[libc] Add `link.h` and `elf.h` placeholder #97504

izaakschroeder · 2024-07-03T01:16:31Z

This is a stacked PR that builds on #97501 and completes the effort to compile libunwind + libc without baremetal mode. This is part of #97191.

llvmbot · 2024-07-03T01:17:03Z

@llvm/pr-subscribers-libc

Author: Izaak Schroeder (izaakschroeder)

Changes

Builds on #97501 and completes the effort to compile libunwind + libc without baremetal mode. This is part of #97191.

Patch is 27.26 KiB, truncated to 20.00 KiB below, full version: https://github.com/llvm/llvm-project/pull/97504.diff

34 Files Affected:

(modified) libc/config/linux/aarch64/entrypoints.txt (+11)
(modified) libc/config/linux/aarch64/headers.txt (+3)
(modified) libc/config/linux/api.td (+13)
(modified) libc/config/linux/x86_64/entrypoints.txt (+11)
(modified) libc/config/linux/x86_64/headers.txt (+3)
(modified) libc/include/CMakeLists.txt (+29)
(added) libc/include/dlfcn.h.def (+17)
(added) libc/include/elf.h.def (+14)
(added) libc/include/link.h.def (+16)
(modified) libc/include/llvm-libc-macros/CMakeLists.txt (+12)
(added) libc/include/llvm-libc-macros/dlfcn-macros.h (+23)
(added) libc/include/llvm-libc-macros/elf-macros.h (+18)
(modified) libc/include/llvm-libc-macros/link-macros.h (+24-2)
(modified) libc/include/llvm-libc-types/CMakeLists.txt (+3)
(added) libc/include/llvm-libc-types/Dl_info.h (+19)
(added) libc/include/llvm-libc-types/__dl_iterate_phdr_callback_t.h (+17)
(added) libc/include/llvm-libc-types/struct_dl_phdr_info.h (+26)
(modified) libc/spec/linux.td (+30)
(modified) libc/spec/posix.td (+43)
(modified) libc/src/CMakeLists.txt (+2)
(added) libc/src/dlfcn/CMakeLists.txt (+54)
(added) libc/src/dlfcn/dladdr.cpp (+17)
(added) libc/src/dlfcn/dladdr.h (+20)
(added) libc/src/dlfcn/dlclose.cpp (+17)
(added) libc/src/dlfcn/dlclose.h (+18)
(added) libc/src/dlfcn/dlerror.cpp (+19)
(added) libc/src/dlfcn/dlerror.h (+18)
(added) libc/src/dlfcn/dlopen.cpp (+17)
(added) libc/src/dlfcn/dlopen.h (+18)
(added) libc/src/dlfcn/dlsym.cpp (+17)
(added) libc/src/dlfcn/dlsym.h (+18)
(added) libc/src/link/CMakeLists.txt (+9)
(added) libc/src/link/dl_iterate_phdr.cpp (+21)
(added) libc/src/link/dl_iterate_phdr.h (+20)

diff --git a/libc/config/linux/aarch64/entrypoints.txt b/libc/config/linux/aarch64/entrypoints.txt
index 940df63e3912b..fe4cec1d7a77f 100644
--- a/libc/config/linux/aarch64/entrypoints.txt
+++ b/libc/config/linux/aarch64/entrypoints.txt
@@ -17,6 +17,14 @@ set(TARGET_LIBC_ENTRYPOINTS
     libc.src.ctype.tolower
     libc.src.ctype.toupper
 
+    # dlfcn.h entrypoints
+    libc.src.dlfcn.dlopen
+    libc.src.dlfcn.dlsym
+    libc.src.dlfcn.dlclose
+    libc.src.dlfcn.dlerror
+    libc.src.dlfcn.dlsym
+    libc.src.dlfcn.dladdr
+
     # errno.h entrypoints
     libc.src.errno.errno
 
@@ -26,6 +34,9 @@ set(TARGET_LIBC_ENTRYPOINTS
     libc.src.fcntl.open
     libc.src.fcntl.openat
 
