[libc] Remove the #include <stdlib.h> header

libc/hdr/CMakeLists.txt

@@ -81,6 +81,17 @@ add_proxy_header_library(
     libc.include.signal
 )
 
+add_proxy_header_library(
+  stdlib_macros
+  HDRS
+    stdlib_macros.h
+  DEPENDS
+    .stdlib_overlay
+  FULL_BUILD_DEPENDS
+    libc.include.stdlib
+    libc.include.llvm-libc-macros.stdlib_macros
+)
+
 add_header_library(stdio_overlay HDRS stdio_overlay.h)
 
 add_proxy_header_library(

libc/hdr/stdlib_macros.h

@@ -0,0 +1,22 @@
+//===-- Definition of macros from stdlib.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_HDR_STDLIB_MACROS_H
+#define LLVM_LIBC_HDR_STDLIB_MACROS_H
+
+#ifdef LIBC_FULL_BUILD
+
+#include "include/llvm-libc-macros/stdlib-macros.h"
+
+#else // Overlay mode
+
+#include "stdlib_overlay.h"
+
+#endif // LLVM_LIBC_FULL_BUILD
+
+#endif // LLVM_LIBC_HDR_STDLIB_MACROS_H

libc/hdr/stdlib_overlay.h

@@ -0,0 +1,36 @@
+//===-- Including stdlib.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_STDLIB_OVERLAY_H
+#define LLVM_LIBC_HDR_STDLIB_OVERLAY_H
+
+#ifdef LIBC_FULL_BUILD
+#error "This header should only be included in overlay mode"
+#endif
+
+// Overlay mode
+
+// glibc <stdlib.h> header might provide extern inline definitions for few
+// functions, causing external alias errors.  They are guarded by
+// `__USE_FORTIFY_LEVEL`, which will be temporarily disabled.
+
+#ifdef __USE_FORTIFY_LEVEL
+#define LIBC_OLD_USE_FORTIFY_LEVEL __USE_FORTIFY_LEVEL
+#undef __USE_FORTIFY_LEVEL
+#define __USE_FORTIFY_LEVEL 0
+#endif
+
+#include <stdlib.h>
+
+#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
+
+#endif

libc/hdr/types/CMakeLists.txt

@@ -1,3 +1,36 @@
+add_proxy_header_library(
+  div_t
+  HDRS
+    div_t.h
+  DEPENDS
+    libc.hdr.stdlib_overlay
+  FULL_BUILD_DEPENDS
+    libc.include.llvm-libc-types.div_t
+    libc.include.stdlib
+)
+
+add_proxy_header_library(
+  ldiv_t
+  HDRS
+    ldiv_t.h
+  DEPENDS
+    libc.hdr.stdlib_overlay
+  FULL_BUILD_DEPENDS
+    libc.include.llvm-libc-types.ldiv_t
+    libc.include.stdlib
+)
+
+add_proxy_header_library(
+  lldiv_t
+  HDRS
+    lldiv_t.h
+  DEPENDS
+    libc.hdr.stdlib_overlay
+  FULL_BUILD_DEPENDS
+    libc.include.llvm-libc-types.lldiv_t
+    libc.include.stdlib
+)
+
 add_proxy_header_library(
   sigset_t
   HDRS
@@ -46,6 +79,14 @@ add_proxy_header_library(
     libc.include.llvm-libc-types.struct_timespec
 )
 
+add_proxy_header_library(
+  size_t
+  HDRS
+    size_t.h
+  FULL_BUILD_DEPENDS
+    libc.include.llvm-libc-types.size_t
+)
+
 add_proxy_header_library(
   mode_t
   HDRS

libc/hdr/types/div_t.h

@@ -0,0 +1,22 @@
+//===-- Definition of macros from div_t.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_HDR_TYPES_DIV_T_H
+#define LLVM_LIBC_HDR_TYPES_DIV_T_H
+
+#ifdef LIBC_FULL_BUILD
+
+#include "include/llvm-libc-types/div_t.h"
+
+#else // Overlay mode
+
+#include "hdr/stdlib_overlay.h"
+
+#endif // LLVM_LIBC_FULL_BUILD
+
+#endif // LLVM_LIBC_HDR_TYPES_DIV_T_H

libc/hdr/types/ldiv_t.h

@@ -0,0 +1,22 @@
+//===-- Definition of macros from ldiv_t.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_HDR_TYPES_LDIV_T_H
+#define LLVM_LIBC_HDR_TYPES_LDIV_T_H
+
+#ifdef LIBC_FULL_BUILD
+
+#include "include/llvm-libc-types/ldiv_t.h"
+
+#else // Overlay mode
+
+#include "hdr/stdlib_overlay.h"
+
+#endif // LLVM_LIBC_FULL_BUILD
+
+#endif // LLVM_LIBC_HDR_TYPES_LDIV_T_H

libc/hdr/types/lldiv_t.h

@@ -0,0 +1,22 @@
+//===-- Definition of macros from lldiv_t.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_HDR_TYPES_LLDIV_T_H
+#define LLVM_LIBC_HDR_TYPES_LLDIV_T_H
+
+#ifdef LIBC_FULL_BUILD
+
+#include "include/llvm-libc-types/lldiv_t.h"
+
+#else // Overlay mode
+
+#include "hdr/stdlib_overlay.h"
+
+#endif // LLVM_LIBC_FULL_BUILD
+
+#endif // LLVM_LIBC_HDR_TYPES_LLDIV_T_H

libc/hdr/types/size_t.h

@@ -0,0 +1,23 @@
+//===-- Proxy for size_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_SIZE_T_H
+#define LLVM_LIBC_HDR_TYPES_SIZE_T_H
+
+#ifdef LIBC_FULL_BUILD
+
+#include "include/llvm-libc-types/size_t.h"
+
+#else
+
+#define __need_size_t
+#include <stddef.h>
+#undef __need_size_t
+
+#endif // LIBC_FULL_BUILD
+
+#endif // LLVM_LIBC_HDR_TYPES_SIZE_T_H

libc/src/__support/CPP/new.cpp

@@ -7,7 +7,7 @@
 //===----------------------------------------------------------------------===//
 
