userland: add archive tools and pinned GoAWK, esbuild, and QuickJS

userland/goawk/source/internal/parseutil/filereader.go

@@ -0,0 +1,55 @@
+// Package parseutil contains various utilities for parsing GoAWK source code.
+package parseutil
+
+import (
+	"bytes"
+	"io"
+)
+
+// FileReader serves two purposes:
+// 1. read input sources and join them into a single source (slice of bytes)
+// 2. track the lines counts of each input source
+type FileReader struct {
+	files  []file
+	source bytes.Buffer
+}
+
+type file struct {
+	path  string
+	lines int
+}
+
+// AddFile adds a single source file.
+func (fr *FileReader) AddFile(path string, source io.Reader) error {
+	curLen := fr.source.Len()
+	_, err := fr.source.ReadFrom(source)
+	if err != nil {
+		return err
+	}
+	if !bytes.HasSuffix(fr.source.Bytes(), []byte("\n")) {
+		// Append newline to file in case it doesn't end with one
+		fr.source.WriteByte('\n')
+	}
+	content := fr.source.Bytes()[curLen:]
+	lines := bytes.Count(content, []byte("\n"))
+	fr.files = append(fr.files, file{path, lines})
+	return nil
+}
+
+// FileLine resolves an overall line number from the concatenated source code
+// to the local line number in that source file (identified by path).
+func (fr *FileReader) FileLine(line int) (path string, fileLine int) {
+	startLine := 1
+	for _, f := range fr.files {
+		if line >= startLine && line < startLine+f.lines {
+			return f.path, line - startLine + 1
+		}
+		startLine += f.lines
+	}
+	return "", 0
+}
+
+// Source returns the concatenated source code from all files added.
+func (fr *FileReader) Source() []byte {
+	return fr.source.Bytes()
+}