builtin.closure: use fixed sized arrays for closure_thunk and closure_get_data_bytes (#25720)

Author: spytheman

vlib/builtin/closure/closure.c.v

@@ -29,21 +29,21 @@ pub const closure_thunk = $if amd64 {
     [
     u8(0xF3), 0x44, 0x0F, 0x7E, 0x3D, 0xF7, 0xBF, 0xFF, 0xFF,  // movq  xmm15, QWORD PTR [rip - userdata]
         0xFF, 0x25, 0xF9, 0xBF, 0xFF, 0xFF                     // jmp  QWORD PTR [rip - fn]
-    ]
+    ]!
 } $else $if i386 {
     [
     u8(0xe8), 0x00, 0x00, 0x00, 0x00,        // call here
         // here:
         0x59,                                // pop  ecx
         0x66, 0x0F, 0x6E, 0xF9,              // movd xmm7, ecx
         0xff, 0xA1, 0xff, 0xbf, 0xff, 0xff,  // jmp  DWORD PTR [ecx - 0x4001] # <fn>
-    ]
+    ]!
 } $else $if arm64 {
     [
     u8(0x11), 0x00, 0xFE, 0x5C,  // ldr d17, userdata
         0x30, 0x00, 0xFE, 0x58,  // ldr x16, fn
         0x00, 0x02, 0x1F, 0xD6   // br  x16
-    ]
+    ]!
 } $else $if arm32 {
     [
     u8(0x04), 0xC0, 0x4F, 0xE2,  // adr ip, here
@@ -52,28 +52,28 @@ pub const closure_thunk = $if amd64 {
         0x90, 0xCA, 0x07, 0xEE,  // vmov s15, ip
         0x00, 0xC0, 0x9C, 0xE5,  // ldr  ip, [ip, 0]
         0x1C, 0xFF, 0x2F, 0xE1   // bx   ip
-    ]
+    ]!
 } $else $if rv64 {
     [
     u8(0x97), 0xCF, 0xFF, 0xFF,  // auipc t6, 0xffffc
         0x03, 0xBF, 0x8F, 0x00,  // ld    t5, 8(t6)
         0x07, 0xB3, 0x0F, 0x00,  // fld   ft6, 0(t6)
         0x67, 0x00, 0x0F, 0x00,  // jr    t5
-    ]
+    ]!
 } $else $if rv32 {
     [
     u8(0x97), 0xCF, 0xFF, 0xFF,  // auipc t6, 0xffffc
         0x03, 0xAF, 0x4F, 0x00,  // lw    t5, 4(t6)
         0x07, 0xAB, 0x0F, 0x00,  // flw   fs6, 0(t6)
         0x67, 0x00, 0x0F, 0x00   // jr    t5
-    ]
+    ]!
 } $else $if s390x {
     [
     u8(0xC0), 0x70, 0xFF, 0xFF, 0xE0, 0x00,  // larl %r7, -16384
         0x68, 0xF0, 0x70, 0x00,              // ld   %f15, 0(%r7)
         0xE3, 0x70, 0x70, 0x08, 0x00, 0x04,  // lg   %r7, 8(%r7)
         0x07, 0xF7,                          // br   %r7
-    ]
+    ]!
 } $else $if ppc64le {
     [
     u8(0xa6), 0x02, 0x08, 0x7c,	// mflr   %r0
@@ -85,67 +85,67 @@ pub const closure_thunk = $if amd64 {
         0xa6, 0x03, 0x08, 0x7c,	// mtlr   %r0
         0xa6, 0x03, 0xc9, 0x7d,	// mtctr  %r14
         0x20, 0x04, 0x80, 0x4e,	// bctr
-    ]
+    ]!
 } $else $if loongarch64 {
     [
     u8(0x92), 0xFF, 0xFF, 0x1D,  // pcaddu12i t6, -4
         0x48, 0x02, 0x80, 0x2B,  // fld.d     f8, t6, 0
         0x51, 0x22, 0xC0, 0x28,  // ld.d      t5, t6, 8
         0x20, 0x02, 0x00, 0x4C,  // jr        t5
-    ]
+    ]!
 } $else {
-    []u8{}
+    [u8(0)]!
 }
 
