add custom_realloc

Signed-off-by: Mattias Andrée <maandree@operamail.com>

2 files changed, 60 insertions, 0 deletions

diff --git a/include/slibc-alloc.h b/include/slibc-alloc.h
index 3c92fcf..7bd2e81 100644
--- a/include/slibc-alloc.h
+++ b/include/slibc-alloc.h
@@ -109,6 +109,31 @@ void* secure_realloc(void*, size_t)
   __GCC_ONLY(__attribute__((warn_unused_result)));
 
 /**
+ * This function behaves exactly like `realloc`,
+ * except you can freely select what memory it clears.
+ * 
+ * `crealloc(p, n)` is equivalent to (but slightly fast than)
+ * `custom_realloc(p, n, 1, 1, 1)`.
+ * 
+ * `fast_realloc(p, n)` is equivalent to (but slightly fast than)
+ * `custom_realloc(p, n, 0, 0, 0)`.
+ * 
+ * `secure_realloc(p, n)` is equivalent to (but slightly fast than)
+ * `custom_realloc(p, n, 1, 0, 1)`.
+ * 
+ * @param   ptr         The old allocation, see `realloc` for more details.
+ * @param   size        The new allocation size, see `realloc` for more details.
+ * @param   clear_old   Whether the disowned area is cleared, even if `ptr` is returned.
+ * @param   clear_new   Whether the newly claimed area is cleared.
+ * @param   clear_free  Whether the old allocation is cleared if a new pointer is returned.
+ * @return              The new allocation, see `realloc` for more details.
+ * 
+ * @throws  ENOMEM  The process cannot allocate more memory.
+ */
+void* custom_realloc(void*, size_t, int, int, int)
+  __GCC_ONLY(__attribute__((warn_unused_result)));
+
+/**
  * This function behaves exactly like `fast_realloc`, except:
  * - Its behaviour is undefined if `ptr` is `NULL`.
  * - Its behaviour is undefined if `size` equals the old allocation size.
diff --git a/src/slibc-alloc.c b/src/slibc-alloc.c
index 2043ce0..1b85aad 100644
--- a/src/slibc-alloc.c
+++ b/src/slibc-alloc.c
@@ -89,6 +89,13 @@ size_t allocsize(void* segment)
 
 /**
  * Common code for realloc-functions, apart from `naive_realloc`.
+ * 
+ * @param   ptr:void*       The old allocation, see `realloc` for more details.
+ * @param   size:size_t     The new allocation size, see `realloc` for more details.
+ * @param   CLEAR_OLD:int   Whether the disowned area is cleared, even if `ptr` is returned.
+ * @param   CLEAR_NEW:int   Whether the newly claimed area is cleared.
+ * @param   CLEAR_FREE:int  Whether the old allocation is cleared if a new pointer is returned.
+ * @return                  The new allocation, see `realloc` for more details.
  */
 #define REALLOC(ptr, size, CLEAR_OLD, CLEAR_NEW, CLEAR_FREE)	\
   size_t old_size;						\
@@ -172,6 +179,34 @@ void* secure_realloc(void* ptr, size_t size)
 
 
 /**
+ * This function behaves exactly like `realloc`,
+ * except you can freely select what memory it clears.
+ * 
+ * `crealloc(p, n)` is equivalent to (but slightly fast than)
+ * `custom_realloc(p, n, 1, 1, 1)`.
+ * 
+ * `fast_realloc(p, n)` is equivalent to (but slightly fast than)
+ * `custom_realloc(p, n, 0, 0, 0)`.
+ * 
+ * `secure_realloc(p, n)` is equivalent to (but slightly fast than)
+ * `custom_realloc(p, n, 1, 0, 1)`.
+ * 
+ * @param   ptr         The old allocation, see `realloc` for more details.
+ * @param   size        The new allocation size, see `realloc` for more details.
+ * @param   clear_old   Whether the disowned area is cleared, even if `ptr` is returned.
+ * @param   clear_new   Whether the newly claimed area is cleared.
+ * @param   clear_free  Whether the old allocation is cleared if a new pointer is returned.
+ * @return              The new allocation, see `realloc` for more details.
+ * 
+ * @throws  ENOMEM  The process cannot allocate more memory.
+ */
+void* custom_realloc(void* ptr, size_t size, int clear_old, int clear_new, int clear_free)
+{
+  REALLOC(ptr, size, clear_old, clear_new, clear_free);
+}
+
+
+/**
  * This function behaves exactly like `fast_realloc`, except:
  * - Its behaviour is undefined if `ptr` is `NULL`.
  * - Its behaviour is undefined if `size` equals the old allocation size.