bee/vendor/github.com/derekparker/delve/pkg/dwarf/frame/entries.go

78 lines
1.9 KiB
Go

package frame
import (
"encoding/binary"
"fmt"
"sort"
)
// Represents a Common Information Entry in
// the Dwarf .debug_frame section.
type CommonInformationEntry struct {
Length uint32
CIE_id uint32
Version uint8
Augmentation string
CodeAlignmentFactor uint64
DataAlignmentFactor int64
ReturnAddressRegister uint64
InitialInstructions []byte
staticBase uint64
}
// Represents a Frame Descriptor Entry in the
// Dwarf .debug_frame section.
type FrameDescriptionEntry struct {
Length uint32
CIE *CommonInformationEntry
Instructions []byte
begin, size uint64
order binary.ByteOrder
}
// Returns whether or not the given address is within the
// bounds of this frame.
func (fde *FrameDescriptionEntry) Cover(addr uint64) bool {
return (addr - fde.begin) < fde.size
}
// Address of first location for this frame.
func (fde *FrameDescriptionEntry) Begin() uint64 {
return fde.begin
}
// Address of last location for this frame.
func (fde *FrameDescriptionEntry) End() uint64 {
return fde.begin + fde.size
}
// Set up frame for the given PC.
func (fde *FrameDescriptionEntry) EstablishFrame(pc uint64) *FrameContext {
return executeDwarfProgramUntilPC(fde, pc)
}
type FrameDescriptionEntries []*FrameDescriptionEntry
func NewFrameIndex() FrameDescriptionEntries {
return make(FrameDescriptionEntries, 0, 1000)
}
type ErrNoFDEForPC struct {
PC uint64
}
func (err *ErrNoFDEForPC) Error() string {
return fmt.Sprintf("could not find FDE for PC %#v", err.PC)
}
// Returns the Frame Description Entry for the given PC.
func (fdes FrameDescriptionEntries) FDEForPC(pc uint64) (*FrameDescriptionEntry, error) {
idx := sort.Search(len(fdes), func(i int) bool {
return fdes[i].Cover(pc) || fdes[i].Begin() >= pc
})
if idx == len(fdes) || !fdes[idx].Cover(pc) {
return nil, &ErrNoFDEForPC{pc}
}
return fdes[idx], nil
}