fix: correct compile target and path resolution for multifile diagnostics

interop.v

@@ -13,9 +13,51 @@ import time
 fn resolve_v_compiler_exe() string {
 	configured := os.getenv('VLS_V_COMMAND').trim_space()
 	if configured != '' {
+		unwrapped := resolve_wrapper_target(configured)
+		if unwrapped != '' {
+			return unwrapped
+		}
 		return configured
 	}
-	return os.find_abs_path_of_executable('v') or { 'v' }
+	found := os.find_abs_path_of_executable('v') or { 'v' }
+	unwrapped := resolve_wrapper_target(found)
+	if unwrapped != '' {
+		return unwrapped
+	}
+	return found
+}
+
+// resolve_wrapper_target unwraps a Windows launcher shim (a `.bat`/`.cmd`
+// file that forwards to the real compiler executable) so compiler-relative
+// lookups such as the vlib directory resolve against the real installation
+// instead of the shim's directory. It returns '' when `candidate` is not a
+// wrapper or no usable target is found, in which case the caller keeps the
+// original path.
+fn resolve_wrapper_target(candidate string) string {
+	if candidate == '' || candidate == 'v' {
+		return ''
+	}
+	lower := candidate.to_lower()
+	if !(lower.ends_with('.bat') || lower.ends_with('.cmd')) {
+		return ''
+	}
+	content := os.read_file(candidate) or { return '' }
+	for line in content.split_into_lines() {
+		trimmed := line.trim_space()
+		if !trimmed.starts_with('"') {
+			continue
+		}
+		end := trimmed[1..].index('"') or { continue }
+		target := trimmed[1..end + 1]
+		target_lower := target.to_lower()
+		if target_lower.ends_with('.bat') || target_lower.ends_with('.cmd') {
+			continue
+		}
+		if os.is_file(target) {
+			return target
+		}
+	}
+	return ''
 }
 
 // compiler_is_available reports whether the V compiler was resolved to a real
@@ -1204,12 +1246,13 @@ fn (mut app App) prepare_compilation_overlay_with(real_path string, work_dir str
 
 // source_path_from_overlay maps compiler paths in the temporary project back to
 // their original source paths.
-fn source_path_from_overlay_with_windows_rules(reported_path string, overlay CompilationOverlay, windows bool) string {
+fn source_path_from_overlay_with_windows_rules(reported_path string, overlay CompilationOverlay, windows bool, base_dir string) string {
 	mut candidate := normalize_overlay_path_with_windows_rules(reported_path, windows)
+	resolve_base := if base_dir != '' { base_dir } else { overlay.temp_work_dir }
 	if candidate.starts_with('./') || candidate.starts_with('.\\') {
-		candidate = os.join_path(overlay.temp_work_dir, candidate[2..])
+		candidate = os.join_path(resolve_base, candidate[2..])
 	} else if !os.is_abs_path(candidate) {
-		candidate = os.join_path(overlay.temp_work_dir, candidate)
+		candidate = os.join_path(resolve_base, candidate)
 	}
 	candidate = normalize_overlay_path_with_windows_rules(candidate, windows)
 	temp_root := normalize_overlay_path_with_windows_rules(overlay.temp_root, windows)
@@ -1220,11 +1263,11 @@ fn source_path_from_overlay_with_windows_rules(reported_path string, overlay Com
 	return candidate
 }
 
-fn source_path_from_overlay(reported_path string, overlay CompilationOverlay) string {
+fn source_path_from_overlay(reported_path string, overlay CompilationOverlay, base_dir string) string {
 	$if windows {
-		return source_path_from_overlay_with_windows_rules(reported_path, overlay, true)
+		return source_path_from_overlay_with_windows_rules(reported_path, overlay, true, base_dir)
 	}
-	return source_path_from_overlay_with_windows_rules(reported_path, overlay, false)
+	return source_path_from_overlay_with_windows_rules(reported_path, overlay, false, base_dir)
 }
 
