Gabor Horvath [Tue, 23 Feb 2016 12:34:39 +0000 (12:34 +0000)]
[analyzer] Improve pointer arithmetic checker.
This patch is intended to improve pointer arithmetic checker.
From now on it only warns when the pointer arithmetic is likely to cause an
error. For example when the pointer points to a single object, or an array of
derived types.
Lex: Return "" when HeaderMap::lookupFilename fails
Change getString() to return Optional<StringRef>, and change
lookupFilename() to return an empty string if either one of the prefix
and suffix can't be found.
This is a more robust follow-up to r261461, but it's still not entirely
satisfactory. Ideally we'd report that the header map is corrupt;
perhaps something for a follow-up.
Lex: Check for 0 buckets on header map construction
Switch to using `isPowerOf2_32()` to check whether the buckets are a
power of two, and as a side benefit reject loading a header map with no
buckets. This is a follow-up to r261448.
The VFS overlay mapping between virtual paths and real paths is done through
the 'external-contents' entries in YAML files, which contains hardcoded paths
to the real files.
When a module compilation crashes, headers are dumped into <name>.cache/vfs
directory and are mapped via the <name>.cache/vfs/vfs.yaml. The script
generated for reproduction uses -ivfsoverlay pointing to file to gather the
mapping between virtual paths and files inside <name>.cache/vfs. Currently, we
are only capable of reproducing such crashes in the same machine as they
happen, because of the hardcoded paths in 'external-contents'.
To be able to reproduce a crash in another machine, this patch introduces a new
option in the VFS yaml file called 'overlay-relative'. When it's equal to
'true' it means that the provided path to the YAML file through the
-ivfsoverlay option should also be used to prefix the final path for every
'external-contents'.
Example, given the invocation snippet "... -ivfsoverlay
<name>.cache/vfs/vfs.yaml" and the following entry in the yaml file:
Here, a file manager request for virtual "/usr/include/stdio.h", that will map
into real path "/<absolute_path_to>/<name>.cache/vfs/usr/include/stdio.h.
This is a useful feature for debugging module crashes in machines other than
the one where the error happened.
Handle ".", ".." and "./" with trailing slashes while collecting files
to be dumped into the vfs overlay directory.
Include the support for symlinks into components. Given the path:
/install-dir/bin/../lib/clang/3.8.0/include/altivec.h, if "bin"
component is a symlink, it's not safe to use `path::remove_dots` here,
and `realpath` is used to get the right answer. Since `realpath`
is expensive, we only do it at collecting time (which only happens
during the crash reproducer) and cache the base directory for fast lookups.
Overall, this makes the input to the VFS YAML file to be canonicalized
to never contain traversal components.
Devin Coughlin [Mon, 22 Feb 2016 17:56:24 +0000 (17:56 +0000)]
[analyzer] Detect duplicate [super dealloc] calls
Add an alpha path checker that warns about duplicate calls to [super dealloc].
This will form the foundation of a checker that will detect uses of
'self' after calling [super dealloc].
We gave a VBTable dllimport storage class and external linkage while
also providing an initializer. An initializer is only valid if the
VBTable has available_externally linkage. Fix this by setting the
linkage to available_externally in situ while generating the
initializer.
Anton Yartsev [Sun, 21 Feb 2016 17:04:26 +0000 (17:04 +0000)]
[analyzer][scan-build] Non-existing directory for scan-build output.
Makes scan-build successfully accept non-existing output directories provided via "-o" option. The directory is created in this case. This behavior is conforming to the old perl scan-build implementation.
(http://reviews.llvm.org/D17091)
Lex: Never overflow the file in HeaderMap::lookupFilename()
If a header map file is corrupt, the strings in the string table may not
be null-terminated. The logic here previously relied on `MemoryBuffer`
always being null-terminated, but this isn't actually guaranteed by the
class AFAICT. Moreover, we're seeing a lot of crash traces at calls to
`strlen()` inside of `lookupFilename()`, so something is going wrong
there.
Instead, use `strnlen()` to get the length, and check for corruption.
Also remove code paths that could call `StringRef(nullptr)`. r261459
made these rather obvious (although they'd been there all along).
Lex: Check whether the header map buffer has space for the buckets
Check up front whether the header map buffer has space for all of its
declared buckets.
There was already a check in `getBucket()`, but it had UB (comparing
pointers that were outside of objects in the error path) and was
insufficient (only checking for a single byte of the relevant bucket).
I fixed the check, moved it to `checkHeader()`, and left a fixed version
behind as an assertion.
If the number of buckets is not a power of two, immediately recognize
the header map as corrupt, rather than waiting for the first lookup. I
converted the later check to an assert.
