMapping(ETIME, "Timer expired"),
-    MsgMapping(ENOSR, "Out of streams resources"),
-    MsgMapping(ENONET, "Machine is not on the network"),
-    MsgMapping(ENOPKG, "Package not installed"),
-    MsgMapping(EREMOTE, "Object is remote"),
-    MsgMapping(ENOLINK, "Link has been severed"),
-    MsgMapping(EADV, "Advertise error"),
-    MsgMapping(ESRMNT, "Srmount error"),
-    MsgMapping(ECOMM, "Communication error on send"),
-    MsgMapping(EPROTO, "Protocol error"),
-    MsgMapping(EMULTIHOP, "Multihop attempted"),
-    MsgMapping(EDOTDOT, "RFS specific error"),
-    MsgMapping(EBADMSG, "Bad message"),
-    MsgMapping(EOVERFLOW, "Value too large for defined data type"),
-    MsgMapping(ENOTUNIQ, "Name not unique on network"),
-    MsgMapping(EBADFD, "File descriptor in bad state"),
-    MsgMapping(EREMCHG, "Remote address changed"),
-    MsgMapping(ELIBACC, "Can not access a needed shared library"),
-    MsgMapping(ELIBBAD, "Accessing a corrupted shared library"),
-    MsgMapping(ELIBSCN, ".lib section in a.out corrupted"),
-    MsgMapping(ELIBMAX, "Attempting to link in too many shared libraries"),
-    MsgMapping(ELIBEXEC, "Cannot exec a shared library directly"),
-    MsgMapping(EILSEQ, "Invalid or incomplete multibyte or wide character"),
-    MsgMapping(ERESTART, "Interrupted system call should be restarted"),
-    MsgMapping(ESTRPIPE, "Streams pipe error"),
-    MsgMapping(EUSERS, "Too many users"),
-    MsgMapping(ENOTSOCK, "Socket operation on non-socket"),
-    MsgMapping(EDESTADDRREQ, "Destination address required"),
-    MsgMapping(EMSGSIZE, "Message too long"),
-    MsgMapping(EPROTOTYPE, "Protocol wrong type for socket"),
-    MsgMapping(ENOPROTOOPT, "Protocol not available"),
-    MsgMapping(EPROTONOSUPPORT, "Protocol not supported"),
-    MsgMapping(ESOCKTNOSUPPORT, "Socket type not supported"),
-    MsgMapping(ENOTSUP, "Operation not supported"),
-    MsgMapping(EPFNOSUPPORT, "Protocol family not supported"),
-    MsgMapping(EAFNOSUPPORT, "Address family not supported by protocol"),
-    MsgMapping(EADDRINUSE, "Address already in use"),
-    MsgMapping(EADDRNOTAVAIL, "Cannot assign requested address"),
-    MsgMapping(ENETDOWN, "Network is down"),
-    MsgMapping(ENETUNREACH, "Network is unreachable"),
-    MsgMapping(ENETRESET, "Network dropped connection on reset"),
-    MsgMapping(ECONNABORTED, "Software caused connection abort"),
-    MsgMapping(ECONNRESET, "Connection reset by peer"),
-    MsgMapping(ENOBUFS, "No buffer space available"),
-    MsgMapping(EISCONN, "Transport endpoint is already connected"),
-    MsgMapping(ENOTCONN, "Transport endpoint is not connected"),
-    MsgMapping(ESHUTDOWN, "Cannot send after transport endpoint shutdown"),
-    MsgMapping(ETOOMANYREFS, "Too many references: cannot splice"),
-    MsgMapping(ETIMEDOUT, "Connection timed out"),
-    MsgMapping(ECONNREFUSED, "Connection refused"),
-    MsgMapping(EHOSTDOWN, "Host is down"),
-    MsgMapping(EHOSTUNREACH, "No route to host"),
-    MsgMapping(EALREADY, "Operation already in progress"),
-    MsgMapping(EINPROGRESS, "Operation now in progress"),
-    MsgMapping(ESTALE, "Stale file handle"),
-    MsgMapping(EUCLEAN, "Structure needs cleaning"),
-    MsgMapping(ENOTNAM, "Not a XENIX named type file"),
-    MsgMapping(ENAVAIL, "No XENIX semaphores available"),
-    MsgMapping(EISNAM, "Is a named type file"),
-    MsgMapping(EREMOTEIO, "Remote I/O error"),
-    MsgMapping(EDQUOT, "Disk quota exceeded"),
-    MsgMapping(ENOMEDIUM, "No medium found"),
-    MsgMapping(EMEDIUMTYPE, "Wrong medium type"),
-    MsgMapping(ECANCELED, "Operation canceled"),
-    MsgMapping(ENOKEY, "Required key not available"),
-    MsgMapping(EKEYEXPIRED, "Key has expired"),
-    MsgMapping(EKEYREVOKED, "Key has been revoked"),
-    MsgMapping(EKEYREJECTED, "Key was rejected by service"),
-    MsgMapping(EOWNERDEAD, "Owner died"),
-    MsgMapping(ENOTRECOVERABLE, "State not recoverable"),
-    MsgMapping(ERFKILL, "Operation not possible due to RF-kill"),
-    MsgMapping(EHWPOISON, "Memory page has hardware error"),
-};
-
-constexpr size_t RAW_ARRAY_LEN = sizeof(raw_err_array) / sizeof(MsgMapping);
-constexpr size_t TOTAL_STR_LEN = total_str_len(raw_err_array, RAW_ARRAY_LEN);
+// error numbers as indexes. The current linux configuration has 132 values with
+// the maximum value being 133 (41 and 58 are skipped). If other platforms use
+// negative numbers or discontiguous ranges, then the array should be turned
+// into a proper hashmap.
+constexpr size_t ERR_ARRAY_SIZE =
+    max_key_val(PLATFORM_ERRORS.data(), RAW_ARRAY_LEN) + 1;
 
