377 Commits

Author SHA1 Message Date
Balazs Benics
5c23e27ba1 [analyzer][NFC] Move away from using raw-for loops inside StaticAnalyzer
I'm involved with the Static Analyzer for the most part.
I think we should embrace newer language standard features and gradually
move forward.

Differential Revision: https://reviews.llvm.org/D154325
2023-07-05 08:56:13 +02:00
Michael Klein
3b6a368d76 [analyzer] Fix QTimer::singleShot NewDeleteLeaks false positive
Fixes #39713

fferential Revision: https://reviews.llvm.org/D150552
2023-05-16 15:38:55 +02:00
isuckatcs
d65379c8d4 [analyzer] Remove the loop from the exploded graph caused by missing information in program points
This patch adds CFGElementRef to ProgramPoints
and helps the analyzer to differentiate between
two otherwise identically looking ProgramPoints.

Fixes #60412

Differential Revision: https://reviews.llvm.org/D143328
2023-03-04 02:01:45 +01:00
Kazu Hirata
6ad0788c33 [clang] Use std::optional instead of llvm::Optional (NFC)
This patch replaces (llvm::|)Optional< with std::optional<.  I'll post
a separate patch to remove #include "llvm/ADT/Optional.h".

This is part of an effort to migrate from llvm::Optional to
std::optional:

https://discourse.llvm.org/t/deprecating-llvm-optional-x-hasvalue-getvalue-getvalueor/63716
2023-01-14 12:31:01 -08:00
serge-sans-paille
d9ab3e82f3
[clang] Use a StringRef instead of a raw char pointer to store builtin and call information
This avoids recomputing string length that is already known at compile time.

It has a slight impact on preprocessing / compile time, see

https://llvm-compile-time-tracker.com/compare.php?from=3f36d2d579d8b0e8824d9dd99bfa79f456858f88&to=e49640c507ddc6615b5e503144301c8e41f8f434&stat=instructions:u

This a recommit of e953ae5bbc313fd0cc980ce021d487e5b5199ea4 and the subsequent fixes caa713559bd38f337d7d35de35686775e8fb5175 and 06b90e2e9c991e211fecc97948e533320a825470.

The above patchset caused some version of GCC to take eons to compile clang/lib/Basic/Targets/AArch64.cpp, as spotted in aa171833ab0017d9732e82b8682c9848ab25ff9e.
The fix is to make BuiltinInfo tables a compilation unit static variable, instead of a private static variable.

Differential Revision: https://reviews.llvm.org/D139881
2022-12-27 09:55:19 +01:00
Vitaly Buka
aa171833ab Revert "[clang] Use a StringRef instead of a raw char pointer to store builtin and call information"
Revert "Fix lldb option handling since e953ae5bbc313fd0cc980ce021d487e5b5199ea4 (part 2)"
Revert "Fix lldb option handling since e953ae5bbc313fd0cc980ce021d487e5b5199ea4"

GCC build hangs on this bot https://lab.llvm.org/buildbot/#/builders/37/builds/19104
compiling CMakeFiles/obj.clangBasic.dir/Targets/AArch64.cpp.d

The bot uses GNU 11.3.0, but I can reproduce locally with gcc (Debian 12.2.0-3) 12.2.0.

This reverts commit caa713559bd38f337d7d35de35686775e8fb5175.
This reverts commit 06b90e2e9c991e211fecc97948e533320a825470.
This reverts commit e953ae5bbc313fd0cc980ce021d487e5b5199ea4.
2022-12-25 23:12:47 -08:00
serge-sans-paille
e953ae5bbc
[clang] Use a StringRef instead of a raw char pointer to store builtin and call information
This avoids recomputing string length that is already known at compile
time.

It has a slight impact on preprocessing / compile time, see

https://llvm-compile-time-tracker.com/compare.php?from=3f36d2d579d8b0e8824d9dd99bfa79f456858f88&to=e49640c507ddc6615b5e503144301c8e41f8f434&stat=instructions:u

This is a recommit of 719d98dfa841c522d8d452f0685e503538415a53 that into
account a GGC issue (probably
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=92181) when dealing with
intiailizer_list and constant expressions.

