buildx/bake/hclparser/hclparser.go
Justin Chadwell 03885ec9f1 hclparser: strip out blocks for json files
Body.JustAttributes cannot distinguish between blocks and attributes for
JSON files, so the variable block could be included in the list of
attributes returned.

This patch ensures that JSON and HCL files behave the same way by
removing all known block types first, from the provided config schema
and then from a generated definitions schema.

Fixes #1051

Signed-off-by: Justin Chadwell <me@jedevc.com>
2022-04-28 10:22:20 +01:00

551 lines
12 KiB
Go

package hclparser
import (
"fmt"
"math"
"math/big"
"reflect"
"strconv"
"strings"
"github.com/docker/buildx/util/userfunc"
"github.com/hashicorp/hcl/v2"
"github.com/hashicorp/hcl/v2/gohcl"
"github.com/pkg/errors"
"github.com/zclconf/go-cty/cty"
)
type Opt struct {
LookupVar func(string) (string, bool)
Vars map[string]string
ValidateLabel func(string) error
}
type variable struct {
Name string `json:"-" hcl:"name,label"`
Default *hcl.Attribute `json:"default,omitempty" hcl:"default,optional"`
Body hcl.Body `json:"-" hcl:",body"`
}
type functionDef struct {
Name string `json:"-" hcl:"name,label"`
Params *hcl.Attribute `json:"params,omitempty" hcl:"params"`
Variadic *hcl.Attribute `json:"variadic_param,omitempty" hcl:"variadic_params"`
Result *hcl.Attribute `json:"result,omitempty" hcl:"result"`
}
type inputs struct {
Variables []*variable `hcl:"variable,block"`
Functions []*functionDef `hcl:"function,block"`
Remain hcl.Body `json:"-" hcl:",remain"`
}
type parser struct {
opt Opt
vars map[string]*variable
attrs map[string]*hcl.Attribute
funcs map[string]*functionDef
ectx *hcl.EvalContext
progress map[string]struct{}
progressF map[string]struct{}
doneF map[string]struct{}
}
func (p *parser) loadDeps(exp hcl.Expression, exclude map[string]struct{}) hcl.Diagnostics {
fns, hcldiags := funcCalls(exp)
if hcldiags.HasErrors() {
return hcldiags
}
for _, fn := range fns {
if err := p.resolveFunction(fn); err != nil {
return hcl.Diagnostics{
&hcl.Diagnostic{
Severity: hcl.DiagError,
Summary: "Invalid expression",
Detail: err.Error(),
Subject: exp.Range().Ptr(),
Context: exp.Range().Ptr(),
},
}
}
}
for _, v := range exp.Variables() {
if _, ok := exclude[v.RootName()]; ok {
continue
}
if err := p.resolveValue(v.RootName()); err != nil {
return hcl.Diagnostics{
&hcl.Diagnostic{
Severity: hcl.DiagError,
Summary: "Invalid expression",
Detail: err.Error(),
Subject: v.SourceRange().Ptr(),
Context: v.SourceRange().Ptr(),
},
}
}
}
return nil
}
func (p *parser) resolveFunction(name string) error {
if _, ok := p.doneF[name]; ok {
return nil
}
f, ok := p.funcs[name]
if !ok {
if _, ok := p.ectx.Functions[name]; ok {
return nil
}
return errors.Errorf("undefined function %s", name)
}
if _, ok := p.progressF[name]; ok {
return errors.Errorf("function cycle not allowed for %s", name)
}
p.progressF[name] = struct{}{}
paramExprs, paramsDiags := hcl.ExprList(f.Params.Expr)
if paramsDiags.HasErrors() {
return paramsDiags
}
var diags hcl.Diagnostics
params := map[string]struct{}{}
for _, paramExpr := range paramExprs {
param := hcl.ExprAsKeyword(paramExpr)
if param == "" {
diags = append(diags, &hcl.Diagnostic{
Severity: hcl.DiagError,
Summary: "Invalid param element",
Detail: "Each parameter name must be an identifier.",
Subject: paramExpr.Range().Ptr(),
})
}
params[param] = struct{}{}
}
var variadic hcl.Expression
if f.Variadic != nil {
variadic = f.Variadic.Expr
param := hcl.ExprAsKeyword(variadic)
if param == "" {
diags = append(diags, &hcl.Diagnostic{
Severity: hcl.DiagError,
Summary: "Invalid param element",
Detail: "Each parameter name must be an identifier.",
Subject: f.Variadic.Range.Ptr(),
})
}
params[param] = struct{}{}
}
if diags.HasErrors() {
return diags
}
if diags := p.loadDeps(f.Result.Expr, params); diags.HasErrors() {
return diags
}
v, diags := userfunc.NewFunction(f.Params.Expr, variadic, f.Result.Expr, func() *hcl.EvalContext {
