Update function parameter types from usize to size_t across multiple files to ensure consistency with the new type alias.

Signed-off-by: Cong Wang <cwang@multikernel.io>

Author: congwang-mk

SPEC.md

@@ -217,7 +217,7 @@ KernelScript automatically extracts kernel function signatures from BTF (BPF Typ
 ```kernelscript
 // Function entrance probe (uses fprobe)
 @probe("sys_read")
-fn function_entrance(fd: u32, buf: *u8, count: usize) -> i32 {
+fn function_entrance(fd: u32, buf: *u8, count: size_t) -> i32 {
     // Direct access to function parameters with correct types
     // Compiler automatically extracts signature from BTF:
     // long sys_read(unsigned int fd, char __user *buf, size_t count)
@@ -2575,7 +2575,7 @@ pin var global_counters : array<u32, GlobalCounter>(256)
 pin var event_stream : hash<u32, Event>(1024)
 
 @probe("sys_read")
-fn producer(fd: u32, buf: *u8, count: usize) -> i32 {
+fn producer(fd: u32, buf: *u8, count: size_t) -> i32 {
     var pid = bpf_get_current_pid_tgid() as u32
     
     // Update global counter (accessible by other programs)
@@ -2595,7 +2595,7 @@ fn producer(fd: u32, buf: *u8, count: usize) -> i32 {
 }
 
 @probe("sys_write")
-fn consumer(fd: u32, buf: *u8, count: usize) -> i32 {
+fn consumer(fd: u32, buf: *u8, count: size_t) -> i32 {
     var pid = bpf_get_current_pid_tgid() as u32
     
     // Access global counter (same map as producer program)

examples/map_operations_demo.ks

@@ -207,7 +207,7 @@ fn event_logger(ctx: *trace_event_raw_sys_enter) -> i32 {
 
 // Program 4: Sequential access pattern demonstration
 @probe("vfs_read")
-fn data_processor(file: *file, buf: *u8, count: usize, pos: *i64) -> i32 {
+fn data_processor(file: *file, buf: *u8, count: size_t, pos: *i64) -> i32 {
     // Sequential access pattern - will be detected and optimized
     for (i in 0..32) {
         var element = sequential_data[i]

src/btf_stubs.c

@@ -272,6 +272,14 @@ static char* resolve_type_to_string(struct btf *btf, int type_id) {
             return strdup("*u8");
         }
 
+        if (kind == BTF_KIND_TYPEDEF) {
+            /* Check for special typedef names like size_t */
+            const char *typedef_name = btf__name_by_offset(btf, t->name_off);
+            if (typedef_name && strcmp(typedef_name, "size_t") == 0) {
+                return strdup("size_t");  /* Map size_t to KernelScript size_t type alias */
+            }
+        }
+        
         t = btf__type_by_id(btf, t->type);
         if (!t) break;
         kind = btf_kind(t);
@@ -408,6 +416,14 @@ value btf_resolve_type_stub(value btf_handle, value type_id) {
             CAMLreturn(caml_copy_string("*u8"));
         }
 
+        if (kind == BTF_KIND_TYPEDEF) {
+            /* Check for special typedef names like size_t */
+            const char *typedef_name = btf__name_by_offset(btf, t->name_off);
+            if (typedef_name && strcmp(typedef_name, "size_t") == 0) {
+                CAMLreturn(caml_copy_string("size_t"));  /* Map size_t to KernelScript size_t type alias */
+            }
+        }
+        
         /* Follow the type chain */
         t = btf__type_by_id(btf, t->type);
         if (!t) break;

src/ir.ml

@@ -716,7 +716,6 @@ let rec ast_type_to_ir_type = function
   | Xdp_md -> IRContext XdpCtx
   | TracepointContext -> IRContext TracepointCtx
   | Xdp_action -> IRAction Xdp_actionType
-  | UserType "usize" -> IRU64 (* usize maps to 64-bit unsigned integer *)
   | UserType name -> IRStruct (name, []) (* Resolved by type checker *)
   | Function (param_types, return_type) -> 
       (* Function types are represented as proper function pointers *)

src/stdlib.ml

@@ -250,6 +250,9 @@ let get_kernel_implementation name =
 
 (** Builtin type definitions *)