 #include "new.h"
-#include <stdlib.h>
+#include <stdlib.h> // For free, etc
 
 void operator delete(void *mem) noexcept { ::free(mem); }
 

libc/src/__support/File/dir.h

@@ -15,7 +15,6 @@
 #include "src/__support/threads/mutex.h"
 
 #include <dirent.h>
-#include <stdlib.h>
 
 namespace LIBC_NAMESPACE_DECL {
 

libc/src/stdlib/CMakeLists.txt

@@ -221,7 +221,7 @@ add_entrypoint_object(
   HDRS
     div.h
   DEPENDS
-    libc.include.stdlib
+    libc.hdr.types.div_t
     libc.src.__support.integer_operations
 )
 
@@ -232,7 +232,7 @@ add_entrypoint_object(
   HDRS
     ldiv.h
   DEPENDS
-    libc.include.stdlib
+    libc.hdr.types.ldiv_t
     libc.src.__support.integer_operations
 )
 
@@ -243,7 +243,7 @@ add_entrypoint_object(
   HDRS
     lldiv.h
   DEPENDS
-    libc.include.stdlib
+    libc.hdr.types.lldiv_t
     libc.src.__support.integer_operations
 )
 
@@ -277,7 +277,7 @@ add_entrypoint_object(
     qsort.h
   DEPENDS
     .qsort_util
-    libc.include.stdlib
+    libc.hdr.types.size_t
 )
 
 add_entrypoint_object(
@@ -288,7 +288,7 @@ add_entrypoint_object(
     qsort_r.h
   DEPENDS
     .qsort_util
-    libc.include.stdlib
+    libc.hdr.types.size_t
 )
 
 add_object_library(
@@ -309,7 +309,7 @@ add_entrypoint_object(
     rand.h
   DEPENDS
     .rand_util
-    libc.include.stdlib
+    libc.hdr.stdlib_macros
     libc.src.__support.threads.sleep
 )
 
@@ -321,7 +321,6 @@ add_entrypoint_object(
     srand.h
   DEPENDS
     .rand_util
-    libc.include.stdlib
 )
 
 if(NOT LIBC_TARGET_OS_IS_GPU)

libc/src/stdlib/div.h

@@ -9,8 +9,8 @@
 #ifndef LLVM_LIBC_SRC_STDLIB_DIV_H
 #define LLVM_LIBC_SRC_STDLIB_DIV_H
 
+#include "hdr/types/div_t.h"
 #include "src/__support/macros/config.h"
-#include <stdlib.h>
 
 namespace LIBC_NAMESPACE_DECL {
 

libc/src/stdlib/exit.h

@@ -10,7 +10,6 @@
 #define LLVM_LIBC_SRC_STDLIB_EXIT_H
 
 #include "src/__support/macros/config.h"
-#include <stdlib.h>
 
 namespace LIBC_NAMESPACE_DECL {
 

libc/src/stdlib/free.h

@@ -7,7 +7,6 @@
 //===----------------------------------------------------------------------===//
 
 #include "src/__support/macros/config.h"
-#include <stdlib.h>
 
 #ifndef LLVM_LIBC_SRC_STDLIB_FREE_H
 #define LLVM_LIBC_SRC_STDLIB_FREE_H

libc/src/stdlib/ldiv.h

@@ -9,8 +9,8 @@
 #ifndef LLVM_LIBC_SRC_STDLIB_LDIV_H
 #define LLVM_LIBC_SRC_STDLIB_LDIV_H
 
+#include "hdr/types/ldiv_t.h"
 #include "src/__support/macros/config.h"
-#include <stdlib.h>
 
 namespace LIBC_NAMESPACE_DECL {
 

libc/src/stdlib/lldiv.h

@@ -8,8 +8,8 @@
 #ifndef LLVM_LIBC_SRC_STDLIB_LLDIV_H
 #define LLVM_LIBC_SRC_STDLIB_LLDIV_H
 
+#include "hdr/types/lldiv_t.h"
 #include "src/__support/macros/config.h"
-#include <stdlib.h>
 
 namespace LIBC_NAMESPACE_DECL {
 

libc/src/stdlib/malloc.h

@@ -6,8 +6,8 @@
 //
 //===----------------------------------------------------------------------===//
 
+#include "hdr/types/size_t.h"
 #include "src/__support/macros/config.h"
-#include <stdlib.h>
 
 #ifndef LLVM_LIBC_SRC_STDLIB_MALLOC_H
 #define LLVM_LIBC_SRC_STDLIB_MALLOC_H

libc/src/stdlib/qsort.h

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

libc/src/stdlib/qsort_r.h

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

libc/src/stdlib/rand.h

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

libc/src/stdlib/srand.h

@@ -10,7 +10,6 @@
 #define LLVM_LIBC_SRC_STDLIB_SRAND_H
 
 #include "src/__support/macros/config.h"
-#include <stdlib.h>
 
 namespace LIBC_NAMESPACE_DECL {