Workaround this by avoiding initializer list, at the expense of a
temporary plain old array.

Differential Revision: https://reviews.llvm.org/D139881
2022-12-24 10:25:06 +01:00
serge-sans-paille
07d9ab9aa5
Revert "[clang] Use a StringRef instead of a raw char pointer to store builtin and call information"
There are still remaining issues with GCC 12, see for instance

https://lab.llvm.org/buildbot/#/builders/93/builds/12669

This reverts commit 5ce4e92264102de21760c94db9166afe8f71fcf6.
2022-12-23 13:29:21 +01:00
serge-sans-paille
5ce4e92264
[clang] Use a StringRef instead of a raw char pointer to store builtin and call information
This avoids recomputing string length that is already known at compile
time.

It has a slight impact on preprocessing / compile time, see

https://llvm-compile-time-tracker.com/compare.php?from=3f36d2d579d8b0e8824d9dd99bfa79f456858f88&to=e49640c507ddc6615b5e503144301c8e41f8f434&stat=instructions:u

This is a recommit of 719d98dfa841c522d8d452f0685e503538415a53 with a
change to llvm/utils/TableGen/OptParserEmitter.cpp to cope with GCC bug
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=108158

Differential Revision: https://reviews.llvm.org/D139881
2022-12-23 12:48:17 +01:00
serge-sans-paille
b7065a31b5
Revert "[clang] Use a StringRef instead of a raw char pointer to store builtin and call information"
Failing builds: https://lab.llvm.org/buildbot#builders/9/builds/19030
This is GCC specific and has been reported upstream: https://gcc.gnu.org/bugzilla/show_bug.cgi?id=108158

This reverts commit 719d98dfa841c522d8d452f0685e503538415a53.
2022-12-23 11:36:56 +01:00
serge-sans-paille
719d98dfa8
[clang] Use a StringRef instead of a raw char pointer to store builtin and call information
This avoids recomputing string length that is already known at compile
time.

It has a slight impact on preprocessing / compile time, see

https://llvm-compile-time-tracker.com/compare.php?from=3f36d2d579d8b0e8824d9dd99bfa79f456858f88&to=e49640c507ddc6615b5e503144301c8e41f8f434&stat=instructions:u

Differential Revision: https://reviews.llvm.org/D139881
2022-12-23 10:31:47 +01:00
Fangrui Song
53e5cd4d3e llvm::Optional::value => operator*/operator->
std::optional::value() has undesired exception checking semantics and is
unavailable in older Xcode (see _LIBCPP_AVAILABILITY_BAD_OPTIONAL_ACCESS). The
call sites block std::optional migration.

This makes `ninja clang` work in the absence of llvm::Optional::value.
2022-12-17 06:37:59 +00:00
Fangrui Song
21c4dc7997 std::optional::value => operator*/operator->
value() has undesired exception checking semantics and calls
__throw_bad_optional_access in libc++. Moreover, the API is unavailable without
_LIBCPP_NO_EXCEPTIONS on older Mach-O platforms (see
_LIBCPP_AVAILABILITY_BAD_OPTIONAL_ACCESS).

This fixes clang.
2022-12-17 00:42:05 +00:00
Kazu Hirata
eacf7c874b [StaticAnalyzer] Use std::optional in MallocChecker.cpp (NFC)
This is part of an effort to migrate from llvm::Optional to
std::optional:

https://discourse.llvm.org/t/deprecating-llvm-optional-x-hasvalue-getvalue-getvalueor/63716
2022-12-10 21:15:43 -08:00
Kazu Hirata
02c905cd4d [Checkers] Use std::optional in MallocChecker.cpp (NFC)
This is part of an effort to migrate from llvm::Optional to
std::optional:

https://discourse.llvm.org/t/deprecating-llvm-optional-x-hasvalue-getvalue-getvalueor/63716
2022-12-10 08:04:28 -08:00
Kazu Hirata
180600660b [StaticAnalyzer] Use std::nullopt instead of None (NFC)
This patch mechanically replaces None with std::nullopt where the
compiler would warn if None were deprecated.  The intent is to reduce
the amount of manual work required in migrating from Optional to
std::optional.