 let builtin_types = [
+  (* Standard C types as type aliases *)
+  TypeDef (TypeAlias ("size_t", U64));  (* size_t maps to 64-bit unsigned integer *)
+  
   (* Kernel allocation flags enum *)
   TypeDef (EnumDef ("gfp_flag", [
     ("GFP_KERNEL", Some 0x0001);

src/type_checker.ml

@@ -220,8 +220,6 @@ let rec resolve_user_type ctx = function
   | UserType "xdp_md" -> Xdp_md
   | UserType "xdp_action" -> Xdp_action
   | UserType "__sk_buff" -> Struct "__sk_buff"
-
-  | UserType "usize" -> U64  (* usize maps to 64-bit unsigned integer *)
   | UserType name ->
       (* Look up type alias in the context *)
       (try

tests/test_probe.ml

@@ -54,17 +54,17 @@ module MockProbeBTF = struct
   let mock_kernel_functions = [
     {
       name = "sys_read";
-      parameters = [("fd", "u32"); ("buf", "*u8"); ("count", "usize")];
+      parameters = [("fd", "u32"); ("buf", "*u8"); ("count", "size_t")];
       return_type = "isize";
     };
     {
       name = "vfs_write";
-      parameters = [("file", "*file"); ("buf", "*u8"); ("count", "usize"); ("pos", "*i64")];
+      parameters = [("file", "*file"); ("buf", "*u8"); ("count", "size_t"); ("pos", "*i64")];
       return_type = "isize";
     };
     {
       name = "tcp_sendmsg";
-      parameters = [("sk", "*sock"); ("msg", "*msghdr"); ("size", "usize")];
+      parameters = [("sk", "*sock"); ("msg", "*msghdr"); ("size", "size_t")];
       return_type = "i32";
     };
   ]
@@ -75,7 +75,7 @@ end
 (* 1. Parser Tests *)
 let test_probe_attribute_parsing _ =
   let source = "@probe(\"sys_read\")
-fn sys_read_handler(fd: u32, buf: *u8, count: usize) -> i32 {
+fn sys_read_handler(fd: u32, buf: *u8, count: size_t) -> i32 {
     return 0
 }" in
   let ast = parse_string source in
@@ -92,7 +92,7 @@ fn sys_read_handler(fd: u32, buf: *u8, count: usize) -> i32 {
 
 let test_probe_multiple_parameters _ =
   let source = "@probe(\"vfs_write\")
-fn vfs_write_handler(file: *file, buf: *u8, count: usize, pos: *i64) -> i32 {
+fn vfs_write_handler(file: *file, buf: *u8, count: size_t, pos: *i64) -> i32 {
     return 0
 }" in
   let ast = parse_string source in
@@ -138,7 +138,7 @@ fn empty_target_handler(fd: u32) -> i32 {
 (* 2. Type Checking Tests *)
 let test_probe_type_checking _ =
   let source = "@probe(\"sys_read\")
-fn sys_read_handler(fd: u32, buf: *u8, count: usize) -> i32 {
+fn sys_read_handler(fd: u32, buf: *u8, count: size_t) -> i32 {
     return 0
 }" in
   let ast = parse_string source in
@@ -147,7 +147,7 @@ fn sys_read_handler(fd: u32, buf: *u8, count: usize) -> i32 {
 
 let test_probe_parameter_validation _ =
   let source = "@probe(\"sys_read\")
-fn sys_read_handler(fd: u32, buf: *u8, count: usize) -> i32 {
+fn sys_read_handler(fd: u32, buf: *u8, count: size_t) -> i32 {
     return 0
 }" in
   let ast = parse_string source in
@@ -166,8 +166,8 @@ fn sys_read_handler(fd: u32, buf: *u8, count: usize) -> i32 {
              (match fd_type with U32 -> true | _ -> false);
            check bool "Second parameter type should be Pointer" true
              (match buf_type with Pointer _ -> true | _ -> false);
-           check bool "Third parameter type should be UserType usize" true
-             (match count_type with UserType "usize" -> true | _ -> false)
+           check bool "Third parameter type should be UserType size_t" true
+             (match count_type with UserType "size_t" -> true | _ -> false)
        | _ -> fail "Expected exactly three parameters")
   | _ -> fail "Expected AttributedFunction"
 
@@ -232,7 +232,7 @@ fn invalid_handler(ctx: *pt_regs) -> i32 {
 (* 3. IR Generation Tests *)
 let test_probe_ir_generation _ =
   let source = "@probe(\"sys_read\")
-fn sys_read_handler(fd: u32, buf: *u8, count: usize) -> i32 {
