New test subject

plugin/main.cpp

@@ -198,11 +198,11 @@ void scan_stmt_for_offsetof(const char *funcname, gimple_stmt_iterator *gsi) {
 	gassign *as = gimple_build_assign(lhs, val);
 	gsi_replace(gsi, as, true);
 
-	/*
+    if (strncmp(type_str, "struct ", 7) == 0)
-	TODO -> type_str contains "struct " but target set does not
+        type_str = type_str + 7;
+
 	if (!is_target(type_str))
         return;
-	*/
 
 	// Insert label
 	MemberAccessInfo info;
@@ -279,24 +279,28 @@ struct gimplabels_pass : gimple_opt_pass {
                                ? IDENTIFIER_POINTER(DECL_NAME(fun->decl))
                                : "<anon>";
 
-        std::cout << std::endl << "Handling function \"" << funcname << "\"..." << std::endl;
+        constexpr bool verbose = false;
+        std::size_t base_access_count = g_member_accesses.size();
+        std::cout << (verbose ? "\n" : "") << "Handling function \"" << funcname << "\"..." << std::endl;
 
         // Iteration über alle Grundblöcke und Anweisungen
         basic_block bb;
         FOR_EACH_BB_FN(bb, fun) {
             for (gimple_stmt_iterator gsi = gsi_start_bb(bb); !gsi_end_p(gsi); gsi_next(&gsi)) {
                 gimple *stmt = gsi_stmt(gsi);
+                if (verbose)
                     print_gimple_stmt (stdout, stmt, 0, TDF_NONE);
                 scan_stmt_for_offsetof(funcname, &gsi);
                 for (unsigned i = 0; i < gimple_num_ops(stmt); ++i) {
                     tree op = gimple_op(stmt, i);
+                    if (verbose)
                         plugin_debug_tree(op);
                     scan_tree_for_components(op, funcname, &gsi);
                 }
             }
         }
 
-        std::cout << "Number of accesses: " << g_member_accesses.size() << std::endl;
+        std::cout << "    Number of accesses: " << (g_member_accesses.size() - base_access_count) << std::endl;
         return 0;
     }
 };

subject/main.c

@@ -1,39 +1,80 @@
+// test_task_struct.c
 #include <stdio.h>
-#include <stddef.h>
+#include <stddef.h> // for offsetof
-#include <stdlib.h>
 
 #define container_of(ptr, type, member) ({ \
     const typeof(((type*)0)->member)* __mptr = (ptr); \
     (type*)((char*)__mptr - offsetof(type, member)); })
 
-struct A;
+// Minimal doubly linked list
-struct B;
+struct list_head {
-
+    struct list_head *next, *prev;
-struct A {
-	char m0;
-	int m1;
-	struct B* m2;
 };
 
-struct B {
+static inline void INIT_LIST_HEAD(struct list_head *list)
-	int m0;
+{
-	char m1;
+    list->next = list;
-	short m2;
+    list->prev = list;
-	struct A* m3;
+}
-	float m4;
+
-	struct A m5;
+static inline void __list_add(struct list_head *new,
-	struct B* m6;
+                              struct list_head *prev,
+                              struct list_head *next)
+{
+    next->prev = new;
+    new->next = next;
+    new->prev = prev;
+    prev->next = new;
+}
+
+static inline void list_add(struct list_head *new, struct list_head *head)
+{
+    __list_add(new, head, head->next);
+}
+
+static inline void list_add_tail(struct list_head *new, struct list_head *head)
+{
+    __list_add(new, head->prev, head);
+}
+
+#define list_entry(ptr, type, member) \
+    container_of(ptr, type, member)
+
+#define list_for_each(pos, head) \
+    for (pos = (head)->next; pos != (head); pos = pos->next)
+
+// A small struct like the Linux kernel's task_struct
+struct task_struct {
+    int pid;
+    const char *comm;
+    struct list_head tasks;  // linkage for global task list
 } __attribute__((slr));
 
-int main(int argc, char** argv) {
+int main(void)
-	struct A a = { 'x', 52, NULL };
+{
-	struct B b = { 1, 2, 3, NULL, 4.f, a, NULL };
+    struct list_head task_list;
+    INIT_LIST_HEAD(&task_list);
 
-	b.m2 = 42;
+    struct task_struct t1 = { .pid = 1, .comm = "init" };
+    struct task_struct t2 = { .pid = 2, .comm = "kthreadd" };
+    struct task_struct t3 = { .pid = 3, .comm = "worker" };
 
-	struct B* someB = (struct B*)malloc(sizeof(struct B));
+    INIT_LIST_HEAD(&t1.tasks);
-	float* someB_m4 = &someB->m4;
+    INIT_LIST_HEAD(&t2.tasks);
-	container_of(someB_m4, struct B, m4)->m1 = 'x'; // the "sub 0x..." is currently not recognized via ADDR_EXPR
+    INIT_LIST_HEAD(&t3.tasks);
+
+    list_add_tail(&t1.tasks, &task_list);
+    list_add_tail(&t2.tasks, &task_list);
+    list_add_tail(&t3.tasks, &task_list);
+
+    printf("Task list:\n");
+
+    struct list_head *pos;
+    list_for_each(pos, &task_list) {
+        struct task_struct *task = list_entry(pos, struct task_struct, tasks);
+        printf("  pid=%d, comm=%s\n", task->pid, task->comm);
+    }
 
     return 0;
 }
+