Change 1: we used to add static sanitizer runtimes at the
very beginning of the linker invocation, even before crtbegin.o, which
is gross and not correct in general. Fix this: now addSanitizerRuntimes()
adds all sanitizer-related link flags to the end of the linker invocation
being constructed. It means, that we should call this function in the
correct place, namely, before AddLinkerInputs() to make sure sanitizer
versions of library functions will be preferred.
Change 2: Put system libraries sanitizer libraries depend on at the
end of the linker invocation, where all the rest system libraries are
located. Respect --nodefaultlibs and --nostdlib flags. This is another way
to fix PR15823. Original fix landed in r215940 put "-lpthread" and friends
immediately after static ASan runtime, before the user linker inputs.
This caused significant slowdown in dynamic linker for large binaries
linked against thousands of shared objects. Instead, to mark system
libraries as DT_NEEDED we prepend them with "--no-as-needed" flag,
discarding the "-Wl,--as-needed" flag that could be provided by the user.
Otherwise, this change is a code cleanup. Instead of having a special method
for each sanitizer, we introduce a function collectSanitizerRuntimes() that
analyzes -fsanitize= flags and returns the set of static and shared
libraries that needs to be linked.
llvm-svn: 217817
There is no reason to have different library names for shared and static
cases on linux. It also breaks Android where we install the shared asan-rt
library into the system and should keep the old name.
This change reverts most of r216380 limiting it to win32 targets only.
llvm-svn: 216533
1. Always put static sanitizer runtimes to the front of the linker
invocation line. This was already done for all sanitizers except UBSan:
in case user provides static libstdc++ we need to make sure that new/delete
operator definitions are picked from sanitizer runtimes instead of libstdc++.
We have to put UBSan runtime first for similar reasons: it depends on some
libstdc++ parts (e.g. __dynamic_cast function), and has to go first in
link line to ensure these functions will be picked up from libstdc++.
2. Put sanitizer libraries system dependencies (-ldl, -lpthread etc.) right
after sanitizer runtimes. This will ensure these libraries participate in
the link even if user provided -Wl,-as-needed flag. This should fix PR15823.
3. In case we link in several sanitizer runtimes (e.g. "ubsan", "ubsan_cxx"
and "san"), add system dependencies (-ldl, -lpthread, ...) only once.
llvm-svn: 215940
Summary:
This flag can be used to force linking of CXX-specific parts
of sanitizer runtimes into the final executable. It gives more precise
control than --driver-mode=g++ and comes handy when user links several
object files with sanitized C++ code into an executable, but wants
to provide libstdc++ himself, instead of relying on Clang dirver's
behavior.
Test Plan: clang regression test suite
Reviewers: chandlerc, rsmith
Reviewed By: rsmith
Subscribers: cfe-commits
Differential Revision: http://reviews.llvm.org/D4824
llvm-svn: 215252
It used to be a feature of UBSan (it could sanitize a standalone
shared object instead of the whole program), but now it causes
more problems, like PR20165.
llvm-svn: 212064
library. That results in the linker resolving all references to weak symbols in
the DSO to the definition from within that DSO. Ironically, this rarely causes
observable problems, except that it causes ubsan's own dynamic type check to
spuriously fail (because we fail to properly merge type_info object names).
llvm-svn: 210220
asan_cxx containts replacements for new/delete operators, and should
only be linked in C++ mode. We plan to start building this part
with exception support to make new more standard-compliant.
See https://code.google.com/p/address-sanitizer/issues/detail?id=295
for more details.
llvm-svn: 208610
If -fsanitize=leak is specified, link the program with the
LeakSanitizer runtime. Ignore this option when -fsanitize=address is specified,
because AddressSanitizer has this functionality built in.
llvm-svn: 182729
Sanitizer runtime intercepts functions from librt. Not doing this will fail
if the librt dependency is not present at program startup (ex. comes from a
dlopen()ed library).
llvm-svn: 182645
linker via --dynamic-list instead of using --export-dynamic. This reduces the
size of the dynamic symbol table, and thus of the binary (in some cases by up
to ~30%).
llvm-svn: 177783
* libclang_rt-san-* is sanitizer_common, and is linked in only if no other
sanitizer runtime is present.
* libclang_rt-ubsan-* is the piece of the runtime which doesn't depend on
a C++ ABI library, and is always linked in.
* libclang_rt-ubsan_cxx-* is the piece of the runtime which depends on a
C++ ABI library, and is only linked in when linking a C++ binary.
This change also switches us to using -whole-archive for the ubsan runtime
(which is made possible by the above split), and switches us to only linking
the sanitizer runtime into the main binary and not into DSOs (which is made
possible by using -whole-archive).
The motivation for this is to only link a single copy of sanitizer_common
into any binary. This is becoming important now because we want to share
more state between multiple sanitizers in the same process (for instance,
we want a single shared output mutex).
The Darwin ubsan runtime is unchanged; because we use a DSO there, we don't
need this complexity.
llvm-svn: 177605
Alexey Samsonov