+    # link.h entrypoints
+    libc.src.link.dl_iterate_phdr
+
     # sched.h entrypoints
     libc.src.sched.sched_get_priority_max
     libc.src.sched.sched_get_priority_min
diff --git a/libc/config/linux/aarch64/headers.txt b/libc/config/linux/aarch64/headers.txt
index 7d25877cefcc8..ebe053af99d80 100644
--- a/libc/config/linux/aarch64/headers.txt
+++ b/libc/config/linux/aarch64/headers.txt
@@ -1,6 +1,8 @@
 set(TARGET_PUBLIC_HEADERS
     libc.include.assert
     libc.include.ctype
+    libc.include.dlfcn
+    libc.include.elf
     libc.include.errno
     libc.include.features
     libc.include.fenv
@@ -8,6 +10,7 @@ set(TARGET_PUBLIC_HEADERS
     libc.include.stdint
     libc.include.inttypes
     libc.include.limits
+    libc.include.link
     libc.include.math
     libc.include.pthread
     libc.include.signal
diff --git a/libc/config/linux/api.td b/libc/config/linux/api.td
index eb0090c80b0da..3ff99f263f811 100644
--- a/libc/config/linux/api.td
+++ b/libc/config/linux/api.td
@@ -308,3 +308,16 @@ def SearchAPI : PublicAPI<"search.h"> {
 def SysStatvfsAPI : PublicAPI<"sys/statvfs.h"> {
   let Types = ["fsblkcnt_t", "fsfilcnt_t", "struct statvfs"];
 }
+
+def LinkAPI : PublicAPI<"link.h"> {
+  let Types = [
+    "struct dl_phdr_info",
+    "__dl_iterate_phdr_callback_t"
+  ];
+}
+
+def DlfcnAPI : PublicAPI<"dlfcn.h"> {
+  let Types = [
+    "Dl_info"
+  ];
+}
diff --git a/libc/config/linux/x86_64/entrypoints.txt b/libc/config/linux/x86_64/entrypoints.txt
index 09f04fb31dfd8..18e682e52bb12 100644
--- a/libc/config/linux/x86_64/entrypoints.txt
+++ b/libc/config/linux/x86_64/entrypoints.txt
@@ -17,6 +17,14 @@ set(TARGET_LIBC_ENTRYPOINTS
     libc.src.ctype.tolower
     libc.src.ctype.toupper
 
+    # dlfcn.h entrypoints
+    libc.src.dlfcn.dlopen
+    libc.src.dlfcn.dlsym
+    libc.src.dlfcn.dlclose
+    libc.src.dlfcn.dlerror
+    libc.src.dlfcn.dlsym
+    libc.src.dlfcn.dladdr
+
     # errno.h entrypoints
     libc.src.errno.errno
 
@@ -26,6 +34,9 @@ set(TARGET_LIBC_ENTRYPOINTS
     libc.src.fcntl.open
     libc.src.fcntl.openat
 
+    # link.h entrypoints
+    libc.src.link.dl_iterate_phdr
+
     # sched.h entrypoints
     libc.src.sched.sched_get_priority_max
     libc.src.sched.sched_get_priority_min
diff --git a/libc/config/linux/x86_64/headers.txt b/libc/config/linux/x86_64/headers.txt
index 44d640b75e2bf..903771c5f96a6 100644
--- a/libc/config/linux/x86_64/headers.txt
+++ b/libc/config/linux/x86_64/headers.txt
@@ -2,6 +2,8 @@ set(TARGET_PUBLIC_HEADERS
     libc.include.assert
     libc.include.ctype
     libc.include.dirent
+    libc.include.dlfcn
+    libc.include.elf
     libc.include.errno
     libc.include.fcntl
     libc.include.features
@@ -10,6 +12,7 @@ set(TARGET_PUBLIC_HEADERS
     libc.include.stdint
     libc.include.inttypes
     libc.include.limits
+    libc.include.link
     libc.include.math
     libc.include.pthread
     libc.include.sched
diff --git a/libc/include/CMakeLists.txt b/libc/include/CMakeLists.txt
index 3ab7817d8568b..a39c1c118165f 100644
--- a/libc/include/CMakeLists.txt
+++ b/libc/include/CMakeLists.txt
@@ -51,6 +51,16 @@ add_gen_header(
     .llvm_libc_common_h
 )
 
