Refactor cgen's write{Load,Save}DerivedVar
diff --git a/internal/cgen/func.go b/internal/cgen/func.go
index db48434..5b7c97e 100644
--- a/internal/cgen/func.go
+++ b/internal/cgen/func.go
@@ -384,8 +384,10 @@
if g.currFunk.derivedVars != nil {
for _, o := range g.currFunk.astFunc.In().Fields() {
o := o.AsField()
- if err := g.writeLoadDerivedVar(b, "", aPrefix, o.Name(), o.XType(), true); err != nil {
- return err
+ if _, ok := g.currFunk.derivedVars[o.Name()]; ok {
+ if err := g.writeInitialLoadDerivedVar(b, o); err != nil {
+ return err
+ }
}
}
b.writes("\n")
@@ -480,8 +482,10 @@
} else if g.currFunk.derivedVars != nil {
for _, o := range g.currFunk.astFunc.In().Fields() {
o := o.AsField()
- if err := g.writeSaveDerivedVar(b, "", aPrefix, o.Name(), o.XType()); err != nil {
- return err
+ if _, ok := g.currFunk.derivedVars[o.Name()]; ok {
+ if err := g.writeFinalSaveDerivedVar(b, o); err != nil {
+ return err
+ }
}
}
b.writes("\n")
diff --git a/internal/cgen/statement.go b/internal/cgen/statement.go
index a16e66a..7ff3efe 100644
--- a/internal/cgen/statement.go
+++ b/internal/cgen/statement.go
@@ -452,8 +452,10 @@
if g.currFunk.derivedVars != nil {
for _, o := range g.currFunk.astFunc.In().Fields() {
o := o.AsField()
- if err := g.writeSaveDerivedVar(b, "", aPrefix, o.Name(), o.XType()); err != nil {
- return err
+ if _, ok := g.currFunk.derivedVars[o.Name()]; ok {
+ if err := g.writeFinalSaveDerivedVar(b, o); err != nil {
+ return err
+ }
}
}
}
diff --git a/internal/cgen/var.go b/internal/cgen/var.go
index a06eda9..6106b29 100644
--- a/internal/cgen/var.go
+++ b/internal/cgen/var.go
@@ -69,160 +69,183 @@
}
}
-func (g *gen) writeLoadDerivedVar(b *buffer, hack string, prefix string, name t.ID, typ *a.TypeExpr, header bool) error {
- // TODO: remove this hack. We're picking up the wrong name for "src:r,
- // dummy:args.src".
- if name.Str(g.tm) == "dummy" {
- name = g.tm.ByName("src")
- }
- // TODO: also remove this hack.
- if hack == "w" {
- b.printf("%s%sw = %sw.data.ptr + %sw.meta.wi;\n", iopPrefix, vPrefix, uPrefix, uPrefix)
- return nil
- } else if hack == "r" {
- b.printf("%s%sr = %sr.data.ptr + %sr.meta.ri;\n", iopPrefix, vPrefix, uPrefix, uPrefix)
- return nil
- }
-
- elem := ""
- if typ.IsIOType() {
- if typ.QID()[1] == t.IDIOReader {
- elem = "const uint8_t"
- } else {
- elem = "uint8_t"
+func (g *gen) derivedVarCNames(typ *a.TypeExpr) (elem string, i1 string, i2 string, isWriter bool, retErr error) {
+ if typ.Decorator() == 0 {
+ if qid := typ.QID(); qid[0] == t.IDBase {
+ switch qid[1] {
+ case t.IDIOReader:
+ return "uint8_t", "meta.ri", "meta.wi", false, nil
+ case t.IDIOWriter:
+ return "uint8_t", "meta.wi", "data.len", true, nil
+ case t.IDTokenReader:
+ return "wuffs_base__token", "meta.ri", "meta.wi", false, nil
+ case t.IDTokenWriter:
+ return "wuffs_base__token", "meta.wi", "data.len", true, nil
+ }
}
- } else if typ.IsTokenType() {
