add option to disable realloc and free

CHANGELOG.md

@@ -3,6 +3,7 @@
 ## Develop
 
 - Rework library CMake with removed INTERFACE type
+- Add `LWMEM_CFG_SUPPORT_REALLOC_AND_FREE` to disable realloc and free functions
 
 ## v2.1.0
 

lwmem/src/include/lwmem/lwmem.h

@@ -110,11 +110,13 @@ typedef struct {
 size_t lwmem_assignmem_ex(lwmem_t* lwobj, const lwmem_region_t* regions);
 void* lwmem_malloc_ex(lwmem_t* lwobj, const lwmem_region_t* region, const size_t size);
 void* lwmem_calloc_ex(lwmem_t* lwobj, const lwmem_region_t* region, const size_t nitems, const size_t size);
+#if LWMEM_CFG_SUPPORT_REALLOC_AND_FREE || __DOXYGEN__
 void* lwmem_realloc_ex(lwmem_t* lwobj, const lwmem_region_t* region, void* const ptr, const size_t size);
 uint8_t lwmem_realloc_s_ex(lwmem_t* lwobj, const lwmem_region_t* region, void** const ptr, const size_t size);
 void lwmem_free_ex(lwmem_t* lwobj, void* const ptr);
 void lwmem_free_s_ex(lwmem_t* lwobj, void** const ptr);
 size_t lwmem_get_size_ex(lwmem_t* lwobj, void* ptr);
+#endif /* LWMEM_CFG_SUPPORT_REALLOC_AND_FREE || __DOXYGEN__ */
 #if LWMEM_CFG_ENABLE_STATS || __DOXYGEN__
 void lwmem_get_stats_ex(lwmem_t* lwobj, lwmem_stats_t* stats);
 #endif /* LWMEM_CFG_ENABLE_STATS || __DOXYGEN__ */
@@ -136,7 +138,7 @@ lwmem_region_t regions[] = {
 \endcode
  * \return          `0` on failure, number of final regions used for memory manager on success
  */
-#define lwmem_assignmem(regions)       lwmem_assignmem_ex(NULL, (regions))
+#define lwmem_assignmem(regions)   lwmem_assignmem_ex(NULL, (regions))
 
 /**
  * \note            This is a wrapper for \ref lwmem_malloc_ex function.
@@ -145,7 +147,7 @@ lwmem_region_t regions[] = {
  * \return          Pointer to allocated memory on success, `NULL` otherwise
  * \note            This function is thread safe when \ref LWMEM_CFG_OS is enabled
  */
-#define lwmem_malloc(size)             lwmem_malloc_ex(NULL, NULL, (size))
+#define lwmem_malloc(size)         lwmem_malloc_ex(NULL, NULL, (size))
 
 /**
  * \note            This is a wrapper for \ref lwmem_calloc_ex function.
@@ -155,7 +157,9 @@ lwmem_region_t regions[] = {
  * \return          Pointer to allocated memory on success, `NULL` otherwise
  * \note            This function is thread safe when \ref LWMEM_CFG_OS is enabled
  */
-#define lwmem_calloc(nitems, size)     lwmem_calloc_ex(NULL, NULL, (nitems), (size))
+#define lwmem_calloc(nitems, size) lwmem_calloc_ex(NULL, NULL, (nitems), (size))
+
+#if LWMEM_CFG_SUPPORT_REALLOC_AND_FREE || __DOXYGEN__
 
 /**
  * \note            This is a wrapper for \ref lwmem_realloc_ex function.
@@ -205,12 +209,18 @@ lwmem_region_t regions[] = {
  */
 #define lwmem_get_size(ptr)            lwmem_get_size_ex(NULL, (ptr))
 
+#endif /* LWMEM_CFG_SUPPORT_REALLOC_AND_FREE || __DOXYGEN__ */
+
+#if LWMEM_CFG_ENABLE_STATS || __DOXYGEN__
+
 /**
  * \note            This is a wrapper for \ref lwmem_get_stats_ex function.
  *                      It operates in default LwMEM instance
  * \param[in]       ptr: Pointer to lwmem_stats_t to store result
  */
-#define lwmem_get_stats(stats)         lwmem_get_stats_ex(NULL, (stats))
+#define lwmem_get_stats(stats) lwmem_get_stats_ex(NULL, (stats))
+
+#endif /* LWMEM_CFG_ENABLE_STATS || __DOXYGEN__ */
 
 #if defined(LWMEM_DEV) && !__DOXYGEN__
 unsigned char lwmem_debug_create_regions(lwmem_region_t** regs_out, size_t count, size_t size);

lwmem/src/include/lwmem/lwmem.hpp

@@ -93,6 +93,7 @@ class LwmemLight {
         return lwmem_calloc_ex(&m_lw, nullptr, nitems, size);
     }
 