+add_gen_header(
+  dlfcn
+  DEF_FILE dlfcn.h.def
+  GEN_HDR dlfcn.h
+  DEPENDS
+    .llvm-libc-types.Dl_info
+    .llvm-libc-macros.dlfcn_macros
+    .llvm_libc_common_h
+)
+
 add_gen_header(
   features
   DEF_FILE features.h.def
@@ -358,6 +368,25 @@ add_gen_header(
     .llvm-libc-types.posix_spawn_file_actions_t
 )
 
+add_gen_header(
+  link
+  DEF_FILE link.h.def
+  GEN_HDR link.h
+  DEPENDS
+    .llvm_libc_common_h
+    .llvm-libc-types.struct_dl_phdr_info
+    .llvm-libc-types.__dl_iterate_phdr_callback_t
+    .llvm-libc-macros.link_macros
+)
+
+add_gen_header(
+  elf
+  DEF_FILE elf.h.def
+  GEN_HDR elf.h
+  DEPENDS
+    .llvm-libc-macros.elf_macros
+)
+
 # TODO: Not all platforms will have a include/sys directory. Add the sys
 # directory and the targets for sys/*.h files conditional to the OS requiring
 # them.
diff --git a/libc/include/dlfcn.h.def b/libc/include/dlfcn.h.def
new file mode 100644
index 0000000000000..31395871c6b97
--- /dev/null
+++ b/libc/include/dlfcn.h.def
@@ -0,0 +1,17 @@
+//===-- C standard library header dlfcn.h ---------------------------------===//
+//
+// 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_DLFCN_H
+#define LLVM_LIBC_DLFCN_H
+
+#include "__llvm-libc-common.h"
+#include "llvm-libc-macros/dlfcn-macros.h"
+
+%%public_api()
+
+#endif // LLVM_LIBC_DLFCN_H
diff --git a/libc/include/elf.h.def b/libc/include/elf.h.def
new file mode 100644
index 0000000000000..1c9d11929029f
--- /dev/null
+++ b/libc/include/elf.h.def
@@ -0,0 +1,14 @@
+//===-- C standard library header elf.h -----------------------------------===//
+//
+// 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_ELF_H
+#define LLVM_LIBC_ELF_H
+
+#include "llvm-libc-macros/elf-macros.h"
+
+#endif // LLVM_LIBC_ELF_H
diff --git a/libc/include/link.h.def b/libc/include/link.h.def
new file mode 100644
index 0000000000000..353398e4f3c88
--- /dev/null
+++ b/libc/include/link.h.def
@@ -0,0 +1,16 @@
+//===-- C standard library header link.h ----------------------------------===//
+//
+// 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_LINK_H
+#define LLVM_LIBC_LINK_H
+
+#include "llvm-libc-macros/link-macros.h"
+
+%%public_api()
+
+#endif // LLVM_LIBC_LINK_H
