[libc-commits] [libc] 54f7d98 - [libc][netdb] Implement gai_strerror POSIX function. (#221138)
via libc-commits
libc-commits at lists.llvm.org
Fri Sep 4 07:54:26 PDT 2026
Author: Alexey Samsonov
Date: 2026-09-04T07:54:21-07:00
New Revision: 54f7d98d52413399a14111bfede1c9e388ac62c7
URL: https://github.com/llvm/llvm-project/commit/54f7d98d52413399a14111bfede1c9e388ac62c7
DIFF: https://github.com/llvm/llvm-project/commit/54f7d98d52413399a14111bfede1c9e388ac62c7.diff
LOG: [libc][netdb] Implement gai_strerror POSIX function. (#221138)
`gai_strerror` is defined in POSIX and used to provide human-readable
strings for `EAI_*` error codes returned by
`getaddrinfo` and `getnameinfo`.
Provide our implementation via simple switch. Provide string values
based on the POSIX documentation for `EAI_`
values in
https://pubs.opengroup.org/onlinepubs/9799919799/basedefs/netdb.h.html,
but shorten them for brevity.
Added:
libc/src/netdb/gai_strerror.cpp
libc/src/netdb/gai_strerror.h
libc/test/src/netdb/gai_strerror_test.cpp
Modified:
libc/config/linux/aarch64/entrypoints.txt
libc/config/linux/x86_64/entrypoints.txt
libc/include/netdb.yaml
libc/src/netdb/CMakeLists.txt
libc/test/src/netdb/CMakeLists.txt
Removed:
################################################################################
diff --git a/libc/config/linux/aarch64/entrypoints.txt b/libc/config/linux/aarch64/entrypoints.txt
index 554513e686eab..cf6a6c2815a7b 100644
--- a/libc/config/linux/aarch64/entrypoints.txt
+++ b/libc/config/linux/aarch64/entrypoints.txt
@@ -1404,6 +1404,7 @@ if(LLVM_LIBC_ENABLE_EXPERIMENTAL_ENTRYPOINTS)
# netdb.h entrypoints
libc.src.netdb.freeaddrinfo
+ libc.src.netdb.gai_strerror
libc.src.netdb.getaddrinfo
# regex.h entrypoints
diff --git a/libc/config/linux/x86_64/entrypoints.txt b/libc/config/linux/x86_64/entrypoints.txt
index 43c04275ef8e4..28f2b9a480ef3 100644
--- a/libc/config/linux/x86_64/entrypoints.txt
+++ b/libc/config/linux/x86_64/entrypoints.txt
@@ -1635,6 +1635,7 @@ if(LLVM_LIBC_ENABLE_EXPERIMENTAL_ENTRYPOINTS)
# netdb.h entrypoints
libc.src.netdb.freeaddrinfo
+ libc.src.netdb.gai_strerror
libc.src.netdb.getaddrinfo
# regex.h entrypoints
diff --git a/libc/include/netdb.yaml b/libc/include/netdb.yaml
index b98f30fd1a2f2..6dc873ae13f11 100644
--- a/libc/include/netdb.yaml
+++ b/libc/include/netdb.yaml
@@ -33,6 +33,12 @@ functions:
return_type: void
arguments:
- type: struct addrinfo *
+ - name: gai_strerror
+ standards:
+ - posix
+ return_type: const char *
+ arguments:
+ - type: int
- name: getaddrinfo
standards:
- posix
diff --git a/libc/src/netdb/CMakeLists.txt b/libc/src/netdb/CMakeLists.txt
index 5533695158291..f2a8ccb4da896 100644
--- a/libc/src/netdb/CMakeLists.txt
+++ b/libc/src/netdb/CMakeLists.txt
@@ -10,6 +10,18 @@ add_entrypoint_object(
libc.src.__support.macros.config
)
+add_entrypoint_object(
+ gai_strerror
+ SRCS
+ gai_strerror.cpp
+ HDRS
+ gai_strerror.h
+ DEPENDS
+ libc.hdr.netdb_macros
+ libc.src.__support.common
+ libc.src.__support.macros.config
+)
+
add_entrypoint_object(
getaddrinfo
SRCS
diff --git a/libc/src/netdb/gai_strerror.cpp b/libc/src/netdb/gai_strerror.cpp
new file mode 100644
index 0000000000000..378917707ceee
--- /dev/null
+++ b/libc/src/netdb/gai_strerror.cpp
@@ -0,0 +1,48 @@
+//===----------------------------------------------------------------------===//
+//
+// 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
+//
+//===----------------------------------------------------------------------===//
+///
+/// \file
+/// Implementation of gai_strerror.
