builder,pref: add -file-list support (implement feature #25707) (#25749)

Author: kbkpbot

vlib/v/builder/builder_test.v

@@ -43,3 +43,42 @@ fn test_conditional_executable_removal() {
 	dump(after_second_run___)
 	assert executable in after_second_run___
 }
+
+fn test_file_list() {
+	os.chdir(test_path)!
+	os.mkdir_all('filelist')!
+	os.write_file('filelist/main.v', 'module main
+fn main() {
+        part_a := AS{}
+        part_b := BS{}
+        println("\${part_a}=>\${part_b}")
+}')!
+	os.write_file('filelist/part_a.v', 'module main
+pub struct AS{}
+')!
+
+	os.write_file('filelist/part_b.v', 'module main
+pub struct BS{}
+')!
+
+	// `part_c.v` is not included in the compilation
+	// or there will be a conflit definition of `struct BS`
+	os.write_file('filelist/part_c.v', 'module main
+pub struct BS{}
+')!
+	mut executable := 'filelist_check'
+	$if windows {
+		executable += '.exe'
+	}
+
+	original_file_list_ := os.ls(test_path)!
+	dump(original_file_list_)
+	assert executable !in original_file_list_
+
+	cmd := '${os.quoted_path(vexe)} -o ${executable} filelist/main.v -file-list "filelist/part_a.v,filelist/part_b.v,"'
+	os.execute(cmd)
+	after_compile_file_list := os.ls(test_path)!.filter(os.exists(it))
+	dump(after_compile_file_list)
+	assert executable in after_compile_file_list
+	assert os.execute('./${executable}').output.trim_space() == 'AS{}=>BS{}'
+}

vlib/v/builder/compile.v

@@ -369,6 +369,24 @@ pub fn (v &Builder) get_user_files() []string {
 		user_files << single_test_v_file
 		dir = os.dir(single_test_v_file)
 	}
+	v.add_file_or_dir(mut user_files, dir)
+	for f in v.pref.file_list {
+		file := f.trim_space()
+		if file.len > 0 {
+			v.add_file_or_dir(mut user_files, file)
+		}
+	}
+	if user_files.len == 0 {
+		println('No input .v files')
+		exit(1)
+	}
+	if v.pref.is_verbose {
+		v.log('user_files: ${user_files}')
+	}
+	return user_files
+}
+
+fn (v &Builder) add_file_or_dir(mut user_files []string, dir string) {
 	does_exist := os.exists(dir)
 	if !does_exist {
 		verror("${dir} doesn't exist")
@@ -381,7 +399,7 @@ pub fn (v &Builder) get_user_files() []string {
 		// Just compile one file and get parent dir
 		user_files << single_v_file
 		if v.pref.is_verbose {
-			v.log('> just compile one file: "${single_v_file}"')
+			v.log('> add one file: "${single_v_file}"')
 		}
 	} else if os.is_dir(dir) {
 		if v.pref.is_verbose {
@@ -395,12 +413,4 @@ pub fn (v &Builder) get_user_files() []string {
 		println('unknown file extension `${ext}`')
 		exit(1)
 	}
-	if user_files.len == 0 {
-		println('No input .v files')
-		exit(1)
-	}
-	if v.pref.is_verbose {
-		v.log('user_files: ${user_files}')
-	}
-	return user_files
 }

vlib/v/help/build/build.txt

@@ -92,6 +92,12 @@ NB: the build flags are shared with the run command too:
        `./v -exclude @vlib/math/*.c.v vlib/math/math_test.v`
             ^ run the math test file, using only pure .v files, excluding the .c.v overrides.
 
+  -file-list
+    Specifies a comma-separated list of paths for compilation. Paths can be to individual .v files
+	or directories; all .v files found recursively within directories are included.
+    Example:
+       `./v main.v -file-list "src/part_a.v,src/part_b.v,lib/moda"
+
   -prod
     Compile the executable in production mode, where most optimizations are enabled.
     Note that most V warnings turn to errors, if you pass -prod, so you will have

vlib/v/pref/pref.v

@@ -203,8 +203,9 @@ pub mut:
 	line_info        string // `-line-info="file.v:28"`: for "mini VLS" (shows information about objects on provided line)
 	linfo            LineInfo
 
-	run_only []string // VTEST_ONLY_FN and -run-only accept comma separated glob patterns.
-	exclude  []string // glob patterns for excluding .v files from the list of .v files that otherwise would have been used for a compilation, example: `-exclude @vlib/math/*.c.v`
+	run_only  []string // VTEST_ONLY_FN and -run-only accept comma separated glob patterns.
+	exclude   []string // glob patterns for excluding .v files from the list of .v files that otherwise would have been used for a compilation, example: `-exclude @vlib/math/*.c.v`
+	file_list []string // A list of .v files or directories. All .v files found recursively in directories will be included in the compilation.
 	// Only test_ functions that match these patterns will be run. -run-only is valid only for _test.v files.
 	// -d vfmt and -d another=0 for `$if vfmt { will execute }` and `$if another ? { will NOT get here }`
 	compile_defines     []string          // just ['vfmt']
@@ -740,6 +741,10 @@ pub fn parse_args_and_show_errors(known_external_commands []string, args []strin
 				res.exclude << patterns
 				i++
 			}
+			'-file-list' {
+				res.file_list = cmdline.option(args[i..], arg, '').split_any(',')
+				i++
+			}
 			'-test-runner' {
 				res.test_runner = cmdline.option(args[i..], arg, res.test_runner)
 				i++