 static constexpr MessageMapper<ERR_ARRAY_SIZE, TOTAL_STR_LEN>
-    error_mapper(raw_err_array, RAW_ARRAY_LEN);
+    error_mapper(PLATFORM_ERRORS.data(), RAW_ARRAY_LEN);
 
 cpp::string_view build_error_string(int err_num, cpp::span<char> buffer) {
   // if the buffer can't hold "Unknown error" + ' ' + num_str, then just
   // return "Unknown error".
   if (buffer.size() <
       (sizeof("Unknown error") + 1 + IntegerToString::dec_bufsize<int>()))
     return const_cast<char *>("Unknown error");
 

libc/src/__support/StringUtil/message_mapper.h

 //===-- A class for number to string mappings -------------------*- C++ -*-===//
 //
 // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
 // See https://llvm.org/LICENSE.txt for license information.
 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
 //
 //===----------------------------------------------------------------------===//
 
 #ifndef LLVM_LIBC_SRC_SUPPORT_STRING_UTIL_MESSAGE_MAPPER_H
 #define LLVM_LIBC_SRC_SUPPORT_STRING_UTIL_MESSAGE_MAPPER_H
 
+#include "src/__support/CPP/array.h"
 #include "src/__support/CPP/optional.h"
 #include "src/__support/CPP/string_view.h"
 #include <stddef.h>
 
 namespace __llvm_libc {
 namespace internal {
 
 struct MsgMapping {
   int num;
   cpp::string_view msg;
 
+  constexpr MsgMapping() : num(0), msg() { ; }
+
   constexpr MsgMapping(int init_num, const char *init_msg)
       : num(init_num), msg(init_msg) {
     ;
   }
 };
 
 constexpr size_t total_str_len(const MsgMapping *array, size_t len) {
   size_t total = 0;
   for (size_t i = 0; i < len; ++i) {
     // add 1 for the null terminator.
     total += array[i].msg.size() + 1;
   }
   return total;
 }
 
+constexpr size_t max_key_val(const MsgMapping *array, size_t len) {
+  int max = 0;
+  for (size_t i = 0; i < len; ++i) {
+    if (array[i].num > max) {
+      max = array[i].num;
+    }
+  }
+  // max will never be negative since the starting value is 0. This is good,
+  // since it's used as a length.
+  return static_cast<size_t>(max);
+}
+
 template <size_t ARR_SIZE, size_t TOTAL_STR_LEN> class MessageMapper {
   int msg_offsets[ARR_SIZE] = {-1};
   char string_array[TOTAL_STR_LEN] = {'\0'};
 
 public:
   constexpr MessageMapper(const MsgMapping raw_array[], size_t raw_array_len) {
     cpp::string_view string_mappings[ARR_SIZE] = {""};
     for (size_t i = 0; i < raw_array_len; ++i)
if (num >= 0 && static_cast<size_t>(num) < ARR_SIZE &&
         msg_offsets[num] != -1) {
       return {string_array + msg_offsets[num]};
     } else {
       return cpp::optional<cpp::string_view>();
     }
   }
 };
 
+template <size_t N> using MsgTable = cpp::array<MsgMapping, N>;
+
+template <size_t N1, size_t N2>
+constexpr MsgTable<N1 + N2> operator+(const MsgTable<N1> &t1,
+                                      const MsgTable<N2> &t2) {
+  MsgTable<N1 + N2> res{};
+  for (size_t i = 0; i < N1; ++i)
+    res[i] = t1[i];
+  for (size_t i = 0; i < N2; ++i)
+    res[N1 + i] = t2[i];
+  return res;
+}
+
 } // namespace internal
 } // namespace __llvm_libc
 