This is part of an effort to migrate from llvm::Optional to
std::optional:

https://discourse.llvm.org/t/deprecating-llvm-optional-x-hasvalue-getvalue-getvalueor/63716
2022-12-03 11:34:24 -08:00
Rageking8
94738a5ac3 Fix duplicate word typos; NFC
This revision fixes typos where there are 2 consecutive words which are
duplicated. There should be no code changes in this revision (only
changes to comments and docs). Do let me know if there are any
undesirable changes in this revision. Thanks.
2022-11-08 07:21:23 -05:00
isuckatcs
a46154cb1c [analyzer] Warn if the size of the array in new[] is undefined
This patch introduces a new checker, called NewArraySize checker,
which detects if the expression that yields the element count of
the array in new[], results in an Undefined value.

Differential Revision: https://reviews.llvm.org/D131299
2022-09-04 23:06:58 +02:00
Fangrui Song
32197830ef [clang][clang-tools-extra] LLVM_NODISCARD => [[nodiscard]]. NFC 2022-08-09 07:11:18 +00:00
Kazu Hirata
3f3930a451 Remove redundaunt virtual specifiers (NFC)
Identified with tidy-modernize-use-override.
2022-07-25 23:00:59 -07:00
Kazu Hirata
cb2c8f694d [clang] Use value instead of getValue (NFC) 2022-07-13 23:39:33 -07:00
Kazu Hirata
97afce08cb [clang] Don't use Optional::hasValue (NFC)
This patch replaces Optional::hasValue with the implicit cast to bool
in conditionals only.
2022-06-25 22:26:24 -07:00
Kazu Hirata
3b7c3a654c Revert "Don't use Optional::hasValue (NFC)"
This reverts commit aa8feeefd3ac6c78ee8f67bf033976fc7d68bc6d.
2022-06-25 11:56:50 -07:00
Kazu Hirata
aa8feeefd3 Don't use Optional::hasValue (NFC) 2022-06-25 11:55:57 -07:00
Kazu Hirata
452db157c9 [clang] Don't use Optional::hasValue (NFC) 2022-06-20 10:51:34 -07:00
Balazs Benics
96ccb690a0 [analyzer][NFC] Prefer using isa<> instead getAs<> in conditions
Depends on D125709

Reviewed By: martong

Differential Revision: https://reviews.llvm.org/D127742
2022-06-15 16:58:13 +02:00
Balazs Benics
f1b18a79b7 [analyzer][NFC] Remove dead code and modernize surroundings
Thanks @kazu for helping me clean these parts in D127799.

I'm leaving the dump methods, along with the unused visitor handlers and
the forwarding methods.

The dead parts actually helped to uncover two bugs, to which I'm going
to post separate patches.

Reviewed By: martong

Differential Revision: https://reviews.llvm.org/D127836
2022-06-15 16:50:12 +02:00
Balazs Benics
5a2e595eb8 [analyzer] Fix Static Analyzer g_memdup false-positive
`g_memdup()` allocates and copies memory, thus we should not assume that
the returned memory region is uninitialized because it might not be the
case.

PS: It would be even better to copy the bindings to mimic the actual
content of the buffer, but this works too.

Fixes #53617

Reviewed By: martong

Differential Revision: https://reviews.llvm.org/D124436
2022-05-02 10:35:51 +02:00
Vince Bridgers
5114db933d [analyzer] Clean checker options from bool to DefaultBool (NFC)
A recent review emphasized the preference to use DefaultBool instead of
bool for checker options. This change is a NFC and cleans up some of the
instances where bool was used, and could be changed to DefaultBool.

Reviewed By: steakhal

Differential Revision: https://reviews.llvm.org/D123464
2022-04-23 14:47:29 -05:00
Nathan James
cfb8169059
[clang] Add a raw_ostream operator<< overload for QualType
Under the hood this prints the same as `QualType::getAsString()` but cuts out the middle-man when that string is sent to another raw_ostream.

Also cleaned up all the call sites where this occurs.