+///
+//===----------------------------------------------------------------------===//
+
+#include "src/netdb/gai_strerror.h"
+#include "hdr/netdb_macros.h"
+#include "src/__support/common.h"
+#include "src/__support/macros/config.h"
+
+namespace LIBC_NAMESPACE_DECL {
+
+LLVM_LIBC_FUNCTION(const char *, gai_strerror, (int errcode)) {
+ switch (errcode) {
+ case EAI_AGAIN:
+ return "Name could not be resolved at this time";
+ case EAI_BADFLAGS:
+ return "Flags had an invalid value";
+ case EAI_FAIL:
+ return "Non-recoverable error occurred";
+ case EAI_FAMILY:
+ return "Address family not recognized";
+ case EAI_MEMORY:
+ return "Memory allocation failure";
+ case EAI_NONAME:
+ return "Name does not resolve for the supplied parameters";
+ case EAI_OVERFLOW:
+ return "Argument buffer overflowed";
+ case EAI_SERVICE:
+ return "Service not recognized for specified socket type";
+ case EAI_SOCKTYPE:
+ return "Intended socket type not recognized";
+ case EAI_SYSTEM:
+ return "System error";
+ default:
+ return "Unknown error";
+ }
+}
+
+} // namespace LIBC_NAMESPACE_DECL
diff --git a/libc/src/netdb/gai_strerror.h b/libc/src/netdb/gai_strerror.h
new file mode 100644
index 0000000000000..8ef8b352ff582
--- /dev/null
+++ b/libc/src/netdb/gai_strerror.h
@@ -0,0 +1,25 @@
+//===----------------------------------------------------------------------===//
+//
+// 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
+//
+//===----------------------------------------------------------------------===//
+///
+/// \file
+/// Implementation header for gai_strerror.
+///
+//===----------------------------------------------------------------------===//
+
+#ifndef LLVM_LIBC_SRC_NETDB_GAI_STRERROR_H
+#define LLVM_LIBC_SRC_NETDB_GAI_STRERROR_H
+
+#include "src/__support/macros/config.h"
+
+namespace LIBC_NAMESPACE_DECL {
+
+const char *gai_strerror(int errcode);
+
+} // namespace LIBC_NAMESPACE_DECL
+
+#endif // LLVM_LIBC_SRC_NETDB_GAI_STRERROR_H
diff --git a/libc/test/src/netdb/CMakeLists.txt b/libc/test/src/netdb/CMakeLists.txt
index bb2113840d993..608d7f38acabe 100644
--- a/libc/test/src/netdb/CMakeLists.txt
+++ b/libc/test/src/netdb/CMakeLists.txt
@@ -1,5 +1,16 @@
add_custom_target(libc-netdb-tests)
+add_libc_test(
+ gai_strerror_test
+ SUITE
+ libc-netdb-tests
+ SRCS
+ gai_strerror_test.cpp
+ DEPENDS
+ libc.hdr.netdb_macros
+ libc.src.netdb.gai_strerror
+)
+
add_libc_test(
netdb_test
SUITE
diff --git a/libc/test/src/netdb/gai_strerror_test.cpp b/libc/test/src/netdb/gai_strerror_test.cpp
new file mode 100644
index 0000000000000..13ba07a2b0270
--- /dev/null
+++ b/libc/test/src/netdb/gai_strerror_test.cpp
@@ -0,0 +1,43 @@
+//===----------------------------------------------------------------------===//
+//
+// 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
+//
+//===----------------------------------------------------------------------===//
+///
+/// \file
+/// Unittests for gai_strerror.
+///
+//===----------------------------------------------------------------------===//
+
+#include "hdr/netdb_macros.h"
+#include "src/netdb/gai_strerror.h"
+#include "test/UnitTest/Test.h"
+
+TEST(LlvmLibcGaiStrerrorTest, AllKnownErrors) {
+ EXPECT_STREQ(LIBC_NAMESPACE::gai_strerror(EAI_AGAIN),
+ "Name could not be resolved at this time");
+ EXPECT_STREQ(LIBC_NAMESPACE::gai_strerror(EAI_BADFLAGS),
+ "Flags had an invalid value");
+ EXPECT_STREQ(LIBC_NAMESPACE::gai_strerror(EAI_FAIL),
+ "Non-recoverable error occurred");
+ EXPECT_STREQ(LIBC_NAMESPACE::gai_strerror(EAI_FAMILY),
+ "Address family not recognized");
+ EXPECT_STREQ(LIBC_NAMESPACE::gai_strerror(EAI_MEMORY),
+ "Memory allocation failure");
+ EXPECT_STREQ(LIBC_NAMESPACE::gai_strerror(EAI_NONAME),
+ "Name does not resolve for the supplied parameters");
+ EXPECT_STREQ(LIBC_NAMESPACE::gai_strerror(EAI_OVERFLOW),
+ "Argument buffer overflowed");
+ EXPECT_STREQ(LIBC_NAMESPACE::gai_strerror(EAI_SERVICE),
+ "Service not recognized for specified socket type");
+ EXPECT_STREQ(LIBC_NAMESPACE::gai_strerror(EAI_SOCKTYPE),
+ "Intended socket type not recognized");
+ EXPECT_STREQ(LIBC_NAMESPACE::gai_strerror(EAI_SYSTEM), "System error");
+}
+
+TEST(LlvmLibcGaiStrerrorTest, UnknownErrors) {
+ EXPECT_STREQ(LIBC_NAMESPACE::gai_strerror(100), "Unknown error");
+ EXPECT_STREQ(LIBC_NAMESPACE::gai_strerror(-1000), "Unknown error");
+}
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