pkg, prog: add per-field direction attribute

12 files changed, 199 insertions, 24 deletions

diff --git a/pkg/ast/ast.go b/pkg/ast/ast.go
index c0707aca9..66dfc11bd 100644
--- a/pkg/ast/ast.go
+++ b/pkg/ast/ast.go
@@ -223,6 +223,7 @@ type Field struct {
 	Pos      Pos
 	Name     *Ident
 	Type     *Type
+	Attrs    []*Type
 	NewBlock bool // separated from previous fields by a new line
 	Comments []*Comment
 }
diff --git a/pkg/ast/clone.go b/pkg/ast/clone.go
index ece4ba594..23e4f421c 100644
--- a/pkg/ast/clone.go
+++ b/pkg/ast/clone.go
@@ -168,6 +168,7 @@ func (n *Field) Clone() Node {
 		Pos:      n.Pos,
 		Name:     n.Name.Clone().(*Ident),
 		Type:     n.Type.Clone().(*Type),
+		Attrs:    cloneTypes(n.Attrs),
 		NewBlock: n.NewBlock,
 		Comments: cloneComments(n.Comments),
 	}
diff --git a/pkg/ast/format.go b/pkg/ast/format.go
index 3803d1e66..6b16f4015 100644
--- a/pkg/ast/format.go
+++ b/pkg/ast/format.go
@@ -113,11 +113,7 @@ func (n *Call) serialize(w io.Writer) {
 		fmt.Fprintf(w, " %v", fmtType(n.Ret))
 	}
 	if len(n.Attrs) != 0 {
-		fmt.Fprintf(w, " (")
-		for i, t := range n.Attrs {
-			fmt.Fprintf(w, "%v%v", comma(i, ""), fmtType(t))
-		}
-		fmt.Fprintf(w, ")")
+		fmt.Fprintf(w, " %v", fmtTypeList(n.Attrs, "(", ")"))
 	}
 	fmt.Fprintf(w, "\n")
 }
@@ -148,13 +144,17 @@ func (n *Struct) serialize(w io.Writer) {
 		for tabs := len(f.Name.Name)/tabWidth + 1; tabs < maxTabs; tabs++ {
 			fmt.Fprintf(w, "\t")
 		}
-		fmt.Fprintf(w, "%v\n", fmtType(f.Type))
+		fmt.Fprintf(w, "%v", fmtType(f.Type))
+		if len(f.Attrs) != 0 {
+			fmt.Fprintf(w, "\t%v", fmtTypeList(f.Attrs, "(", ")"))
+		}
+		fmt.Fprintf(w, "\n")
 	}
 	for _, com := range n.Comments {
 		fmt.Fprintf(w, "#%v\n", com.Text)
 	}
 	fmt.Fprintf(w, "%c", closing)
-	if attrs := fmtTypeList(n.Attrs); attrs != "" {
+	if attrs := fmtTypeList(n.Attrs, "[", "]"); attrs != "" {
 		fmt.Fprintf(w, " %v", attrs)
 	}
 	fmt.Fprintf(w, "\n")
@@ -197,20 +197,20 @@ func fmtType(t *Type) string {
 	for _, c := range t.Colon {
 		v += ":" + fmtType(c)
 	}
-	v += fmtTypeList(t.Args)
+	v += fmtTypeList(t.Args, "[", "]")
 	return v
 }
 
-func fmtTypeList(args []*Type) string {
+func fmtTypeList(args []*Type, opening, closing string) string {
 	if len(args) == 0 {
 		return ""
 	}
 	w := new(bytes.Buffer)
-	fmt.Fprintf(w, "[")
+	fmt.Fprint(w, opening)
 	for i, t := range args {
 		fmt.Fprintf(w, "%v%v", comma(i, ""), fmtType(t))
 	}
-	fmt.Fprintf(w, "]")
+	fmt.Fprint(w, closing)
 	return w.String()
 }
 
diff --git a/pkg/ast/parser.go b/pkg/ast/parser.go
index 025c5dcc2..20898169e 100644
--- a/pkg/ast/parser.go
+++ b/pkg/ast/parser.go
@@ -290,7 +290,7 @@ func (p *parser) parseCall(name *Ident) *Call {
 	}
 	p.consume(tokLParen)
 	for p.tok != tokRParen {
-		c.Args = append(c.Args, p.parseField())
+		c.Args = append(c.Args, p.parseField(false))
 		p.expect(tokComma, tokRParen)
 		p.tryConsume(tokComma)
 	}
@@ -376,7 +376,7 @@ func (p *parser) parseStruct(name *Ident) *Struct {
 			str.Comments = comments
 			break
 		}
-		fld := p.parseField()
+		fld := p.parseField(true)
 		fld.NewBlock = newBlock
 		fld.Comments = comments
 		str.Fields = append(str.Fields, fld)
@@ -403,13 +403,24 @@ func (p *parser) parseCommentBlock() []*Comment {
 	return comments
 }
 
