[libc] Add strerror and strerror_k to the GPU

[jhuber6]

Summary:
The GPU ignores errno primarily, but targets want these functions to
be defined for certain C standard interfaces. This patch enables them
and makes the test function on non-Linux targets.

[llvmbot]

@llvm/pr-subscribers-libc

Author: Joseph Huber (jhuber6)

Changes

Summary:
The GPU ignores errno primarily, but targets want these functions to
be defined for certain C standard interfaces. This patch enables them
and makes the test function on non-Linux targets.

---

Full diff: https://github.com/llvm/llvm-project/pull/99083.diff

2 Files Affected:

• (modified) libc/config/gpu/entrypoints.txt (+2)
• (modified) libc/test/src/string/strerror_test.cpp (+4-141)

diff --git a/libc/config/gpu/entrypoints.txt b/libc/config/gpu/entrypoints.txt
index 63228216c85ec..36c5b8c808528 100644
--- a/libc/config/gpu/entrypoints.txt
+++ b/libc/config/gpu/entrypoints.txt
@@ -47,6 +47,8 @@ set(TARGET_LIBC_ENTRYPOINTS
     libc.src.string.strcpy
     libc.src.string.strcspn
     libc.src.string.strdup
+    libc.src.string.strerror
+    libc.src.string.strerror_r
     libc.src.string.strlcat
     libc.src.string.strlcpy
     libc.src.string.strlen
diff --git a/libc/test/src/string/strerror_test.cpp b/libc/test/src/string/strerror_test.cpp
index cfc79481699bc..6c59c709df24b 100644
--- a/libc/test/src/string/strerror_test.cpp
+++ b/libc/test/src/string/strerror_test.cpp
@@ -6,153 +6,16 @@
 //
 //===----------------------------------------------------------------------===//
 
+#include "src/__support/StringUtil/platform_errors.h"
+#include "src/__support/macros/properties/architectures.h"
 #include "src/string/strerror.h"
 #include "test/UnitTest/Test.h"
 
 TEST(LlvmLibcStrErrorTest, KnownErrors) {
   ASSERT_STREQ(LIBC_NAMESPACE::strerror(0), "Success");
 
-  const char *message_array[] = {
-      "Success",
-      "Operation not permitted",
-      "No such file or directory",
-      "No such process",
-      "Interrupted system call",
-      "Input/output error",
-      "No such device or address",
-      "Argument list too long",
-      "Exec format error",
-      "Bad file descriptor",
-      "No child processes",
-      "Resource temporarily unavailable",
-      "Cannot allocate memory",
-      "Permission denied",
-      "Bad address",
-      "Block device required",
-      "Device or resource busy",
-      "File exists",
-      "Invalid cross-device link",
-      "No such device",
-      "Not a directory",
-      "Is a directory",
-      "Invalid argument",
-      "Too many open files in system",
-      "Too many open files",
-      "Inappropriate ioctl for device",
-      "Text file busy",
-      "File too large",
-      "No space left on device",
-      "Illegal seek",
-      "Read-only file system",
-      "Too many links",
-      "Broken pipe",
-      "Numerical argument out of domain",
-      "Numerical result out of range",
-      "Resource deadlock avoided",
-      "File name too long",
-      "No locks available",
-      "Function not implemented",
-      "Directory not empty",
-      "Too many levels of symbolic links",
-      "Unknown error 41", // Unknown
-      "No message of desired type",
-      "Identifier removed",
-      "Channel number out of range",
-      "Level 2 not synchronized",
-      "Level 3 halted",
-      "Level 3 reset",
-      "Link number out of range",
-      "Protocol driver not attached",
-      "No CSI structure available",
-      "Level 2 halted",
-      "Invalid exchange",
-      "Invalid request descriptor",
-      "Exchange full",
-      "No anode",
-      "Invalid request code",
-      "Invalid slot",
-      "Unknown error 58", // Unknown
-      "Bad font file format",
-      "Device not a stream",
-      "No data available",
-      "Timer expired",
-      "Out of streams resources",
-      "Machine is not on the network",
-      "Package not installed",
-      "Object is remote",
-      "Link has been severed",
-      "Advertise error",
-      "Srmount error",
-      "Communication error on send",
-      "Protocol error",
-      "Multihop attempted",
-      "RFS specific error",
-      "Bad message",
-      "Value too large for defined data type",
-      "Name not unique on network",
-      "File descriptor in bad state",
-      "Remote address changed",
-      "Can not access a needed shared library",
-      "Accessing a corrupted shared library",
-      ".lib section in a.out corrupted",
-      "Attempting to link in too many shared libraries",
-      "Cannot exec a shared library directly",
-      "Unknown error 84", // Unknown
-      "Interrupted system call should be restarted",
-      "Streams pipe error",
-      "Too many users",
-      "Socket operation on non-socket",
-      "Destination address required",
-      "Message too long",
-      "Protocol wrong type for socket",
-      "Protocol not available",
-      "Protocol not supported",
-      "Socket type not supported",
-      "Operation not supported",
-      "Protocol family not supported",
-      "Address family not supported by protocol",
-      "Address already in use",
-      "Cannot assign requested address",
-      "Network is down",
-      "Network is unreachable",
-      "Network dropped connection on reset",
-      "Software caused connection abort",
-      "Connection reset by peer",
-      "No buffer space available",
-      "Transport endpoint is already connected",
-      "Transport endpoint is not connected",
-      "Cannot send after transport endpoint shutdown",
-      "Too many references: cannot splice",
-      "Connection timed out",
-      "Connection refused",
-      "Host is down",
-      "No route to host",
-      "Operation already in progress",
-      "Operation now in progress",
-      "Stale file handle",
-      "Structure needs cleaning",
-      "Not a XENIX named type file",
-      "No XENIX semaphores available",
-      "Is a named type file",
-      "Remote I/O error",
-      "Disk quota exceeded",
-      "No medium found",
-      "Wrong medium type",
-      "Operation canceled",
-      "Required key not available",
-      "Key has expired",
-      "Key has been revoked",
-      "Key was rejected by service",
-      "Owner died",
-      "State not recoverable",
-      "Operation not possible due to RF-kill",
-      "Memory page has hardware error",
-  };
-
-  for (size_t i = 0; i < (sizeof(message_array) / sizeof(char *)); ++i) {
-    EXPECT_STREQ(LIBC_NAMESPACE::strerror(static_cast<int>(i)),
-                 message_array[i]);
-  }
+  for (auto [i, msg] : LIBC_NAMESPACE::PLATFORM_ERRORS)
+    EXPECT_STREQ(LIBC_NAMESPACE::strerror(static_cast<int>(i)), msg.begin());
 }
 
 TEST(LlvmLibcStrErrorTest, UnknownErrors) {

[michaelrj-google]

While you're doing this, could you also readd EILSEQ? It's a C standard error so we do need to provide it.

It just needs to be added to libc/include/llvm-libc-macros/generic-error-number-macros.h and added back to the list of error strings (see jplehr@aea35ab).

[michaelrj-google]

I'm somewhat hesitant to do it this way, since it's effectively comparing the values against themselves, but I can't think of a better solution.