add a function which clears a list

list_clear(&plist)

the function will run through every elements and clear them.
the prehead is updated (first and size are set to 0)

1 files changed, 40 insertions, 0 deletions

diff --git a/list.asm b/list.asm
index a463c8e..50c86b3 100644
--- a/list.asm
+++ b/list.asm
@@ -21,6 +21,7 @@
 ;; THE SOFTWARE.
 
 extern malloc
+extern free
 
 ;; initializes the list stored at address $rdi with default values
 global list_init:function
@@ -32,6 +33,10 @@ global list_new_raw:function
 ;; same as list_new_raw, unless the list is initialized with default values
 global list_new:function
 
+;; remove every element of the list pointed to by $rip.
+;; the elements are freed using free() from the libc
+global list_clear:function
+
 ;; create a new element (using dynamic allocation) at the end of the list
 ;; stored at address $rdi. the created element will contain the value of $rsi
 ;; if, unlikely, the allocation fails, $rax will contain -1.
@@ -87,6 +92,41 @@ list_new_raw: ;; {{{
     ret
 
 ;; }}}
+list_clear: ;; {{{
+
+    enter 0, 0
+
+    mov ecx, [rdi + list_t.size] ; load the size of the list into the counter
+
+    test ecx, ecx
+    je .end
+
+    mov rsi, QWORD [rdi + list_t.first]
+
+    ; the list is reset to its initial state
+    mov DWORD [rdi + list_t.size], 0
+    mov QWORD [rdi + list_t.first], 0
+
+    .loop:
+    push QWORD [rsi + elem_t.next]
+    push rcx
+
+    mov rdi, rsi
+    call free
+
+    pop rcx
+    pop rsi
+
+    dec ecx
+
+    test ecx, ecx
+    jne .loop
+
+    .end
+    leave
+    ret
+
+;; }}}
 list_append: ;; {{{
 
     enter 0x18, 0