v.util: prepare for removing vlib/v/util/module.v - improve tracing, comment edge cases with actual data

vlib/v/util/module.v

@@ -1,14 +1,23 @@
 module util
 
+// 2022-01-30 TODO: this whole file should not exist :-|. It should just use the existing `v.vmod` instead,
+// 2022-01-30 that already does handle v.mod lookup properly, stopping at .git folders, supporting `.v.mod.stop` etc.
 import os
 import v.pref
 
-[if trace_mod_path_to_full_name ?]
+[if trace_util_qualify ?]
-fn trace_mod_path_to_full_name(line string, mod string, file_path string, res string) {
+fn trace_qualify(callfn string, mod string, file_path string, kind_res string, result string, detail string) {
-	eprintln('> $line ${@FN} mod: ${mod:-20} | file_path: ${file_path:-30} | result: $res')
+	eprintln('> ${callfn:15}: ${mod:-18} | file_path: ${file_path:-71} | => ${kind_res:14}: ${result:-18} ; $detail')
 }
 
+// 2022-01-30 qualify_import - used by V's parser, to find the full module name of import statements
+// 2022-01-30 i.e. when parsing `import automaton` inside a .v file in examples/game_of_life/life_gg.v
+// 2022-01-30 it returns just 'automaton'
+// 2022-01-30 TODO: this seems to always just return `mod` itself, for modules inside the V main folder.
+// 2022-01-30 It does also return `mod` itself, for stuff installed in ~/.vmodules like `vls` but for
+// 2022-01-30 other reasons (see res 2 below).
 pub fn qualify_import(pref &pref.Preferences, mod string, file_path string) string {
+	// comments are from workdir: /v/vls
 	mut mod_paths := pref.lookup_path.clone()
 	mod_paths << os.vmodules_paths()
 	mod_path := mod.replace('.', os.path_separator)
@@ -16,32 +25,62 @@ pub fn qualify_import(pref &pref.Preferences, mod string, file_path string) stri
 		try_path := os.join_path_single(search_path, mod_path)
 		if os.is_dir(try_path) {
 			if m1 := mod_path_to_full_name(pref, mod, try_path) {
-				trace_mod_path_to_full_name(@LINE, mod, try_path, m1)
+				trace_qualify(@FN, mod, file_path, 'import_res 1', m1, try_path)
+				// >  qualify_import: term | file_path: /v/vls/server/diagnostics.v | => import_res 1: term  ; /v/cleanv/vlib/term
 				return m1
 			}
 		}
 	}
 	if m1 := mod_path_to_full_name(pref, mod, file_path) {
-		trace_mod_path_to_full_name(@LINE, mod, file_path, m1)
+		trace_qualify(@FN, mod, file_path, 'import_res 2', m1, file_path)
+		// >  qualify_module: analyzer           | file_path: /v/vls/analyzer/store.v  | =>   module_res 2: analyzer           ; clean_file_path - getwd == mod
+		// >  qualify_import: analyzer.depgraph  | file_path: /v/vls/analyzer/store.v  | =>   import_res 2: analyzer.depgraph  ; /v/vls/analyzer/store.v
+		// >  qualify_import: tree_sitter        | file_path: /v/vls/analyzer/store.v  | =>   import_res 2: tree_sitter        ; /v/vls/analyzer/store.v
+		// >  qualify_import: tree_sitter_v      | file_path: /v/vls/analyzer/store.v  | =>   import_res 1: tree_sitter_v      ; ~/.vmodules/tree_sitter_v
+		// >  qualify_import: jsonrpc            | file_path: /v/vls/server/features.v | =>   import_res 2: jsonrpc            ; /v/vls/server/features.v
 		return m1
 	}
+	trace_qualify(@FN, mod, file_path, 'import_res 3', mod, '---, mod_path: $mod_path')
+	// >  qualify_import: server | file_path: cmd/vls/host.v | =>   import_res 3: server ; ---
+	// >  qualify_import: cli    | file_path: cmd/vls/main.v | =>   import_res 1: cli    ; /v/cleanv/vlib/cli
+	// >  qualify_import: server | file_path: cmd/vls/main.v | =>   import_res 3: server ; ---
+	// >  qualify_import: os     | file_path: cmd/vls/main.v | =>   import_res 1: os     ; /v/cleanv/vlib/os
 	return mod
 }
 
