vfmt: add support for VDIFF_TOOL, detect more diffing tools (#5857)

vlib/os/os_windows.c.v

@@ -265,8 +265,9 @@ pub fn exec(cmd string) ?Result {
 	C.ExpandEnvironmentStringsW(cmd.to_wide(), voidptr(&command_line), 32768)
 	create_process_ok := C.CreateProcessW(0, command_line, 0, 0, C.TRUE, 0, 0, 0, voidptr(&start_info), voidptr(&proc_info))
 	if !create_process_ok {
-		error_msg := get_error_msg(int(C.GetLastError()))
-		return error('exec failed (CreateProcess): $error_msg cmd: $cmd')
+		error_num := int(C.GetLastError())
+		error_msg := get_error_msg(error_num)
+		return error('exec failed (CreateProcess) with code $error_num: $error_msg cmd: $cmd')
 	}
 	C.CloseHandle(child_stdin)
 	C.CloseHandle(child_stdout_write)

vlib/v/util/diff.v

@@ -0,0 +1,82 @@
+module util
+
+import os
+import time
+
+// iterates through a list of known diff cli commands
+// and returns it with basic options
+pub fn find_working_diff_command() ?string {
+	env_difftool := os.getenv('VDIFF_TOOL')
+	env_diffopts := os.getenv('VDIFF_OPTIONS')
+	mut known_diff_tools := []string{}
+	if env_difftool.len > 0 {
+		known_diff_tools << env_difftool
+	}
+	known_diff_tools << [
+		'colordiff', 'gdiff', 'diff', 'colordiff.exe',
+		'diff.exe', 'opendiff', 'code', 'code.cmd'
+	]
+	// NOTE: code.cmd is the Windows variant of the `code` cli tool
+	for diffcmd in known_diff_tools {
+		if diffcmd == 'opendiff' { // opendiff has no `--version` option
+			if opendiff_exists() {
+				return diffcmd
+			}
+			continue
+		}
+		p := os.exec('$diffcmd --version') or {
+			continue
+		}
+		if p.exit_code == 127 && diffcmd == env_difftool {
+			// user setup is wonky, fix it
+			return error('could not find specified VDIFF_TOOL $diffcmd')
+		}
+		if p.exit_code == 0 { // success
+			if diffcmd in ['code', 'code.cmd'] {
+				// there is no guarantee that the env opts exist
+				// or include `-d`, so (harmlessly) add it
+				return '$diffcmd $env_diffopts -d'
+			}
+			return '$diffcmd $env_diffopts'
+		}
+	}
+	return error('No working "diff" command found')
+}
+
+// determine if the FileMerge opendiff tool is available
+fn opendiff_exists() bool {
+	o := os.exec('opendiff') or {
+		return false
+	}
+	if o.exit_code == 1 { // failed (expected), but found (i.e. not 127)
+		if o.output.contains('too few arguments') { // got some exptected output
+			return true
+		}
+	}
+	return false
+}
+
+pub fn color_compare_files(diff_cmd, file1, file2 string) string {
+	if diff_cmd != '' {
+		full_cmd := '$diff_cmd --minimal --text --unified=2 ' +
+			' --show-function-line="fn " "$file1" "$file2" '
+		x := os.exec(full_cmd) or {
+			return 'comparison command: `$full_cmd` failed'
+		}
+		return x.output.trim_right('\r\n')
+	}
+	return ''
+}
+
+pub fn color_compare_strings(diff_cmd, expected, found string) string {
+	cdir := os.cache_dir()
+	ctime := time.sys_mono_now()
+	e_file := os.join_path(cdir, '${ctime}.expected.txt')
+	f_file := os.join_path(cdir, '${ctime}.found.txt')
+	os.write_file(e_file, expected)
+	os.write_file(f_file, found)
+	res := color_compare_files(diff_cmd, e_file, f_file)
+	os.rm(e_file)
+	os.rm(f_file)
+	return res
+}

