[cfe-dev] external libraries and dataflow sanitizer

[Christian Convey]

Hello, I was wondering with dataflow sanitizer what the preferred mechanism
is for handling un-instrumented functions in external libraries?

I'm using a fresh download / build of 3.6 from github, specifically llvm,
clang, and compiler-rt.  I built them with cmake, and the "check-all" tests
succeeded.

I'm able to run the dataflow sanitizer example code
<http://clang.llvm.org/docs/DataFlowSanitizer.html#example> without a
problem.

I then tweaked the example to also call the "readline" function.  Here's
<http://pastebin.com/eUwcNGL7> the modified code.  When I tried to build
it, I got an undefined linker error regarding "dfs$readline", shown here
<http://pastebin.com/uLM0wdnA>.

>From the dataflow design document
<http://clang.llvm.org/docs/DataFlowSanitizer.html#id3>, I thought the
solution might be to write my own special-case file.  That results in
linker errors regarding functions like "dfsan_create_label", show here
<http://pastebin.com/J6BGr5n1>.

The only solution that worked for me was to create a copy of the existing
blacklist file
"/home/cconvey/src/llvm-install/lib/clang/3.6.0/dfsan_abilist.txt", add an
entry for "readline" to the end of it, and specify that as my blacklist.
That seemed to work fine, shown here <http://pastebin.com/QDgq7q8X>.

Is that the preferred approach for the moment: cloning the
"dfsan_abilist.txt" file, and appending external library functions as
needed?
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