[all-commits] [llvm/llvm-project] a16fff: [Support] Make DataExtractor string functions erro...

[Pavel Labath via All-commits]

  Branch: refs/heads/master
  Home:   https://github.com/llvm/llvm-project
  Commit: a16fffa3f6add51fe1c6ee975ace56aa06a3bea7
      https://github.com/llvm/llvm-project/commit/a16fffa3f6add51fe1c6ee975ace56aa06a3bea7
  Author: Pavel Labath <pavel at labath.sk>
  Date:   2020-04-06 (Mon, 06 Apr 2020)

  Changed paths:
    M llvm/include/llvm/Support/DataExtractor.h
    M llvm/lib/Support/DataExtractor.cpp
    M llvm/unittests/Support/DataExtractorTest.cpp

  Log Message:
  -----------
  [Support] Make DataExtractor string functions error-aware

Summary:
This patch adds an optional Error argument to DataExtractor functions
for string extraction, and makes them behave like other DataExtractor
functions (set the error if extraction fails, don't do anything if the
error is already set).

I have merged the StringRef and C string versions of the functions to
reduce code duplication.

Reviewers: dblaikie, MaskRay

Subscribers: hiraditya, llvm-commits

Tags: #llvm

Differential Revision: https://reviews.llvm.org/D77307


  Commit: 9154a6398eda31bfbfac3291250a2968629ebc78
      https://github.com/llvm/llvm-project/commit/9154a6398eda31bfbfac3291250a2968629ebc78
  Author: Pavel Labath <pavel at labath.sk>
  Date:   2020-04-06 (Mon, 06 Apr 2020)

  Changed paths:
    M llvm/include/llvm/Support/DataExtractor.h
    M llvm/lib/Support/DataExtractor.cpp
    M llvm/unittests/Support/DataExtractorTest.cpp

  Log Message:
  -----------
  [llvm/Support] Make more DataExtractor methods error-aware

Summary:
This patch adds the optional Error argument, and the Cursor variants to
more DataExtractor methods. The functions now behave the same way as
other error-aware functions (they set the error when they fail, and
don't do anything if the error is already set).

I have merged the LEB128 implementations via a template (similarly to
how fixed-size functions are handled) to reduce code duplication.

Depends on D77304.

Reviewers: dblaikie, aprantl

Subscribers: hiraditya, llvm-commits

Tags: #llvm

Differential Revision: https://reviews.llvm.org/D77306


  Commit: 8f1233699bf64fca1a94dcffe955396f05fdb957
      https://github.com/llvm/llvm-project/commit/8f1233699bf64fca1a94dcffe955396f05fdb957
  Author: Pavel Labath <pavel at labath.sk>
  Date:   2020-04-06 (Mon, 06 Apr 2020)

  Changed paths:
    M llvm/include/llvm/Support/LEB128.h
    M llvm/unittests/Support/LEB128Test.cpp

  Log Message:
  -----------
  [llvm/Support] Don't crash on empty nullptr ranges when decoding LEBs

Summary:
If the decoding functions are called with both start and end pointers
being nullptr, the function will crash due to a nullptr dereference.
This happens because the function does not recognise nullptr as a valid
end pointer.

Obviously, nobody is going to pass null pointers here deliberately, but
it can happen indirectly (as it did for me), when calling these
functions on an ArrayRef, as a default-initialized empty ArrayRef will
have both begin() and end() pointers equal to nullptr.

The fix is to simply remove the nullptr check. Passing nullptr for "end"
with a valid "begin" pointer will still work, as one cannot reach
nullptr by incrementing a valid pointer without triggerring UB.

Reviewers: dblaikie

Subscribers: llvm-commits

Tags: #llvm

Differential Revision: https://reviews.llvm.org/D77304


Compare: https://github.com/llvm/llvm-project/compare/ff858d77810a...8f1233699bf6