ast,checker,parser,cgen: [c:'sym'] rework; allow compiling code from .v files tagged with [translated] without needing -translated too (#17125)

vlib/v/ast/ast.v

@@ -529,6 +529,7 @@ pub:
 	is_keep_alive      bool        // passed memory must not be freed (by GC) before function returns
 	is_unsafe          bool        // true, when [unsafe] is used on a fn
 	is_markused        bool        // true, when an explict `[markused]` tag was put on a fn; `-skip-unused` will not remove that fn
+	is_file_translated bool        // true, when the file it resides in is `[translated]`
 	receiver           StructField // TODO this is not a struct field
 	receiver_pos       token.Pos   // `(u User)` in `fn (u User) name()` position
 	is_method          bool
@@ -593,6 +594,7 @@ pub mut:
 	is_keep_alive      bool // GC must not free arguments before fn returns
 	is_noreturn        bool // whether the function/method is marked as [noreturn]
 	is_ctor_new        bool // if JS ctor calls requires `new` before call, marked as `[use_new]` in V
+	is_file_translated bool // true, when the file it resides in is `[translated]`
 	args               []CallArg
 	expected_arg_types []Type
 	comptime_ret_val   bool

vlib/v/ast/table.v

@@ -106,6 +106,7 @@ pub:
 	is_keep_alive      bool // passed memory must not be freed (by GC) before function returns
 	is_method          bool // true for `fn (x T) name()`, and for interface declarations (which are also for methods)
 	no_body            bool // a pure declaration like `fn abc(x int)`; used in .vh files, C./JS. fns.
+	is_file_translated bool // true, when the file it resides in is `[translated]`
 	mod                string
 	file               string
 	file_mode          Language

vlib/v/checker/fn.v

@@ -887,6 +887,7 @@ fn (mut c Checker) fn_call(mut node ast.CallExpr, mut continue_check &bool) ast.
 		return ast.void_type
 	}
 
+	node.is_file_translated = func.is_file_translated
 	node.is_noreturn = func.is_noreturn
 	node.is_ctor_new = func.is_ctor_new
 	if !found_in_args {
@@ -909,7 +910,7 @@ fn (mut c Checker) fn_call(mut node ast.CallExpr, mut continue_check &bool) ast.
 	}
 	node.is_keep_alive = func.is_keep_alive
 	if func.language == .v && func.no_body && !c.pref.translated && !c.file.is_translated
-		&& !func.is_unsafe && func.mod != 'builtin' {
+		&& !func.is_unsafe && !func.is_file_translated && func.mod != 'builtin' {
 		c.error('cannot call a function that does not have a body', node.pos)
 	}
 	if node.concrete_types.len > 0 && func.generic_names.len > 0

vlib/v/gen/c/cgen.v

@@ -4357,15 +4357,16 @@ fn (mut g Gen) ident(node ast.Ident) {
 			}
 		}
 	} else if node.info is ast.IdentFn {
-		if g.pref.translated || g.file.is_translated {
-			// `p_mobjthinker` => `P_MobjThinker`
-			if func := g.table.find_fn(node.name) {
 		// TODO PERF fn lookup for each fn call in translated mode
+		if func := g.table.find_fn(node.name) {
+			if g.pref.translated || g.file.is_translated || func.is_file_translated {
+				// `p_mobjthinker` => `P_MobjThinker`
 				if cattr := func.attrs.find_first('c') {
 					name = cattr.arg
 				}
 			}
 		}
+
 		if g.pref.obfuscate && g.cur_mod.name == 'main' && name.starts_with('main__') {
 			key := node.name
 			g.write('/* obf identfn: ${key} */')

vlib/v/gen/c/fn.v

@@ -446,7 +446,7 @@ fn (mut g Gen) c_fn_name(node &ast.FnDecl) !string {
 		name = g.generic_fn_name(g.cur_concrete_types, name)
 	}
 
-	if g.pref.translated || g.file.is_translated {
+	if g.pref.translated || g.file.is_translated || node.is_file_translated {
 		if cattr := node.attrs.find_first('c') {
 			// This fixes unknown symbols errors when building separate .c => .v files into .o files
 			// example:
@@ -1362,7 +1362,7 @@ fn (mut g Gen) fn_call(node ast.CallExpr) {
 	} else {
 		name = c_name(name)
 	}
-	if g.pref.translated || g.file.is_translated {
+	if g.pref.translated || g.file.is_translated || node.is_file_translated {
 		// For `[c: 'P_TryMove'] fn p_trymove( ... `
 		// every time `p_trymove` is called, `P_TryMove` must be generated instead.
 		if f := g.table.find_fn(node.name) {

vlib/v/gen/c/testdata/translated/sym.c

@@ -0,0 +1,3 @@
+int ExternalSymbol(char *hello) {
+	return *hello;
+}

vlib/v/gen/c/testdata/translated/translated_module_actual.v

@@ -0,0 +1,7 @@
+[translated]
+module translated
+
+#include "@VMODROOT/sym.c"
+
+[c: 'ExternalSymbol']
+pub fn external_symbol(&char) int

vlib/v/gen/c/testdata/translated_module.c.must_have

@@ -0,0 +1,2 @@
+int ExternalSymbol(char* );
+int a = ExternalSymbol("hello");

vlib/v/gen/c/testdata/translated_module.out

@@ -0,0 +1 @@
+result: 104

vlib/v/gen/c/testdata/translated_module.vv

@@ -0,0 +1,9 @@
+module main
+
+import v.gen.c.testdata.translated { external_symbol }
+
+fn main() {
+	a := external_symbol(c'hello')
+	println('result: ${a}')
+	assert a == 104
+}

vlib/v/parser/fn.v

@@ -495,6 +495,7 @@ run them via `v file.v` instead',
 			is_test: is_test
 			is_keep_alive: is_keep_alive
 			is_method: false
+			is_file_translated: p.is_translated
 			//
 			attrs: p.attrs
 			is_conditional: conditional_ctdefine_idx != ast.invalid_type_idx
@@ -550,6 +551,7 @@ run them via `v file.v` instead',
 		is_keep_alive: is_keep_alive
 		is_unsafe: is_unsafe
 		is_markused: is_markused
+		is_file_translated: p.is_translated
 		//
 		attrs: p.attrs
 		is_conditional: conditional_ctdefine_idx != ast.invalid_type_idx