return p.ectx
})
if diags.HasErrors() {
return diags
}
p.doneF[name] = struct{}{}
p.ectx.Functions[name] = v
return nil
}
func (p *parser) resolveValue(name string) (err error) {
if _, ok := p.ectx.Variables[name]; ok {
return nil
}
if _, ok := p.progress[name]; ok {
return errors.Errorf("variable cycle not allowed for %s", name)
}
p.progress[name] = struct{}{}
var v *cty.Value
defer func() {
if v != nil {
p.ectx.Variables[name] = *v
}
}()
def, ok := p.attrs[name]
if _, builtin := p.opt.Vars[name]; !ok && !builtin {
vr, ok := p.vars[name]
if !ok {
return errors.Errorf("undefined variable %q", name)
}
def = vr.Default
}
if def == nil {
val, ok := p.opt.Vars[name]
if !ok {
val, _ = p.opt.LookupVar(name)
}
vv := cty.StringVal(val)
v = &vv
return
}
if diags := p.loadDeps(def.Expr, nil); diags.HasErrors() {
return diags
}
vv, diags := def.Expr.Value(p.ectx)
if diags.HasErrors() {
return diags
}
_, isVar := p.vars[name]
if envv, ok := p.opt.LookupVar(name); ok && isVar {
if vv.Type().Equals(cty.Bool) {
b, err := strconv.ParseBool(envv)
if err != nil {
return errors.Wrapf(err, "failed to parse %s as bool", name)
}
vv := cty.BoolVal(b)
v = &vv
return nil
} else if vv.Type().Equals(cty.String) {
vv := cty.StringVal(envv)
v = &vv
return nil
} else if vv.Type().Equals(cty.Number) {
n, err := strconv.ParseFloat(envv, 64)
if err == nil && (math.IsNaN(n) || math.IsInf(n, 0)) {
err = errors.Errorf("invalid number value")
}
if err != nil {
return errors.Wrapf(err, "failed to parse %s as number", name)
}
vv := cty.NumberVal(big.NewFloat(n))
v = &vv
return nil
} else {
// TODO: support lists with csv values
return errors.Errorf("unsupported type %s for variable %s", v.Type(), name)
}
}
v = &vv
return nil
}
func Parse(b hcl.Body, opt Opt, val interface{}) hcl.Diagnostics {
reserved := map[string]struct{}{}
schema, _ := gohcl.ImpliedBodySchema(val)
for _, bs := range schema.Blocks {
reserved[bs.Type] = struct{}{}
}
for k := range opt.Vars {
reserved[k] = struct{}{}
}
var defs inputs
if err := gohcl.DecodeBody(b, nil, &defs); err != nil {
return err
}
defsSchema, _ := gohcl.ImpliedBodySchema(defs)
if opt.LookupVar == nil {
opt.LookupVar = func(string) (string, bool) {
return "", false
}
}
if opt.ValidateLabel == nil {
opt.ValidateLabel = func(string) error {
return nil
}
}
p := &parser{
opt: opt,
vars: map[string]*variable{},
attrs: map[string]*hcl.Attribute{},
funcs: map[string]*functionDef{},
progress: map[string]struct{}{},
progressF: map[string]struct{}{},
doneF: map[string]struct{}{},
ectx: &hcl.EvalContext{
Variables: map[string]cty.Value{},
Functions: stdlibFunctions,
},
}
for _, v := range defs.Variables {
// TODO: validate name
if _, ok := reserved[v.Name]; ok {
continue
}
p.vars[v.Name] = v
}
for _, v := range defs.Functions {
// TODO: validate name
if _, ok := reserved[v.Name]; ok {
continue
}
p.funcs[v.Name] = v
}
content, b, diags := b.PartialContent(schema)
if diags.HasErrors() {
return diags
}
_, b, diags = b.PartialContent(defsSchema)
if diags.HasErrors() {
return diags
}
attrs, diags := b.JustAttributes()
if diags.HasErrors() {
if d := removeAttributesDiags(diags, reserved, p.vars); len(d) > 0 {
return d
}
}
for _, v := range attrs {
if _, ok := reserved[v.Name]; ok {
continue
}
p.attrs[v.Name] = v
}
delete(p.attrs, "function")
for k := range p.opt.Vars {
_ = p.resolveValue(k)
}
for k := range p.attrs {
if err := p.resolveValue(k); err != nil {
if diags, ok := err.(hcl.Diagnostics); ok {
return diags
}
return hcl.Diagnostics{
&hcl.Diagnostic{
Severity: hcl.DiagError,
Summary: "Invalid attribute",
Detail: err.Error(),
Subject: &p.attrs[k].Range,
Context: &p.attrs[k].Range,
},
}
}
}
for k := range p.vars {
if err := p.resolveValue(k); err != nil {
if diags, ok := err.(hcl.Diagnostics); ok {
return diags
}
r := p.vars[k].Body.MissingItemRange()
return hcl.Diagnostics{
&hcl.Diagnostic{
Severity: hcl.DiagError,
Summary: "Invalid value",
Detail: err.Error(),
Subject: &r,
Context: &r,
