[libc] Add dlfcn.h placeholder

libc/config/linux/aarch64/entrypoints.txt

@@ -17,6 +17,12 @@ 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
+
     # errno.h entrypoints
     libc.src.errno.errno
 

libc/config/linux/aarch64/headers.txt

@@ -1,6 +1,7 @@
 set(TARGET_PUBLIC_HEADERS
     libc.include.assert
     libc.include.ctype
+    libc.include.dlfcn
     libc.include.errno
     libc.include.features
     libc.include.fenv

libc/config/linux/x86_64/entrypoints.txt

@@ -17,6 +17,12 @@ 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
+
     # errno.h entrypoints
     libc.src.errno.errno
 

libc/config/linux/x86_64/headers.txt

@@ -2,6 +2,7 @@ set(TARGET_PUBLIC_HEADERS
     libc.include.assert
     libc.include.ctype
     libc.include.dirent
+    libc.include.dlfcn
     libc.include.errno
     libc.include.fcntl
     libc.include.features

libc/include/CMakeLists.txt

@@ -51,6 +51,15 @@ add_gen_header(
     .llvm_libc_common_h
 )
 
+add_gen_header(
+  dlfcn
+  DEF_FILE dlfcn.h.def
+  GEN_HDR dlfcn.h
+  DEPENDS
+    .llvm-libc-macros.dlfcn_macros
+    .llvm_libc_common_h
+)
+
 add_gen_header(
   features
   DEF_FILE features.h.def

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

libc/include/llvm-libc-macros/CMakeLists.txt

@@ -277,3 +277,9 @@ add_macro_header(
   HDR
     stdckdint-macros.h
 )
+
+add_macro_header(
+  dlfcn_macros
+  HDR
+    dlfcn-macros.h
+)

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

libc/spec/posix.td

@@ -222,6 +222,40 @@ def POSIX : StandardSpec<"POSIX"> {
       []  // Functions
   >;
 
+  HeaderSpec DlFcn = HeaderSpec<
+    "dlfcn.h",
+    [
+      Macro<"RTLD_LAZY">,
+      Macro<"RTLD_NOW">,
+      Macro<"RTLD_GLOBAL">,
+      Macro<"RTLD_LOCAL">,
+    ],
+    [],  // Types
+    [], // Enumerations
+    [
+      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 +1724,7 @@ def POSIX : StandardSpec<"POSIX"> {
     ArpaInet,
     CType,
     Dirent,
+    DlFcn,
     Errno,
     FCntl,
     PThread,

libc/src/CMakeLists.txt

@@ -11,6 +11,7 @@ add_subdirectory(stdio)
 add_subdirectory(stdlib)
 add_subdirectory(string)
 add_subdirectory(wchar)
+add_subdirectory(dlfcn)
 
 if(${LIBC_TARGET_OS} STREQUAL "linux")
   add_subdirectory(dirent)

libc/src/dlfcn/CMakeLists.txt

@@ -0,0 +1,43 @@
+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
+)

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

libc/src/dlfcn/dlclose.h

@@ -0,0 +1,18 @@
+//===-- Implementation header of dlclose ------------------------*- 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_DLCLOSE_H
+#define LLVM_LIBC_SRC_DLFCN_DLCLOSE_H
+
+namespace LIBC_NAMESPACE {
+
+int dlclose(void *);
+
+} // namespace LIBC_NAMESPACE
+
+#endif // LLVM_LIBC_SRC_DLFCN_DLCLOSE_H

libc/src/dlfcn/dlerror.cpp

@@ -0,0 +1,19 @@
+//===-- Implementation of delerror ----------------------------------------===//
+//
+// 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 "dlerror.h"
+
+#include "src/__support/common.h"
+
+namespace LIBC_NAMESPACE {
+
+LLVM_LIBC_FUNCTION(char *, dlerror, ()) {
+  return const_cast<char *>("unsupported");
+}
+
+} // namespace LIBC_NAMESPACE

libc/src/dlfcn/dlerror.h

@@ -0,0 +1,18 @@
+//===-- Implementation header of dlerror ------------------------*- 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_DLERROR_H
+#define LLVM_LIBC_SRC_DLFCN_DLERROR_H
+
+namespace LIBC_NAMESPACE {
+
+char *dlerror();
+
+} // namespace LIBC_NAMESPACE
+
+#endif // LLVM_LIBC_SRC_DLFCN_DLERROR_H

libc/src/dlfcn/dlopen.cpp

@@ -0,0 +1,17 @@
+//===-- Implementation of dlopen -----------------------------------------===//
+//
+// 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 "dlopen.h"
+
+#include "src/__support/common.h"
+
+namespace LIBC_NAMESPACE {
+
+LLVM_LIBC_FUNCTION(void *, dlopen, (const char *, int)) { return nullptr; }
+
+} // namespace LIBC_NAMESPACE

libc/src/dlfcn/dlopen.h

@@ -0,0 +1,18 @@
+//===-- Implementation header of dlopen -------------------------*- 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_DLOPEN_H
+#define LLVM_LIBC_SRC_DLFCN_DLOPEN_H
+
+namespace LIBC_NAMESPACE {
+
+void *dlopen(const char *, int);
+
+} // namespace LIBC_NAMESPACE
+
+#endif // LLVM_LIBC_SRC_DLFCN_DLOPEN_H

libc/src/dlfcn/dlsym.cpp

@@ -0,0 +1,17 @@
+//===-- Implementation of dlsym ------------------------------------------===//
+//
+// 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 "dlsym.h"
+
+#include "src/__support/common.h"
+
+namespace LIBC_NAMESPACE {
+
+LLVM_LIBC_FUNCTION(void *, dlsym, (void *, const char *)) { return nullptr; }
+
+} // namespace LIBC_NAMESPACE

libc/src/dlfcn/dlsym.h

@@ -0,0 +1,18 @@
+//===-- Implementation header of dlsym --------------------------*- 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_DLSYM_H
+#define LLVM_LIBC_SRC_DLFCN_DLSYM_H
+
+namespace LIBC_NAMESPACE {
+
+void *dlsym(void *, const char *);
+
+} // namespace LIBC_NAMESPACE
+
+#endif // LLVM_LIBC_SRC_DLFCN_DLSYM_H