- if typ.QID()[1] == t.IDTokenReader {
- elem = "const wuffs_base__token"
- } else {
- elem = "wuffs_base__token"
- }
- } else {
- return nil
+ }
+ return "", "", "", false, fmt.Errorf("unsupported derivedVarCNames type %q", typ.Str(g.tm))
+}
+
+func (g *gen) writeInitialLoadDerivedVar(b *buffer, n *a.Field) error {
+ elem, i1, i2, isWriter, err := g.derivedVarCNames(n.XType())
+ if err != nil {
+ return err
+ }
+ preName := aPrefix + n.Name().Str(g.tm)
+ c := ""
+ if !isWriter {
+ c = "const "
}
- if g.currFunk.derivedVars == nil {
- return nil
- }
- if _, ok := g.currFunk.derivedVars[name]; !ok {
- return nil
- }
-
- preName := prefix + name.Str(g.tm)
- i1, i2 := "meta.ri", "meta.wi"
- if q := typ.QID()[1]; (q == t.IDIOWriter) || (q == t.IDTokenWriter) {
- i1, i2 = "meta.wi", "data.len"
- }
-
- if header {
- b.printf("%s* %s%s = NULL;\n", elem, iopPrefix, preName)
- b.printf("%s* %s%s WUFFS_BASE__POTENTIALLY_UNUSED = NULL;\n", elem, io0Prefix, preName)
- b.printf("%s* %s%s WUFFS_BASE__POTENTIALLY_UNUSED = NULL;\n", elem, io1Prefix, preName)
- b.printf("%s* %s%s WUFFS_BASE__POTENTIALLY_UNUSED = NULL;\n", elem, io2Prefix, preName)
- }
+ b.printf("%s%s* %s%s = NULL;\n", c, elem, iopPrefix, preName)
+ b.printf("%s%s* %s%s WUFFS_BASE__POTENTIALLY_UNUSED = NULL;\n", c, elem, io0Prefix, preName)
+ b.printf("%s%s* %s%s WUFFS_BASE__POTENTIALLY_UNUSED = NULL;\n", c, elem, io1Prefix, preName)
+ b.printf("%s%s* %s%s WUFFS_BASE__POTENTIALLY_UNUSED = NULL;\n", c, elem, io2Prefix, preName)
b.printf("if (%s) {\n", preName)
- if header {
- b.printf("%s%s = %s->data.ptr;\n", io0Prefix, preName, preName)
- b.printf("%s%s = %s%s + %s->%s;\n", io1Prefix, preName, io0Prefix, preName, preName, i1)
- b.printf("%s%s = %s%s;\n", iopPrefix, preName, io1Prefix, preName)
- b.printf("%s%s = %s%s + %s->%s;\n", io2Prefix, preName, io0Prefix, preName, preName, i2)
+ b.printf("%s%s = %s->data.ptr;\n", io0Prefix, preName, preName)
+ b.printf("%s%s = %s%s + %s->%s;\n", io1Prefix, preName, io0Prefix, preName, preName, i1)
+ b.printf("%s%s = %s%s;\n", iopPrefix, preName, io1Prefix, preName)
+ b.printf("%s%s = %s%s + %s->%s;\n", io2Prefix, preName, io0Prefix, preName, preName, i2)
- if q := typ.QID()[1]; (q == t.IDIOWriter) || (q == t.IDTokenWriter) {
- b.printf("if (%s->meta.closed) {\n", preName)
- b.printf("%s%s = %s%s;\n", io2Prefix, preName, iopPrefix, preName)
- b.printf("}\n")
- }
- } else {
- b.printf("%s%s = %s->data.ptr + %s->%s;\n", iopPrefix, preName, preName, preName, i1)
+ if isWriter {
+ b.printf("if (%s->meta.closed) {\n", preName)
+ b.printf("%s%s = %s%s;\n", io2Prefix, preName, iopPrefix, preName)
+ b.printf("}\n")
}
b.printf("}\n")
return nil
}
-func (g *gen) writeSaveDerivedVar(b *buffer, hack string, prefix string, name t.ID, typ *a.TypeExpr) error {
- // TODO: remove this hack. We're picking up the wrong name for "src:r,
- // dummy:args.src".