diff --git a/libc/include/llvm-libc-macros/CMakeLists.txt b/libc/include/llvm-libc-macros/CMakeLists.txt
index f6af11abd4dd7..60c8f5a9cd3de 100644
--- a/libc/include/llvm-libc-macros/CMakeLists.txt
+++ b/libc/include/llvm-libc-macros/CMakeLists.txt
@@ -277,3 +277,15 @@ add_macro_header(
   HDR
     stdckdint-macros.h
 )
+
+add_macro_header(
+  dlfcn_macros
+  HDR
+    dlfcn-macros.h
+)
+
+add_macro_header(
+  elf_macros
+  HDR
+    elf-macros.h
+)
diff --git a/libc/include/llvm-libc-macros/dlfcn-macros.h b/libc/include/llvm-libc-macros/dlfcn-macros.h
new file mode 100644
index 0000000000000..dcd202b9ab435
--- /dev/null
+++ b/libc/include/llvm-libc-macros/dlfcn-macros.h
@@ -0,0 +1,23 @@
+//===-- Definition of macros from dlfcn.h ---------------------------------===//
+//
+// 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_MACROS_DLFCN_MACROS_H
+#define LLVM_LIBC_MACROS_DLFCN_MACROS_H
+
+#define RTLD_LAZY 0x00001
+#define RTLD_NOW 0x00002
+#define RTLD_GLOBAL 0x00100
+#define RTLD_LOCAL 0
+
+// Non-standard stuff here
+#define RTLD_BINDING_MASK 0x3
+#define RTLD_NOLOAD 0x00004
+#define RTLD_DEEPBIND 0x00008
+#define RTLD_NODELETE 0x01000
+
+#endif // LLVM_LIBC_MACROS_DLFCN_MACROS_H
diff --git a/libc/include/llvm-libc-macros/elf-macros.h b/libc/include/llvm-libc-macros/elf-macros.h
new file mode 100644
index 0000000000000..fa4442abf0f5c
--- /dev/null
+++ b/libc/include/llvm-libc-macros/elf-macros.h
@@ -0,0 +1,18 @@
+//===-- Definition of macros from elf.h -----------------------------------===//
+//
+// 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_MACROS_ELF_MACROS_H
+#define LLVM_LIBC_MACROS_ELF_MACROS_H
+
+#if __has_include(<linux/elf.h>)
+#include <linux/elf.h>
+#else
+#error "cannot use <sys/elf.h> without proper system headers."
+#endif
+
+#endif // LLVM_LIBC_MACROS_ELF_MACROS_H
diff --git a/libc/include/llvm-libc-macros/link-macros.h b/libc/include/llvm-libc-macros/link-macros.h
index 5c8cadab8e71c..f7461d9527a47 100644
--- a/libc/include/llvm-libc-macros/link-macros.h
+++ b/libc/include/llvm-libc-macros/link-macros.h
@@ -6,8 +6,30 @@
 //
 //===----------------------------------------------------------------------===//
 
