all: get -usecache working with mods in ~/.vmodules (ui examples)

vlib/v/builder/cc.v

@@ -385,13 +385,6 @@ fn (mut v Builder) cc() {
 					if imp == 'webview' {
 						continue
 					}
-					// println('cache: import "$imp"')
-					mod_path := imp.replace('.', os.path_separator)
-					// TODO: to get import path all imports (even relative) we can use:
-					// import_path := v.find_module_path(imp, ast_file.path) or {
-					// verror('cannot import module "$imp" (not found)')
-					// break
-					// }
 					// The problem is cmd/v is in module main and imports
 					// the relative module named help, which is built as cmd.v.help not help
 					// currently this got this workign by building into main, see ast.FnDecl in cgen
@@ -402,7 +395,11 @@ fn (mut v Builder) cc() {
 					// if os.is_dir(af_base_dir + os.path_separator + mod_path) {
 					// continue
 					// }
-					imp_path := os.join_path('vlib', mod_path)
+					// imp_path := os.join_path('vlib', mod_path)
+					imp_path := v.find_module_path(imp, ast_file.path) or {
+						verror('cannot import module "$imp" (not found)')
+						break
+					}
 					obj_path := v.rebuild_cached_module(vexe, imp_path)
 					libs += ' ' + obj_path
 					if obj_path.ends_with('vlib/ui.o') {

vlib/v/gen/cgen.v

@@ -3,6 +3,7 @@
 // that can be found in the LICENSE file.
 module gen
 
+import os
 import strings
 import v.ast
 import v.table
@@ -138,6 +139,18 @@ const (
 
 pub fn cgen(files []ast.File, table &table.Table, pref &pref.Preferences) string {
 	// println('start cgen2')
+	mut module_built := ''
+	if pref.build_mode == .build_module {
+		// TODO: detect this properly for all cases
+		// either get if from an earlier stage or use the lookup paths
+		if pref.path.contains('vlib' + os.path_separator) {
+			module_built = pref.path.after('vlib' + os.path_separator).replace(os.path_separator,
+				'.')
+		} else if pref.path.contains('.vmodules' + os.path_separator) {
+			module_built = pref.path.after('.vmodules' + os.path_separator).replace(os.path_separator,
+				'.')
+		}
+	}
 	mut g := Gen{
 		out: strings.new_builder(1000)
 		cheaders: strings.new_builder(8192)
@@ -164,7 +177,7 @@ pub fn cgen(files []ast.File, table &table.Table, pref &pref.Preferences) string
 		fn_decl: 0
 		autofree: true
 		indent: -1
-		module_built: pref.path.after('vlib/').replace('/', '.')
+		module_built: module_built
 	}
 	for mod in g.table.modules {
 		g.inits[mod] = strings.new_builder(100)

vlib/v/parser/parser.v

@@ -1622,7 +1622,7 @@ fn (mut p Parser) module_decl() ast.Module {
 		// is not imported.
 		// So here we fetch the name of the module by looking at the path that's being built.
 		word := p.pref.path.after('/')
-		if full_mod == word {
+		if full_mod == word && p.pref.path.contains('vlib') {
 			full_mod = p.pref.path.after('vlib/').replace('/', '.')
 			// println('new full mod =$full_mod')
 		}

vlib/v/table/table.v

@@ -678,8 +678,9 @@ pub fn (t &Table) mktyp(typ Type) Type {
 	}
 }
 
-// Once we have a module format we can read from module file instead
+// TODO: Once we have a module format we can read from module file instead
-// this is not optimal
+// this is not optimal. it depends on the full import being in table.imports
+// already, we can instead lookup the module path and then work it out
 pub fn (table &Table) qualify_module(mod string, file_path string) string {
 	for m in table.imports {
 		// if m.contains('gen') { println('qm=$m') }