[libc] Add link.h and elf.h

izaakschroeder · izaakschroeder · commit 90f5bcbc9c21 · 2024-07-02T20:22:27.000-07:00
diff --git a/libc/config/linux/aarch64/entrypoints.txt b/libc/config/linux/aarch64/entrypoints.txt
@@ -22,6 +22,8 @@ set(TARGET_LIBC_ENTRYPOINTS
     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
@@ -32,6 +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
@@ -2,13 +2,15 @@ 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
     libc.include.float
     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
@@ -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
@@ -22,6 +22,8 @@ set(TARGET_LIBC_ENTRYPOINTS
     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
@@ -32,6 +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
@@ -3,6 +3,7 @@ set(TARGET_PUBLIC_HEADERS
     libc.include.ctype
     libc.include.dirent
     libc.include.dlfcn
+    libc.include.elf
     libc.include.errno
     libc.include.fcntl
     libc.include.features
@@ -11,6 +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
@@ -56,6 +56,7 @@ add_gen_header(
   DEF_FILE dlfcn.h.def
   GEN_HDR dlfcn.h
   DEPENDS
+    .llvm-libc-types.Dl_info
     .llvm-libc-macros.dlfcn_macros
     .llvm_libc_common_h
 )
@@ -367,6 +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/elf.h.def 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
@@ -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
@@ -282,4 +282,10 @@ 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/elf-macros.h 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
@@ -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
@@ -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
@@ -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
@@ -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
@@ -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-macros/link-macros.h"
+#include "llvm-libc-types/size_t.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
@@ -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
@@ -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">;
@@ -230,9 +233,14 @@ def POSIX : StandardSpec<"POSIX"> {
       Macro<"RTLD_GLOBAL">,
       Macro<"RTLD_LOCAL">,
     ],
-    [],  // Types
+    [DlInfo],  // Types
     [], // Enumerations
     [
+      FunctionSpec<
+          "dladdr",
+          RetValSpec<IntType>,
+          [ArgSpec<ConstVoidPtr>, ArgSpec<DlInfoPtr>]
+      >,
       FunctionSpec<
           "dlclose",
           RetValSpec<IntType>,
diff --git a/libc/src/CMakeLists.txt b/libc/src/CMakeLists.txt
@@ -12,6 +12,7 @@ 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
@@ -1,3 +1,14 @@
+add_entrypoint_object(
+  dladdr
+  SRCS
+    dladdr.cpp
+  HDRS
+    dladdr.h
+  DEPENDS
+    libc.include.dlfcn
+    libc.src.errno.errno
+)
+
 add_entrypoint_object(
   dlclose
   SRCS
diff --git a/libc/src/dlfcn/dladdr.cpp b/libc/src/dlfcn/dladdr.cpp
diff --git a/libc/src/dlfcn/dladdr.h b/libc/src/dlfcn/dladdr.h
diff --git a/libc/src/link/CMakeLists.txt b/libc/src/link/CMakeLists.txt
diff --git a/libc/src/link/dl_iterate_phdr.cpp b/libc/src/link/dl_iterate_phdr.cpp
diff --git a/libc/src/link/dl_iterate_phdr.h b/libc/src/link/dl_iterate_phdr.h