Reviewed By: aaron.ballman

Differential Revision: https://reviews.llvm.org/D123926
2022-04-20 22:09:05 +01:00
Vince Bridgers
5fdc4dd777 [analyzer] refactor makeIntValWithPtrWidth, remove getZeroWithPtrWidth (NFC)
This is a NFC refactoring to change makeIntValWithPtrWidth
and remove getZeroWithPtrWidth to use types when forming values to match
pointer widths. Some targets may have different pointer widths depending
upon address space, so this needs to be comprehended.

Reviewed By: steakhal

Differential Revision: https://reviews.llvm.org/D120134
2022-03-23 08:26:37 -05:00
Vince Bridgers
985888411d [analyzer] Refactor makeNull to makeNullWithWidth (NFC)
Usages of makeNull need to be deprecated in favor of makeNullWithWidth
for architectures where the pointer size should not be assumed. This can
occur when pointer sizes can be of different sizes, depending on address
space for example. See https://reviews.llvm.org/D118050 as an example.

This was uncovered initially in a downstream compiler project, and
tested through those systems tests.

steakhal performed systems testing across a large set of open source
projects.

Co-authored-by: steakhal
Resolves: https://github.com/llvm/llvm-project/issues/53664

Reviewed By: NoQ, steakhal

Differential Revision: https://reviews.llvm.org/D119601
2022-03-22 07:35:13 -05:00
Kristóf Umann
d832078904 [analyzer] Improve NoOwnershipChangeVisitor's understanding of deallocators
The problem with leak bug reports is that the most interesting event in the code
is likely the one that did not happen -- lack of ownership change and lack of
deallocation, which is often present within the same function that the analyzer
inlined anyway, but not on the path of execution on which the bug occured. We
struggle to understand that a function was responsible for freeing the memory,
but failed.

D105819 added a new visitor to improve memory leak bug reports. In addition to
inspecting the ExplodedNodes of the bug pat, the visitor tries to guess whether
the function was supposed to free memory, but failed to. Initially (in D108753),
this was done by checking whether a CXXDeleteExpr is present in the function. If
so, we assume that the function was at least party responsible, and prevent the
analyzer from pruning bug report notes in it. This patch improves this heuristic
by recognizing all deallocator functions that MallocChecker itself recognizes,
by reusing MallocChecker::isFreeingCall.

Differential Revision: https://reviews.llvm.org/D118880
2022-03-03 11:27:56 +01:00
Artem Dergachev
e0e174845b [analyzer] Fix a crash in NoStateChangeVisitor with body-farmed stack frames.
LocationContext::getDecl() isn't useful for obtaining the "farmed" body because
the (synthetic) body statement isn't actually attached to the (natural-grown)
declaration in the AST.

Differential Revision: https://reviews.llvm.org/D119509
2022-02-17 10:13:34 -08:00
Kazu Hirata
17d4bd3d78 [clang] Fix bugprone argument comments (NFC)
Identified with bugprone-argument-comment.
2022-01-09 00:19:49 -08:00
Balazs Benics
0b9d3a6e53 [analyzer][NFC] Separate CallDescription from CallEvent
`CallDescriptions` deserve its own translation unit.
This patch simply moves the corresponding parts.
Also includes the `CallDescription.h` where it's necessary.

Reviewed By: martong, xazax.hun, Szelethus

Differential Revision: https://reviews.llvm.org/D113587
2021-11-15 19:10:46 +01:00
Balazs Benics
16be17ad4b [analyzer][NFC] Refactor llvm::isa<> usages in the StaticAnalyzer
It turns out llvm::isa<> is variadic, and we could have used this at a
lot of places.

The following patterns:
  x && isa<T1>(x) || isa<T2>(x) ...
Will be replaced by:
  isa_and_non_null<T1, T2, ...>(x)

Sometimes it caused further simplifications, when it would cause even
more code smell.

Aside from this, keep in mind that within `assert()` or any macro
functions, we need to wrap the isa<> expression within a parenthesis,
due to the parsing of the comma.

Reviewed By: martong

Differential Revision: https://reviews.llvm.org/D111982
2021-10-20 17:43:31 +02:00
Kazu Hirata
0abb5d293c [Sema, StaticAnalyzer] Use StringRef::contains (NFC) 2021-10-20 08:02:36 -07:00
Artem Dergachev
f3ec9d8501 [analyzer] Fix non-obvious analyzer warning: Use of zero-allocated memory.
Clarify the message provided when the analyzer catches the use of memory
that is allocated with size zero.