 #endif // LLVM_LIBC_SRC_SUPPORT_STRING_UTIL_MESSAGE_MAPPER_H

libc/src/__support/StringUtil/signal_to_string.cpp

 //===-- Implementation of a class for mapping signals to strings ----------===//
 //
 // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
 // See https://llvm.org/LICENSE.txt for license information.
 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
 //
 //===----------------------------------------------------------------------===//
 
 #include "src/__support/StringUtil/signal_to_string.h"
 
 #include "src/__support/CPP/span.h"
 #include "src/__support/CPP/string_view.h"
 #include "src/__support/CPP/stringstream.h"
 #include "src/__support/StringUtil/message_mapper.h"
+#include "src/__support/StringUtil/tables/signal_table.h"
 #include "src/__support/integer_to_string.h"
 
 #include <signal.h>
 #include <stddef.h>
 
 namespace __llvm_libc {
 namespace internal {
 
 constexpr size_t max_buff_size() {
   constexpr size_t base_str_len = sizeof("Real-time signal");
   constexpr size_t max_num_len =
       __llvm_libc::IntegerToString::dec_bufsize<int>();
   // the buffer should be able to hold "Real-time signal" + ' ' + num_str
   return (base_str_len + 1 + max_num_len) * sizeof(char);
 }
 
 // This is to hold signal strings that have to be custom built. It may be
 // rewritten on every call to strsignal (or other signal to string function).
 constexpr size_t SIG_BUFFER_SIZE = max_buff_size();
 thread_local char signal_buffer[SIG_BUFFER_SIZE];
 
-constexpr MsgMapping raw_sig_array[] = {
-    MsgMapping(SIGHUP, "Hangup"), MsgMapping(SIGINT, "Interrupt"),
-    MsgMapping(SIGQUIT, "Quit"), MsgMapping(SIGILL, "Illegal instruction"),
-    MsgMapping(SIGTRAP, "Trace/breakpoint trap"),
-    MsgMapping(SIGABRT, "Aborted"), MsgMapping(SIGBUS, "Bus error"),
-    MsgMapping(SIGFPE, "Floating point exception"),
-    MsgMapping(SIGKILL, "Killed"), MsgMapping(SIGUSR1, "User defined signal 1"),
-    MsgMapping(SIGSEGV, "Segmentation fault"),
-    MsgMapping(SIGUSR2, "User defined signal 2"),
-    MsgMapping(SIGPIPE, "Broken pipe"), MsgMapping(SIGALRM, "Alarm clock"),
-    MsgMapping(SIGTERM, "Terminated"),
-    // SIGSTKFLT (may not exist)
-    MsgMapping(SIGCHLD, "Child exited"), MsgMapping(SIGCONT, "Continued"),
-    MsgMapping(SIGSTOP, "Stopped (signal)"), MsgMapping(SIGTSTP, "Stopped"),
-    MsgMapping(SIGTTIN, "Stopped (tty input)"),
-    MsgMapping(SIGTTOU, "Stopped (tty output)"),
-    MsgMapping(SIGURG, "Urgent I/O condition"),
-    MsgMapping(SIGXCPU, "CPU time limit exceeded"),
-    MsgMapping(SIGXFSZ, "File size limit exceeded"),
-    MsgMapping(SIGVTALRM, "Virtual timer expired"),
-    MsgMapping(SIGPROF, "Profiling timer expired"),
-    MsgMapping(SIGWINCH, "Window changed"), MsgMapping(SIGPOLL, "I/O possible"),
-    // SIGPWR (may not exist)
-    MsgMapping(SIGSYS, "Bad system call"),
-
-#ifdef SIGSTKFLT
-    MsgMapping(SIGSTKFLT, "Stack fault"), // unused
-#endif
-#ifdef SIGPWR
-    MsgMapping(SIGPWR, "Power failure"), // ignored
-#endif
-};
-
-// Since the string_mappings array is a map from signal numbers to their
-// corresponding strings, we have to have an array large enough we can use the
-// signal numbers as indexes. The highest signal is SIGSYS at 31, so an array of
-// 32 elements will be large enough to hold all of them.
-constexpr size_t SIG_ARRAY_SIZE = 32;
+constexpr size_t RAW_ARRAY_LEN = PLATFORM_SIGNALS.size();
+constexpr size_t TOTAL_STR_LEN =
+    total_str_len(PLATFORM_SIGNALS.data(), RAW_ARRAY_LEN);
 