+#ifndef LLVM_LIBC_MACROS_LINK_MACROS_H
+#define LLVM_LIBC_MACROS_LINK_MACROS_H
+
+#include "elf-macros.h"
+
 #ifdef __LP64__
-#define ElfW(type) Elf64_ ## type
+#define ElfW(type) Elf64_##type
 #else
-#define ElfW(type) Elf32_ ## type
+#define ElfW(type) Elf32_##type
+#endif
+
+struct link_map {
+  ElfW(Addr) l_addr;
+  char *l_name;
+  ElfW(Dyn) * l_ld;
+  struct link_map *l_next, *l_prev;
+};
+
+struct r_debug {
+  int r_version;
+  struct link_map *r_map;
+  ElfW(Addr) r_brk;
+  enum { RT_CONSISTENT, RT_ADD, RT_DELETE } r_state;
+  ElfW(Addr) r_ldbase;
+};
+
 #endif
diff --git a/libc/include/llvm-libc-types/CMakeLists.txt b/libc/include/llvm-libc-types/CMakeLists.txt
index d8b975572e0dd..016ec14b077e8 100644
--- a/libc/include/llvm-libc-types/CMakeLists.txt
+++ b/libc/include/llvm-libc-types/CMakeLists.txt
@@ -89,6 +89,9 @@ add_header(thrd_t HDR thrd_t.h DEPENDS .__thread_type)
 add_header(tss_t HDR tss_t.h)
 add_header(tss_dtor_t HDR tss_dtor_t.h)
 add_header(__atexithandler_t HDR __atexithandler_t.h)
+add_header(Dl_info HDR Dl_info.h)
+add_header(struct_dl_phdr_info HDR struct_dl_phdr_info.h)
+add_header(__dl_iterate_phdr_callback_t HDR __dl_iterate_phdr_callback_t.h)
 add_header(speed_t HDR speed_t.h)
 add_header(tcflag_t HDR tcflag_t.h)
 add_header(struct_termios HDR struct_termios.h DEPENDS .cc_t .speed_t .tcflag_t)
diff --git a/libc/include/llvm-libc-types/Dl_info.h b/libc/include/llvm-libc-types/Dl_info.h
new file mode 100644
index 0000000000000..bee32015c4008
--- /dev/null
+++ b/libc/include/llvm-libc-types/Dl_info.h
@@ -0,0 +1,19 @@
+//===-- Definition of type Dl_info ----------------------------------------===//
+//
+// 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_TYPES_DL_INFO_H
+#define LLVM_LIBC_TYPES_DL_INFO_H
+
+typedef struct {
+	const char *dli_fname;
+	void *dli_fbase;
+	const char *dli_sname;
+	void *dli_saddr;
+} Dl_info;
+
+#endif // LLVM_LIBC_TYPES_DL_INFO_H
diff --git a/libc/include/llvm-libc-types/__dl_iterate_phdr_callback_t.h b/libc/include/llvm-libc-types/__dl_iterate_phdr_callback_t.h
new file mode 100644
index 0000000000000..9d73e88076e00
--- /dev/null
+++ b/libc/include/llvm-libc-types/__dl_iterate_phdr_callback_t.h
@@ -0,0 +1,17 @@
+//===-- Definition of __dl_iterate_phdr_callback_t type -------------------===//
+//
+// 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_TYPES___DL_ITERATE_PHDR_CALLBACK_T_H
+#define LLVM_LIBC_TYPES___DL_ITERATE_PHDR_CALLBACK_T_H
+
+#include "llvm-libc-types/size_t.h"
+
+typedef int (*__dl_iterate_phdr_callback_t)(struct dl_phdr_info *info,
+                                            size_t size, void *data);
+
+#endif // LLVM_LIBC_TYPES___DL_ITERATE_PHDR_CALLBACK_T_H
diff --git a/libc/include/llvm-libc-types/struct_dl_phdr_info.h b/libc/include/llvm-libc-types/struct_dl_phdr_info.h
new file mode 100644
index 0000000000000..8bbd7811bbe2a
--- /dev/null
+++ b/libc/include/llvm-libc-types/struct_dl_phdr_info.h
@@ -0,0 +1,26 @@
+//===-- Definition of type struct dl_phdr_info ----------------------------===//
+//
+// 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_TYPES_STRUCT_DL_PHDR_INFO_H
+#define LLVM_LIBC_TYPES_STRUCT_DL_PHDR_INFO_H
+
+#include "llvm-libc-types/size_t.h"
+#include "llvm-libc-macros/link-macros.h"
+
+struct dl_phdr_info {
+  ElfW(Addr) dlpi_addr;
+  const char *dlpi_name;
+  const ElfW(Phdr) * dlpi_phdr;
+  ElfW(Half) dlpi_phnum;
+  unsigned long long int dlpi_adds;
+  unsigned long long int dlpi_subs;
+  size_t dlpi_tls_modid;
+  void *dlpi_tls_data;
+};
+
+#endif // LLVM_LIBC_TYPES_STRUCT_DL_PHDR_INFO_H
diff --git a/libc/spec/linux.td b/libc/spec/linux.td
index 82630ff413c73..bd13dd17a85cd 100644
--- a/libc/spec/linux.td
+++ b/libc/spec/linux.td
@@ -3,6 +3,9 @@ def StructEpollEventPtr : PtrType<StructEpollEvent>;
 