+#if LWMEM_CFG_SUPPORT_REALLOC_AND_FREE || __DOXYGEN__
     /**
      * \brief           Reallocate block of memory
      * \param           ptr: Pointer to previously allocated memory block
@@ -114,6 +115,7 @@ class LwmemLight {
     free(void* ptr) {
         lwmem_free_ex(&m_lw, ptr);
     }
+#endif /* LWMEM_CFG_SUPPORT_REALLOC_AND_FREE || __DOXYGEN__ */
 
   private:
     /* Delete unused constructors */

lwmem/src/include/lwmem/lwmem_opt.h

@@ -85,6 +85,21 @@ extern "C" {
 #define LWMEM_CFG_ALIGN_NUM ((size_t)4)
 #endif
 
+/**
+ * \brief           Enables `1` or disables `0` full memory management support.
+ * 
+ * When enabled, library supports allocation, reallocation and freeing of the memory.
+ * When disabled, library only supports allocation, which is useful for
+ * power up memory initialization only.
+ * 
+ * \note            When disabled, \ref lwmem_get_size_ex is also not available,
+ *                  as it is assumed that user won't frequently ask for size of
+ *                  previously allocated block if realloc isn't being used
+ */
+#ifndef LWMEM_CFG_SUPPORT_REALLOC_AND_FREE
+#define LWMEM_CFG_SUPPORT_REALLOC_AND_FREE 1
+#endif
+
 /**
  * \brief           Enables `1` or disables `0` memory cleanup on free operation (or realloc).
  *

lwmem/src/lwmem/lwmem.c

@@ -435,6 +435,8 @@ prv_alloc(lwmem_t* const lwobj, const lwmem_region_t* region, const size_t size)
     return retval;
 }
 
+#if LWMEM_CFG_SUPPORT_REALLOC_AND_FREE
+
 /**
  * \brief           Free input pointer
  * \param[in]       lwobj: LwMEM instance. Set to `NULL` to use default instance
@@ -653,15 +655,12 @@ prv_realloc(lwmem_t* const lwobj, const lwmem_region_t* region, void* const ptr,
              */
             LWMEM_MEMMOVE(new_data_ptr, old_data_ptr, block_size); /* Copy old buffer size to new location */
 
-            lwobj->mem_available_bytes -=
-                prev->size
-                + prev->next
-                      ->size; /* Decrease effective available bytes for free blocks before and after input block */
+            /* Decrease effective available bytes for free blocks before and after input block */
+            lwobj->mem_available_bytes -= prev->size + prev->next->size;
             LWMEM_UPDATE_MIN_FREE(lwobj);
             prev->size += block_size + prev->next->size; /* Increase size of new block by size of 2 free blocks */
-            prevprev->next =
-                prev->next
-                    ->next; /* Remove free block before current one and block after current one from linked list (remove 2) */
+            /* Remove free block before current one and block after current one from linked list (remove 2) */
+            prevprev->next = prev->next->next;
             block = prev; /* Previous block is now current */
 
             prv_split_too_big_block(lwobj, block, final_size); /* Split block if it is too big */
@@ -684,14 +683,16 @@ prv_realloc(lwmem_t* const lwobj, const lwmem_region_t* region, void* const ptr,
      */
     retval = prv_alloc(lwobj, region, size); /* Try to allocate new block */
     if (retval != NULL) {
-        block_size =
-            (block->size & ~LWMEM_ALLOC_BIT) - LWMEM_BLOCK_META_SIZE;     /* Get application size from input pointer */
-        LWMEM_MEMCPY(retval, ptr, size > block_size ? block_size : size); /* Copy content to new allocated block */
-        prv_free(lwobj, ptr);                                             /* Free input pointer */
+        /* Get application size from input pointer, then copy content to new block */
+        block_size = (block->size & ~LWMEM_ALLOC_BIT) - LWMEM_BLOCK_META_SIZE;
+        LWMEM_MEMCPY(retval, ptr, size > block_size ? block_size : size);
+        prv_free(lwobj, ptr); /* Free old block */
     }
     return retval;
 }
 
+#endif /* LWMEM_CFG_SUPPORT_REALLOC_AND_FREE */
+
 /**
  * \brief           Initializes and assigns user regions for memory used by allocator algorithm
  * \param[in]       lwobj: LwMEM instance. Set to `NULL` to use default instance
@@ -873,6 +874,8 @@ lwmem_calloc_ex(lwmem_t* lwobj, const lwmem_region_t* region, const size_t nitem
     return ptr;
 }
 
+#if LWMEM_CFG_SUPPORT_REALLOC_AND_FREE || __DOXYGEN__
+
 /**
  * \brief           Reallocates already allocated memory with new size in specific lwmem instance and region.
  *
@@ -1022,6 +1025,8 @@ lwmem_get_size_ex(lwmem_t* lwobj, void* ptr) {
     return len;
 }
 
+#endif /* LWMEM_CFG_SUPPORT_REALLOC_AND_FREE || __DOXYGEN__ */
+
 #if LWMEM_CFG_ENABLE_STATS || __DOXYGEN__
 
 /**