proc: Implements expression interpreter

Supported operators:

- All (binary and unary) operators between basic types except <-,
++ and -- (includes & to take the address of an expression)
- Comparison operators between supported compound types
- Typecast of integer constants into pointer types
- struct members
- indexing of arrays, slices and strings
- slicing of arrays, slices and strings
- pointer dereferencing
- true, false and nil constants

Implements #116, #117 and #251

_fixtures/testvariables3.go

@@ -5,10 +5,49 @@ import (
  "runtime"
 )
 
+type astruct struct {
+ A int
+ B int
+}
+
+type bstruct struct {
+ a astruct
+}
+
+type cstruct struct {
+ pb *bstruct
+ sa []*astruct
+}
+
+func afunc(x int) int {
+ return x + 2
+}
+
+type functype func(int) int
+
 func main() {
  i1 := 1
  i2 := 2
+ f1 := 3.0
+ i3 := 3
  p1 := &i1
+ s1 := []string{"one", "two", "three", "four", "five"}
+ a1 := [5]string{"one", "two", "three", "four", "five"}
+ c1 := cstruct{&bstruct{astruct{1, 2}}, []*astruct{&astruct{1, 2}, &astruct{2, 3}, &astruct{4, 5}}}
+ s2 := []astruct{{1, 2}, {3, 4}, {5, 6}, {7, 8}, {9, 10}, {11, 12}, {13, 14}, {15, 16}}
+ p2 := &(c1.sa[2].B)
+ as1 := astruct{1, 1}
+ var p3 *int
+ str1 := "01234567890"
+ var fn1 functype = afunc
+ var fn2 functype = nil
+ var nilslice []int = nil
+ var nilptr *int = nil
+
+ var amb1 = 1
  runtime.Breakpoint()
- fmt.Println(i1, i2, p1)
+ for amb1 := 0; amb1 < 10; amb1++ {
+ fmt.Println(amb1)
+ }
+ fmt.Println(i1, i2, i3, p1, amb1, s1, a1, p2, p3, s2, as1, str1, f1, fn1, fn2, nilslice, nilptr)
 }

_fixtures/testvariables4.go

@@ -22,8 +22,9 @@ type B struct {
 
 func main() {
  b := B{A: A{-314}, C: &C{"hello"}, a: A{42}, ptr: &A{1337}}
+ b2 := B{A: A{42}, a: A{47}}
  runtime.Breakpoint()
- fmt.Println(b)
+ fmt.Println(b, b2)
  fmt.Println(b.val)
  fmt.Println(b.A.val)
  fmt.Println(b.a.val)

dwarf/reader/reader.go

@@ -151,6 +151,13 @@ func (reader *Reader) SeekToTypeNamed(name string) (*dwarf.Entry, error) {
  return nil, err
  }
 
+ switch entry.Tag {
+ case dwarf.TagArrayType, dwarf.TagBaseType, dwarf.TagClassType, dwarf.TagStructType, dwarf.TagUnionType, dwarf.TagConstType, dwarf.TagVolatileType, dwarf.TagRestrictType, dwarf.TagEnumerationType, dwarf.TagPointerType, dwarf.TagSubroutineType, dwarf.TagTypedef, dwarf.TagUnspecifiedType:
+ //ok
+ default:
+ continue
+ }
+
  n, ok := entry.Val(dwarf.AttrName).(string)
  if !ok {
  continue