-constexpr size_t RAW_ARRAY_LEN = sizeof(raw_sig_array) / sizeof(MsgMapping);
-constexpr size_t TOTAL_STR_LEN = total_str_len(raw_sig_array, RAW_ARRAY_LEN);
+constexpr size_t SIG_ARRAY_SIZE =
+    max_key_val(PLATFORM_SIGNALS.data(), RAW_ARRAY_LEN) + 1;
 
 static constexpr MessageMapper<SIG_ARRAY_SIZE, TOTAL_STR_LEN>
-    signal_mapper(raw_sig_array, RAW_ARRAY_LEN);
+    signal_mapper(PLATFORM_SIGNALS.data(), RAW_ARRAY_LEN);
 
 cpp::string_view build_signal_string(int sig_num, cpp::span<char> buffer) {
   cpp::string_view base_str;
   if (sig_num >= SIGRTMIN && sig_num <= SIGRTMAX) {
     base_str = cpp::string_view("Real-time signal");
     sig_num -= SIGRTMIN;
   } else {
     base_str = cpp::string_view("Unknown signal");

libc/src/__support/StringUtil/tables/CMakeLists.txt

+if(EXISTS ${CMAKE_CURRENT_SOURCE_DIR}/${LIBC_TARGET_OS})
+  add_subdirectory(${LIBC_TARGET_OS})
+endif()
+
+set(error_to_string_platform_dep "")
+if(TARGET libc.src.__support.StringUtil.tables.${LIBC_TARGET_OS}.error_table)
+  set(error_to_string_platform_dep 
+  libc.src.__support.StringUtil.tables.${LIBC_TARGET_OS}.error_table)
+endif()
+
+add_header_library(
+  error_table
+  HDRS
+    error_table.h  
+    stdc_error_table.h  
+    posix_error_table.h  
+  DEPENDS
+    ${error_to_string_platform_dep}
+)
+
+set(signal_to_string_platform_dep "")
+if(TARGET libc.src.__support.StringUtil.tables.${LIBC_TARGET_OS}.signal_table)
+  set(signal_to_string_platform_dep 
+  libc.src.__support.StringUtil.tables.${LIBC_TARGET_OS}.signal_table)
+endif()
+
+add_header_library(
+  signal_table
+  HDRS
+    signal_table.h  
+    stdc_signal_table.h  
+    posix_signal_table.h  
+  DEPENDS
+    ${signal_to_string_platform_dep}
+)

libc/src/__support/StringUtil/tables/error_table.h

+//===-- Map from error numbers to strings -----------------------*- C++ -*-===//
+//
+// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
+// See https://llvm.org/LICENSE.txt for license information.
+// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
+//
+//===----------------------------------------------------------------------===//
+
+#ifndef LLVM_LIBC_SRC_SUPPORT_STRING_UTIL_TABLES_ERROR_TABLE_H
+#define LLVM_LIBC_SRC_SUPPORT_STRING_UTIL_TABLES_ERROR_TABLE_H
+
+#include "src/__support/StringUtil/message_mapper.h"
+
+#include "posix_error_table.h"
+#include "stdc_error_table.h"
+
+#ifdef __linux__
+#include "linux/error_table.h"
+#endif
+
+namespace __llvm_libc::internal {
+
+#ifdef __linux__
+inline constexpr auto PLATFORM_ERRORS =
+    STDC_ERRORS + POSIX_ERRORS + LINUX_ERRORS;
+#else
+inline constexpr auto PLATFORM_ERRORS = STDC_ERRORS;
+#endif
+
+} // namespace __llvm_libc::internal
+
+#endif // LLVM_LIBC_SRC_SUPPORT_STRING_UTIL_TABLES_ERROR_TABLE_H

libc/src/__support/StringUtil/tables/linux/CMakeLists.txt

+add_header_library(
+  error_table
+  HDRS
+    error_table.h
+  DEPENDS
+  libc.src.__support.StringUtil.message_mapper
+  libc.src.errno.errno
+)
+
+add_header_library(
+  signal_table
+  HDRS
+    signal_table.h
+  DEPENDS
+  libc.src.__support.StringUtil.message_mapper
+  libc.include.signal
+)

