Fix the cycle detection in iterate() and rename push() to append()

.gitmodules

@@ -0,0 +1,3 @@
+[submodule "deps/libakerror"]
+	path = deps/libakerror
+	url = https://source.starfort.tech/andrew/libakerror.git

CMakeLists.txt

@@ -1,6 +1,10 @@
 cmake_minimum_required(VERSION 3.10)
 project(akstdlib LANGUAGES C)
 
+set(CMAKE_CXX_FLAGS "${CMAKE_CXX_FLAGS} -g -ggdb -pg")
+set(CMAKE_EXE_LINKER_FLAGS "${CMAKE_EXE_LINKER_FLAGS} -g -ggdb -pg")
+set(CMAKE_SHARED_LINKER_FLAGS "${CMAKE_SHARED_LINKER_FLAGS} -g -ggdb -pg")
+
 if(TARGET akerror::akerror)
   message(STATUS "FOUND akerror::akerror")
 else()
@@ -11,10 +15,14 @@ include(CTest)
 include(GNUInstallDirs)
 include(CMakePackageConfigHelpers)
 
+if(CMAKE_SOURCE_DIR STREQUAL CMAKE_CURRENT_SOURCE_DIR)
+  add_subdirectory(deps/libakerror EXCLUDE_FROM_ALL)
+else()
   if(NOT TARGET akerror::akerror)
     find_package(PkgConfig REQUIRED)
     find_package(akerror REQUIRED)
   endif()
+endif()
 
 set(akstdlib_install_cmakedir "${CMAKE_INSTALL_LIBDIR}/cmake/akstdlib")
 set(prefix      ${CMAKE_INSTALL_PREFIX})

src/stdlib.c

@@ -191,7 +191,7 @@ akerr_ErrorContext AKERR_NOIGNORE *aksl_strhash_djb2(char *str, size_t len, uint
     SUCCEED_RETURN(e);
 }
 
-akerr_ErrorContext AKERR_NOIGNORE *aksl_list_push(aksl_ListNode *list, aksl_ListNode *obj)
+akerr_ErrorContext AKERR_NOIGNORE *aksl_list_append(aksl_ListNode *list, aksl_ListNode *obj)
 {
     PREPARE_ERROR(e);
     FAIL_ZERO_RETURN(e, list, AKERR_NULLPOINTER, "list");
@@ -199,19 +199,20 @@ akerr_ErrorContext AKERR_NOIGNORE *aksl_list_push(aksl_ListNode *list, aksl_List
     aksl_ListNode *slow = list;
     aksl_ListNode *fast = list;
     aksl_ListNode *tail = list;
-    do { 
-	if ( fast != NULL && fast->next != NULL ) {
-	    fast = fast->next->next;
-	}
+    while ( fast != NULL && fast->next != NULL ) {
 	tail = slow;
 	slow = slow->next;
-	if ( fast != NULL && fast == slow) {
-	    FAIL(e, AKERR_CIRCULAR_REFERENCE, "%p", list);
+	fast = fast->next->next;
+	if ( fast == slow) {
+	    FAIL_RETURN(e, AKERR_CIRCULAR_REFERENCE, "%p", list);
+	}
+    }
+    if ( fast != NULL ) {
+	tail = fast;
     }
-    } while ( slow != NULL || (fast != NULL && fast->next != NULL) );
     tail->next = obj;
     obj->next = NULL;
-    obj->prev = slow;
+    obj->prev = tail;
     SUCCEED_RETURN(e);
 }
 
@@ -320,16 +321,23 @@ akerr_ErrorContext AKERR_NOIGNORE *aksl_list_iterate(aksl_ListNode *list, aksl_L
     FAIL_ZERO_RETURN(e, iter, AKERR_NULLPOINTER, "iter");
     aksl_ListNode *slow = list;
     aksl_ListNode *fast = list;
-    aksl_ListNode *tail = list;
-    do {
-	if ( fast != NULL && fast->next != NULL ) {
-	    fast = fast->next->next;
-	}
-	PASS(e, iter(slow, data));
+    while ( fast != NULL && fast->next != NULL ) {
 	slow = slow->next;
-	if ( fast != NULL && fast == slow) {
-	    FAIL(e, AKERR_CIRCULAR_REFERENCE, "%p", list);
+	fast = fast->next->next;
+	if ( fast == slow) {
+	    FAIL_RETURN(e, AKERR_CIRCULAR_REFERENCE, "%p", list);
+	}
+    }
+    while ( slow != NULL ) {
+	ATTEMPT {
+	    CATCH(e, iter(slow, data));
+	    slow = slow->next;
+	} CLEANUP {
+	} PROCESS(e) {
+	} HANDLE(e, AKERR_ITERATOR_BREAK) {
+	    // This is not an error condition, it's just telling us to stop early
+	    SUCCEED_RETURN(e);
+	} FINISH(e, true);
     }
-    } while ( slow != NULL || (fast != NULL && fast->next != NULL) );
     SUCCEED_RETURN(e);
 }