 fn (mut app App) run_v_check(path string, text string) []JsonError {
@@ -1358,9 +1401,9 @@ fn (mut app App) run_v_check(path string, text string) []JsonError {
 	// check: they are shown at once (see DiagnosticsServer.ask).
 	publish := app.diagnostics_partial
 	partial := if publish != unsafe { nil } {
-		fn [publish, diagnostic_source_dir, file_to_check, use_multifile, overlay, real_path, program_uris, path] (answer os.Result) {
+		fn [publish, diagnostic_source_dir, file_to_check, use_multifile, overlay, real_path, program_uris, compile_target, path] (answer os.Result) {
 			found := split_check_errors(answer.output, diagnostic_source_dir, file_to_check,
-				use_multifile, overlay, real_path, program_uris)
+				use_multifile, overlay, real_path, program_uris, compile_target)
 			publish(path, found)
 		}
 	} else {
@@ -1392,7 +1435,7 @@ fn (mut app App) run_v_check(path string, text string) []JsonError {
 	}
 
 	found := split_check_errors(x.output, diagnostic_source_dir, file_to_check, use_multifile,
-		overlay, real_path, program_uris)
+		overlay, real_path, program_uris, compile_target)
 	if server_exe == '' {
 		cleanup_compilation_temp(temp_project_dir, singlefile_tmppath)
 	}
@@ -1438,7 +1481,7 @@ fn (app &App) program_open_files(real_path string, overlay CompilationOverlay) m
 // split_check_errors reads the diagnostics of `output`, what a check printed,
 // for the file at `real_path`, and, when the check covered its program, for the
 // other open files of the program, `program_uris` (see program_open_files).
-fn split_check_errors(output string, diagnostic_source_dir string, file_to_check string, use_multifile bool, overlay CompilationOverlay, real_path string, program_uris map[string]string) CheckErrors {
+fn split_check_errors(output string, diagnostic_source_dir string, file_to_check string, use_multifile bool, overlay CompilationOverlay, real_path string, program_uris map[string]string, base_dir string) CheckErrors {
 	// Parse V3's native flat-AST checker diagnostics so ordinary diagnostics stay
 	// on the default backend.
 	mut v_errors := parse_v_check_diagnostics(output, diagnostic_source_dir)
@@ -1455,7 +1498,7 @@ fn split_check_errors(output string, diagnostic_source_dir string, file_to_check
 	}
 	mut filtered_errors := []JsonError{}
 	for err in v_errors {
-		err_file := source_path_from_overlay(err.path, overlay)
+		err_file := source_path_from_overlay(err.path, overlay, base_dir)
 		if normalized_index_path(err_file) == normalized_index_path(real_path) {
 			filtered_errors << JsonError{
 				path:    real_path
@@ -2439,13 +2482,13 @@ fn (mut app App) run_v_line_info_once(method Method, path string, line_info stri
 
 	log('RUN RES ${x}')
 	return app.line_info_result(method, path, line_info, output, use_multifile, temp_project_dir,
-		overlay)
+		overlay, compile_target)
 }
 
 // line_info_result turns what the compiler printed into the answer the client
 // expects. Both the one-shot process and the persistent compiler end here, so
 // the two paths cannot drift apart.
-fn (mut app App) line_info_result(method Method, path string, line_info string, output string, use_multifile bool, temp_project_dir string, overlay CompilationOverlay) ResponseResult {
+fn (mut app App) line_info_result(method Method, path string, line_info string, output string, use_multifile bool, temp_project_dir string, overlay CompilationOverlay, compile_target string) ResponseResult {
 	// Default to JSON null so any unhandled method branch produces a valid LSP response.
 	mut result := ResponseResult('null')
 	match method {
@@ -2508,7 +2551,7 @@ fn (mut app App) line_info_result(method Method, path string, line_info string,
 				col := fields[fields.len - 1].int()
 				mut uri_path := os.to_slash(fields[..fields.len - 2].join(':'))
 				if use_multifile && temp_project_dir != '' {
-					uri_path = source_path_from_overlay(uri_path, overlay)
+					uri_path = source_path_from_overlay(uri_path, overlay, compile_target)
 					log('MAPPED TO uri_path=${uri_path}')
 				}
 				// Build a proper percent-encoded DocumentUri so paths containing
@@ -2518,7 +2561,6 @@ fn (mut app App) line_info_result(method Method, path string, line_info string,
 				result = app.compiler_location(uri_path, line_nr, col)
 			}
 		}
-		else {}
 	}
 
 	return result

interop_test.v

@@ -38,6 +38,83 @@ fn test_resolve_v_compiler_exe_prefers_configured_command() {
 	assert resolve_v_compiler_exe() == configured
 }
 