libc/src/__support/StringUtil/tables/linux/error_table.h

+//===-- Map from error numbers to strings on linux --------------*- C++ -*-===//
+//
+// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
+// See https://llvm.org/LICENSE.txt for license information.
+// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
+//
+//===----------------------------------------------------------------------===//
+
+#ifndef LLVM_LIBC_SRC_SUPPORT_STRING_UTIL_TABLES_LINUX_ERROR_TABLE_H
+#define LLVM_LIBC_SRC_SUPPORT_STRING_UTIL_TABLES_LINUX_ERROR_TABLE_H
+
+#include "src/errno/libc_errno.h" // For error macros
+
+#include "src/__support/CPP/array.h"
+#include "src/__support/StringUtil/message_mapper.h"
+
+namespace __llvm_libc::internal {
+
+constexpr MsgTable<52> LINUX_ERRORS = {
+    MsgMapping(ENOTBLK, "Block device required"),
+    MsgMapping(ECHRNG, "Channel number out of range"),
+    MsgMapping(EL2NSYNC, "Level 2 not synchronized"),
+    MsgMapping(EL3HLT, "Level 3 halted"),
+    MsgMapping(EL3RST, "Level 3 reset"),
+    MsgMapping(ELNRNG, "Link number out of range"),
+    MsgMapping(EUNATCH, "Protocol driver not attached"),
+    MsgMapping(ENOCSI, "No CSI structure available"),
+    MsgMapping(EL2HLT, "Level 2 halted"),
+    MsgMapping(EBADE, "Invalid exchange"),
+    MsgMapping(EBADR, "Invalid request descriptor"),
+    MsgMapping(EXFULL, "Exchange full"),
+    MsgMapping(ENOANO, "No anode"),
+    MsgMapping(EBADRQC, "Invalid request code"),
+    MsgMapping(EBADSLT, "Invalid slot"),
+    MsgMapping(EBFONT, "Bad font file format"),
+    MsgMapping(ENONET, "Machine is not on the network"),
+    MsgMapping(ENOPKG, "Package not installed"),
+    MsgMapping(EREMOTE, "Object is remote"),
+    MsgMapping(EADV, "Advertise error"),
+    MsgMapping(ESRMNT, "Srmount error"),
+    MsgMapping(ECOMM, "Communication error on send"),
+    MsgMapping(EDOTDOT, "RFS specific error"),
+    MsgMapping(ENOTUNIQ, "Name not unique on network"),
+    MsgMapping(EBADFD, "File descriptor in bad state"),
+    MsgMapping(EREMCHG, "Remote address changed"),
+    MsgMapping(ELIBACC, "Can not access a needed shared library"),
+    MsgMapping(ELIBBAD, "Accessing a corrupted shared library"),
+    MsgMapping(ELIBSCN, ".lib section in a.out corrupted"),
+    MsgMapping(ELIBMAX, "Attempting to link in too many shared libraries"),
+    MsgMapping(ELIBEXEC, "Cannot exec a shared library directly"),
+    MsgMapping(ERESTART, "Interrupted system call should be restarted"),
+    MsgMapping(ESTRPIPE, "Streams pipe error"),
+    MsgMapping(EUSERS, "Too many users"),
+    MsgMapping(ESOCKTNOSUPPORT, "Socket type not supported"),
+    MsgMapping(EPFNOSUPPORT, "Protocol family not supported"),
+    MsgMapping(ESHUTDOWN, "Cannot send after transport endpoint shutdown"),
+    MsgMapping(ETOOMANYREFS, "Too many references: cannot splice"),
+    MsgMapping(EHOSTDOWN, "Host is down"),
+    MsgMapping(EUCLEAN, "Structure needs cleaning"),
+    MsgMapping(ENOTNAM, "Not a XENIX named type file"),
+    MsgMapping(ENAVAIL, "No XENIX semaphores available"),
+    MsgMapping(EISNAM, "Is a named type file"),
+    MsgMapping(EREMOTEIO, "Remote I/O error"),
+    MsgMapping(ENOMEDIUM, "No medium found"),
+    MsgMapping(EMEDIUMTYPE, "Wrong medium type"),
+    MsgMapping(ENOKEY, "Required key not available"),
+    MsgMapping(EKEYEXPIRED, "Key has expired"),
+    MsgMapping(EKEYREVOKED, "Key has been revoked"),
+    MsgMapping(EKEYREJECTED, "Key was rejected by service"),
+    MsgMapping(ERFKILL, "Operation not possible due to RF-kill"),
+    MsgMapping(EHWPOISON, "Memory page has hardware error"),
+};
+
+} // namespace __llvm_libc::internal
+
+#endif // LLVM_LIBC_SRC_SUPPORT_STRING_UTIL_TABLES_LINUX_ERROR_TABLE_H