 def StructEpollData : NamedType<"struct epoll_data">;
 
+def StructDlPhdrInfo : NamedType<"struct dl_phdr_info">;
+def DlIteratePhdrCallback : NamedType<"__dl_iterate_phdr_callback_t">;
+
 def Linux : StandardSpec<"Linux"> {
   HeaderSpec Errno = HeaderSpec<
       "errno.h",
@@ -264,8 +267,35 @@ def Linux : StandardSpec<"Linux"> {
       ]
   >;
 
+  HeaderSpec Link = HeaderSpec<
+     "link.h",
+      [], // Macros
+      [StructDlPhdrInfo, DlIteratePhdrCallback], // Types
+      [], // Enumerations
+      [
+        FunctionSpec<
+          "dl_iterate_phdr",
+          RetValSpec<IntType>,
+          [
+            ArgSpec<DlIteratePhdrCallback>,
+            ArgSpec<VoidPtr>
+          ]
+        >,
+      ]  // Functions
+  >;
+
+  HeaderSpec Elf = HeaderSpec<
+     "elf.h",
+      [], // Macros
+      [], // Types
+      [], // Enumerations
+      []  // Functions
+  >;
+
   let Headers = [
+    Elf,
     Errno,
+    Link,
     SysEpoll,
     SysMMan,
     SysPrctl,
diff --git a/libc/spec/posix.td b/libc/spec/posix.td
index d14047548e104..1a829704c0667 100644
--- a/libc/spec/posix.td
+++ b/libc/spec/posix.td
@@ -21,6 +21,9 @@ def PThreadOnceT : NamedType<"pthread_once_t">;
 def PThreadOnceTPtr : PtrType<PThreadOnceT>;
 def PThreadOnceCallback : NamedType<"__pthread_once_func_t">;
 
+def DlInfo : NamedType<"Dl_info">;
+def DlInfoPtr : PtrType<DlInfo>;
+
 def InoT : NamedType<"ino_t">;
 def UidT : NamedType<"uid_t">;
 def GidT : NamedType<"gid_t">;
@@ -222,6 +225,45 @@ def POSIX : StandardSpec<"POSIX"> {
       []  // Functions
   >;
 
+  HeaderSpec DlFcn = HeaderSpec<
+    "dlfcn.h",
+    [
+      Macro<"RTLD_LAZY">,
+      Macro<"RTLD_NOW">,
+      Macro<"RTLD_GLOBAL">,
+      Macro<"RTLD_LOCAL">,
+    ],
+    [DlInfo],  // Types
+    [], // Enumerations
+    [
+      FunctionSpec<
+          "dladdr",
+          RetValSpec<IntType>,
+          [ArgSpec<ConstVoidPtr>, ArgSpec<DlInfoPtr>]
+      >,
+      FunctionSpec<
+          "dlclose",
+          RetValSpec<IntType>,
+          [ArgSpec<VoidPtr>]
+      >,
+      FunctionSpec<
+          "dlerror",
+          RetValSpec<CharPtr>,
+          []
+      >,
+      FunctionSpec<
+          "dlopen",
+          RetValSpec<VoidPtr>,
+          [ArgSpec<ConstCharPtr>, ArgSpec<IntType>]
+      >,
+      FunctionSpec<
+          "dlsym",
+          RetValSpec<VoidPtr>,
+          [ArgSpec<VoidRestrictedPtr>, ArgSpec<ConstCharRestrictedPtr>]
+      >,
+    ]
+  >;
+
   HeaderSpec FCntl = HeaderSpec<
     "fcntl.h",
     [], // Macros
@@ -1690,6 +1732,7 @@ def POSIX : StandardSpec<"POSIX"> {
     ArpaInet,
     CType,
     Dirent,
+    DlFcn,
     Errno,
     FCntl,
     PThread,
diff --git a/libc/src/CMakeLists.txt b/libc/src/CMakeLists.txt
index 09b16be1e2d42..9ff88cffc487c 100644
--- a/libc/src/CMakeLists.txt
+++ b/libc/src/CMakeLists.txt
@@ -11,6 +11,8 @@ add_subdirectory(stdio)
 add_subdirectory(stdlib)
 add_subdirectory(string)
 add_subdirectory(wchar)
+add_subdirectory(dlfcn)
+add_subdirectory(link)
 
