[libc] Add proxy headers to handle memory allocation associated with the header `#include <stdlib.h>

libc/hdr/CMakeLists.txt

@@ -23,6 +23,16 @@ function(add_proxy_header_library target_name)
   )
 endfunction()
 
+add_proxy_header_library(
+  aligned_alloc
+  HDRS
+    aligned_alloc.h
+  DEPENDS
+    .stdlib_overlay
+  FULL_BUILD_DEPENDS
+    libc.include.stdlib
+)
+
 add_proxy_header_library(
   math_macros
   HDRS
@@ -81,6 +91,8 @@ add_proxy_header_library(
     libc.include.signal
 )
 
+add_header_library(stdlib_overlay HDRS stdlib_overlay.h)
+
 add_proxy_header_library(
   stdlib_macros
   HDRS
@@ -152,6 +164,16 @@ add_proxy_header_library(
     libc.include.float
 )
 
+add_proxy_header_library(
+  free
+  HDRS
+    free.h
+  DEPENDS
+    .stdlib_overlay
+  FULL_BUILD_DEPENDS
+    libc.include.stdlib
+)
+
 add_proxy_header_library(
   limits_macros
   HDRS
@@ -170,6 +192,26 @@ add_proxy_header_library(
     libc.include.link
 )
 
+add_proxy_header_library(
+  malloc
+  HDRS
+    malloc.h
+  DEPENDS
+    .stdlib_overlay
+  FULL_BUILD_DEPENDS
+    libc.include.stdlib
+)
+
+add_proxy_header_library(
+  realloc
+  HDRS
+    realloc.h
+  DEPENDS
+    .stdlib_overlay
+  FULL_BUILD_DEPENDS
+    libc.include.stdlib
+)
+
 add_proxy_header_library(
   sys_auxv_macros
   HDRS

libc/hdr/aligned_alloc.h

@@ -0,0 +1,21 @@
+//===-- Definition of the aligned_alloc.h proxy ---------------------------===//
+//
+// 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_ALIGNED_ALLOC_H
+#define LLVM_LIBC_HDR_ALIGNED_ALLOC_H
+
+#ifdef LIBC_FULL_BUILD
+extern "C" void *aligned_alloc(size_t, size_t);
+
+#else // Overlay mode
+
+#include "stdlib_overlay.h"
+
+#endif
+
+#endif

libc/hdr/free.h

@@ -0,0 +1,21 @@
+//===-- Definition of the free.h proxy ------------------------------------===//
+//
+// 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_FREE_H
+#define LLVM_LIBC_HDR_FREE_H
+
+#ifdef LIBC_FULL_BUILD
+extern "C" void free(void *);
+
+#else // Overlay mode
+
+#include "stdlib_overlay.h"
+
+#endif
+
+#endif

libc/hdr/malloc.h

@@ -0,0 +1,21 @@
+//===-- Definition of the malloc.h proxy ----------------------------------===//
+//
+// 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_MALLOC_H
+#define LLVM_LIBC_HDR_MALLOC_H
+
+#ifdef LIBC_FULL_BUILD
+extern "C" void *malloc(size_t);
+
+#else // Overlay mode
+
+#include "stdlib_overlay.h"
+
+#endif
+
+#endif

libc/hdr/realloc.h

@@ -0,0 +1,21 @@
+//===-- Definition of the realloc.h proxy ---------------------------------===//
+//
+// 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_REALLOC_H
+#define LLVM_LIBC_HDR_REALLOC_H
+
+#ifdef LIBC_FULL_BUILD
+extern "C" void *realloc(void *ptr, size_t new_size);
+
+#else // Overlay mode
+
+#include "stdlib_overlay.h"
+
+#endif
+
+#endif

libc/src/__support/CMakeLists.txt

@@ -236,6 +236,9 @@ add_header_library(
   HDRS
     char_vector.h
   DEPENDS
+    libc.hdr.free
+    libc.hdr.malloc
+    libc.hdr.realloc
     libc.src.__support.common
 )
 

libc/src/__support/CPP/CMakeLists.txt

@@ -80,8 +80,10 @@ add_header_library(
   HDRS
     string.h
   DEPENDS
-    libc.include.stdlib
     .string_view
+    libc.hdr.free
+    libc.hdr.malloc
+    libc.hdr.realloc 
     libc.src.__support.common
     libc.src.__support.integer_to_string
     libc.src.string.memory_utils.inline_memcpy
@@ -199,7 +201,9 @@ add_object_library(
   HDRS
     new.h
   DEPENDS
-    libc.include.stdlib
+    libc.hdr.free
+    libc.hdr.malloc
+    libc.hdr.aligned_alloc 
     libc.src.__support.common
     libc.src.__support.macros.properties.os
 )