-func (p *parser) parseField() *Field {
+func (p *parser) parseField(parseAttrs bool) *Field {
 	name := p.parseIdent()
-	return &Field{
+
+	field := &Field{
 		Pos:  name.Pos,
 		Name: name,
 		Type: p.parseType(),
 	}
+
+	if parseAttrs && p.tryConsume(tokLParen) {
+		field.Attrs = append(field.Attrs, p.parseType())
+		for p.tryConsume(tokComma) {
+			field.Attrs = append(field.Attrs, p.parseType())
+		}
+		p.consume(tokRParen)
+	}
+
+	return field
 }
 
 func (p *parser) parseType() *Type {
diff --git a/pkg/ast/testdata/errors.txt b/pkg/ast/testdata/errors.txt
index 30af16d9a..463158756 100644
--- a/pkg/ast/testdata/errors.txt
+++ b/pkg/ast/testdata/errors.txt
@@ -30,6 +30,7 @@ call() ("attr1")
 call() (42)
 call() (				### unexpected '\n', expecting int, identifier, string
 call() ()				### unexpected ')', expecting int, identifier, string
+call(foo int32 (attr))	### unexpected '(', expecting ',', ')'
 
 define FOO bar
 
@@ -81,3 +82,15 @@ type templ_struct0[A, B] {
 	typ	const[A, int16]
 	data	B
 } [align_4]
+
+s4 {
+	f0 int8 (attr)
+	f1 int8 (attr1, attr2[arg1, "arg2"])
+	f2 int8 ("attr1")
+}
+
+s5 {
+	f0 int8 (	### unexpected '\n', expecting int, identifier, string
+
+s6 {
+	f0 int8 ()	### unexpected ')', expecting int, identifier, string
\ No newline at end of file
diff --git a/pkg/ast/walk.go b/pkg/ast/walk.go
index fe64b0676..84a3c67c3 100644
--- a/pkg/ast/walk.go
+++ b/pkg/ast/walk.go
@@ -118,6 +118,9 @@ func (n *Type) walk(cb func(Node)) {
 func (n *Field) walk(cb func(Node)) {
 	cb(n.Name)
 	cb(n.Type)
+	for _, a := range n.Attrs {
+		cb(a)
+	}
 	for _, c := range n.Comments {
 		cb(c)
 	}
diff --git a/pkg/compiler/attrs.go b/pkg/compiler/attrs.go
index c0fa04211..5de19f884 100644
--- a/pkg/compiler/attrs.go
+++ b/pkg/compiler/attrs.go
@@ -23,9 +23,13 @@ var (
 	attrVarlen = &attrDesc{Name: "varlen"}
 	attrSize   = &attrDesc{Name: "size", HasArg: true}
 	attrAlign  = &attrDesc{Name: "align", HasArg: true}
+	attrIn     = &attrDesc{Name: "in"}
+	attrOut    = &attrDesc{Name: "out"}
+	attrInOut  = &attrDesc{Name: "inout"}
 
 	structAttrs = makeAttrs(attrPacked, attrSize, attrAlign)
 	unionAttrs  = makeAttrs(attrVarlen, attrSize)
+	fieldAttrs  = makeAttrs(attrIn, attrOut, attrInOut)
 	callAttrs   = make(map[string]*attrDesc)
 )
 
diff --git a/pkg/compiler/check.go b/pkg/compiler/check.go
index 9bb8c1c0c..468b6e35e 100644
--- a/pkg/compiler/check.go
+++ b/pkg/compiler/check.go
@@ -168,6 +168,14 @@ func (comp *compiler) checkStructFields(n *ast.Struct, typ, name string) {
 	if len(n.Fields) < 1 {
 		comp.error(n.Pos, "%v %v has no fields, need at least 1 field", typ, name)
 	}
+	for _, f := range n.Fields {
+		attrs := comp.parseAttrs(fieldAttrs, f, f.Attrs)
+
+		if attrs[attrIn]+attrs[attrOut]+attrs[attrInOut] > 1 {
+			_, typ, _ := f.Info()
+			comp.error(f.Pos, "%v has multiple direction attributes", typ)
+		}
+	}
 }
 