+fn test_resolve_wrapper_target_ignores_plain_executable() {
+	assert resolve_wrapper_target('C:\\v\\v.exe') == ''
+	assert resolve_wrapper_target('/usr/local/bin/v') == ''
+	assert resolve_wrapper_target('') == ''
+	assert resolve_wrapper_target('v') == ''
+}
+
+fn test_resolve_wrapper_target_ignores_missing_wrapper() {
+	missing := os.join_path(os.temp_dir(), 'vls_no_such_wrapper_${os.getpid()}.bat')
+	assert resolve_wrapper_target(missing) == ''
+}
+
+fn test_resolve_wrapper_target_unwraps_bat_forwarding_to_exe() {
+	base := os.join_path(os.temp_dir(), 'vls_wrapper_probe_${os.getpid()}')
+	bin := os.join_path(base, '.bin')
+	interop_test_must_mkdir_all(bin)
+	defer {
+		os.rmdir_all(base) or {}
+	}
+	target := os.join_path(base, 'v.exe')
+	interop_test_must_write_file(target, '')
+	wrapper := os.join_path(bin, 'v.bat')
+	interop_test_must_write_file(wrapper, '@echo off\n"${target}" %*\n')
+	assert resolve_wrapper_target(wrapper) == target
+}
+
+fn test_resolve_wrapper_target_ignores_bat_without_quoted_target() {
+	base := os.join_path(os.temp_dir(), 'vls_wrapper_bare_${os.getpid()}')
+	interop_test_must_mkdir_all(base)
+	defer {
+		os.rmdir_all(base) or {}
+	}
+	wrapper := os.join_path(base, 'v.bat')
+	interop_test_must_write_file(wrapper, '@echo off\nv.exe %*\n')
+	assert resolve_wrapper_target(wrapper) == ''
+}
+
+fn test_resolve_wrapper_target_ignores_wrapper_chain() {
+	base := os.join_path(os.temp_dir(), 'vls_wrapper_chain_${os.getpid()}')
+	interop_test_must_mkdir_all(base)
+	defer {
+		os.rmdir_all(base) or {}
+	}
+	inner := os.join_path(base, 'inner.bat')
+	interop_test_must_write_file(inner, '@echo off\necho hi\n')
+	outer := os.join_path(base, 'outer.bat')
+	interop_test_must_write_file(outer, '@echo off\n"${inner}" %*\n')
+	assert resolve_wrapper_target(outer) == ''
+}
+
+fn test_resolve_v_compiler_exe_unwraps_configured_wrapper() {
+	old_command := os.getenv('VLS_V_COMMAND')
+	defer {
+		if old_command == '' {
+			os.unsetenv('VLS_V_COMMAND')
+		} else {
+			os.setenv('VLS_V_COMMAND', old_command, true)
+		}
+	}
+	base := os.join_path(os.temp_dir(), 'vls_wrapper_env_${os.getpid()}')
+	bin := os.join_path(base, '.bin')
+	interop_test_must_mkdir_all(bin)
+	defer {
+		os.rmdir_all(base) or {}
+	}
+	target := os.join_path(base, 'v.exe')
+	interop_test_must_write_file(target, '')
+	// A real V installation holds vlib next to the compiler; without it the
+	// walk-up has no V home to find.
+	interop_test_must_mkdir_all(os.join_path(base, 'vlib'))
+	wrapper := os.join_path(bin, 'v.bat')
+	interop_test_must_write_file(wrapper, '@echo off\n"${target}" %*\n')
+	os.setenv('VLS_V_COMMAND', wrapper, true)
+	assert resolve_v_compiler_exe() == target
+	assert find_v_dir() == os.dir(os.real_path(target))
+}
+
 // --- uri_to_path tests ---
 