+// 2022-01-30 qualify_module - used by V's parser to find the full module name
+// 2022-01-30 i.e. when parsing `module textscanner`, inside vlib/strings/textscanner/textscanner.v
+// 2022-01-30 it will return `strings.textscanner`
 pub fn qualify_module(pref &pref.Preferences, mod string, file_path string) string {
 	if mod == 'main' {
+		trace_qualify(@FN, mod, file_path, 'module_res 1', mod, 'main')
 		return mod
 	}
 	clean_file_path := file_path.all_before_last(os.path_separator)
 	// relative module (relative to working directory)
 	// TODO: find most stable solution & test with -usecache
+	//
+	// TODO 2022-01-30: Using os.getwd() here does not seem right *at all* imho.
+	// TODO 2022-01-30: That makes lookup dependent on fragile enviroment factors.
+	// TODO 2022-01-30: The lookup should be relative to the folder, in which the current file is,
+	// TODO 2022-01-30: *NOT* to the working folder of the compiler, which can change easily.
 	if clean_file_path.replace(os.getwd() + os.path_separator, '') == mod {
+		trace_qualify(@FN, mod, file_path, 'module_res 2', mod, 'clean_file_path - getwd == mod, clean_file_path: $clean_file_path')
 		return mod
 	}
 	if m1 := mod_path_to_full_name(pref, mod, clean_file_path) {
-		trace_mod_path_to_full_name(@LINE, mod, clean_file_path, m1)
+		trace_qualify(@FN, mod, file_path, 'module_res 3', m1, 'm1 == f($clean_file_path)')
+		// >  qualify_module: net  | file_path: /v/cleanv/vlib/net/util.v     | =>   module_res 3: net     ; m1 == f(/v/cleanv/vlib/net)
+		// >  qualify_module: term | file_path: /v/cleanv/vlib/term/control.v | =>   module_res 3: term    ; m1 == f(/v/cleanv/vlib/term)
+		// >  qualify_module: log  | file_path: /v/vls/lsp/log/log.v          | =>   module_res 3: lsp.log ; m1 == f(/v/vls/lsp/log)
+
+		// zzz BUG: when ../v.mod exists above V root folder:
+		// zzz >  qualify_module: help | file_path: /v/cleanv/cmd/v/help/help.v   | =>   module_res 3: v.cmd.v.help  ; m1 == f(/v/cleanv/cmd/v/help)
 		return m1
 	}
+	// zzzzzzz WORKING, when there is NO ../v.mod:
+	// zzzzzzz >  qualify_module: help | file_path: /v/cleanv/cmd/v/help/help.v   | =>   module_res 4: help          ; ---, clean_file_path: /v/cleanv/cmd/v/help
+	trace_qualify(@FN, mod, file_path, 'module_res 4', mod, '---, clean_file_path: $clean_file_path')
 	return mod
 }
 
@@ -50,11 +89,19 @@ pub fn qualify_module(pref &pref.Preferences, mod string, file_path string) stri
 // * if possible split this function in two, one which gets the
 // parent module path and another which turns it into the full name
 // * create shared logic between these fns and builder.find_module_path
-pub fn mod_path_to_full_name(pref &pref.Preferences, mod string, path string) ?string {
+// 2022-01-30 TODO: the reliance on os.path_separator here, is also a potential problem.
+// 2022-01-30 On windows that leads to:
+// 2022-01-30 `v path/subfolder/` behaving very differently than `v path\subfolder\`
+// 2022-01-30 (see daa5be4, that skips checking `vlib/v/checker/tests/modules/deprecated_module`
+// 2022-01-30 just on windows, because while `vlib\v\checker\tests\modules\deprecated_module` works,
+// 2022-01-30 it leads to path differences, and the / version on windows triggers a module lookip bug,
+// 2022-01-30 leading to completely different errors)
+fn mod_path_to_full_name(pref &pref.Preferences, mod string, path string) ?string {
 	// TODO: explore using `pref.lookup_path` & `os.vmodules_paths()`
 	// absolute paths instead of 'vlib' & '.vmodules'
 	mut vmod_folders := ['vlib', '.vmodules', 'modules']
-	for base in pref.lookup_path.map(os.base(it)) {
+	bases := pref.lookup_path.map(os.base(it))
+	for base in bases {
 		if base !in vmod_folders {
 			vmod_folders << base
 		}