Differential Revision: https://reviews.llvm.org/D111655
2021-10-12 10:41:00 -07:00
Kristóf Umann
9d359f6c73 [analyzer] MallocChecker: Add notes from NoOwnershipChangeVisitor only when a function "intents", but doesn't change ownership, enable by default
D105819 Added NoOwnershipChangeVisitor, but it is only registered when an
off-by-default, hidden checker option was enabled. The reason behind this was
that it grossly overestimated the set of functions that really needed a note:

std::string getTrainName(const Train *T) {
  return T->name;
} // note: Retuning without changing the ownership of or deallocating memory
// Umm... I mean duh? Nor would I expect this function to do anything like that...

void foo() {
  Train *T = new Train("Land Plane");
  print(getTrainName(T)); // note: calling getTrainName / returning from getTrainName
} // warn: Memory leak

This patch adds a heuristic that guesses that any function that has an explicit
operator delete call could have be responsible for deallocating the memory that
ended up leaking. This is waaaay too conservative (see the TODOs in the new
function), but it safer to err on the side of too little than too much, and
would allow us to enable the option by default *now*, and add refinements
one-by-one.

Differential Revision: https://reviews.llvm.org/D108753
2021-09-13 15:01:20 +02:00
Kristóf Umann
0213d7ec0c [analyzer][NFCI] Allow clients of NoStateChangeFuncVisitor to check entire function calls, rather than each ExplodedNode in it
Fix a compilation error due to a missing 'template' keyword.

Differential Revision: https://reviews.llvm.org/D108695
2021-09-13 13:50:01 +02:00
Jessica Paquette
b9e57e0305 Revert "[analyzer][NFCI] Allow clients of NoStateChangeFuncVisitor to check entire function calls, rather than each ExplodedNode in it"
This reverts commit a375bfb5b729e0f3ca8d5e001f423fa89e74de87.

This was causing a bot to crash:

https://green.lab.llvm.org/green/job/clang-stage1-cmake-RA-incremental/23380/
2021-09-03 10:28:07 -07:00
Kristóf Umann
a375bfb5b7 [analyzer][NFCI] Allow clients of NoStateChangeFuncVisitor to check entire function calls, rather than each ExplodedNode in it
D105553 added NoStateChangeFuncVisitor, an abstract class to aid in creating
notes such as "Returning without writing to 'x'", or "Returning without changing
the ownership status of allocated memory". Its clients need to define, among
other things, what a change of state is.

For code like this:

f() {
  g();
}

foo() {
  f();
  h();
}

We'd have a path in the ExplodedGraph that looks like this:

             -- <g> -->
            /          \
         ---     <f>    -------->        --- <h> --->
        /                        \      /            \
--------        <foo>             ------    <foo>     -->

When we're interested in whether f neglected to change some property,
NoStateChangeFuncVisitor asks these questions:

                       ÷×~
                -- <g> -->
           ß   /          \$    @&#*
            ---     <f>    -------->        --- <h> --->
           /                        \      /            \
   --------        <foo>             ------    <foo>     -->

Has anything changed in between # and *?
Has anything changed in between & and *?
Has anything changed in between @ and *?
...
Has anything changed in between $ and *?
Has anything changed in between × and ~?
Has anything changed in between ÷ and ~?
...
Has anything changed in between ß and *?
...
This is a rather thorough line of questioning, which is why in D105819, I was
only interested in whether state *right before* and *right after* a function
call changed, and early returned to the CallEnter location:

if (!CurrN->getLocationAs<CallEnter>())
  return;
Except that I made a typo, and forgot to negate the condition. So, in this
patch, I'm fixing that, and under the same hood allow all clients to decide to
do this whole-function check instead of the thorough one.