 if(${LIBC_TARGET_OS} STREQUAL "linux")
   add_subdirectory(dirent)
diff --git a/libc/src/dlfcn/CMakeLists.txt b/libc/src/dlfcn/CMakeLists.txt
new file mode 100644
index 0000000000000..5321499b2e334
--- /dev/null
+++ b/libc/src/dlfcn/CMakeLists.txt
@@ -0,0 +1,54 @@
+add_entrypoint_object(
+  dladdr
+  SRCS
+    dladdr.cpp
+  HDRS
+    dladdr.h
+  DEPENDS
+    libc.include.dlfcn
+    libc.src.errno.errno
+)
+
+add_entrypoint_object(
+  dlclose
+  SRCS
+    dlclose.cpp
+  HDRS
+    dlclose.h
+  DEPENDS
+    libc.include.dlfcn
+    libc.src.errno.errno
+)
+
+add_entrypoint_object(
+  dlerror
+  SRCS
+    dlerror.cpp
+  HDRS
+    dlerror.h
+  DEPENDS
+    libc.include.dlfcn
+    libc.src.errno.errno
+)
+
+add_entrypoint_object(
+  dlopen
+  SRCS
+    dlopen.cpp
+  HDRS
+    dlopen.h
+  DEPENDS
+    libc.include.dlfcn
+    libc.src.errno.errno
+)
+
+add_entrypoint_object(
+  dlsym
+  SRCS
+    dlsym.cpp
+  HDRS
+    dlsym.h
+  DEPENDS
+    libc.include.dlfcn
+    libc.src.errno.errno
+)
diff --git a/libc/src/dlfcn/dladdr.cpp b/libc/src/dlfcn/dladdr.cpp
new file mode 100644
index 0000000000000..00ff1845fbe3e
--- /dev/null
+++ b/libc/src/dlfcn/dladdr.cpp
@@ -0,0 +1,17 @@
+//===-- Implementation of dladdr -----------------------------------------===//
+//
+// 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 "dladdr.h"
+
+#include "src/__support/common.h"
+
+namespace LIBC_NAMESPACE {
+
+LLVM_LIBC_FUNCTION(int, dladdr, (const void *, Dl_info *)) { return 0; }
+
+} // namespace LIBC_NAMESPACE
diff --git a/libc/src/dlfcn/dladdr.h b/libc/src/dlfcn/dladdr.h
new file mode 100644
index 0000000000000..be9a7fec7a5ef
--- /dev/null
+++ b/libc/src/dlfcn/dladdr.h
@@ -0,0 +1,20 @@
+//===-- Implementation header of dladdr ------------------------*- 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_DLFCN_DLADDR_H
+#define LLVM_LIBC_SRC_DLFCN_DLADDR_H
+
+namespace LIBC_NAMESPACE {
+
+#include "include/llvm-libc-types/Dl_info.h"
+
+int dladdr(const void *,Dl_info *);
+
+} // namespace LIBC_NAMESPACE
+
+#endif // LLVM_LIBC_SRC_DLFCN_DLADDR_H
diff --git a/libc/src/dlfcn/dlclose.cpp b/libc/src/dlfcn/dlclose.cpp
new file mode 100644
index 0000000000000..6dc1892120ddd
--- /dev/null
+++ b/libc/src/dlfcn/dlclose.cpp
@@ -0,0 +1,17 @@
+//===-- Implementation of dlclose -----------------------------------------===//
+//
+// 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 "dlclose.h"
+
+#include "src/__support/common.h"
+
+namespace LIBC_NAMESPACE {
+
+LLVM_LIBC_FUNCTION(int, dlclose, (void *)) { return -1; }
+
+} // namespace LIBC_NAMESPACE
diff --git a/libc/src/dlfcn/dlclose.h b/libc/src/dlfcn/dlclose.h
new file mode 100644
index 000000000...
[truncated]

izaakschroeder · 2024-07-03T01:17:37Z

/cc @michaelrj-google @jhuber6 @SchrodingerZhu

github-actions · 2024-07-03T01:20:44Z

✅ With the latest revision this PR passed the C/C++ code formatter.