},
}
}
}
for k := range p.funcs {
if err := p.resolveFunction(k); err != nil {
if diags, ok := err.(hcl.Diagnostics); ok {
return diags
}
return hcl.Diagnostics{
&hcl.Diagnostic{
Severity: hcl.DiagError,
Summary: "Invalid function",
Detail: err.Error(),
Subject: &p.funcs[k].Params.Range,
Context: &p.funcs[k].Params.Range,
},
}
}
}
for _, a := range content.Attributes {
return hcl.Diagnostics{
&hcl.Diagnostic{
Severity: hcl.DiagError,
Summary: "Invalid attribute",
Detail: "global attributes currently not supported",
Subject: &a.Range,
Context: &a.Range,
},
}
}
m := map[string]map[string][]*hcl.Block{}
for _, b := range content.Blocks {
if len(b.Labels) == 0 || len(b.Labels) > 1 {
return hcl.Diagnostics{
&hcl.Diagnostic{
Severity: hcl.DiagError,
Summary: "Invalid block",
Detail: fmt.Sprintf("invalid block label: %v", b.Labels),
Subject: &b.LabelRanges[0],
Context: &b.LabelRanges[0],
},
}
}
bm, ok := m[b.Type]
if !ok {
bm = map[string][]*hcl.Block{}
m[b.Type] = bm
}
lbl := b.Labels[0]
bm[lbl] = append(bm[lbl], b)
}
vt := reflect.ValueOf(val).Elem().Type()
numFields := vt.NumField()
type value struct {
reflect.Value
idx int
}
type field struct {
idx int
typ reflect.Type
values map[string]value
}
types := map[string]field{}
for i := 0; i < numFields; i++ {
tags := strings.Split(vt.Field(i).Tag.Get("hcl"), ",")
types[tags[0]] = field{
idx: i,
typ: vt.Field(i).Type,
values: make(map[string]value),
}
}
diags = hcl.Diagnostics{}
for _, b := range content.Blocks {
v := reflect.ValueOf(val)
t, ok := types[b.Type]
if !ok {
continue
}
vv := reflect.New(t.typ.Elem().Elem())
diag := gohcl.DecodeBody(b.Body, p.ectx, vv.Interface())
if diag.HasErrors() {
diags = append(diags, diag...)
continue
}
if err := opt.ValidateLabel(b.Labels[0]); err != nil {
return hcl.Diagnostics{
&hcl.Diagnostic{
Severity: hcl.DiagError,
Summary: "Invalid name",
Detail: err.Error(),
Subject: &b.LabelRanges[0],
},
}
}
lblIndex := setLabel(vv, b.Labels[0])
oldValue, exists := t.values[b.Labels[0]]
if !exists && lblIndex != -1 {
if v.Elem().Field(t.idx).Type().Kind() == reflect.Slice {
for i := 0; i < v.Elem().Field(t.idx).Len(); i++ {
if b.Labels[0] == v.Elem().Field(t.idx).Index(i).Elem().Field(lblIndex).String() {
exists = true
oldValue = value{Value: v.Elem().Field(t.idx).Index(i), idx: i}
break
}
}
}
}
if exists {
if m := oldValue.Value.MethodByName("Merge"); m.IsValid() {
m.Call([]reflect.Value{vv})
} else {
v.Elem().Field(t.idx).Index(oldValue.idx).Set(vv)
}
} else {
slice := v.Elem().Field(t.idx)
if slice.IsNil() {
slice = reflect.New(t.typ).Elem()
}
t.values[b.Labels[0]] = value{Value: vv, idx: slice.Len()}
v.Elem().Field(t.idx).Set(reflect.Append(slice, vv))
}
}
if diags.HasErrors() {
return diags
}
return nil
}
func setLabel(v reflect.Value, lbl string) int {
// cache field index?
numFields := v.Elem().Type().NumField()
for i := 0; i < numFields; i++ {
for _, t := range strings.Split(v.Elem().Type().Field(i).Tag.Get("hcl"), ",") {
if t == "label" {
v.Elem().Field(i).Set(reflect.ValueOf(lbl))
return i
}
}
}
return -1
}
func removeAttributesDiags(diags hcl.Diagnostics, reserved map[string]struct{}, vars map[string]*variable) hcl.Diagnostics {
var fdiags hcl.Diagnostics
for _, d := range diags {
if fout := func(d *hcl.Diagnostic) bool {
// https://github.com/docker/buildx/pull/541
if d.Detail == "Blocks are not allowed here." {
return true
}
for r := range reserved {
// JSON body objects don't handle repeated blocks like HCL but
// reserved name attributes should be allowed when multi bodies are merged.
// https://github.com/hashicorp/hcl/blob/main/json/spec.md#blocks
if strings.HasPrefix(d.Detail, fmt.Sprintf(`Argument "%s" was already set at `, r)) {
return true
}
}
for v := range vars {
// Do the same for global variables
if strings.HasPrefix(d.Detail, fmt.Sprintf(`Argument "%s" was already set at `, v)) {
return true
}
}
return false
}(d); !fout {
fdiags = append(fdiags, d)
}
}
return fdiags
}