i#1734 Dr. Fuzz: enable replace buffer by default for fuzzing with input files

Commit log for first patchset:
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i#1734 Dr. Fuzz: enable replace buffer by default for fuzzing with input files

- set options.fuzz_replace_buffer to be true if fuzzing with input files
- set shadow value of fuzz buffer as initialized if replacing buffer
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[bruening, 2016-01-15 15:25:33]

> i#1734 Dr. Fuzz: enable replace buffer by default for fuzzing with input files

Either s/replace buffer/-fuzz_replace_buffer/ or make it grammatically correct
s/replace/replacing the/

Otherwise LGTM

https://codereview.appspot.com/285860043/diff/1/drmemory/fuzzer.c
File drmemory/fuzzer.c (right):

https://codereview.appspot.com/285860043/diff/1/drmemory/fuzzer.c#newcode1498
drmemory/fuzzer.c:1498: options.fuzz_replace_buffer ? false : true);
I had to go look this up -- can you add "/*save input*/" or sthg

https://codereview.appspot.com/285860043/diff/1/tests/fuzz/CMakeLists.txt
File tests/fuzz/CMakeLists.txt (right):

https://codereview.appspot.com/285860043/diff/1/tests/fuzz/CMakeLists.txt#new...
tests/fuzz/CMakeLists.txt:80:
"-fuzz_function;repeatme;-fuzz_input_file;${INPUT_DATA};-fuzz_num_iters;0;-no_fuzz_replace_buffer")
If replace_buffer is auto-turned-on, do we not support this combo here that
you're testing?

[zhaoqin, 2016-01-15 16:04:45]

https://codereview.appspot.com/285860043/diff/1/drmemory/fuzzer.c
File drmemory/fuzzer.c (right):

https://codereview.appspot.com/285860043/diff/1/drmemory/fuzzer.c#newcode1498
drmemory/fuzzer.c:1498: options.fuzz_replace_buffer ? false : true);
On 2016/01/15 15:25:32, bruening wrote:
> I had to go look this up -- can you add "/*save input*/" or sthg

Done.

https://codereview.appspot.com/285860043/diff/1/tests/fuzz/CMakeLists.txt
File tests/fuzz/CMakeLists.txt (right):

https://codereview.appspot.com/285860043/diff/1/tests/fuzz/CMakeLists.txt#new...
tests/fuzz/CMakeLists.txt:80:
"-fuzz_function;repeatme;-fuzz_input_file;${INPUT_DATA};-fuzz_num_iters;0;-no_fuzz_replace_buffer")
On 2016/01/15 15:25:33, bruening wrote:
> If replace_buffer is auto-turned-on, do we not support this combo here that
> you're testing?

We may want to support turning it off by user due to the potential problem of
replacing buffer, i.e., the pointer is stored somewhere else.
That's why I check !option_specified.fuzz_replace_buffer before turning it on.

[zhaoqin, 2016-01-15 16:06:17]

Commit log for latest patchset:
---------------
i#1734 Dr. Fuzz: enable -fuzz_replace_buffer for fuzzing with input files

- set options.fuzz_replace_buffer to be true if fuzzing with input files
- set shadow value of fuzz buffer as initialized if replacing buffer

Review-URL: https://codereview.appspot.com/285860043
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