Differential Revision: https://reviews.llvm.org/D108695
2021-09-03 13:50:18 +02:00
Kristóf Umann
3891b45a06 Revert "[analyzer][NFCI] Allow clients of NoStateChangeFuncVisitor to check entire function calls, rather than each ExplodedNode in it"
This reverts commit 7d0e62bfb773c68d2bc8831fddcc8536f4613190.
2021-09-02 17:19:49 +02:00
Kristóf Umann
7d0e62bfb7 [analyzer][NFCI] Allow clients of NoStateChangeFuncVisitor to check entire function calls, rather than each ExplodedNode in it
D105553 added NoStateChangeFuncVisitor, an abstract class to aid in creating
notes such as "Returning without writing to 'x'", or "Returning without changing
the ownership status of allocated memory". Its clients need to define, among
other things, what a change of state is.

For code like this:

f() {
  g();
}

foo() {
  f();
  h();
}

We'd have a path in the ExplodedGraph that looks like this:

             -- <g> -->
            /          \
         ---     <f>    -------->        --- <h> --->
        /                        \      /            \
--------        <foo>             ------    <foo>     -->

When we're interested in whether f neglected to change some property,
NoStateChangeFuncVisitor asks these questions:

                       ÷×~
                -- <g> -->
           ß   /          \$    @&#*
            ---     <f>    -------->        --- <h> --->
           /                        \      /            \
   --------        <foo>             ------    <foo>     -->

Has anything changed in between # and *?
Has anything changed in between & and *?
Has anything changed in between @ and *?
...
Has anything changed in between $ and *?
Has anything changed in between × and ~?
Has anything changed in between ÷ and ~?
...
Has anything changed in between ß and *?
...
This is a rather thorough line of questioning, which is why in D105819, I was
only interested in whether state *right before* and *right after* a function
call changed, and early returned to the CallEnter location:

if (!CurrN->getLocationAs<CallEnter>())
  return;
Except that I made a typo, and forgot to negate the condition. So, in this
patch, I'm fixing that, and under the same hood allow all clients to decide to
do this whole-function check instead of the thorough one.

Differential Revision: https://reviews.llvm.org/D108695
2021-09-02 16:56:32 +02:00
Kristóf Umann
2d3668c997 [analyzer] MallocChecker: Add a visitor to leave a note on functions that could have, but did not change ownership on leaked memory
This is a rather common feedback we get from out leak checkers: bug reports are
really short, and are contain barely any usable information on what the analyzer
did to conclude that a leak actually happened.

This happens because of our bug report minimizing effort. We construct bug
reports by inspecting the ExplodedNodes that lead to the error from the bottom
up (from the error node all the way to the root of the exploded graph), and mark
entities that were the cause of a bug, or have interacted with it as
interesting. In order to make the bug report a bit less verbose, whenever we
find an entire function call (from CallEnter to CallExitEnd) that didn't talk
about any interesting entity, we prune it (click here for more info on bug
report generation). Even if the event to highlight is exactly this lack of
interaction with interesting entities.

D105553 generalized the visitor that creates notes for these cases. This patch
adds a new kind of NoStateChangeVisitor that leaves notes in functions that
took a piece of dynamically allocated memory that later leaked as parameter,
and didn't change its ownership status.

Differential Revision: https://reviews.llvm.org/D105553
2021-08-16 16:19:00 +02:00
Martin Storsjö
e5c7c171e5 [clang] Rename StringRef _lower() method calls to _insensitive()
This is mostly a mechanical change, but a testcase that contains
parts of the StringRef class (clang/test/Analysis/llvm-conventions.cpp)
isn't touched.
2021-06-25 00:22:01 +03:00
Valeriy Savchenko
92d03c20ea [analyzer] Add forwarding addVisitor method
The majority of all `addVisitor` callers follow the same pattern:
  addVisitor(std::make_unique<SomeVisitor>(arg1, arg2, ...));

This patches introduces additional overload for `addVisitor` to simplify
that pattern:
  addVisitor<SomeVisitor>(arg1, arg2, ...);

Differential Revision: https://reviews.llvm.org/D103457
2021-06-03 17:10:16 +03:00
Charusso
9b3df78b4c [analyzer] DynamicSize: Rename 'size' to 'extent' 2021-04-05 19:20:43 +02:00
Charusso
df64f471d1 [analyzer] DynamicSize: Store the dynamic size
This patch introduces a way to store the size.

Reviewed By: NoQ

Differential Revision: https://reviews.llvm.org/D69726
2021-04-05 19:04:53 +02:00