compiler-rt/lib/ubsan/ubsan_monitor.cpp

   1 //===-- ubsan_monitor.cpp ---------------------------------------*- C++ -*-===//
   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 // Hooks which allow a monitor process to inspect UBSan's diagnostics.
  10 //
  11 //===----------------------------------------------------------------------===//
  12
  13 #include "ubsan_monitor.h"
  14
  15 using namespace __ubsan;
  16
  17 UndefinedBehaviorReport::UndefinedBehaviorReport(const char *IssueKind,
  18                                                  Location &Loc,
  19                                                  InternalScopedString &Msg)
  20     : IssueKind(IssueKind), Loc(Loc) {
  21   // We have the common sanitizer reporting lock, so it's safe to register a
  22   // new UB report.
  23   RegisterUndefinedBehaviorReport(this);
  24
  25   // Make a copy of the diagnostic.
  26   if (Msg.length())
  27     Buffer.Append(Msg.data());
  28
  29   // Let the monitor know that a report is available.
  30   __ubsan_on_report();
  31 }
  32
  33 static UndefinedBehaviorReport *CurrentUBR;
  34
  35 void __ubsan::RegisterUndefinedBehaviorReport(UndefinedBehaviorReport *UBR) {
  36   CurrentUBR = UBR;
  37 }
  38
  39 SANITIZER_WEAK_DEFAULT_IMPL
  40 void __ubsan::__ubsan_on_report(void) {}
  41
  42 void __ubsan::__ubsan_get_current_report_data(const char **OutIssueKind,
  43                                               const char **OutMessage,
  44                                               const char **OutFilename,
  45                                               unsigned *OutLine,
  46                                               unsigned *OutCol,
  47                                               char **OutMemoryAddr) {
  48   if (!OutIssueKind || !OutMessage || !OutFilename || !OutLine || !OutCol ||
  49       !OutMemoryAddr)
  50     UNREACHABLE("Invalid arguments passed to __ubsan_get_current_report_data");
  51
  52   InternalScopedString &Buf = CurrentUBR->Buffer;
  53
  54   // Ensure that the first character of the diagnostic text can't start with a
  55   // lowercase letter.
  56   char FirstChar = *Buf.data();
  57   if (FirstChar >= 'a' && FirstChar <= 'z')
  58     *Buf.data() += 'A' - 'a';
  59
  60   *OutIssueKind = CurrentUBR->IssueKind;
  61   *OutMessage = Buf.data();
  62   if (!CurrentUBR->Loc.isSourceLocation()) {
  63     *OutFilename = "<unknown>";
  64     *OutLine = *OutCol = 0;
  65   } else {
  66     SourceLocation SL = CurrentUBR->Loc.getSourceLocation();
  67     *OutFilename = SL.getFilename();
  68     *OutLine = SL.getLine();
  69     *OutCol = SL.getColumn();
  70   }
  71
  72   if (CurrentUBR->Loc.isMemoryLocation())
  73     *OutMemoryAddr = (char *)CurrentUBR->Loc.getMemoryLocation();
  74   else
  75     *OutMemoryAddr = nullptr;
  76 }