[libc-commits] [libc] [libc] Install dladdr on X86 (PR #156500)

[Aiden Grossman via libc-commits]

https://github.com/boomanaiden154 created https://github.com/llvm/llvm-project/pull/156500

This patch adds dladdr to the X86 entrypoints and also does the necessary plumbing so that dladdr.cpp will actually compile.

This depends on #156195.

>From 3df7a201f0465885cd500c64db0fb5d6f59470de Mon Sep 17 00:00:00 2001
From: Aiden Grossman <aidengrossman at google.com>
Date: Tue, 2 Sep 2025 17:18:30 +0000
Subject: [PATCH] [libc] Install dladdr on X86

This patch adds dladdr to the X86 entrypoints and also does the
necessary plumbing so that dladdr.cpp will actually compile.

This depends on #156195.
---
 libc/config/linux/x86_64/entrypoints.txt |  1 +
 libc/hdr/types/CMakeLists.txt            |  9 +++++++++
 libc/hdr/types/dl_info.h                 | 21 +++++++++++++++++++++
 libc/src/dlfcn/CMakeLists.txt            |  1 +
 libc/src/dlfcn/dladdr.cpp                |  3 ++-
 libc/src/dlfcn/dladdr.h                  |  2 ++
 6 files changed, 36 insertions(+), 1 deletion(-)
 create mode 100644 libc/hdr/types/dl_info.h

diff --git a/libc/config/linux/x86_64/entrypoints.txt b/libc/config/linux/x86_64/entrypoints.txt
index c64db2cc3548f..bfd13f744f6cf 100644
--- a/libc/config/linux/x86_64/entrypoints.txt
+++ b/libc/config/linux/x86_64/entrypoints.txt
@@ -18,6 +18,7 @@ set(TARGET_LIBC_ENTRYPOINTS
     libc.src.ctype.toupper
 
     # dlfcn.h entrypoints
+    libc.src.dlfcn.dladdr
     libc.src.dlfcn.dlclose
     libc.src.dlfcn.dlerror
     libc.src.dlfcn.dlopen
diff --git a/libc/hdr/types/CMakeLists.txt b/libc/hdr/types/CMakeLists.txt
index 02fe1adc264fb..21971a4004760 100644
--- a/libc/hdr/types/CMakeLists.txt
+++ b/libc/hdr/types/CMakeLists.txt
@@ -461,3 +461,12 @@ add_proxy_header_library(
     libc.include.llvm-libc-types.struct_sched_param
     libc.include.sched
 )
+
+add_proxy_header_library(
+  dl_info
+  HDRS
+    dl_info.h
+  FULL_BUILD_DEPENDS
+    libc.include.llvm-libc-types.dl_info
+    libc.include.dlfcn
+)
diff --git a/libc/hdr/types/dl_info.h b/libc/hdr/types/dl_info.h
new file mode 100644
index 0000000000000..c7428319e0597
--- /dev/null
+++ b/libc/hdr/types/dl_info.h
@@ -0,0 +1,21 @@
+//===-- Proxy for struct timespec  ----------------------------------------===//
+//
+// 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_HDR_TYPES_DLINFO_H
+#define LLVM_LIBC_HDR_TYPES_DLINFO_H
+
+#ifdef LIBC_FULL_BUILD
+
+#include "include/llvm-libc-types/Dl_info.h"
+
+#else
+
+#include <dlfcn.h>
+
+#endif // LIBC_FULL_BUILD
+
+#endif // LLVM_LIBC_HDR_TYPES_STRUCT_TIMESPEC_H
diff --git a/libc/src/dlfcn/CMakeLists.txt b/libc/src/dlfcn/CMakeLists.txt
index 2ee3ac074267f..876d915c84064 100644
--- a/libc/src/dlfcn/CMakeLists.txt
+++ b/libc/src/dlfcn/CMakeLists.txt
@@ -54,4 +54,5 @@ add_entrypoint_object(
     dladdr.h
   DEPENDS
     libc.include.dlfcn
+    libc.hdr.types.dl_info
 )
diff --git a/libc/src/dlfcn/dladdr.cpp b/libc/src/dlfcn/dladdr.cpp
index 3db68b4a4c729..7e2a1544ada74 100644
--- a/libc/src/dlfcn/dladdr.cpp
+++ b/libc/src/dlfcn/dladdr.cpp
@@ -15,7 +15,8 @@ namespace LIBC_NAMESPACE_DECL {
 
 // TODO: https:// github.com/llvm/llvm-project/issues/97929
 LLVM_LIBC_FUNCTION(int, dladdr,
-                   (const void *__restrict addr, Dl_info *__restrict info)) {
+                   ([[maybe_unused]] const void *__restrict addr,
+                    [[maybe_unused]] Dl_info *__restrict info)) {
   return -1;
 }
 
diff --git a/libc/src/dlfcn/dladdr.h b/libc/src/dlfcn/dladdr.h
index abbc9a9008d92..1fabe8163902a 100644
--- a/libc/src/dlfcn/dladdr.h
+++ b/libc/src/dlfcn/dladdr.h
@@ -11,6 +11,8 @@
 
 #include "src/__support/macros/config.h"
 
+#include "hdr/types/dl_info.h"
+
 namespace LIBC_NAMESPACE_DECL {
 
 int dladdr(const void *__restrict, Dl_info *__restrict);