Split the implementation of `HeaderMap` into `HeaderMapImpl` so that we
can write unit tests that don't depend on the `FileManager`, and then
write a few tests that cover the types of corrupt header maps already
detected.
This also moves type and constant definitions from HeaderMap.cpp to
HeaderMapTypes.h so that the test can access them.
Roman Divacky [Sat, 20 Feb 2016 08:31:24 +0000 (08:31 +0000)]
Fix handling of vaargs on PPC32 when going from regsave to overflow.
It can happen that when we only have 1 more register left in the regsave
area we need to store a value bigger than 1 register and therefore we
go to the overflow area. In this case we have to leave the last slot
in the regsave area unused and keep using overflow area. Do this
by storing a limit value to the used register counter in the overflow block.
Issue diagnosed by and solution tested by Mark Millard!
Richard Smith [Fri, 19 Feb 2016 22:43:58 +0000 (22:43 +0000)]
[modules] Do less scanning of macro definition chains when computing the set of
exported module macros outside local submodule visibility mode. Related to
PR24667.
Richard Smith [Fri, 19 Feb 2016 22:25:36 +0000 (22:25 +0000)]
[modules] Flatten -fmodule-name= and -fmodule-implementation-of= into a single
option. Previously these options could both be used to specify that you were
compiling the implementation file of a module, with a different set of minor
bugs in each case.
This change removes -fmodule-implementation-of, and instead tracks a flag to
determine whether we're currently building a module. -fmodule-name now behaves
the same way that -fmodule-implementation-of previously did.
Alexey Bataev [Fri, 19 Feb 2016 11:23:28 +0000 (11:23 +0000)]
pr26544: Bitfield layout with pragma pack and attributes "packed" and
"aligned", by Vladimir Yakovlev
Fix clang/gcc incompatibility of bitfields layout in the presence of
pragma packed and attributes aligned and packed.
Differential Revision: http://reviews.llvm.org/D17023
JF Bastien [Fri, 19 Feb 2016 06:54:45 +0000 (06:54 +0000)]
ARM: fix VFP asm constraints
Summary:
Rich Felker was sad that clang used 'w' and 'P' for VFP constraints when GCC documents them as 't' and 'w':
https://gcc.gnu.org/onlinedocs/gcc/Machine-Constraints.html
This was added way back in 2008:
http://lists.llvm.org/pipermail/cfe-commits/Week-of-Mon-20080421/005393.html
Nico Weber [Fri, 19 Feb 2016 01:52:46 +0000 (01:52 +0000)]
Implement the likely resolution of core issue 253.
C++11 requires const objects to have a user-provided constructor, even for
classes without any fields. DR 253 relaxes this to say "If the implicit default
constructor initializes all subobjects, no initializer should be required."
clang is currently the only compiler that implements this C++11 rule, and e.g.
libstdc++ relies on something like DR 253 to compile in newer versions. This
change makes it possible to build code that says `const vector<int> v;' again
when using libstdc++5.2 and _GLIBCXX_DEBUG
(https://gcc.gnu.org/bugzilla/show_bug.cgi?id=60284).
Devin Coughlin [Fri, 19 Feb 2016 01:35:10 +0000 (01:35 +0000)]
[analyzer] Add checker callback for beginning of function.
Add a checker callback that is called when the analyzer starts analyzing a
function either at the top level or when inlined. This will be used by a
follow-on patch making the DeallocChecker path sensitive.
Reid Kleckner [Fri, 19 Feb 2016 00:56:56 +0000 (00:56 +0000)]
Add call to find_package to load LLVM dependencies
ClangConfig requires LLVMConfig, so add find_package call in
ClangConfig so find_package(clang REQUIRED CONFIG) will just work. This
makes it easier for cmake based projects to use clang, e.g., tools using
ClangTooling.
Richard Trieu [Thu, 18 Feb 2016 23:58:40 +0000 (23:58 +0000)]
Add -Wcomma warning to Clang.
-Wcomma will detect and warn on most uses of the builtin comma operator. It
currently whitelists the first and third statements of the for-loop. For other
cases, the warning can be silenced by casting the first operand of the comma
operator to void.
David L. Jones [Thu, 18 Feb 2016 20:27:16 +0000 (20:27 +0000)]
Use Backend_EmitMCNull for null codegen unit tests.
Using Backend_EmitLL attemps to create a file with an empty filename.
This is problematic in certain environments: an empty filename may be
illegal, or the default output path may not be writable (in the case
where an empty filename would otherwise have some non-failing
semantics). This patch switches to use Backend_EmitMCNull, which
allows CodeGen to run, but does not attempt to create or write an
output file.
