Avoid copies on calls to parser.Sources() (#1811)

Signed-off-by: Jon Johnson <jon.johnson@chainguard.dev>

internal/command/format/diagnostic.go

@@ -12,6 +12,7 @@ import (
 	"sort"
 	"strings"
 
+	"github.com/hashicorp/hcl/v2"
 	viewsjson "github.com/opentofu/opentofu/internal/command/views/json"
 	"github.com/opentofu/opentofu/internal/tfdiags"
 
@@ -31,7 +32,7 @@ var disabledColorize = &colorstring.Colorize{
 // at all. Although the long-form text parts of the message are wrapped,
 // not all aspects of the message are guaranteed to fit within the specified
 // terminal width.
-func Diagnostic(diag tfdiags.Diagnostic, sources map[string][]byte, color *colorstring.Colorize, width int) string {
+func Diagnostic(diag tfdiags.Diagnostic, sources map[string]*hcl.File, color *colorstring.Colorize, width int) string {
 	return DiagnosticFromJSON(viewsjson.NewDiagnostic(diag, sources), color, width)
 }
 
@@ -127,7 +128,7 @@ func DiagnosticFromJSON(diag *viewsjson.Diagnostic, color *colorstring.Colorize,
 //
 // It is intended for use in automation and other contexts in which diagnostic
 // messages are parsed from the OpenTofu output.
-func DiagnosticPlain(diag tfdiags.Diagnostic, sources map[string][]byte, width int) string {
+func DiagnosticPlain(diag tfdiags.Diagnostic, sources map[string]*hcl.File, width int) string {
 	return DiagnosticPlainFromJSON(viewsjson.NewDiagnostic(diag, sources), width)
 }
 

internal/command/format/diagnostic_test.go

@@ -269,8 +269,8 @@ func TestDiagnostic(t *testing.T) {
 		},
 	}
 
-	sources := map[string][]byte{
-		"test.tf": []byte(`test source code`),
+	sources := map[string]*hcl.File{
+		"test.tf": {Bytes: []byte(`test source code`)},
 	}
 
 	// This empty Colorize just passes through all of the formatting codes
@@ -577,8 +577,8 @@ Whatever shall we do?
 		},
 	}
 
-	sources := map[string][]byte{
-		"test.tf": []byte(`test source code`),
+	sources := map[string]*hcl.File{
+		"test.tf": {Bytes: []byte(`test source code`)},
 	}
 
 	for name, test := range tests {
@@ -676,12 +676,12 @@ func TestDiagnostic_nonOverlappingHighlightContext(t *testing.T) {
 			End:      hcl.Pos{Line: 4, Column: 2, Byte: 60},
 		},
 	})
-	sources := map[string][]byte{
-		"source.tf": []byte(`x = somefunc("testing", {
+	sources := map[string]*hcl.File{
+		"source.tf": {Bytes: []byte(`x = somefunc("testing", {
   alpha = "foo"
   beta  = "bar"
 })
-`),
+`)},
 	}
 	color := &colorstring.Colorize{
 		Colors:  colorstring.DefaultColors,
@@ -725,12 +725,12 @@ func TestDiagnostic_emptyOverlapHighlightContext(t *testing.T) {
 			End:      hcl.Pos{Line: 4, Column: 1, Byte: 39},
 		},
 	})
-	sources := map[string][]byte{
-		"source.tf": []byte(`variable "x" {
+	sources := map[string]*hcl.File{
+		"source.tf": {Bytes: []byte(`variable "x" {
   default = {
     "foo"
   }
-`),
+`)},
 	}
 	color := &colorstring.Colorize{
 		Colors:  colorstring.DefaultColors,
@@ -773,12 +773,12 @@ func TestDiagnosticPlain_emptyOverlapHighlightContext(t *testing.T) {
 			End:      hcl.Pos{Line: 4, Column: 1, Byte: 39},
 		},
 	})
-	sources := map[string][]byte{
-		"source.tf": []byte(`variable "x" {
+	sources := map[string]*hcl.File{
+		"source.tf": {Bytes: []byte(`variable "x" {
   default = {
     "foo"
   }
-`),
+`)},
 	}
 
 	expected := `

internal/command/meta_config.go

@@ -380,7 +380,7 @@ func (m *Meta) inputForSchema(given cty.Value, schema *configschema.Block) (cty.
 //
 // If a config loader has not yet been instantiated then no files could have
 // been loaded already, so this method returns a nil map in that case.
-func (m *Meta) configSources() map[string][]byte {
+func (m *Meta) configSources() map[string]*hcl.File {
 	if m.configLoader == nil {
 		return nil
 	}

internal/command/views/json/diagnostic.go

@@ -133,7 +133,7 @@ type DiagnosticFunctionCall struct {
 
 // NewDiagnostic takes a tfdiags.Diagnostic and a map of configuration sources,
 // and returns a Diagnostic struct.
-func NewDiagnostic(diag tfdiags.Diagnostic, sources map[string][]byte) *Diagnostic {
+func NewDiagnostic(diag tfdiags.Diagnostic, sources map[string]*hcl.File) *Diagnostic { //nolint:funlen,gocognit,gocyclo,cyclop // TODO(1818): Refactor this function.
 	var sev string
 	switch diag.Severity() {
 	case tfdiags.Error:
@@ -200,7 +200,9 @@ func NewDiagnostic(diag tfdiags.Diagnostic, sources map[string][]byte) *Diagnost
 
 		var src []byte
 		if sources != nil {
-			src = sources[highlightRange.Filename]
+			if f, ok := sources[highlightRange.Filename]; ok {
+				src = f.Bytes
+			}
 		}
 