SchrodingerZhu

LGTM but need a small fix

libc/src/link/dl_iterate_phdr.cpp

Headers for #97504

petrhosek · 2024-07-19T05:26:05Z

libc/src/dlfcn/dladdr.cpp

+
+namespace LIBC_NAMESPACE {
+
+// TODO(@izaakschroeder): https://github.com/llvm/llvm-project/issues/97929


The format I've seen more commonly used in LLVM is TODO(#97929): More details....

nickdesaulniers · 2024-10-08T17:31:51Z

What's the status of this PR? Should it be closed?

michaelrj-google · 2025-04-01T17:23:50Z

Closing as not superseded, link and elf headers are available.

llvmbot added the libc label Jul 3, 2024

izaakschroeder changed the title ~~[libc] Add link.h and elf.h~~ [libc] Add link.h and elf.h Jul 3, 2024

izaakschroeder mentioned this pull request Jul 3, 2024

[libc] build clang #97191

Open

39 tasks

izaakschroeder force-pushed the libc-link branch from c140a00 to 90f5bcb Compare July 3, 2024 03:22

SchrodingerZhu requested changes Jul 3, 2024

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libc/src/link/dl_iterate_phdr.cpp Outdated Show resolved Hide resolved

izaakschroeder force-pushed the libc-link branch from 90f5bcb to d7610bc Compare July 4, 2024 03:32

SchrodingerZhu approved these changes Jul 4, 2024

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izaakschroeder force-pushed the libc-link branch from d7610bc to cc98775 Compare July 6, 2024 23:45

izaakschroeder mentioned this pull request Jul 6, 2024

[libc] Add link.h and elf.h headers #97924

Merged

izaakschroeder changed the title ~~[libc] Add link.h and elf.h~~ [libc] Add link.h and elf.h placeholder Jul 6, 2024

SchrodingerZhu pushed a commit that referenced this pull request Jul 7, 2024

[libc] Add link.h and elf.h headers (#97924)

ba25507

Headers for #97504

This was referenced Jul 7, 2024

[libc] Implement link.dl_iterate_phdr #97928

Open

[libc] Implement dlfcn.dladdr #97929

Open

[libc] Add link.h and elf.h

e50ab27

izaakschroeder force-pushed the libc-link branch from cc98775 to e50ab27 Compare July 7, 2024 01:23

petrhosek reviewed Jul 19, 2024

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michaelrj-google closed this Apr 1, 2025

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[libc] Add `link.h` and `elf.h` placeholder #97504

[libc] Add `link.h` and `elf.h` placeholder #97504

izaakschroeder commented Jul 3, 2024 •

edited

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izaakschroeder commented Jul 3, 2024

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petrhosek Jul 19, 2024

nickdesaulniers commented Oct 8, 2024

michaelrj-google commented Apr 1, 2025


		namespace LIBC_NAMESPACE {

		// TODO(@izaakschroeder): https://github.com/llvm/llvm-project/issues/97929

[libc] Add link.h and elf.h placeholder #97504

[libc] Add link.h and elf.h placeholder #97504

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izaakschroeder commented Jul 3, 2024 • edited Loading

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izaakschroeder commented Jul 3, 2024

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nickdesaulniers commented Oct 8, 2024

michaelrj-google commented Apr 1, 2025

[libc] Add `link.h` and `elf.h` placeholder #97504

[libc] Add `link.h` and `elf.h` placeholder #97504

izaakschroeder commented Jul 3, 2024 •

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github-actions bot commented Jul 3, 2024 •

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