cgen,json2: improve -nofloat support (#13117)

vlib/v/gen/c/cgen.v

@@ -645,6 +645,9 @@ pub fn (mut g Gen) init() {
 				g.cheaders.writeln(get_guarded_include_text('<stddef.h>', 'The C compiler can not find <stddef.h>. Please install build-essentials')) // size_t, ptrdiff_t
 			}
 		}
+		if g.pref.nofloat {
+			g.cheaders.writeln('#define VNOFLOAT 1')
+		}
 		g.cheaders.writeln(c_builtin_types)
 		if g.pref.is_bare {
 			g.cheaders.writeln(c_bare_headers)

vlib/v/gen/c/cheaders.v

@@ -656,10 +656,19 @@ typedef uint8_t byte;
 typedef uint32_t rune;
 typedef size_t usize;
 typedef ptrdiff_t isize;
+#ifndef VNOFLOAT 
 typedef float f32;
 typedef double f64;
+#else
+typedef int32_t f32;
+typedef int64_t f64;
+#endif
 typedef int64_t int_literal;
+#ifndef VNOFLOAT
 typedef double float_literal;
+#else
+typedef int64_t float_literal;
+#endif
 typedef unsigned char* byteptr;
 typedef void* voidptr;
 typedef char* charptr;

vlib/x/json2/decoder.v

@@ -106,9 +106,11 @@ fn (mut p Parser) decode_value() ?Any {
 			kind := p.tok.kind
 			p.next_with_err() ?
 			if p.convert_type {
+				$if !nofloat ? {
 					if kind == .float {
 						return Any(tl.f64())
 					}
+				}
 				return Any(tl.i64())
 			}
 			return Any(tl)

vlib/x/json2/encoder.v

@@ -73,19 +73,26 @@ pub fn (f Any) json_str() string {
 			return f.str()
 		}
 		f32 {
+			$if !nofloat ? {
 				str_f32 := f.str()
 				if str_f32.ends_with('.') {
 					return '${str_f32}0'
 				}
 				return str_f32
 			}
+
+			return '0'
+		}
 		f64 {
+			$if !nofloat ? {
 				str_f64 := f.str()
 				if str_f64.ends_with('.') {
 					return '${str_f64}0'
 				}
 				return str_f64
 			}
+			return '0'
+		}
 		map[string]Any {
 			return f.str()
 		}