 		// If we have a source file for the diagnostic, we can emit a code

internal/command/views/json/diagnostic_test.go

@@ -26,17 +26,17 @@ func TestNewDiagnostic(t *testing.T) {
 	// Common HCL for diags with source ranges. This does not have any real
 	// semantic errors, but we can synthesize fake HCL errors which will
 	// exercise the diagnostic rendering code using this
-	sources := map[string][]byte{
-		"test.tf": []byte(`resource "test_resource" "test" {
+	sources := map[string]*hcl.File{
+		"test.tf": {Bytes: []byte(`resource "test_resource" "test" {
   foo = var.boop["hello!"]
   bar = {
     baz = maybe
   }
 }
-`),
-		"short.tf":       []byte("bad source code"),
-		"odd-comment.tf": []byte("foo\n\n#\n"),
-		"values.tf": []byte(`[
+`)},
+		"short.tf":       {Bytes: []byte("bad source code")},
+		"odd-comment.tf": {Bytes: []byte("foo\n\n#\n")},
+		"values.tf": {Bytes: []byte(`[
   var.a,
   var.b,
   var.c,
@@ -49,7 +49,7 @@ func TestNewDiagnostic(t *testing.T) {
   var.j,
   var.k,
 ]
-`),
+`)},
 	}
 	testCases := map[string]struct {
 		diag interface{} // allow various kinds of diags

internal/command/views/view.go

@@ -6,6 +6,7 @@
 package views
 
 import (
+	"github.com/hashicorp/hcl/v2"
 	"github.com/mitchellh/colorstring"
 	"github.com/opentofu/opentofu/internal/command/arguments"
 	"github.com/opentofu/opentofu/internal/command/format"
@@ -40,7 +41,7 @@ type View struct {
 	// have associated source code in the configuration. This function pointer
 	// will be dereferenced as late as possible when rendering diagnostics in
 	// order to access the config loader cache.
-	configSources func() map[string][]byte
+	configSources func() map[string]*hcl.File
 }
 
 // Initialize a View with the given streams, a disabled colorize object, and a
@@ -53,7 +54,7 @@ func NewView(streams *terminal.Streams) *View {
 			Disable: true,
 			Reset:   true,
 		},
-		configSources: func() map[string][]byte { return nil },
+		configSources: func() map[string]*hcl.File { return nil },
 	}
 }
 
@@ -82,7 +83,7 @@ func (v *View) Configure(view *arguments.View) {
 
 // SetConfigSources overrides the default no-op callback with a new function
 // pointer, and should be called when the config loader is initialized.
-func (v *View) SetConfigSources(cb func() map[string][]byte) {
+func (v *View) SetConfigSources(cb func() map[string]*hcl.File) {
 	v.configSources = cb
 }
 

internal/configs/configload/loader.go

@@ -9,6 +9,7 @@ import (
 	"fmt"
 	"path/filepath"
 
+	"github.com/hashicorp/hcl/v2"
 	"github.com/hashicorp/terraform-svchost/disco"
 	"github.com/opentofu/opentofu/internal/configs"
 	"github.com/opentofu/opentofu/internal/registry"
@@ -111,7 +112,7 @@ func (l *Loader) Parser() *configs.Parser {
 
 // Sources returns the source code cache for the underlying parser of this
 // loader. This is a shorthand for l.Parser().Sources().
-func (l *Loader) Sources() map[string][]byte {
+func (l *Loader) Sources() map[string]*hcl.File {
 	return l.parser.Sources()
 }
 

internal/configs/configload/loader_snapshot.go

@@ -196,7 +196,7 @@ func (l *Loader) addModuleToSnapshot(snap *Snapshot, key string, dir string, sou
 			})
 			continue
 		}
-		snapMod.Files[filepath.Clean(filename)] = src
+		snapMod.Files[filepath.Clean(filename)] = src.Bytes
 	}
 
 	snap.Modules[key] = snapMod

internal/configs/parser.go

@@ -92,8 +92,8 @@ func (p *Parser) LoadHCLFile(path string) (hcl.Body, hcl.Diagnostics) {
 // Sources returns a map of the cached source buffers for all files that
 // have been loaded through this parser, with source filenames (as requested
 // when each file was opened) as the keys.
-func (p *Parser) Sources() map[string][]byte {
-	return p.p.Sources()
+func (p *Parser) Sources() map[string]*hcl.File {
+	return p.p.Files()
 }
 
 // ForceFileSource artificially adds source code to the cache of file sources,