 func (comp *compiler) checkFieldGroup(fields []*ast.Field, what, ctx string) {
@@ -267,6 +275,16 @@ func (comp *compiler) checkAttributeValues() {
 					desc.CheckConsts(comp, n, attr)
 				}
 			}
+			// Check each field's attributes.
+			st := decl.(*ast.Struct)
+			for _, f := range st.Fields {
+				for _, attr := range f.Attrs {
+					desc := fieldAttrs[attr.Ident]
+					if desc.CheckConsts != nil {
+						desc.CheckConsts(comp, f, attr)
+					}
+				}
+			}
 		}
 	}
 }
@@ -614,7 +632,11 @@ func (comp *compiler) checkTypeCtors(t *ast.Type, dir prog.Dir, isArg bool,
 		}
 		checked[key] = true
 		for _, fld := range s.Fields {
-			comp.checkTypeCtors(fld.Type, dir, false, ctors, inputs, checked)
+			fldDir, fldHasDir := comp.genFieldDir(fld)
+			if !fldHasDir {
+				fldDir = dir
+			}
+			comp.checkTypeCtors(fld.Type, fldDir, false, ctors, inputs, checked)
 		}
 		return
 	}
diff --git a/pkg/compiler/gen.go b/pkg/compiler/gen.go
index d4834e40e..bd487432a 100644
--- a/pkg/compiler/gen.go
+++ b/pkg/compiler/gen.go
@@ -441,10 +441,28 @@ func (comp *compiler) genFieldArray(fields []*ast.Field, argSizes []uint64) []pr
 	return res
 }
 
+func (comp *compiler) genFieldDir(f *ast.Field) (prog.Dir, bool) {
+	attrs := comp.parseAttrs(fieldAttrs, f, f.Attrs)
+	switch {
+	case attrs[attrIn] != 0:
+		return prog.DirIn, true
+	case attrs[attrOut] != 0:
+		return prog.DirOut, true
+	case attrs[attrInOut] != 0:
+		return prog.DirInOut, true
+	default:
+		return prog.DirIn, false
+	}
+}
+
 func (comp *compiler) genField(f *ast.Field, argSize uint64) prog.Field {
+	dir, hasDir := comp.genFieldDir(f)
+
 	return prog.Field{
-		Name: f.Name.Name,
-		Type: comp.genType(f.Type, argSize),
+		Name:         f.Name.Name,
+		Type:         comp.genType(f.Type, argSize),
+		HasDirection: hasDir,
+		Direction:    dir,
 	}
 }
 
diff --git a/pkg/compiler/testdata/all.txt b/pkg/compiler/testdata/all.txt
index b9e144d73..17b7c838d 100644
--- a/pkg/compiler/testdata/all.txt
+++ b/pkg/compiler/testdata/all.txt
@@ -276,7 +276,15 @@ s4 {
 	f2	int8
 } [size[19]]
 
-foo_s0(a ptr[in, s0], b ptr[in, s1], c ptr[in, s2], d ptr[in, s4])
+s5 {
+	f_in0		int32	(in)
+	f_in1		int32[0:1]	(in)
+	f_out		int32	(out)
+	f_inout0	int32	(inout)
+	f_inout1	int32[0:1]	(inout)
+}
+
+foo_s0(a ptr[in, s0], b ptr[in, s1], c ptr[in, s2], d ptr[in, s4], e ptr[in, s5])
 