+fn sys_read_handler(fd: u32, buf: *u8, count: size_t) -> i32 {
     return 0
 }" in
   let ast = parse_string source in
@@ -247,7 +247,7 @@ fn sys_read_handler(fd: u32, buf: *u8, count: usize) -> i32 {
 
 let test_probe_complex_parameters _ =
   let source = "@probe(\"tcp_sendmsg\")
-fn tcp_sendmsg_handler(sk: *sock, msg: *msghdr, size: usize) -> i32 {
+fn tcp_sendmsg_handler(sk: *sock, msg: *msghdr, size: size_t) -> i32 {
     return 0
 }" in
   let ast = parse_string source in
@@ -262,7 +262,7 @@ fn tcp_sendmsg_handler(sk: *sock, msg: *msghdr, size: usize) -> i32 {
 
 let test_probe_function_signature_validation _ =
   let source = "@probe(\"vfs_write\")
-fn vfs_write_handler(file: *file, buf: *u8, count: usize, pos: *i64) -> i32 {
+fn vfs_write_handler(file: *file, buf: *u8, count: size_t, pos: *i64) -> i32 {
     return 0
 }" in
   let ast = parse_string source in
@@ -279,7 +279,7 @@ fn vfs_write_handler(file: *file, buf: *u8, count: usize, pos: *i64) -> i32 {
 (* 4. Code Generation Tests *)
 let test_fprobe_section_name_generation _ =
   let source = "@probe(\"sys_read\")
-fn sys_read_handler(fd: u32, buf: *u8, count: usize) -> i32 {
+fn sys_read_handler(fd: u32, buf: *u8, count: size_t) -> i32 {
     return 0
 }" in
   let ast = parse_string source in
@@ -315,7 +315,7 @@ fn vfs_read_handler(ctx: *pt_regs) -> i32 {
 
 let test_fprobe_complex_section_generation _ =
   let source = "@probe(\"tcp_sendmsg\")
-fn tcp_sendmsg_handler(sk: *sock, msg: *msghdr, size: usize) -> i32 {
+fn tcp_sendmsg_handler(sk: *sock, msg: *msghdr, size: size_t) -> i32 {
     return 0
 }" in
   let ast = parse_string source in
@@ -338,7 +338,7 @@ fn tcp_sendmsg_handler(sk: *sock, msg: *msghdr, size: usize) -> i32 {
 
 let test_fprobe_ebpf_codegen _ =
   let source = "@probe(\"sys_read\")
-fn sys_read_handler(fd: u32, buf: *u8, count: usize) -> i32 {
+fn sys_read_handler(fd: u32, buf: *u8, count: size_t) -> i32 {
     return 0
 }" in
   let ast = parse_string source in
@@ -379,7 +379,7 @@ fn vfs_read_handler(ctx: *pt_regs) -> i32 {
 
 let test_fprobe_includes_generation _ =
   let source = "@probe(\"sys_read\")
-fn sys_read_handler(fd: u32, buf: *u8, count: usize) -> i32 {
+fn sys_read_handler(fd: u32, buf: *u8, count: size_t) -> i32 {
     return 0
 }" in
   let ast = parse_string source in
@@ -541,7 +541,7 @@ fn sys_open_handler(ctx: *pt_regs) -> i32 {
 
 let test_fprobe_network_function _ =
   let source = "@probe(\"tcp_sendmsg\")
-fn tcp_sendmsg_handler(sk: *sock, msg: *msghdr, size: usize) -> i32 {
+fn tcp_sendmsg_handler(sk: *sock, msg: *msghdr, size: size_t) -> i32 {
     return 0
 }" in
   let ast = parse_string source in
@@ -559,7 +559,7 @@ fn tcp_sendmsg_handler(sk: *sock, msg: *msghdr, size: usize) -> i32 {
 
 let test_probe_multiple_functions _ =
   let source = "@probe(\"sys_read\")
-fn sys_read_handler(fd: u32, buf: *u8, count: usize) -> i32 {
+fn sys_read_handler(fd: u32, buf: *u8, count: size_t) -> i32 {
     return 0
 }
 

tests/test_program_ref.ml

@@ -47,7 +47,7 @@ fn main() -> i32 {
 (** Test program reference with different program types *)
 let test_different_program_types () =
   let program_text = {|
-@probe("sys_read") fn kprobe_tracer(fd: u32, buf: *u8, count: usize) -> i32 {
+@probe("sys_read") fn kprobe_tracer(fd: u32, buf: *u8, count: size_t) -> i32 {
   return 0
 }
 

tests/test_ringbuf.ml

@@ -502,7 +502,7 @@ var security_events : ringbuf<SecurityEvent>(8192)
   return XDP_PASS
 }
 
-@probe("sys_read") fn security_prog(fd: u32, buf: *u8, count: usize) -> i32 {
+@probe("sys_read") fn security_prog(fd: u32, buf: *u8, count: size_t) -> i32 {
   var sec_event = security_events.reserve()
   if (sec_event != null) {
     security_events.submit(sec_event)