debug: Prints more specific error messages.
Change-Id: Ib59508eff6c84e1653cfe365429b7c3851c680b6
Reviewed-on: https://go-review.googlesource.com/1997
Reviewed-by: Rob Pike <r@golang.org>
Reviewed-by: Nigel Tao <nigeltao@golang.org>
diff --git a/ogle/program/server/print.go b/ogle/program/server/print.go
index ccf8df3..7e2d8b5 100644
--- a/ogle/program/server/print.go
+++ b/ogle/program/server/print.go
@@ -43,32 +43,21 @@
cacheAddr address // Starting address of cache.
}
-// printf prints to printBuf, unless there has been an error.
+// printf prints to printBuf.
func (p *Printer) printf(format string, args ...interface{}) {
- if p.err != nil {
- return
- }
fmt.Fprintf(&p.printBuf, format, args...)
}
-// errorf sets the sticky error for the printer, if not already set.
+// errorf prints the error to printBuf, then sets the sticky error for the
+// printer, if not already set.
func (p *Printer) errorf(format string, args ...interface{}) {
+ fmt.Fprintf(&p.printBuf, "<"+format+">", args...)
if p.err != nil {
return
}
p.err = fmt.Errorf(format, args...)
}
-// ok checks the error. If it is the first non-nil error encountered,
-// it is printed to printBuf, parenthesized for discrimination, and remembered.
-func (p *Printer) ok(err error) bool {
- if p.err == nil && err != nil {
- p.printf("(%s)", err)
- p.err = err
- }
- return p.err == nil
-}
-
// peek reads len bytes at offset, leaving p.tmp with the data and sized appropriately.
// It uses the cache if the request is within it.
func (p *Printer) peek(a address, length int64) bool {
@@ -77,7 +66,8 @@
copy(p.tmp, p.cache[a-p.cacheAddr:])
return true
}
- return p.ok(p.peeker.peek(uintptr(a), p.tmp))
+ err := p.peeker.peek(uintptr(a), p.tmp)
+ return err == nil
}
// setCache initializes the cache to contain the contents of the
@@ -89,11 +79,13 @@
p.cache = make([]byte, length)
}
p.cacheAddr = a
- ok := p.ok(p.peeker.peek(uintptr(a), p.cache))
- if !ok {
+ err := p.peeker.peek(uintptr(a), p.cache)
+ if err != nil {
+ // If the peek failed, don't cache anything.
p.resetCache()
+ return false
}
- return ok
+ return true
}
func (p *Printer) resetCache() {
@@ -221,23 +213,32 @@
}
if p.peek(a, 1) {
p.printf("%t", p.tmp[0] != 0)
+ } else {
+ p.errorf("couldn't read bool")
}
case *dwarf.PtrType:
// This type doesn't define the ByteSize attribute.
if p.peek(a, int64(p.arch.PointerSize)) {
p.printf("%#x", p.arch.Uintptr(p.tmp))
+ } else {
+ p.errorf("couldn't read pointer")
}
case *dwarf.IntType:
// Sad we can't tell a rune from an int32.
if p.peek(a, typ.ByteSize) {
p.printf("%d", p.arch.IntN(p.tmp))
+ } else {
+ p.errorf("couldn't read int")
}
case *dwarf.UintType:
if p.peek(a, typ.ByteSize) {
p.printf("%d", p.arch.UintN(p.tmp))
+ } else {
+ p.errorf("couldn't read uint")
}
case *dwarf.FloatType:
if !p.peek(a, typ.ByteSize) {
+ p.errorf("couldn't read float")
return
}
switch typ.ByteSize {
@@ -250,6 +251,7 @@
}
case *dwarf.ComplexType:
if !p.peek(a, typ.ByteSize) {
+ p.errorf("couldn't read complex")
return
}
switch typ.ByteSize {
@@ -343,11 +345,13 @@
structType := typ.Type.(*dwarf.PtrType).Type.(*dwarf.StructType)
// Indirect through the pointer.
if !p.peek(a, int64(p.arch.PointerSize)) {
+ p.errorf("couldn't read map")
return
}
a = address(p.arch.Uintptr(p.tmp[:p.arch.PointerSize]))
// Now read the struct.
if !p.peek(a, structType.ByteSize) {
+ p.errorf("couldn't read map")
return
}
// From runtime/hashmap.go; We need to walk the map data structure.
@@ -398,6 +402,7 @@
// After the header, the bucket struct has an array of keys followed by an array of elements.
// Load this bucket struct into p's cache and initialize "pointers" to the key and value slices.
if !p.setCache(a, desc.bucketSize) {
+ p.errorf("couldn't read map")
return
}
keyAddr := a + bucketCnt + address(p.arch.PointerSize)
@@ -434,7 +439,7 @@
// Slices look like a struct with fields array *elemtype, len uint32/64, cap uint32/64.
// BUG: Slice header appears to have fields with ByteSize == 0
if !p.peek(a, typ.ByteSize) {
- p.errorf("slice header has no known size")
+ p.errorf("couldn't read slice")
return
}
lo := typ.Field[0].ByteOffset
@@ -464,7 +469,7 @@
// Strings look like a struct with fields array *elemtype, len uint64.
// TODO uint64 on 386 too?
if !p.peek(a, typ.ByteSize) {
- p.errorf("string header has no known size")
+ p.errorf("couldn't read string")
return
}
// BUG: String header appears to have fields with ByteSize == 0
@@ -477,10 +482,16 @@
if length > uint64(cap(p.tmp)) {
if p.peek(address(ptr), int64(cap(p.tmp))) {
p.printf("%q...", p.tmp)
+ } else {
+ p.errorf("couldn't read string")
+ return
}
} else {
if p.peek(address(ptr), int64(length)) {
p.printf("%q", p.tmp[:length])
+ } else {
+ p.errorf("couldn't read string")
+ return
}
}
}
