libsanitizer/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), Buffer(Msg.length() + 1) {
  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   Buffer.append("%s", Msg.data());
  27
  28   // Let the monitor know that a report is available.
  29   __ubsan_on_report();
  30 }
  31
  32 static UndefinedBehaviorReport *CurrentUBR;
  33
  34 void __ubsan::RegisterUndefinedBehaviorReport(UndefinedBehaviorReport *UBR) {
  35   CurrentUBR = UBR;
  36 }
  37
  38 SANITIZER_WEAK_DEFAULT_IMPL
  39 void __ubsan::__ubsan_on_report(void) {}
  40
  41 void __ubsan::__ubsan_get_current_report_data(const char **OutIssueKind,
  42                                               const char **OutMessage,
  43                                               const char **OutFilename,
  44                                               unsigned *OutLine,
  45                                               unsigned *OutCol,
  46                                               char **OutMemoryAddr) {
  47   if (!OutIssueKind || !OutMessage || !OutFilename || !OutLine || !OutCol ||
  48       !OutMemoryAddr)
  49     UNREACHABLE("Invalid arguments passed to __ubsan_get_current_report_data");
  50
  51   InternalScopedString &Buf = CurrentUBR->Buffer;
  52
  53   // Ensure that the first character of the diagnostic text can't start with a
  54   // lowercase letter.
  55   char FirstChar = Buf.data()[0];
  56   if (FirstChar >= 'a' && FirstChar <= 'z')
  57     Buf.data()[0] = FirstChar - 'a' + 'A';
  58
  59   *OutIssueKind = CurrentUBR->IssueKind;
  60   *OutMessage = Buf.data();
  61   if (!CurrentUBR->Loc.isSourceLocation()) {
  62     *OutFilename = "<unknown>";
  63     *OutLine = *OutCol = 0;
  64   } else {
  65     SourceLocation SL = CurrentUBR->Loc.getSourceLocation();
  66     *OutFilename = SL.getFilename();
  67     *OutLine = SL.getLine();
  68     *OutCol = SL.getColumn();
  69   }
  70
  71   if (CurrentUBR->Loc.isMemoryLocation())
  72     *OutMemoryAddr = (char *)CurrentUBR->Loc.getMemoryLocation();
  73   else
  74     *OutMemoryAddr = nullptr;
  75 }