pref,parser: implement support for -force-bounds-checking to enable easier testing of functions tagged with @[direct_array_access] (essentially turning off that flag)

Author: spytheman

vlib/v/parser/fn.v

@@ -217,7 +217,9 @@ fn (mut p Parser) fn_decl() ast.FnDecl {
 				is_deprecated = true
 			}
 			'direct_array_access' {
-				is_direct_arr = true
+				if !p.pref.force_bounds_checking {
+					is_direct_arr = true
+				}
 			}
 			'keep_args_alive' {
 				is_keep_alive = true

vlib/v/pref/pref.v

@@ -171,7 +171,8 @@ pub mut:
 	cppcompiler               string       // the name of the CPP compiler used
 	third_party_option        string
 	building_v                bool
-	no_bounds_checking        bool   // `-no-bounds-checking` turns off *all* bounds checks for all functions at runtime, as if they all had been tagged with `[direct_array_access]`
+	no_bounds_checking        bool   // `-no-bounds-checking` turns off *all* bounds checks for all functions at runtime, as if they all had been tagged with `@[direct_array_access]`
+	force_bounds_checking     bool   // `-force-bounds-checking` turns ON *all* bounds checks, even for functions that *were* tagged with `@[direct_array_access]`
 	autofree                  bool   // `v -manualfree` => false, `v -autofree` => true; false by default for now.
 	print_autofree_vars       bool   // print vars that are not freed by autofree
 	print_autofree_vars_in_fn string // same as above, but only for a single fn
@@ -640,6 +641,9 @@ pub fn parse_args_and_show_errors(known_external_commands []string, args []strin
 				res.compile_defines_all << 'no_bounds_checking'
 				res.build_options << arg
 			}
+			'-force-bounds-checking' {
+				res.force_bounds_checking = true
+			}
 			'-no-builtin' {
 				res.no_builtin = true
 				res.build_options << arg
@@ -1036,6 +1040,11 @@ pub fn parse_args_and_show_errors(known_external_commands []string, args []strin
 			}
 		}
 	}
+	if res.force_bounds_checking {
+		res.no_bounds_checking = false
+		res.compile_defines = res.compile_defines.filter(it == 'no_bounds_checking')
+		res.compile_defines_all = res.compile_defines_all.filter(it == 'no_bounds_checking')
+	}
 	if res.trace_calls {
 		if res.trace_fns.len == 0 {
 			res.trace_fns << '*'