libc/src/__support/StringUtil/tables/linux/signal_table.h

+//===-- Map from signal numbers to strings on linux -------------*- C++ -*-===//
+//
+// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
+// See https://llvm.org/LICENSE.txt for license information.
+// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
+//
+//===----------------------------------------------------------------------===//
+
+#ifndef LLVM_LIBC_SRC_SUPPORT_STRING_UTIL_TABLES_LINUX_SIGNAL_TABLE_H
+#define LLVM_LIBC_SRC_SUPPORT_STRING_UTIL_TABLES_LINUX_SIGNAL_TABLE_H
+
+#include <signal.h>
+
+#include "src/__support/StringUtil/message_mapper.h"
+
+namespace __llvm_libc::internal {
+
+// The array being larger than necessary isn't a problem. The MsgMappings will
+// be set to their default state which maps 0 to an empty string. This will get
+// filtered out in the MessageMapper building stage.
+inline constexpr const MsgTable<3> LINUX_SIGNALS = {
+#ifdef SIGSTKFLT
+    MsgMapping(SIGSTKFLT, "Stack fault"), // unused
+#endif
+    MsgMapping(SIGWINCH, "Window changed"),
+#ifdef SIGPWR
+    MsgMapping(SIGPWR, "Power failure"), // ignored
+#endif
+};
+
+} // namespace __llvm_libc::internal
+
+#endif // LLVM_LIBC_SRC_SUPPORT_STRING_UTIL_TABLES_LINUX_SIGNAL_TABLE_H

libc/src/__support/StringUtil/tables/posix_error_table.h

+//===-- Map from error numbers to strings in posix --------------*- C++ -*-===//
+//
+// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
+// See https://llvm.org/LICENSE.txt for license information.
+// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
+//
+//===----------------------------------------------------------------------===//
+
+#ifndef LLVM_LIBC_SRC_SUPPORT_STRING_UTIL_TABLES_POSIX_ERROR_TABLE_H
+#define LLVM_LIBC_SRC_SUPPORT_STRING_UTIL_TABLES_POSIX_ERROR_TABLE_H
+
+#include "src/errno/libc_errno.h" // For error macros
+
+#include "src/__support/CPP/array.h"
+#include "src/__support/StringUtil/message_mapper.h"
+
+namespace __llvm_libc::internal {
+
+inline constexpr MsgTable<76> POSIX_ERRORS = {
+    MsgMapping(EPERM, "Operation not permitted"),
+    MsgMapping(ENOENT, "No such file or directory"),
+    MsgMapping(ESRCH, "No such process"),
+    MsgMapping(EINTR, "Interrupted system call"),
+    MsgMapping(EIO, "Input/output error"),
+    MsgMapping(ENXIO, "No such device or address"),
+    MsgMapping(E2BIG, "Argument list too long"),
+    MsgMapping(ENOEXEC, "Exec format error"),
+    MsgMapping(EBADF, "Bad file descriptor"),
+    MsgMapping(ECHILD, "No child processes"),
+    MsgMapping(EAGAIN, "Resource temporarily unavailable"),
+    MsgMapping(ENOMEM, "Cannot allocate memory"),
+    MsgMapping(EACCES, "Permission denied"),
+    MsgMapping(EFAULT, "Bad address"),
+    MsgMapping(EBUSY, "Device or resource busy"),
+    MsgMapping(EEXIST, "File exists"),
+    MsgMapping(EXDEV, "Invalid cross-device link"),
+    MsgMapping(ENODEV, "No such device"),
+    MsgMapping(ENOTDIR, "Not a directory"),
+    MsgMapping(EISDIR, "Is a directory"),
+    MsgMapping(EINVAL, "Invalid argument"),
+    MsgMapping(ENFILE, "Too many open files in system"),
+    MsgMapping(EMFILE, "Too many open files"),
+    MsgMapping(ENOTTY, "Inappropriate ioctl for device"),
+    MsgMapping(ETXTBSY, "Text file busy"),
+    MsgMapping(EFBIG, "File too large"),
+    MsgMapping(ENOSPC, "No space left on device"),
+    MsgMapping(ESPIPE, "Illegal seek"),
+    MsgMapping(EROFS, "Read-only file system"),
+    MsgMapping(EMLINK, "Too many links"),
+    MsgMapping(EPIPE, "Broken pipe"),
+    MsgMapping(EDEADLK, "Resource deadlock avoided"),
+    MsgMapping(ENAMETOOLONG, "File name too long"),
+    MsgMapping(ENOLCK, "No locks available"),
+    MsgMapping(ENOSYS, "Function not implemented"),
+    MsgMapping(ENOTEMPTY, "Directory not empty"),
+    MsgMapping(ELOOP, "Too many levels of symbolic links"),
+    MsgMapping(ENOMSG, "No message of desired type"),
+    MsgMapping(EIDRM, "Identifier removed"),
+    MsgMapping(ENOSTR, "Device not a stream"),
+    MsgMapping(ENODATA, "No data available"),
+    MsgMapping(ETIME, "Timer expired"),
+    MsgMapping(ENOSR, "Out of streams resources"),
+    MsgMapping(ENOLINK, "Link has been severed"),
+    MsgMapping(EPROTO, "Protocol error"),
+    MsgMapping(EMULTIHOP, "Multihop attempted"),
+    MsgMapping(EBADMSG, "Bad message"),
+    MsgMapping(EOVERFLOW, "Value too large for defined data type"),
+    MsgMapping(ENOTSOCK, "Socket operation on non-socket"),
+    MsgMapping(EDESTADDRREQ, "Destination address required"),
+    MsgMapping(EMSGSIZE, "Message too long"),
+    MsgMapping(EPROTOTYPE, "Protocol wrong type for socket"),
+    MsgMapping(ENOPROTOOPT, "Protocol not available"),
+    MsgMapping(EPROTONOSUPPORT, "Protocol not supported"),
+    MsgMapping(ENOTSUP, "Operation not supported"),
+    MsgMapping(EAFNOSUPPORT, "Address family not supported by protocol"),
+    MsgMapping(EADDRINUSE, "Address already in use"),
+    MsgMapping(EADDRNOTAVAIL, "Cannot assign requested address"),
+    MsgMapping(ENETDOWN, "Network is down"),
+    MsgMapping(ENETUNREACH, "Network is unreachable"),
+    MsgMapping(ENETRESET, "Network dropped connection on reset"),
+    MsgMapping(ECONNABORTED, "Software caused connection abort"),
+    MsgMapping(ECONNRESET, "Connection reset by peer"),
+    MsgMapping(ENOBUFS, "No buffer space available"),
+    MsgMapping(EISCONN, "Transport endpoint is already connected"),
+    MsgMapping(ENOTCONN, "Transport endpoint is not connected"),
+    MsgMapping(ETIMEDOUT, "Connection timed out"),
+    MsgMapping(ECONNREFUSED, "Connection refused"),
+    MsgMapping(EHOSTUNREACH, "No route to host"),
+    MsgMapping(EALREADY, "Operation already in progress"),
+    MsgMapping(EINPROGRESS, "Operation now in progress"),
+    MsgMapping(ESTALE, "Stale file handle"),
+    MsgMapping(EDQUOT, "Disk quota exceeded"),
+    MsgMapping(ECANCELED, "Operation canceled"),
+    MsgMapping(EOWNERDEAD, "Owner died"),
+    MsgMapping(ENOTRECOVERABLE, "State not recoverable"),
+};
+
+} // namespace __llvm_libc::internal
+
+#endif // LLVM_LIBC_SRC_SUPPORT_STRING_UTIL_TABLES_POSIX_ERROR_TABLE_H

