If the user requested a zero-base-shadow sanitizer, infer -pie and -fPIC when appropriate.
Differential Revision: http://llvm-reviews.chandlerc.com/D502
git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@179082 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/docs/MemorySanitizer.rst b/docs/MemorySanitizer.rst
index fdb8a81..439acc4 100644
--- a/docs/MemorySanitizer.rst
+++ b/docs/MemorySanitizer.rst
@@ -46,7 +46,7 @@
return 0;
}
- % clang -fsanitize=memory -fPIE -pie -fno-omit-frame-pointer -g -O2 umr.cc
+ % clang -fsanitize=memory -fno-omit-frame-pointer -g -O2 umr.cc
If a bug is detected, the program will print an error message to
stderr and exit with a non-zero exit code. Currently, MemorySanitizer
@@ -103,7 +103,7 @@
.. code-block:: console
- % clang -fsanitize=memory -fsanitize-memory-track-origins -fPIE -pie -fno-omit-frame-pointer -g -O2 umr.cc
+ % clang -fsanitize=memory -fsanitize-memory-track-origins -fno-omit-frame-pointer -g -O2 umr.cc
% ./a.out 2>log
% projects/compiler-rt/lib/asan/scripts/asan_symbolize.py / < log | c++filt
==14425== WARNING: MemorySanitizer: UMR (uninitialized-memory-read)
@@ -160,7 +160,10 @@
address space. This means that tools like ``ulimit`` may not work as
usually expected.
* Static linking is not supported.
-* Non-position-independent executables are not supported.
+* Non-position-independent executables are not supported. Therefore, the
+ ``fsanitize=memory`` flag will cause Clang to act as though the ``-fPIE``
+ flag had been supplied if compiling without ``-fPIC``, and as though the
+ ``-pie`` flag had been supplied if linking an executable.
* Depending on the version of Linux kernel, running without ASLR may
be not supported. Note that GDB disables ASLR by default. To debug
instrumented programs, use "set disable-randomization off".