 fn test_uri_to_path_unix_style() {
@@ -167,7 +244,7 @@ fn test_source_path_from_overlay_normalizes_windows_relative_join() {
 		temp_root:           r'C:\temp\overlay'
 		temp_work_dir:       r'C:\temp\overlay\src'
 	}
-	mapped := source_path_from_overlay_with_windows_rules('./main.v', overlay, true)
+	mapped := source_path_from_overlay_with_windows_rules('./main.v', overlay, true, '')
 	assert mapped == 'C:/repo/src/main.v'
 }
 
@@ -1716,7 +1793,7 @@ fn test_prepare_compilation_overlay_preserves_nested_symlink_layout() {
 	assert overlay.temp_work_dir == os.join_path(overlay.temp_root, 'src')
 	assert overlay.temp_source_file == os.join_path(overlay.temp_root, 'src', 'main.v')
 	assert os.read_file(overlay.temp_source_file) or { '' } == unsaved_content
-	mapped_path := source_path_from_overlay(overlay.temp_source_file, overlay)
+	mapped_path := source_path_from_overlay(overlay.temp_source_file, overlay, '')
 	assert normalize_overlay_path(mapped_path) == normalize_overlay_path(main_file)
 }
 
@@ -1754,7 +1831,7 @@ fn test_prepare_compilation_overlay_preserves_posix_backslashes() {
 		assert overlay.source_root == project_dir
 		assert overlay.source_display_root == project_dir
 		assert os.read_file(overlay.temp_source_file) or { '' } == unsaved_content
-		mapped_path := source_path_from_overlay(overlay.temp_source_file, overlay)
+		mapped_path := source_path_from_overlay(overlay.temp_source_file, overlay, '')
 		assert mapped_path == main_file
 	}
 }

rename_conflicts.v

@@ -345,7 +345,8 @@ fn parse_name_pos(answer string, overlay CompilationOverlay) ?NamePos {
 		|| !fields[fields.len - 2].is_int() {
 		return none
 	}
-	path := source_path_from_overlay(os.to_slash(fields[..fields.len - 2].join(':')), overlay)
+	path := source_path_from_overlay(os.to_slash(fields[..fields.len - 2].join(':')), overlay,
+		overlay.temp_work_dir)
 	return NamePos{
 		path: normalize_overlay_path(path)
 		line: fields[fields.len - 2].int() - 1

v3_line_info.v

@@ -79,7 +79,7 @@ fn (mut app App) v3_line_info(method Method, path string, real_path string, line
 	}
 	log('V3 answered ${output.len} bytes')
 	return app.line_info_result(method, path, line_info, output, true, result.project.overlay.temp_root,
-		result.project.overlay)
+		result.project.overlay, result.project.overlay.temp_work_dir)
 }
 
 // V3Hover is what V3 answers for a hover: what it says of the name under the
@@ -117,7 +117,8 @@ fn (mut app App) v3_hover(uri string, real_path string, line_info string) ?V3Hov
 	mut declared_at := ?Location(none)
 	if definition != '' {
 		located := app.line_info_result(.definition, uri, definition_info, definition,
-			true, result.project.overlay.temp_root, result.project.overlay)
+			true, result.project.overlay.temp_root, result.project.overlay,
+			result.project.overlay.temp_work_dir)
 		if located is Location {
 			declared_at = located
 		}
@@ -510,7 +511,8 @@ fn (mut app App) v3_prefetch_anchors(locations []Location, mut cache map[string]
 				continue
 			}
 			found := app.line_info_result(.definition, loc.uri, questions[i].line_info, output,
-				true, result.project.overlay.temp_root, result.project.overlay)
+				true, result.project.overlay.temp_root, result.project.overlay,
+				result.project.overlay.temp_work_dir)
 			if found is Location && found.uri != '' {
 				cache[anchor_cache_key(loc.uri, loc.range.start.line, loc.range.start.char)] = found
 			}