vlib/v/util/errors.v

@@ -6,7 +6,6 @@ module util
 import os
 import term
 import v.token
-import time
 
 // The filepath:line:col: format is the default C compiler error output format.
 // It allows editors and IDE's like emacs to quickly find the errors in the
@@ -89,7 +88,7 @@ pub fn formatted_error(kind, omsg, filepath string, pos token.Position) string {
 		}
 	}
 	column := imax(0, pos.pos - p - 1)
-	position := '${path}:${pos.line_nr+1}:${util.imax(1,column+1)}:'
+	position := '$path:${pos.line_nr+1}:${imax(1,column+1)}:'
 	scontext := source_context(kind, source, column, pos).join('\n')
 	final_position := bold(position)
 	final_kind := bold(color(kind, kind))
@@ -112,11 +111,8 @@ pub fn source_context(kind, source string, column int, pos token.Position) []str
 		sline := source_lines[iline]
 		start_column := imax(0, imin(column, sline.len))
 		end_column := imax(0, imin(column + imax(0, pos.len), sline.len))
-		cline := if iline == pos.line_nr {
-			sline[..start_column] + color(kind, sline[start_column..end_column]) + sline[end_column..]
-		} else {
-			sline
-		}
+		cline := if iline == pos.line_nr { sline[..start_column] + color(kind, sline[start_column..end_column]) +
+				sline[end_column..] } else { sline }
 		clines << '${iline+1:5d} | ' + cline.replace('\t', tab_spaces)
 		//
 		if iline == pos.line_nr {
@@ -126,18 +122,10 @@ pub fn source_context(kind, source string, column int, pos token.Position) []str
 			// use strings.repeat(` `, col) to form it.
 			mut pointerline := ''
 			for bchar in sline[..start_column] {
-				x := if bchar.is_space() {
-					bchar
-				} else {
-					` `
-				}
+				x := if bchar.is_space() { bchar } else { ` ` }
 				pointerline += x.str()
 			}
-			underline := if pos.len > 1 {
-				'~'.repeat(end_column - start_column)
-			} else {
-				'^'
-			}
+			underline := if pos.len > 1 { '~'.repeat(end_column - start_column) } else { '^' }
 			pointerline += bold(color(kind, underline))
 			clines << '      | ' + pointerline.replace('\t', tab_spaces)
 		}
@@ -147,44 +135,6 @@ pub fn source_context(kind, source string, column int, pos token.Position) []str
 
 pub fn verror(kind, s string) {
 	final_kind := bold(color(kind, kind))
-	eprintln('${final_kind}: $s')
+	eprintln('$final_kind: $s')
 	exit(1)
 }
-
-pub fn find_working_diff_command() ?string {
-	for diffcmd in ['colordiff', 'gdiff', 'diff', 'colordiff.exe', 'diff.exe'] {
-		p := os.exec('$diffcmd --version') or {
-			continue
-		}
-		if p.exit_code == 0 {
-			return diffcmd
-		}
-	}
-	return error('no working diff command found')
-}
-
-pub fn color_compare_files(diff_cmd, file1, file2 string) string {
-	if diff_cmd != '' {    	
-		mut other_options := os.getenv('VDIFF_OPTIONS')
-		full_cmd := '$diff_cmd --minimal --text --unified=2 ' +
-		        ' --show-function-line="fn " $other_options "$file1" "$file2" '
-		x := os.exec(full_cmd) or {
-			return 'comparison command: `${full_cmd}` failed'
-		}
-		return x.output.trim_right('\r\n')
-    }
-    return ''
-}
-
-pub fn color_compare_strings(diff_cmd string, expected string, found string) string {
-	cdir := os.cache_dir()
-	ctime := time.sys_mono_now()
-	e_file := os.join_path(cdir, '${ctime}.expected.txt')
-	f_file := os.join_path(cdir, '${ctime}.found.txt')
-	os.write_file( e_file, expected)
-	os.write_file( f_file, found)
-	res := util.color_compare_files(diff_cmd, e_file, f_file)
-	os.rm( e_file )
-	os.rm( f_file )
-	return res
-}

vlib/v/util/util.v

@@ -12,9 +12,7 @@ pub const (
 
 // math.bits is needed by strconv.ftoa
 pub const (
-	builtin_module_parts = ['math.bits', 'strconv', 'strconv.ftoa', 'hash.wyhash', 'strings',
-		'builtin'
-	]
+	builtin_module_parts = ['math.bits', 'strconv', 'strconv.ftoa', 'hash.wyhash', 'strings', 'builtin']
 )
 
 pub const (
@@ -167,7 +165,7 @@ pub fn launch_tool(is_verbose bool, tool_name string, args []string) {
 		}
 		if tool_compilation.exit_code != 0 {
 			mut err := 'Permission denied'
-			if !tool_compilation.output.contains('Permission denied') {
+			if !tool_compilation.output.contains(err) {
 				err = '\n$tool_compilation.output'
 			}
 			eprintln('cannot compile `$tool_source`: $err')