tests/test_linkedlist.c

@@ -1,33 +1,74 @@
+#include <stdio.h>
 #include <akstdlib.h>
 
+
+// This iterator does nothing but print the node names it is visiting
 akerr_ErrorContext AKERR_NOIGNORE *myiter(aksl_ListNode *node, void *data)
 {
+    int count = 0;
     PREPARE_ERROR(e);
-	int count;
     FAIL_ZERO_RETURN(e, node, AKERR_NULLPOINTER, "node");
     FAIL_ZERO_RETURN(e, node->data, AKERR_NULLPOINTER, "node->data");
-	// This function doesn't use *data so we don't check it
+    PASS(e, aksl_fprintf(&count, stderr, "Visiting node : %s\n", node->data));
+    SUCCEED_RETURN(e);
+}
 
-	PASS(e, aksl_fprintf(&count, stderr, "Visiting node : %s", node->data));
+// This iterator function exits early once the index in `(int *)data` is reached
+akerr_ErrorContext AKERR_NOIGNORE *myiter_earlyhalt(aksl_ListNode *node, void *data)
+{
+    int *idx;
+    int count = 0;
+    PREPARE_ERROR(e);
+    FAIL_ZERO_RETURN(e, node, AKERR_NULLPOINTER, "node");
+    FAIL_ZERO_RETURN(e, node->data, AKERR_NULLPOINTER, "node->data");
+    FAIL_ZERO_RETURN(e, data, AKERR_NULLPOINTER, "data");
+    idx = (int *)data;
+    if ( *idx == 1 ) {
+	// This exception is eaten by the iterator, we will never see it
+	FAIL_RETURN(e, AKERR_ITERATOR_BREAK, "stop");
+    }
+    *idx += 1;
     SUCCEED_RETURN(e);
 }
 
 int main(void)
 {
 	PREPARE_ERROR(e);
+	int idx = 0;
 	aksl_ListNode mylist;
-	char *node1str = "Node 1";
 	aksl_ListNode node1;
-	char *node2str = "Node 2";
 	aksl_ListNode node2;
 
-	node1->data = (void *)&node1str;
-	PASS(e, aksl_list_push(&mylist, &node1));
+	ATTEMPT {
+	    memset((void *)&mylist, 0x00, sizeof(aksl_ListNode));
+	    memset((void *)&node1, 0x00, sizeof(aksl_ListNode));
+	    memset((void *)&node2, 0x00, sizeof(aksl_ListNode));
 
-	node2->data = (void *)&node2str;
-	PASS(e, aksl_list_push(&mylist, &node2));
+	    mylist.data = "Root";
 	    
-	PASS(e, aksl_list_iterate(&mylist, &myiter, NULL));
+	    node1.data = "Node 1";
+	    CATCH(e, aksl_list_append(&mylist, &node1));
 	    
-	SUCCEED_RETURN(e);
+	    node2.data = "Node 2";
+	    CATCH(e, aksl_list_append(&mylist, &node2));
+
+	    // Iterate over all nodes in the list using the myiter() function
+	    CATCH(e, aksl_list_iterate(&mylist, &myiter, NULL));
+
+	    // Iterate over up to the first 2 nodes in the list and then exit early
+	    idx = 0;
+	    CATCH(e, aksl_list_iterate(&mylist, &myiter_earlyhalt, &idx));
+	    CATCH(e, aksl_fprintf(&count, stderr, "Iterator exited early at index %d\n", idx));
+
+	    // Break the list with a circular reference, and iterate it again
+	    node2.next = &mylist;
+	    CATCH(e, aksl_list_iterate(&mylist, &myiter, NULL));
+	    
+	} CLEANUP {
+	} PROCESS(e) {
+	} HANDLE(e, AKERR_CIRCULAR_REFERENCE) {
+	    fprintf(stderr, "Circular reference error caught\n");
+	} FINISH_NORETURN(e);
+
+	return 0;
 }