libc/src/__support/CPP/new.cpp

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

libc/src/__support/CPP/new.h

@@ -9,12 +9,14 @@
 #ifndef LLVM_LIBC_SRC___SUPPORT_CPP_NEW_H
 #define LLVM_LIBC_SRC___SUPPORT_CPP_NEW_H
 
+#include "hdr/aligned_alloc.h"
+#include "hdr/free.h"
+#include "hdr/malloc.h"
 #include "src/__support/common.h"
 #include "src/__support/macros/config.h"
 #include "src/__support/macros/properties/os.h"
 
 #include <stddef.h> // For size_t
-#include <stdlib.h> // For malloc, free etc.
 
 // Defining members in the std namespace is not preferred. But, we do it here
 // so that we can use it to define the operator new which takes std::align_val_t

libc/src/__support/CPP/string.h

@@ -9,6 +9,9 @@
 #ifndef LLVM_LIBC_SRC___SUPPORT_CPP_STRING_H
 #define LLVM_LIBC_SRC___SUPPORT_CPP_STRING_H
 
+#include "hdr/free.h"
+#include "hdr/malloc.h"
+#include "hdr/realloc.h"
 #include "src/__support/CPP/string_view.h"
 #include "src/__support/integer_to_string.h" // IntegerToString
 #include "src/__support/macros/config.h"
@@ -17,7 +20,6 @@
 #include "src/string/string_utils.h" // string_length
 
 #include <stddef.h> // size_t
-#include <stdlib.h> // malloc, free
 
 namespace LIBC_NAMESPACE_DECL {
 namespace cpp {

libc/src/__support/File/CMakeLists.txt

@@ -18,6 +18,7 @@ add_object_library(
     libc.src.__support.error_or
     libc.hdr.types.off_t
     libc.hdr.stdio_macros
+    libc.hdr.realloc
 )
 
 add_object_library(

libc/src/__support/File/file.cpp

@@ -8,6 +8,7 @@
 
 #include "file.h"
 
+#include "hdr/realloc.h"
 #include "hdr/stdio_macros.h"
 #include "hdr/types/off_t.h"
 #include "src/__support/CPP/new.h"

libc/src/__support/char_vector.h

@@ -9,11 +9,13 @@
 #ifndef LLVM_LIBC_SRC___SUPPORT_CHARVECTOR_H
 #define LLVM_LIBC_SRC___SUPPORT_CHARVECTOR_H
 
+#include "hdr/free.h"
+#include "hdr/malloc.h"
+#include "hdr/realloc.h"
 #include "src/__support/common.h" // LIBC_INLINE
 #include "src/__support/macros/config.h"
 
 #include <stddef.h> // size_t
-#include <stdlib.h> // malloc, realloc, free
 
 namespace LIBC_NAMESPACE_DECL {
 

libc/src/stdio/printf_core/CMakeLists.txt

@@ -129,11 +129,12 @@ add_header_library(
   HDRS
     vasprintf_internal.h
   DEPENDS
+    libc.hdr.malloc
+    libc.hdr.free
+    libc.hdr.realloc
     libc.src.__support.arg_list
     libc.src.stdio.printf_core.printf_main
     libc.src.stdio.printf_core.writer
-    libc.src.stdlib.malloc
-    libc.src.stdlib.realloc
 )
 
 if(NOT (TARGET libc.src.__support.File.file) AND LLVM_LIBC_FULL_BUILD)

libc/src/stdio/printf_core/vasprintf_internal.h

@@ -6,12 +6,14 @@
 //
 //===----------------------------------------------------------------------===//
 
+#include "hdr/free.h"
+#include "hdr/malloc.h"
+#include "hdr/realloc.h"
 #include "src/__support/arg_list.h"
 #include "src/stdio/printf.h"
 #include "src/stdio/printf_core/core_structs.h"
 #include "src/stdio/printf_core/printf_main.h"
 #include "src/stdio/printf_core/writer.h"
-#include <stdlib.h> // malloc, realloc, free
 
 namespace LIBC_NAMESPACE_DECL {
 namespace printf_core {