- if name.Str(g.tm) == "dummy" {
- name = g.tm.ByName("src")
+func (g *gen) writeFinalSaveDerivedVar(b *buffer, n *a.Field) error {
+ _, i1, _, _, err := g.derivedVarCNames(n.XType())
+ if err != nil {
+ return err
}
- // TODO: also remove this hack.
- if hack == "w" {
- b.printf("%sw.meta.wi = ((size_t)(%s%sw - %sw.data.ptr));\n", uPrefix, iopPrefix, vPrefix, uPrefix)
- return nil
- } else if hack == "r" {
- b.printf("%sr.meta.ri = ((size_t)(%s%sr - %sr.data.ptr));\n", uPrefix, iopPrefix, vPrefix, uPrefix)
- return nil
- }
+ preName := aPrefix + n.Name().Str(g.tm)
- if !typ.IsIOTokenType() {
- return nil
- }
- if g.currFunk.derivedVars == nil {
- return nil
- }
- if _, ok := g.currFunk.derivedVars[name]; !ok {
- return nil
- }
-
- preName := prefix + name.Str(g.tm)
- index := "ri"
- if q := typ.QID()[1]; (q == t.IDIOWriter) || (q == t.IDTokenWriter) {
- index = "wi"
- }
-
- b.printf("if (%s) {\n%s->meta.%s = ((size_t)(%s%s - %s->data.ptr));\n}\n",
- preName, preName, index, iopPrefix, preName, preName)
+ b.printf("if (%s) {\n%s->%s = ((size_t)(%s%s - %s->data.ptr));\n}\n",
+ preName, preName, i1, iopPrefix, preName, preName)
return nil
}
-func (g *gen) writeLoadExprDerivedVars(b *buffer, n *a.Expr) error {
- if g.currFunk.derivedVars == nil {
- return nil
+func (g *gen) writeLoadDerivedVar(b *buffer, n *a.Expr) error {
+ _, i1, _, _, err := g.derivedVarCNames(n.MType())
+ if err != nil {
+ return err
}
- if n.Operator() != t.IDOpenParen {
+
+ switch n.Operator() {
+ case 0:
+ name := n.Ident().Str(g.tm)
+ b.printf("%s%s%s = %s%s.data.ptr + %s%s.%s;\n",
+ iopPrefix, vPrefix, name, uPrefix, name, uPrefix, name, i1)
return nil
- }
- for _, o := range n.Args() {
- o := o.AsArg()
- prefix := aPrefix
- // TODO: don't hard-code these.
