[libc] Add proxy headers to handle memory allocation associated with the header `#include <stdlib.h> (#114690)

This finishes the work from
#114453 by adding proxy headers
for `malloc`, `realloc`, `free` and `aligned_alloc`.

Author: Job Henandez Lara

libc/hdr/CMakeLists.txt

@@ -81,6 +81,8 @@ add_proxy_header_library(
     libc.include.signal
 )
 
+add_header_library(stdlib_overlay HDRS stdlib_overlay.h)
+
 add_proxy_header_library(
   stdlib_macros
   HDRS
@@ -193,3 +195,4 @@ add_proxy_header_library(
 )
 
 add_subdirectory(types)
+add_subdirectory(func)

libc/hdr/func/CMakeLists.txt

@@ -0,0 +1,52 @@
+add_proxy_header_library(
+  aligned_alloc
+  HDRS
+    aligned_alloc.h
+  DEPENDS
+    libc.hdr.stdlib_overlay
+  FULL_BUILD_DEPENDS
+    libc.include.stdlib
+    libc.hdr.types.size_t
+)
+
+add_proxy_header_library(
+  malloc
+  HDRS
+    malloc.h
+  DEPENDS
+    libc.hdr.stdlib_overlay
+  FULL_BUILD_DEPENDS
+    libc.include.stdlib
+    libc.hdr.types.size_t
+)
+
+add_proxy_header_library(
+  realloc
+  HDRS
+    realloc.h
+  DEPENDS
+    libc.hdr.stdlib_overlay
+  FULL_BUILD_DEPENDS
+    libc.include.stdlib
+    libc.hdr.types.size_t
+)
+
+add_proxy_header_library(
+  free
+  HDRS
+    free.h
+  DEPENDS
+    libc.hdr.stdlib_overlay
+  FULL_BUILD_DEPENDS
+    libc.include.stdlib
+)
+
+add_proxy_header_library(
+  _Exit
+  HDRS
+    _Exit.h
+  DEPENDS
+    libc.hdr.stdlib_overlay
+  FULL_BUILD_DEPENDS
+    libc.include.stdlib
+)

libc/hdr/func/_Exit.h

@@ -0,0 +1,21 @@
+//===-- Definition of the _Exit 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_FUNC_EXIT_H
+#define LLVM_LIBC_HDR_FUNC_EXIT_H
+
+#ifdef LIBC_FULL_BUILD
+extern "C" void _Exit(int);
+
+#else // Overlay mode
+
+#include "hdr/stdlib_overlay.h"
+
+#endif
+
+#endif // LLVM_LIBC_HDR_EXIT_H

libc/hdr/func/aligned_alloc.h

@@ -0,0 +1,22 @@
+//===-- 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_FUNC_ALIGNED_ALLOC_H
+#define LLVM_LIBC_HDR_FUNC_ALIGNED_ALLOC_H
+
+#ifdef LIBC_FULL_BUILD
+#include "hdr/types/size_t.h"
+extern "C" void *aligned_alloc(size_t, size_t);
+
+#else // Overlay mode
+
+#include "hdr/stdlib_overlay.h"
+
+#endif
+
+#endif

libc/hdr/func/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_FUNC_FREE_H
+#define LLVM_LIBC_HDR_FUNC_FREE_H
+
+#ifdef LIBC_FULL_BUILD
+extern "C" void free(void *);
+
+#else // Overlay mode
+
+#include "hdr/stdlib_overlay.h"
+
+#endif
+
+#endif

libc/hdr/func/malloc.h

@@ -0,0 +1,22 @@
+//===-- 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_FUNC_MALLOC_H
+#define LLVM_LIBC_HDR_FUNC_MALLOC_H
+
+#ifdef LIBC_FULL_BUILD
+#include "hdr/types/size_t.h"
+extern "C" void *malloc(size_t);
+
+#else // Overlay mode
+
+#include "hdr/stdlib_overlay.h"
+
+#endif
+
+#endif

libc/hdr/func/realloc.h

@@ -0,0 +1,22 @@
+//===-- 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_FUNC_REALLOC_H
+#define LLVM_LIBC_HDR_FUNC_REALLOC_H
+
+#ifdef LIBC_FULL_BUILD
+#include "hdr/types/size_t.h"
+extern "C" void *realloc(void *ptr, size_t new_size);
+
+#else // Overlay mode
+
+#include "hdr/stdlib_overlay.h"
+
+#endif
+
+#endif

libc/src/__support/CMakeLists.txt

@@ -242,6 +242,9 @@ add_header_library(
   HDRS
     char_vector.h
   DEPENDS
+    libc.hdr.func.free
+    libc.hdr.func.malloc
+    libc.hdr.func.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.func.free
+    libc.hdr.func.malloc
+    libc.hdr.func.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.func.free
+    libc.hdr.func.malloc
+    libc.hdr.func.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/func/free.h"
 
 void operator delete(void *mem) noexcept { ::free(mem); }