 # Unions.
 
diff --git a/pkg/compiler/testdata/errors.txt b/pkg/compiler/testdata/errors.txt
index cc0f47508..d3658d239 100644
--- a/pkg/compiler/testdata/errors.txt
+++ b/pkg/compiler/testdata/errors.txt
@@ -346,3 +346,13 @@ struct$fmt0 {
 	f0	fmt[dec, int8:3]		### unexpected ':', only struct fields can be bitfields
 	f1	int32:-1			### bitfield of size 18446744073709551615 is too large for base type of size 32
 }
+
+struct$perfielddir {
+	f0	int32	(in, in)	### duplicate arg/field f0 attribute in
+	f1	int32	(out, out)	### duplicate arg/field f1 attribute out
+	f2	int32	(inout, inout)	### duplicate arg/field f2 attribute inout
+	f3	int32	(in, out)	### arg/field has multiple direction attributes
+	f4	int32	(in, inout)	### arg/field has multiple direction attributes
+	f5	int32	(out, inout)	### arg/field has multiple direction attributes
+	f6	int32	(in, out, inout)	### arg/field has multiple direction attributes
+}
\ No newline at end of file
diff --git a/pkg/compiler/testdata/errors2.txt b/pkg/compiler/testdata/errors2.txt
index 68b8a66df..c862358cf 100644
--- a/pkg/compiler/testdata/errors2.txt
+++ b/pkg/compiler/testdata/errors2.txt
@@ -176,11 +176,26 @@ resource r104[int8]
 resource r105[int8]
 resource r106[int8]		### resource r106 can't be created (never mentioned as a syscall return value or output argument/field)
 resource r107[int8]		### resource r107 can't be created (never mentioned as a syscall return value or output argument/field)
-resource r108[int8]		### resource r108 is never used as an input(such resources are not useful)
-
-foo$300(a0 r100, a1 r101, a2 r102, a3 r103, a4 r104)
-foo$301(a ptr[out, array[r103]], b ptr[in, s300], c r107) r104
-foo$302() r108
+resource r108[int8]		### resource r108 can't be created (never mentioned as a syscall return value or output argument/field)
+resource r109[int8]		### resource r109 can't be created (never mentioned as a syscall return value or output argument/field)
+resource r110[int8]
+resource r111[int8]
+resource r112[int8]		### resource r112 can't be created (never mentioned as a syscall return value or output argument/field)
+resource r113[int8]
+resource r114[int8]
+resource r115[int8]		### resource r115 can't be created (never mentioned as a syscall return value or output argument/field)
+resource r116[int8]		### resource r116 is never used as an input(such resources are not useful)
+resource r117[int8]		### resource r117 is never used as an input(such resources are not useful)
+resource r118[int8]		### resource r118 is never used as an input(such resources are not useful)
+resource r119[int8]		### resource r119 is never used as an input(such resources are not useful)
+resource r120[int8]		### resource r120 can't be created (never mentioned as a syscall return value or output argument/field)
+resource r121[int8]
+
+foo$300(a0 r100, a1 r101, a2 r102, a3 r103, a4 r104, a5 r105, a6 r106, a7 r107, a8 r108)
+foo$301(a0 r109, a1 r110, a2 r111, a3 r112, a4 r113, a5 r114, a6 r115, a7 r120, a8 r121)
+foo$302(a ptr[out, array[r103]], b ptr[in, s300], c r107) r104
+foo$303(a ptr[in, s302], b ptr[in, s303], c ptr[in, s304], d ptr[out, s305], e ptr[inout, s306], f ptr[inout, s307], g ptr[in, s308], h ptr[out, s310])
+foo$304(a ptr[out, r117], b ptr[in, s312], c ptr[in, s313], d ptr[inout, u100]) r116
 
 s300 {
 	f1	ptr[inout, s301]
@@ -191,6 +206,75 @@ s301 {
 	f2	r105
 }
 
+s302 {
+	f1	r108
+}
+
+s303 {
+	f1	r109	(in)
+}
+
+# ptr to struct is in, field is out (valid, resource can be created)
+s304 {
+	f1	r110	(out)
+}
+
+# ptr to struct is out, field is in (error, resource can't be created)
+s305 {
+	f1	r111	(in)
+}
+
+# ptr to struct is inout, field is inout (valid, resource can be created)
+s306 {
+	f1	r111	(inout)
+}
+
+# ptr to struct is inout, fields are in (error) and out (valid)
+s307 {
+	f1	r112	(in)
+	f2	r113	(out)
+}
+
+# recurse the out field inside two levels of in ptrs (valid, resource can be created)
+s308 {
+	f1	ptr[in, s309]
+}
+
+s309 {
+	f1	ptr[out, r114]
+}
+
+# recurse the in field inside two levels of out ptrs (error, resource can't be created)
+s310 {
+	f1	ptr[out, s311]
+}
+
+s311 {
+	f1	ptr[in, r115]
+}
+
+# ptr to struct is in, field is out (error, never used as an input)
+s312 {
+	f1	r118	(out)
+}
+
+# recurse the out field inside two levels of in ptrs (error, never used as an input)
+s313 {
+	f1	ptr[in, s314]
+}
+
+s314 {
+	f1	r119	(out)
+}
+
+u100 [
+	f1	r120	(in)
+	f2	r121	(out)
+]
+
+# TODO: Two instances of the same resource might exist in the same structure as
+# both in and out. How common is this and how to handle this?
+
 # Varlen field tests.
 
 s400 {