- hack := ""
- if s := o.Value().Str(g.tm); s != "args.dst" && s != "args.src" && s != "w" && s != "r" {
- continue
- } else if s == "w" || s == "r" {
- prefix = vPrefix
- hack = s
+
+ case t.IDDot:
+ if lhs := n.LHS().AsExpr(); (lhs.Operator() == 0) && (lhs.Ident() == t.IDArgs) {
+ name := n.Ident().Str(g.tm)
+ b.printf("if (%s%s) {\n", aPrefix, name)
+ b.printf("%s%s%s = %s%s->data.ptr + %s%s->%s;\n",
+ iopPrefix, aPrefix, name, aPrefix, name, aPrefix, name, i1)
+ b.printf("}\n")
+ return nil
}
- if err := g.writeLoadDerivedVar(b, hack, prefix, o.Name(), o.Value().MType(), false); err != nil {
- return err
+ }
+
+ return fmt.Errorf("could not determine derived variables for %q", n.Str(g.tm))
+}
+
+func (g *gen) writeSaveDerivedVar(b *buffer, n *a.Expr) error {
+ _, i1, _, _, err := g.derivedVarCNames(n.MType())
+ if err != nil {
+ return err
+ }
+
+ switch n.Operator() {
+ case 0:
+ name := n.Ident().Str(g.tm)
+ b.printf("%s%s.%s = ((size_t)(%s%s%s - %s%s.data.ptr));\n",
+ uPrefix, name, i1, iopPrefix, vPrefix, name, uPrefix, name)
+ return nil
+
+ case t.IDDot:
+ if lhs := n.LHS().AsExpr(); (lhs.Operator() == 0) && (lhs.Ident() == t.IDArgs) {
+ name := n.Ident().Str(g.tm)
+ b.printf("if (%s%s) {\n", aPrefix, name)
+ b.printf("%s%s->%s = ((size_t)(%s%s%s - %s%s->data.ptr));\n",
+ aPrefix, name, i1, iopPrefix, aPrefix, name, aPrefix, name)
+ b.printf("}\n")
+ return nil
+ }
+ }
+
+ return fmt.Errorf("could not determine derived variables for %q", n.Str(g.tm))
+}
+
+func (g *gen) couldHaveDerivedVar(n *a.Expr) bool {
+ typ := n.MType()
+ if typ.Decorator() != 0 {
+ return false
+ }
+
+ qid := typ.QID()
+ if qid[0] != t.IDBase {
+ return false
+ }
+ switch qid[1] {
+ case t.IDIOReader, t.IDIOWriter, t.IDTokenReader, t.IDTokenWriter:
+ // No-op.
+ default:
+ return false
+ }
+
+ switch n.Operator() {
+ case t.IDDot:
+ if lhs := n.LHS().AsExpr(); (lhs.Operator() == 0) && (lhs.Ident() == t.IDArgs) {
+ if g.currFunk.derivedVars == nil {
+ return false
+ } else if _, ok := g.currFunk.derivedVars[n.Ident()]; !ok {
+ return false
+ }
+ }
+
+ case t.IDOpenParen:
+ switch n.LHS().AsExpr().Ident() {
+ case t.IDEmptyIOReader, t.IDEmptyIOWriter:
+ if n.LHS().AsExpr().LHS().AsExpr().MType().Eq(typeExprUtility) {
+ return false
+ }
+ }
+ }
+
+ return true
+}
+
+func (g *gen) writeLoadExprDerivedVars(b *buffer, n *a.Expr) error {
+ if (g.currFunk.derivedVars != nil) && (n.Operator() == t.IDOpenParen) {
+ for _, o := range n.Args() {
+ if v := o.AsArg().Value(); g.couldHaveDerivedVar(v) {
+ if err := g.writeLoadDerivedVar(b, v); err != nil {
+ return err
+ }
+ }
}
}
return nil
}
func (g *gen) writeSaveExprDerivedVars(b *buffer, n *a.Expr) error {
- if g.currFunk.derivedVars == nil {
- return nil
- }
- if n.Operator() != t.IDOpenParen {
- return nil
- }
- for _, o := range n.Args() {
- o := o.AsArg()
- prefix := aPrefix
- // TODO: don't hard-code these.
- hack := ""
- if s := o.Value().Str(g.tm); s != "args.dst" && s != "args.src" && s != "w" && s != "r" {
- continue
- } else if s == "w" || s == "r" {
- prefix = vPrefix
- hack = s
- }
- if err := g.writeSaveDerivedVar(b, hack, prefix, o.Name(), o.Value().MType()); err != nil {
- return err
+ if (g.currFunk.derivedVars != nil) && (n.Operator() == t.IDOpenParen) {
+ for _, o := range n.Args() {
+ if v := o.AsArg().Value(); g.couldHaveDerivedVar(v) {
+ if err := g.writeSaveDerivedVar(b, v); err != nil {
+ return err
+ }
+ }
}
}
return nil