 const closure_get_data_bytes = $if amd64 {
     [
     u8(0x66), 0x4C, 0x0F, 0x7E, 0xF8,  // movq rax, xmm15
         0xC3                           // ret
-    ]
+    ]!
 } $else $if i386 {
     [
     u8(0x66), 0x0F, 0x7E, 0xF8,              // movd eax, xmm7
         0x8B, 0x80, 0xFB, 0xBF, 0xFF, 0xFF,  // mov eax, DWORD PTR [eax - 0x4005]
         0xc3                                 // ret
-    ]
+    ]!
 } $else $if arm64 {
     [
     u8(0x20), 0x02, 0x66, 0x9E,  // fmov x0, d17
         0xC0, 0x03, 0x5F, 0xD6   // ret
-    ]
+    ]!
 } $else $if arm32 {
     [
     u8(0x90), 0x0A, 0x17, 0xEE,  // vmov r0, s15
         0x04, 0x00, 0x10, 0xE5,  // ldr r0, [r0, #-4]
         0x1E, 0xFF, 0x2F, 0xE1   // bx lr
-    ]
+    ]!
 } $else $if rv64 {
     [
     u8(0x53), 0x05, 0x03, 0xE2,  // fmv.x.d a0, ft6
         0x67, 0x80, 0x00, 0x00,  // ret
-    ]
+    ]!
 } $else $if rv32 {
     [
     u8(0x53), 0x05, 0x0B, 0xE0,  // fmv.x.w a0, fs6
         0x67, 0x80, 0x00, 0x00   // ret
-    ]
+    ]!
 } $else $if s390x {
 	[
     u8(0xB3), 0xCD, 0x00, 0x2F,	 // lgdr %r2, %f15
         0x07, 0xFE,			     // br   %r14
-    ]
+    ]!
 } $else $if ppc64le {
     [
     u8(0x66), 0x00, 0xc3, 0x7d,	// mfvsrd %r3, %f14
         0x20, 0x00, 0x80, 0x4e,	// blr
-    ]
+    ]!
 } $else $if loongarch64 {
     [
     u8(0x04), 0xB9, 0x14, 0x01,  // movfr2gr.d a0, f8
         0x20, 0x00, 0x00, 0x4C,  // ret
-    ]
+    ]!
 } $else {
-    []u8{}
+    [u8(0)]!
 }
 // vfmt on
 
@@ -172,7 +172,7 @@ fn closure_alloc() {
 
 	// Fill page with closure templates
 	for remaining > 0 {
-		unsafe { vmemcpy(x, closure_thunk.data, closure_thunk.len) } // Copy template
+		unsafe { vmemcpy(x, &closure_thunk[0], closure_thunk.len) } // Copy template
 		remaining--
 		unsafe {
 			x += closure_size // Move to next slot
@@ -198,7 +198,7 @@ fn closure_init() {
 		// Temporarily enable write access to executable memory
 		closure_memory_protect_platform(g_closure.closure_ptr, page_size, .read_write)
 		// Copy closure entry stub code
-		vmemcpy(g_closure.closure_ptr, closure_get_data_bytes.data, closure_get_data_bytes.len)
+		vmemcpy(g_closure.closure_ptr, &closure_get_data_bytes[0], closure_get_data_bytes.len)
 		// Re-enormalize execution protection
 		closure_memory_protect_platform(g_closure.closure_ptr, page_size, .read_exec)
 	}

vlib/v/gen/c/consts_and_globals.v

@@ -355,7 +355,7 @@ fn (mut g Gen) const_decl_init_later(mod string, name string, cname string, expr
 	}
 	if g.is_autofree {
 		sym := g.table.sym(typ)
-		if styp.starts_with('Array_') {
+		if sym.kind == .array {
 			if sym.has_method_with_generic_parent('free') {
 				g.cleanup.writeln('\t${styp}_free(&${cname});')
 			} else {