libc/src/__support/StringUtil/tables/posix_signal_table.h

+//===-- Map from signal numbers to strings in posix -------------*- C++ -*-===//
+//
+// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
+// See https://llvm.org/LICENSE.txt for license information.
+// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
+//
+//===----------------------------------------------------------------------===//
+
+#ifndef LLVM_LIBC_SRC_SUPPORT_STRING_UTIL_TABLES_POSIX_SIGNAL_TABLE_H
+#define LLVM_LIBC_SRC_SUPPORT_STRING_UTIL_TABLES_POSIX_SIGNAL_TABLE_H
+
+#include <signal.h>
+
+#include "src/__support/CPP/array.h"
+#include "src/__support/StringUtil/message_mapper.h"
+
+namespace __llvm_libc::internal {
+
+inline constexpr MsgTable<22> POSIX_SIGNALS = {
+    MsgMapping(SIGHUP, "Hangup"),
+    MsgMapping(SIGQUIT, "Quit"),
+    MsgMapping(SIGTRAP, "Trace/breakpoint trap"),
+    MsgMapping(SIGBUS, "Bus error"),
+    MsgMapping(SIGKILL, "Killed"),
+    MsgMapping(SIGUSR1, "User defined signal 1"),
+    MsgMapping(SIGUSR2, "User defined signal 2"),
+    MsgMapping(SIGPIPE, "Broken pipe"),
+    MsgMapping(SIGALRM, "Alarm clock"),
+    MsgMapping(SIGCHLD, "Child exited"),
+    MsgMapping(SIGCONT, "Continued"),
+    MsgMapping(SIGSTOP, "Stopped (signal)"),
+    MsgMapping(SIGTSTP, "Stopped"),
+    MsgMapping(SIGTTIN, "Stopped (tty input)"),
+    MsgMapping(SIGTTOU, "Stopped (tty output)"),
+    MsgMapping(SIGURG, "Urgent I/O condition"),
+    MsgMapping(SIGXCPU, "CPU time limit exceeded"),
+    MsgMapping(SIGXFSZ, "File size limit exceeded"),
+    MsgMapping(SIGVTALRM, "Virtual timer expired"),
+    MsgMapping(SIGPROF, "Profiling timer expired"),
+    MsgMapping(SIGPOLL, "I/O possible"),
+    MsgMapping(SIGSYS, "Bad system call"),
+};
+
+} // namespace __llvm_libc::internal
+
+#endif // LLVM_LIBC_SRC_SUPPORT_STRING_UTIL_TABLES_POSIX_SIGNAL_TABLE_H

