do not allow casting a type to itself

.github/workflows/ci.yml

@@ -41,7 +41,7 @@ jobs:
       run: |
         brew services start postgresql
         sleep 3
-        psql -c 'select rolname from pg_roles'
+        psql -c -d postgres 'select rolname from pg_roles'
         psql -U postgres -c 'create database customerdb;'
         psql -d customerdb -f examples/database/pg/mydb.sql
     - name: Test v->c

vlib/builtin/builtin_nix.v

@@ -53,7 +53,8 @@ fn print_backtrace_skipping_top_frames_linux(skipframes int) bool {
 			nr_ptrs := C.backtrace(*voidptr(buffer), 100)
 			nr_actual_frames := nr_ptrs-skipframes
 			mut sframes := []string
-			csymbols := *byteptr(C.backtrace_symbols(*voidptr(&buffer[skipframes]), nr_actual_frames))
+			csymbols := C.backtrace_symbols(*voidptr(&buffer[skipframes]),
+				nr_actual_frames)
 			for i in 0..nr_actual_frames {  sframes << tos2(csymbols[i]) }
 			for sframe in sframes {
 				executable := sframe.all_before('(')
@@ -72,7 +73,7 @@ fn print_backtrace_skipping_top_frames_linux(skipframes int) bool {
 					output += tos(buf, vstrlen(buf))
 				}
 				output = output.trim_space()+':'
-				if 0 != int(C.pclose(f)) {
+				if 0 != C.pclose(f) {
 					println(sframe) continue
 				}
 				if output in ['??:0:','??:?:'] { output = '' }

vlib/builtin/utf8.v

@@ -155,7 +155,7 @@ fn utf8_len(c byte) int {
 
 // Reads an utf8 character from standard input
 pub fn utf8_getchar() int {
-  c := int(C.getchar())
+  c := C.getchar()
   len := utf8_len(~c)
   if c < 0 {
     return 0
@@ -164,12 +164,12 @@ pub fn utf8_getchar() int {
   } else if len == 1 {
     return -1
   } else {
-    mut uc := int(c & ((1 << (7 - len)) - 1))
+    mut uc := c & ((1 << (7 - len)) - 1)
     for i := 0; i + 1 < len; i++ {
-      c2 := int(C.getchar())
+      c2 := C.getchar()
       if c2 != -1 && (c2 >> 6) == 2 {
         uc <<= 6
-        uc |= int((c2 & 63))
+        uc |= (c2 & 63)
       }  else if c2 == -1 {
         return 0
       } else {

vlib/compiler/gen_c.v

@@ -527,6 +527,10 @@ fn (p mut Parser) cast(typ string) {
 	p.check(.lpar)
 	p.expected_type = typ
 	expr_typ := p.bool_expression()
+	// Do not allow `int(my_int)`
+	if expr_typ == typ {
+		p.warn('casting `$typ` to `$expr_typ` is not needed')
+	}
 	// `face := FT_Face(cobj)` => `FT_Face face = *((FT_Face*)cobj);`
 	casting_voidptr_to_value :=  expr_typ == 'void*' && typ != 'int' &&
 		typ != 'byteptr' &&		!typ.ends_with('*')

vlib/strconv/atoi.v

@@ -61,7 +61,7 @@ pub fn common_parse_uint(s string, _base int, _bit_size int, error_on_non_digit
 	}
 
 	if bit_size == 0 {
-		bit_size = int(int_size)
+		bit_size = int_size
 	} else if bit_size < 0 || bit_size > 64 {
 		// return error('parse_uint: bitsize error $s - $bit_size')
 		return u64(0)
@@ -69,11 +69,11 @@ pub fn common_parse_uint(s string, _base int, _bit_size int, error_on_non_digit
 
 	// Cutoff is the smallest number such that cutoff*base > maxUint64.
 	// Use compile-time constants for common cases.
-	cutoff := u64(max_u64/u64(base)) + u64(1)
+	cutoff := max_u64/u64(base) + u64(1)
 	max_val := if bit_size == 64 {
 		max_u64
 	} else {
-		u64(u64(1)<<u64(bit_size))-u64(1)
+		(u64(1)<<u64(bit_size))-u64(1)
 	}
 
 	mut underscores := false
@@ -160,11 +160,11 @@ pub fn common_parse_int(_s string, base int, _bit_size int, error_on_non_digit b
 	}
 
 	if bit_size == 0 {
-		bit_size = int(int_size)
+		bit_size = int_size
 	}
 
 	// TODO: check should u64(bit_size-1) be size of int (32)?
-	cutoff := u64(u64(1) << u64(bit_size-1))
+	cutoff := u64(1) << u64(bit_size-1)
 	if !neg && un >= cutoff {
 		// return error('parse_int: range error $s0')
         return i64(cutoff - u64(1))