tools: store the V source line of a C error in a bug_reports.v_lines column (#27342)

Author: medvednikov

cmd/tools/modules/vbugreport/c_error_storage.v

@@ -9,16 +9,21 @@ pub:
 	ccompiler    string
 	error_string string
 	lines        string
+	v_lines      string
 }
 
 // new_stored_c_error_report builds the fields stored by the C error report receiver.
+// The generated C context is stored in `lines`, while the corresponding V source
+// context (the V line that caused the C error and its surrounding lines) is stored
+// separately in `v_lines`.
 pub fn new_stored_c_error_report(c_file string, target_os string, ccompiler string, c_error string, c_lines []string, v_lines []string) StoredCErrorReport {
 	return StoredCErrorReport{
 		c_file_name:  normalized_file_name(c_file)
 		target_os:    target_os
 		ccompiler:    ccompiler
 		error_string: c_error_string(c_error)
-		lines:        c_error_report_lines(c_lines, v_lines)
+		lines:        c_lines.join('\n')
+		v_lines:      v_lines.join('\n')
 	}
 }
 
@@ -40,17 +45,6 @@ fn c_error_string(c_output string) string {
 	return ''
 }
 
-fn c_error_report_lines(c_lines []string, v_lines []string) string {
-	mut lines := []string{cap: c_lines.len + v_lines.len}
-	for line in c_lines {
-		lines << line
-	}
-	for line in v_lines {
-		lines << line
-	}
-	return lines.join('\n')
-}
-
 fn normalized_error_string(trimmed string, lower string) ?string {
 	if lower.starts_with('fatal error:') || lower.starts_with('fatal error ') {
 		return 'error: ${trimmed}'

cmd/tools/modules/vbugreport/c_error_storage_test.v

@@ -12,7 +12,8 @@ fn test_new_stored_c_error_report_extracts_sql_fields() {
 	assert report.target_os == 'linux'
 	assert report.ccompiler == 'clang'
 	assert report.error_string == 'error: unknown type name "Foo"'
-	assert report.lines == 'void main__main(void) {\n\tFoo x;\nfoo := Foo{}'
+	assert report.lines == 'void main__main(void) {\n\tFoo x;'
+	assert report.v_lines == 'foo := Foo{}'
 }
 
 fn test_new_stored_c_error_report_handles_windows_c_file_path() {

cmd/tools/vbug-report.v

@@ -188,7 +188,7 @@ fn connect_db(db_path string) !sqlite.DB {
 }
 
 fn init_db(db sqlite.DB) ! {
-	db.exec('create table if not exists bug_reports (
+	db.exec("create table if not exists bug_reports (
 			id text primary key,
 			delete_token text not null,
 			created_at text not null,
@@ -198,12 +198,29 @@ fn init_db(db sqlite.DB) ! {
 				target_os text not null,
 				ccompiler text not null,
 				error_string text not null,
-				lines text not null
-			)')!
+				lines text not null,
+				v_lines text not null default ''
+			)")!
+	// Add columns that were introduced after the table already existed, so older
+	// databases pick them up without losing their stored reports.
+	ensure_column(db, 'bug_reports', 'v_lines', "text not null default ''")!
 	db.exec('create index if not exists idx_bug_reports_created_at
 			on bug_reports(created_at)')!
 }
 
+// ensure_column adds `column` to `table` when it is not present yet. SQLite has no
+// `add column if not exists`, so the existing columns are inspected first.
+fn ensure_column(db sqlite.DB, table string, column string, definition string) ! {
+	rows := db.exec('pragma table_info(${table})')!
+	for row in rows {
+		// pragma table_info columns are: cid, name, type, notnull, dflt_value, pk
+		if row.vals.len > 1 && row.vals[1] == column {
+			return
+		}
+	}
+	db.exec('alter table ${table} add column ${column} ${definition}')!
+}
+
 // create stores a compiler bug report and returns its deletion token.
 @['/bug-report'; post]
 pub fn (mut app App) create(mut ctx Context) veb.Result {
@@ -227,8 +244,8 @@ pub fn (mut app App) create(mut ctx Context) veb.Result {
 	delete_token := rand.uuid_v4()
 	app.db.exec_param_many('insert into bug_reports (
 				id, delete_token, created_at, remote_ip, user_agent,
-				c_file_name, target_os, ccompiler, error_string, lines
-			) values (?, ?, ?, ?, ?, ?, ?, ?, ?, ?)', [
+				c_file_name, target_os, ccompiler, error_string, lines, v_lines
+			) values (?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?)', [
 		id,
 		delete_token,
 		time.utc().format_rfc3339(),
@@ -239,6 +256,7 @@ pub fn (mut app App) create(mut ctx Context) veb.Result {
 		stored_report.ccompiler,
 		stored_report.error_string,
 		stored_report.lines,
+		stored_report.v_lines,
 	]) or { return ctx.server_error('could not store report') }
 	return ctx.json(CreateBugReportResponse{
 		id:           id