[libc] Add unistd overlay

libc/hdr/CMakeLists.txt

@@ -126,10 +126,13 @@ add_proxy_header_library(
     libc.include.llvm-libc-macros.sys_stat_macros
 )
 
+add_header_library(unistd_overlay HDRS unistd_overlay.h)
 add_proxy_header_library(
   unistd_macros
   HDRS
     unistd_macros.h
+  DEPENDS
+    .unistd_overlay
   FULL_BUILD_DEPENDS
     libc.include.unistd
     libc.include.llvm-libc-macros.unistd_macros

libc/hdr/types/CMakeLists.txt

@@ -93,6 +93,14 @@ add_proxy_header_library(
     libc.include.llvm-libc-types.size_t
 )
 
+add_proxy_header_library(
+  ssize_t
+  HDRS
+    ssize_t.h
+  FULL_BUILD_DEPENDS
+    libc.include.llvm-libc-types.ssize_t
+)
+
 add_proxy_header_library(
   mode_t
   HDRS
@@ -311,3 +319,11 @@ add_proxy_header_library(
     libc.include.llvm-libc-types.wint_t
     libc.include.wchar
 )
+
+add_proxy_header_library(
+  uid_t
+  HDRS
+    uid_t.h
+  FULL_BUILD_DEPENDS
+    libc.include.llvm-libc-types.uid_t
+)

libc/hdr/types/uid_t.h

@@ -0,0 +1,22 @@
+//===-- Proxy for uid_t ---------------------------------------------------===//
+//
+// 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_UID_T_H
+#define LLVM_LIBC_HDR_TYPES_UID_T_H
+
+#ifdef LIBC_FULL_BUILD
+
+#include "include/llvm-libc-types/uid_t.h"
+
+#else // Overlay mode
+
+#include <sys/types.h>
+
+#endif // LLVM_LIBC_FULL_BUILD
+
+#endif // LLVM_LIBC_HDR_TYPES_UID_T_H

libc/hdr/unistd_macros.h

@@ -15,7 +15,7 @@
 
 #else // Overlay mode
 
-#include <unistd.h>
+#include "unistd_overlay.h"
 
 #endif // LLVM_LIBC_FULL_BUILD
 

libc/hdr/unistd_overlay.h

@@ -0,0 +1,69 @@
+//===-- Including unistd.h in overlay mode -------------------------------===//
+//
+// 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_UNISTD_OVERLAY_H
+#define LLVM_LIBC_HDR_UNISTD_OVERLAY_H
+
+#ifdef LIBC_FULL_BUILD
+#error "This header should only be included in overlay mode"
+#endif
+
+// Overlay mode
+
+// glibc <unistd.h> header might provide extern inline definitions for few
+// functions, causing external alias errors.  They are guarded by
+// `__USE_EXTERN_INLINES` macro.  We temporarily disable `__USE_EXTERN_INLINES`
+// macro by defining `__NO_INLINE__` before including <stdio.h>.
+// And the same with `__USE_FORTIFY_LEVEL`, which will be temporarily disabled
+// with `_FORTIFY_SOURCE`.
+
+#ifdef _FORTIFY_SOURCE
+#define LIBC_OLD_FORTIFY_SOURCE _FORTIFY_SOURCE
+#undef _FORTIFY_SOURCE
+#endif
+
+#ifdef __USE_EXTERN_INLINES
+#define LIBC_OLD_USE_EXTERN_INLINES
+#undef __USE_EXTERN_INLINES
+#endif
+
+#ifdef __USE_FORTIFY_LEVEL
+#define LIBC_OLD_USE_FORTIFY_LEVEL __USE_FORTIFY_LEVEL
+#undef __USE_FORTIFY_LEVEL
+#define __USE_FORTIFY_LEVEL 0
+#endif
+
+#ifndef __NO_INLINE__
+#define __NO_INLINE__ 1
+#define LIBC_SET_NO_INLINE
+#endif
+
+#include <unistd.h>
+
+#ifdef LIBC_OLD_FORTIFY_SOURCE
+#define _FORTIFY_SOURCE LIBC_OLD_FORTIFY_SOURCE
+#undef LIBC_OLD_FORTIFY_SOURCE
+#endif
+
+#ifdef LIBC_SET_NO_INLINE
+#undef __NO_INLINE__
+#undef LIBC_SET_NO_INLINE
+#endif
+
+#ifdef LIBC_OLD_USE_FORTIFY_LEVEL
+#undef __USE_FORTIFY_LEVEL
+#define __USE_FORTIFY_LEVEL LIBC_OLD_USE_FORTIFY_LEVEL
+#undef LIBC_OLD_USE_FORTIFY_LEVEL
+#endif
+
+#ifdef LIBC_OLD_USE_EXTERN_INLINES
+#define __USE_EXTERN_INLINES
+#undef LIBC_OLD_USE_EXTERN_INLINES
+#endif
+
+#endif // LLVM_LIBC_HDR_UNISTD_OVERLAY_H

libc/src/unistd/dup.h

@@ -9,8 +9,8 @@
 #ifndef LLVM_LIBC_SRC_UNISTD_DUP_H
 #define LLVM_LIBC_SRC_UNISTD_DUP_H
 