Devin Coughlin [Thu, 18 Feb 2016 19:13:30 +0000 (19:13 +0000)]
[analyzer] Improve modeling of ObjC synthesized property setters.
When modeling a call to a setter for a property that is synthesized to be
backed by an instance variable, don't invalidate the entire instance
but rather only the storage for the updated instance variable itself.
This still doesn't model the effect of the setter completely. It doesn't
bind the set value to the ivar storage location because doing so would cause
the set value to escape, removing valuable diagnostics about potential
leaks of the value from the retain count checker.
Serge Pavlov [Thu, 18 Feb 2016 16:42:09 +0000 (16:42 +0000)]
Avoid double deletion in Clang driver.
Llvm module object is shared between CodeGenerator and BackendConsumer,
in both classes it is stored as std::unique_ptr, which is not a good
design solution and can cause double deletion error. Usually it does
not occur because in BackendConsumer::HandleTranslationUnit the
ownership of CodeGenerator over the module is taken away. If however
this method is not called, the module is deleted twice and compiler crashes.
As the module owned by BackendConsumer is always the same as CodeGenerator
has, pointer to llvm module can be removed from BackendGenerator.
Benjamin Kramer [Thu, 18 Feb 2016 15:30:24 +0000 (15:30 +0000)]
[Parse] Code complete expressions in bracket declarators.
Currently we return no results when completing inside of the brackets in
a 'char foo[]' declaration. Let the generic expression completion code
handle it instead. We could get fancier here (e.g. filter non-constant
expressions in contexts where VLAs are not allowed), but it's a strict
improvement over the existing version.
Yury Gribov [Thu, 18 Feb 2016 11:08:46 +0000 (11:08 +0000)]
[analyzer] Add --force-analyze-debug-code option to scan-build
to force debug build and hopefully enable more precise warnings.
Static Analyzer is much more efficient when built in debug mode
(-UNDEBUG) so we advice users to enable it manually. This may be
inconvenient in case of large complex projects (think about Linux
distros e.g. Android or Tizen). This patch adds a flag to scan-build
which inserts -UNDEBUG automatically.
[sanitizer-coverage] allow -fsanitize-coverage=trace-pc w/o any other sanitizer and w/o ...=[func,bb,edge]. This makes this syntax a superset of the GCC's syntax
David Majnemer [Wed, 17 Feb 2016 22:37:45 +0000 (22:37 +0000)]
Don't crash w/ a diagnostic range containing a null byte
We prematurely ended the line at the null byte which caused us to crash
down stream because we tried to reason about columns beyond the end of
the line.
Manman Ren [Wed, 17 Feb 2016 22:05:48 +0000 (22:05 +0000)]
Add 'nopartial' qualifier for availability attributes.
An optional nopartial can be placed after the platform name.
int bar() __attribute__((availability(macosx,nopartial,introduced=10.12))
When deploying back to a platform version prior to when the declaration was
introduced, with 'nopartial', Clang emits an error specifying that the function
is not introduced yet; without 'nopartial', the behavior stays the same: the
declaration is `weakly linked`.
A member is added to the end of AttributeList to save the location of the
'nopartial' keyword. A bool member is added to AvailabilityAttr.
The diagnostics for 'nopartial' not-yet-introduced is handled in the same way as
we handle unavailable cases.
Richard Smith [Wed, 17 Feb 2016 21:52:44 +0000 (21:52 +0000)]
[modules] Cache 'acceptable decl' lookups for namespaces. In projects with
thousands of modules, each of which declares the same namespace, linearly
scanning the redecl chain looking for a visible declaration (once for each leaf
module, for each use) performs very poorly. Namespace visibility can only
decrease when we leave a module during a module build step, and we never care
*which* visible declaration of a namespace we find, so we can cache this very
effectively.
This results in a 35x speedup on one of our internal build steps (2m -> 3.5s),
but is hard to unit test because it requires a very large number of modules.
Ideas for a test appreciated! No functionality change intended other than the
speedup.
[sanitizer-coverage] implement -fsanitize-coverage=trace-pc. This is similar to trace-bb, but has a different API. We already use the equivalent flag in GCC for Linux kernel fuzzing. We may be able to use this flag with AFL too
Akira Hatanaka [Wed, 17 Feb 2016 21:09:50 +0000 (21:09 +0000)]
[CodeGen] Fix an assert in CodeGenFunction::EmitFunctionEpilog
The assert is triggered because isObjCRetainableType() is called on the
canonicalized return type that has been stripped of the typedefs and
attributes attached to it. To fix this assert, this commit gets the
original return type from CurCodeDecl or BlockInfo and uses it instead
of the canoicalized type.
projects / clang / log