v: support `$if prod` (#9228)

doc/docs.md

@@ -3516,6 +3516,10 @@ $if test {
 $if debug {
 	println('debugging')
 }
+// v -prod ...
+$if prod {
+	println('production build')
+}
 // v -d option ...
 $if option ? {
 	println('custom option')
@@ -3529,8 +3533,8 @@ If you're using a custom ifdef, then you do need `$if option ? {}` and compile w
 Full list of builtin options:
 | OS                            | Compilers         | Platforms             | Other                     |
 | ---                           | ---               | ---                   | ---                       |
-| `windows`, `linux`, `macos`   | `gcc`, `tinyc`    | `amd64`, `aarch64`    | `debug`, `test`, `js` |
-| `mac`, `darwin`, `ios`,       | `clang`, `mingw`  | `x64`, `x32`          | `glibc`, `prealloc`   |
+| `windows`, `linux`, `macos`   | `gcc`, `tinyc`    | `amd64`, `aarch64`    | `debug`, `prod`, `test`   |
+| `mac`, `darwin`, `ios`,       | `clang`, `mingw`  | `x64`, `x32`          | `js`, `glibc`, `prealloc` |
 | `android`,`mach`, `dragonfly` | `msvc`            | `little_endian`       | `no_bounds_checking`      |
 | `gnu`, `hpux`, `haiku`, `qnx` | `cplusplus`       | `big_endian`          | |
 | `solaris`, `linux_or_macos`   | | | |

vlib/v/checker/checker.v

@@ -27,7 +27,7 @@ const (
 	]
 	valid_comp_if_compilers = ['gcc', 'tinyc', 'clang', 'mingw', 'msvc', 'cplusplus']
 	valid_comp_if_platforms = ['amd64', 'aarch64', 'x64', 'x32', 'little_endian', 'big_endian']
-	valid_comp_if_other     = ['js', 'debug', 'test', 'glibc', 'prealloc', 'no_bounds_checking']
+	valid_comp_if_other     = ['js', 'debug', 'prod', 'test', 'glibc', 'prealloc', 'no_bounds_checking']
 	array_builtin_methods   = ['filter', 'clone', 'repeat', 'reverse', 'map', 'slice', 'sort',
 		'contains', 'index', 'wait']
 )
@@ -5150,6 +5150,7 @@ fn (mut c Checker) comp_if_branch(cond ast.Expr, pos token.Position) bool {
 				match cond.name {
 					'js' { return c.pref.backend != .js }
 					'debug' { return !c.pref.is_debug }
+					'prod' { return !c.pref.is_prod }
 					'test' { return !c.pref.is_test }
 					'glibc' { return false } // TODO
 					'prealloc' { return !c.pref.prealloc }

vlib/v/gen/c/cgen.v

@@ -423,6 +423,9 @@ pub fn (mut g Gen) init() {
 	if g.pref.is_debug || 'debug' in g.pref.compile_defines {
 		g.comptime_defines.writeln('#define _VDEBUG (1)')
 	}
+	if g.pref.is_prod || 'prod' in g.pref.compile_defines {
+		g.comptime_defines.writeln('#define _VPROD (1)')
+	}
 	if g.pref.is_test || 'test' in g.pref.compile_defines {
 		g.comptime_defines.writeln('#define _VTEST (1)')
 	}

vlib/v/gen/c/comptime.v

@@ -498,6 +498,9 @@ fn (mut g Gen) comp_if_to_ifdef(name string, is_comptime_optional bool) ?string
 		'debug' {
 			return '_VDEBUG'
 		}
+		'prod' {
+			return '_VPROD'
+		}
 		'test' {
 			return '_VTEST'
 		}

vlib/v/tests/prod/assoc.prod.v

@@ -17,4 +17,11 @@ fn get_st() MyStruct {
 fn main() {
 	s := get_st()
 	println(s)
+	$if prod {
+		println('prod mode is on')
+		assert true
+	} $else {
+		println('prod mode is off')
+		assert false
+	}
 }

vlib/v/tests/prod/assoc.prod.v.expected.txt

@@ -1,3 +1,4 @@
 MyStruct{
     s: '6'
 }
+prod mode is on