+#include "hdr/unistd_macros.h"
 #include "src/__support/macros/config.h"
-#include <unistd.h>
 
 namespace LIBC_NAMESPACE_DECL {
 

libc/src/unistd/dup2.h

@@ -9,8 +9,8 @@
 #ifndef LLVM_LIBC_SRC_UNISTD_DUP2_H
 #define LLVM_LIBC_SRC_UNISTD_DUP2_H
 
+#include "hdr/unistd_macros.h"
 #include "src/__support/macros/config.h"
-#include <unistd.h>
 
 namespace LIBC_NAMESPACE_DECL {
 

libc/src/unistd/dup3.h

@@ -9,8 +9,8 @@
 #ifndef LLVM_LIBC_SRC_UNISTD_DUP3_H
 #define LLVM_LIBC_SRC_UNISTD_DUP3_H
 
+#include "hdr/unistd_macros.h"
 #include "src/__support/macros/config.h"
-#include <unistd.h>
 
 namespace LIBC_NAMESPACE_DECL {
 

libc/src/unistd/fork.h

@@ -9,8 +9,9 @@
 #ifndef LLVM_LIBC_SRC_UNISTD_FORK_H
 #define LLVM_LIBC_SRC_UNISTD_FORK_H
 
+#include "hdr/types/pid_t.h"
+#include "hdr/unistd_macros.h"
 #include "src/__support/macros/config.h"
-#include <unistd.h>
 
 namespace LIBC_NAMESPACE_DECL {
 

libc/src/unistd/ftruncate.h

@@ -9,8 +9,9 @@
 #ifndef LLVM_LIBC_SRC_UNISTD_FTRUNCATE_H
 #define LLVM_LIBC_SRC_UNISTD_FTRUNCATE_H
 
+#include "hdr/types/off_t.h"
+#include "hdr/unistd_macros.h"
 #include "src/__support/macros/config.h"
-#include <unistd.h>
 
 namespace LIBC_NAMESPACE_DECL {
 

libc/src/unistd/getcwd.h

@@ -9,8 +9,9 @@
 #ifndef LLVM_LIBC_SRC_UNISTD_GETCWD_H
 #define LLVM_LIBC_SRC_UNISTD_GETCWD_H
 
+#include "hdr/types/size_t.h"
+#include "hdr/unistd_macros.h"
 #include "src/__support/macros/config.h"
-#include <unistd.h>
 
 namespace LIBC_NAMESPACE_DECL {
 

libc/src/unistd/geteuid.h

@@ -9,8 +9,9 @@
 #ifndef LLVM_LIBC_SRC_UNISTD_GETEUID_H
 #define LLVM_LIBC_SRC_UNISTD_GETEUID_H
 
+#include "hdr/types/uid_t.h"
+#include "hdr/unistd_macros.h"
 #include "src/__support/macros/config.h"
-#include <unistd.h>
 
 namespace LIBC_NAMESPACE_DECL {
 

libc/src/unistd/getopt.h

@@ -10,8 +10,8 @@
 #define LLVM_LIBC_SRC_UNISTD_GETOPT_H
 
 #include "hdr/types/FILE.h"
+#include "hdr/unistd_macros.h"
 #include "src/__support/macros/config.h"
-#include <unistd.h>
 
 namespace LIBC_NAMESPACE_DECL {
 

libc/src/unistd/getpid.h

@@ -9,8 +9,9 @@
 #ifndef LLVM_LIBC_SRC_UNISTD_GETPID_H
 #define LLVM_LIBC_SRC_UNISTD_GETPID_H
 
+#include "hdr/types/pid_t.h"
+#include "hdr/unistd_macros.h"
 #include "src/__support/macros/config.h"
-#include <unistd.h>
 
 namespace LIBC_NAMESPACE_DECL {
 

libc/src/unistd/getppid.h

@@ -9,8 +9,9 @@
 #ifndef LLVM_LIBC_SRC_UNISTD_GETPPID_H
 #define LLVM_LIBC_SRC_UNISTD_GETPPID_H
 
+#include "hdr/types/pid_t.h"
+#include "hdr/unistd_macros.h"
 #include "src/__support/macros/config.h"
-#include <unistd.h>
 
 namespace LIBC_NAMESPACE_DECL {
 

libc/src/unistd/getuid.h

@@ -9,8 +9,9 @@
 #ifndef LLVM_LIBC_SRC_UNISTD_GETUID_H
 #define LLVM_LIBC_SRC_UNISTD_GETUID_H
 
+#include "hdr/types/uid_t.h"
+#include "hdr/unistd_macros.h"
 #include "src/__support/macros/config.h"
-#include <unistd.h>
 
 namespace LIBC_NAMESPACE_DECL {
 

libc/src/unistd/isatty.h

@@ -9,8 +9,8 @@
 #ifndef LLVM_LIBC_SRC_UNISTD_ISATTY_H
 #define LLVM_LIBC_SRC_UNISTD_ISATTY_H
 
+#include "hdr/unistd_macros.h"
 #include "src/__support/macros/config.h"
-#include <unistd.h>
 
 namespace LIBC_NAMESPACE_DECL {
 

libc/src/unistd/link.h

@@ -9,8 +9,8 @@
 #ifndef LLVM_LIBC_SRC_UNISTD_LINK_H
 #define LLVM_LIBC_SRC_UNISTD_LINK_H
 
+#include "hdr/unistd_macros.h"
 #include "src/__support/macros/config.h"
-#include <unistd.h>
 
 namespace LIBC_NAMESPACE_DECL {