xref: /freebsd/contrib/llvm-project/llvm/lib/DebugInfo/DWARF/DWARFDebugRangeList.cpp (revision fe6060f10f634930ff71b7c50291ddc610da2475)
1 //===- DWARFDebugRangesList.cpp -------------------------------------------===//
2 //
3 // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
4 // See https://llvm.org/LICENSE.txt for license information.
5 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
6 //
7 //===----------------------------------------------------------------------===//
8 
9 #include "llvm/DebugInfo/DWARF/DWARFDebugRangeList.h"
10 #include "llvm/DebugInfo/DWARF/DWARFContext.h"
11 #include "llvm/Support/Errc.h"
12 #include "llvm/Support/Format.h"
13 #include "llvm/Support/raw_ostream.h"
14 #include <cinttypes>
15 #include <cstdint>
16 
17 using namespace llvm;
18 
19 void DWARFDebugRangeList::clear() {
20   Offset = -1ULL;
21   AddressSize = 0;
22   Entries.clear();
23 }
24 
25 Error DWARFDebugRangeList::extract(const DWARFDataExtractor &data,
26                                    uint64_t *offset_ptr) {
27   clear();
28   if (!data.isValidOffset(*offset_ptr))
29     return createStringError(errc::invalid_argument,
30                        "invalid range list offset 0x%" PRIx64, *offset_ptr);
31 
32   AddressSize = data.getAddressSize();
33   if (AddressSize != 4 && AddressSize != 8)
34     return createStringError(errc::invalid_argument,
35                        "invalid address size: %" PRIu8, AddressSize);
36   Offset = *offset_ptr;
37   while (true) {
38     RangeListEntry Entry;
39     Entry.SectionIndex = -1ULL;
40 
41     uint64_t prev_offset = *offset_ptr;
42     Entry.StartAddress = data.getRelocatedAddress(offset_ptr);
43     Entry.EndAddress =
44         data.getRelocatedAddress(offset_ptr, &Entry.SectionIndex);
45 
46     // Check that both values were extracted correctly.
47     if (*offset_ptr != prev_offset + 2 * AddressSize) {
48       clear();
49       return createStringError(errc::invalid_argument,
50                          "invalid range list entry at offset 0x%" PRIx64,
51                          prev_offset);
52     }
53     if (Entry.isEndOfListEntry())
54       break;
55     Entries.push_back(Entry);
56   }
57   return Error::success();
58 }
59 
60 void DWARFDebugRangeList::dump(raw_ostream &OS) const {
61   for (const RangeListEntry &RLE : Entries) {
62     const char *format_str =
63         (AddressSize == 4 ? "%08" PRIx64 " %08" PRIx64 " %08" PRIx64 "\n"
64                           : "%08" PRIx64 " %016" PRIx64 " %016" PRIx64 "\n");
65     OS << format(format_str, Offset, RLE.StartAddress, RLE.EndAddress);
66   }
67   OS << format("%08" PRIx64 " <End of list>\n", Offset);
68 }
69 
70 DWARFAddressRangesVector DWARFDebugRangeList::getAbsoluteRanges(
71     llvm::Optional<object::SectionedAddress> BaseAddr) const {
72   DWARFAddressRangesVector Res;
73   // debug_addr can't use the max integer tombstone because that's used for the
74   // base address specifier entry - so use max-1.
75   uint64_t Tombstone = dwarf::computeTombstoneAddress(AddressSize) - 1;
76   for (const RangeListEntry &RLE : Entries) {
77     if (RLE.isBaseAddressSelectionEntry(AddressSize)) {
78       BaseAddr = {RLE.EndAddress, RLE.SectionIndex};
79       continue;
80     }
81 
82     DWARFAddressRange E;
83     E.LowPC = RLE.StartAddress;
84     if (E.LowPC == Tombstone)
85       continue;
86     E.HighPC = RLE.EndAddress;
87     E.SectionIndex = RLE.SectionIndex;
88     // Base address of a range list entry is determined by the closest preceding
89     // base address selection entry in the same range list. It defaults to the
90     // base address of the compilation unit if there is no such entry.
91     if (BaseAddr) {
92       if (BaseAddr->Address == Tombstone)
93         continue;
94       E.LowPC += BaseAddr->Address;
95       E.HighPC += BaseAddr->Address;
96       if (E.SectionIndex == -1ULL)
97         E.SectionIndex = BaseAddr->SectionIndex;
98     }
99     Res.push_back(E);
100   }
101   return Res;
102 }
103