libc/src/__support/StringUtil/tables/signal_table.h

+//===-- Map from signal numbers to strings ----------------------*- C++ -*-===//
+//
+// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
+// See https://llvm.org/LICENSE.txt for license information.
+// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
+//
+//===----------------------------------------------------------------------===//
+
+#ifndef LLVM_LIBC_SRC_SUPPORT_STRING_UTIL_TABLES_SIGNAL_TABLE_H
+#define LLVM_LIBC_SRC_SUPPORT_STRING_UTIL_TABLES_SIGNAL_TABLE_H
+
+#include "src/__support/StringUtil/message_mapper.h"
+
+#include "posix_signal_table.h"
+#include "stdc_signal_table.h"
+
+#ifdef __linux__
+#include "linux/signal_table.h"
+#endif
+
+namespace __llvm_libc::internal {
+
+#ifdef __linux__
+inline constexpr auto PLATFORM_SIGNALS =
+    STDC_SIGNALS + POSIX_SIGNALS + LINUX_SIGNALS;
+#else
+inline constexpr auto PLATFORM_SIGNALS = STDC_SIGNALS;
+#endif
+
+} // namespace __llvm_libc::internal
+
+#endif // LLVM_LIBC_SRC_SUPPORT_STRING_UTIL_TABLES_SIGNAL_TABLE_H

libc/src/__support/StringUtil/tables/stdc_error_table.h

+//===-- Map from error numbers to strings in the c std ----------*- C++ -*-===//
+//
+// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
+// See https://llvm.org/LICENSE.txt for license information.
+// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
+//
+//===----------------------------------------------------------------------===//
+
+#ifndef LLVM_LIBC_SRC_SUPPORT_STRING_UTIL_TABLES_STDC_ERROR_TABLE_H
+#define LLVM_LIBC_SRC_SUPPORT_STRING_UTIL_TABLES_STDC_ERROR_TABLE_H
+
+#include "src/errno/libc_errno.h" // For error macros
+
+#include "src/__support/StringUtil/message_mapper.h"
+
+namespace __llvm_libc::internal {
+
+inline constexpr const MsgTable<4> STDC_ERRORS = {
+    MsgMapping(0, "Success"),
+    MsgMapping(EDOM, "Numerical argument out of domain"),
+    MsgMapping(ERANGE, "Numerical result out of range"),
+    MsgMapping(EILSEQ, "Invalid or incomplete multibyte or wide character"),
+};
+
+} // namespace __llvm_libc::internal
+
+#endif // LLVM_LIBC_SRC_SUPPORT_STRING_UTIL_TABLES_LINUX_ERROR_TABLE_H

libc/src/__support/StringUtil/tables/stdc_signal_table.h

+//===-- Map from signal numbers to strings in the c std ---------*- C++ -*-===//
+//
+// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
+// See https://llvm.org/LICENSE.txt for license information.
+// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
+//
+//===----------------------------------------------------------------------===//
+
+#ifndef LLVM_LIBC_SRC_SUPPORT_STRING_UTIL_TABLES_STDC_SIGNAL_TABLE_H
+#define LLVM_LIBC_SRC_SUPPORT_STRING_UTIL_TABLES_STDC_SIGNAL_TABLE_H
+
+#include <signal.h>
+
+#include "src/__support/StringUtil/message_mapper.h"
+
+namespace __llvm_libc::internal {
+
+inline constexpr const MsgTable<6> STDC_SIGNALS = {
+    MsgMapping(SIGINT, "Interrupt"),
+    MsgMapping(SIGILL, "Illegal instruction"),
+    MsgMapping(SIGABRT, "Aborted"),
+    MsgMapping(SIGFPE, "Floating point exception"),
+    MsgMapping(SIGSEGV, "Segmentation fault"),
+    MsgMapping(SIGTERM, "Terminated"),
+};
+
+} // namespace __llvm_libc::internal
+
+#endif // LLVM_LIBC_SRC_SUPPORT_STRING_UTIL_TABLES_LINUX_SIGNAL_TABLE_H