diff options
Diffstat (limited to 'src/cmd/compile/internal/ssa/debug.go')
| -rw-r--r-- | src/cmd/compile/internal/ssa/debug.go | 61 |
1 files changed, 60 insertions, 1 deletions
diff --git a/src/cmd/compile/internal/ssa/debug.go b/src/cmd/compile/internal/ssa/debug.go index 381777c17d..59d0294264 100644 --- a/src/cmd/compile/internal/ssa/debug.go +++ b/src/cmd/compile/internal/ssa/debug.go @@ -1486,8 +1486,67 @@ func (state *debugState) writePendingEntry(varID VarID, endBlock, endValue ID) { state.lists[varID] = list } -// PutLocationList adds list (a location list in its intermediate representation) to listSym. +// PutLocationList adds list (a location list in its intermediate +// representation) to listSym. func (debugInfo *FuncDebug) PutLocationList(list []byte, ctxt *obj.Link, listSym, startPC *obj.LSym) { + if buildcfg.Experiment.Dwarf5 { + debugInfo.PutLocationListDwarf5(list, ctxt, listSym, startPC) + } else { + debugInfo.PutLocationListDwarf4(list, ctxt, listSym, startPC) + } +} + +// PutLocationListDwarf5 adds list (a location list in its intermediate +// representation) to listSym in DWARF 5 format. NB: this is a somewhat +// hacky implementation in that it actually reads a DWARF4 encoded +// info from list (with all its DWARF4-specific quirks) then re-encodes +// it in DWARF5. It would probably be better at some point to have +// ssa/debug encode the list in a version-independent form and then +// have this func (and PutLocationListDwarf4) intoduce the quirks. +func (debugInfo *FuncDebug) PutLocationListDwarf5(list []byte, ctxt *obj.Link, listSym, startPC *obj.LSym) { + getPC := debugInfo.GetPC + + // base address entry + listSym.WriteInt(ctxt, listSym.Size, 1, dwarf.DW_LLE_base_addressx) + listSym.WriteDwTxtAddrx(ctxt, listSym.Size, startPC, ctxt.DwTextCount*2) + + var stbuf, enbuf [10]byte + stb, enb := stbuf[:], enbuf[:] + // Re-read list, translating its address from block/value ID to PC. + for i := 0; i < len(list); { + begin := getPC(decodeValue(ctxt, readPtr(ctxt, list[i:]))) + end := getPC(decodeValue(ctxt, readPtr(ctxt, list[i+ctxt.Arch.PtrSize:]))) + + // Write LLE_offset_pair tag followed by payload (ULEB for start + // and then end). + listSym.WriteInt(ctxt, listSym.Size, 1, dwarf.DW_LLE_offset_pair) + stb, enb = stb[:0], enb[:0] + stb = dwarf.AppendUleb128(stb, uint64(begin)) + enb = dwarf.AppendUleb128(enb, uint64(end)) + listSym.WriteBytes(ctxt, listSym.Size, stb) + listSym.WriteBytes(ctxt, listSym.Size, enb) + + // The encoded data in "list" is in DWARF4 format, which uses + // a 2-byte length; DWARF5 uses an LEB-encoded value for this + // length. Read the length and then re-encode it. + i += 2 * ctxt.Arch.PtrSize + datalen := int(ctxt.Arch.ByteOrder.Uint16(list[i:])) + i += 2 + stb = stb[:0] + stb = dwarf.AppendUleb128(stb, uint64(datalen)) + listSym.WriteBytes(ctxt, listSym.Size, stb) // copy length + listSym.WriteBytes(ctxt, listSym.Size, list[i:i+datalen]) // loc desc + + i += datalen + } + + // Terminator + listSym.WriteInt(ctxt, listSym.Size, 1, dwarf.DW_LLE_end_of_list) +} + +// PutLocationListDwarf4 adds list (a location list in its intermediate +// representation) to listSym in DWARF 4 format. +func (debugInfo *FuncDebug) PutLocationListDwarf4(list []byte, ctxt *obj.Link, listSym, startPC *obj.LSym) { getPC := debugInfo.GetPC if ctxt.UseBASEntries { |