Commit aaa7a7a2 authored by Tom Stellard's avatar Tom Stellard
Browse files

Merging r327863: 

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r327863 | sepavloff | 2018-03-19 09:13:43 -0700 (Mon, 19 Mar 2018) | 12 lines

[Driver] Avoid invalidated iterator in insertTargetAndModeArgs

Doing an .insert() can potentially invalidate iterators by reallocating the
vector's storage. When all the stars align just right, this causes segfaults
or glibc aborts.

Gentoo Linux bug (crashes while building Chromium): https://bugs.gentoo.org/650082.

Patch by Hector Martin!

Differential Revision: https://reviews.llvm.org/D44607

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llvm-svn: 333507
parent c4476884

clang/tools/driver/driver.cpp

+5 −4
Original line number Diff line number Diff line
@@ -212,20 +212,21 @@ static void insertTargetAndModeArgs(const ParsedClangName &NameParts, 
  // Put target and mode arguments at the start of argument list so that

  // arguments specified in command line could override them. Avoid putting

  // them at index 0, as an option like '-cc1' must remain the first.

  auto InsertionPoint = ArgVector.begin();

  if (InsertionPoint != ArgVector.end())

  int InsertionPoint = 0;

  if (ArgVector.size() > 0)

    ++InsertionPoint;



  if (NameParts.DriverMode) {

    // Add the mode flag to the arguments.

    ArgVector.insert(InsertionPoint,

    ArgVector.insert(ArgVector.begin() + InsertionPoint,

                     GetStableCStr(SavedStrings, NameParts.DriverMode));

  }



  if (NameParts.TargetIsValid) {

    const char *arr[] = {"-target", GetStableCStr(SavedStrings,

                                                  NameParts.TargetPrefix)};

    ArgVector.insert(InsertionPoint, std::begin(arr), std::end(arr));

    ArgVector.insert(ArgVector.begin() + InsertionPoint,

                     std::begin(arr), std::end(arr));

  }

}