Commit Graph

101 Commits

Author SHA1 Message Date
Kazu Hirata a41fbb1fc2 [clang/unittests] 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 12:14:19 -08:00
Matheus Izvekov 15f3cd6bfc
[clang] Implement ElaboratedType sugaring for types written bare
Without this patch, clang will not wrap in an ElaboratedType node types written
without a keyword and nested name qualifier, which goes against the intent that
we should produce an AST which retains enough details to recover how things are
written.

The lack of this sugar is incompatible with the intent of the type printer
default policy, which is to print types as written, but to fall back and print
them fully qualified when they are desugared.

An ElaboratedTypeLoc without keyword / NNS uses no storage by itself, but still
requires pointer alignment due to pre-existing bug in the TypeLoc buffer
handling.

---

Troubleshooting list to deal with any breakage seen with this patch:

1) The most likely effect one would see by this patch is a change in how
   a type is printed. The type printer will, by design and default,
   print types as written. There are customization options there, but
   not that many, and they mainly apply to how to print a type that we
   somehow failed to track how it was written. This patch fixes a
   problem where we failed to distinguish between a type
   that was written without any elaborated-type qualifiers,
   such as a 'struct'/'class' tags and name spacifiers such as 'std::',
   and one that has been stripped of any 'metadata' that identifies such,
   the so called canonical types.
   Example:
   ```
   namespace foo {
     struct A {};
     A a;
   };
   ```
   If one were to print the type of `foo::a`, prior to this patch, this
   would result in `foo::A`. This is how the type printer would have,
   by default, printed the canonical type of A as well.
   As soon as you add any name qualifiers to A, the type printer would
   suddenly start accurately printing the type as written. This patch
   will make it print it accurately even when written without
   qualifiers, so we will just print `A` for the initial example, as
   the user did not really write that `foo::` namespace qualifier.

2) This patch could expose a bug in some AST matcher. Matching types
   is harder to get right when there is sugar involved. For example,
   if you want to match a type against being a pointer to some type A,
   then you have to account for getting a type that is sugar for a
   pointer to A, or being a pointer to sugar to A, or both! Usually
   you would get the second part wrong, and this would work for a
   very simple test where you don't use any name qualifiers, but
   you would discover is broken when you do. The usual fix is to
   either use the matcher which strips sugar, which is annoying
   to use as for example if you match an N level pointer, you have
   to put N+1 such matchers in there, beginning to end and between
   all those levels. But in a lot of cases, if the property you want
   to match is present in the canonical type, it's easier and faster
   to just match on that... This goes with what is said in 1), if
   you want to match against the name of a type, and you want
   the name string to be something stable, perhaps matching on
   the name of the canonical type is the better choice.

3) This patch could expose a bug in how you get the source range of some
   TypeLoc. For some reason, a lot of code is using getLocalSourceRange(),
   which only looks at the given TypeLoc node. This patch introduces a new,
   and more common TypeLoc node which contains no source locations on itself.
   This is not an inovation here, and some other, more rare TypeLoc nodes could
   also have this property, but if you use getLocalSourceRange on them, it's not
   going to return any valid locations, because it doesn't have any. The right fix
   here is to always use getSourceRange() or getBeginLoc/getEndLoc which will dive
   into the inner TypeLoc to get the source range if it doesn't find it on the
   top level one. You can use getLocalSourceRange if you are really into
   micro-optimizations and you have some outside knowledge that the TypeLocs you are
   dealing with will always include some source location.

4) Exposed a bug somewhere in the use of the normal clang type class API, where you
   have some type, you want to see if that type is some particular kind, you try a
   `dyn_cast` such as `dyn_cast<TypedefType>` and that fails because now you have an
   ElaboratedType which has a TypeDefType inside of it, which is what you wanted to match.
   Again, like 2), this would usually have been tested poorly with some simple tests with
   no qualifications, and would have been broken had there been any other kind of type sugar,
   be it an ElaboratedType or a TemplateSpecializationType or a SubstTemplateParmType.
   The usual fix here is to use `getAs` instead of `dyn_cast`, which will look deeper
   into the type. Or use `getAsAdjusted` when dealing with TypeLocs.
   For some reason the API is inconsistent there and on TypeLocs getAs behaves like a dyn_cast.

5) It could be a bug in this patch perhaps.

Let me know if you need any help!

Signed-off-by: Matheus Izvekov <mizvekov@gmail.com>

Differential Revision: https://reviews.llvm.org/D112374
2022-07-27 11:10:54 +02:00
Jonas Devlieghere 888673b6e3
Revert "[clang] Implement ElaboratedType sugaring for types written bare"
This reverts commit 7c51f02eff because it
stills breaks the LLDB tests. This was  re-landed without addressing the
issue or even agreement on how to address the issue. More details and
discussion in https://reviews.llvm.org/D112374.
2022-07-14 21:17:48 -07:00
Matheus Izvekov 7c51f02eff
[clang] Implement ElaboratedType sugaring for types written bare
Without this patch, clang will not wrap in an ElaboratedType node types written
without a keyword and nested name qualifier, which goes against the intent that
we should produce an AST which retains enough details to recover how things are
written.

The lack of this sugar is incompatible with the intent of the type printer
default policy, which is to print types as written, but to fall back and print
them fully qualified when they are desugared.

An ElaboratedTypeLoc without keyword / NNS uses no storage by itself, but still
requires pointer alignment due to pre-existing bug in the TypeLoc buffer
handling.

---

Troubleshooting list to deal with any breakage seen with this patch:

1) The most likely effect one would see by this patch is a change in how
   a type is printed. The type printer will, by design and default,
   print types as written. There are customization options there, but
   not that many, and they mainly apply to how to print a type that we
   somehow failed to track how it was written. This patch fixes a
   problem where we failed to distinguish between a type
   that was written without any elaborated-type qualifiers,
   such as a 'struct'/'class' tags and name spacifiers such as 'std::',
   and one that has been stripped of any 'metadata' that identifies such,
   the so called canonical types.
   Example:
   ```
   namespace foo {
     struct A {};
     A a;
   };
   ```
   If one were to print the type of `foo::a`, prior to this patch, this
   would result in `foo::A`. This is how the type printer would have,
   by default, printed the canonical type of A as well.
   As soon as you add any name qualifiers to A, the type printer would
   suddenly start accurately printing the type as written. This patch
   will make it print it accurately even when written without
   qualifiers, so we will just print `A` for the initial example, as
   the user did not really write that `foo::` namespace qualifier.

2) This patch could expose a bug in some AST matcher. Matching types
   is harder to get right when there is sugar involved. For example,
   if you want to match a type against being a pointer to some type A,
   then you have to account for getting a type that is sugar for a
   pointer to A, or being a pointer to sugar to A, or both! Usually
   you would get the second part wrong, and this would work for a
   very simple test where you don't use any name qualifiers, but
   you would discover is broken when you do. The usual fix is to
   either use the matcher which strips sugar, which is annoying
   to use as for example if you match an N level pointer, you have
   to put N+1 such matchers in there, beginning to end and between
   all those levels. But in a lot of cases, if the property you want
   to match is present in the canonical type, it's easier and faster
   to just match on that... This goes with what is said in 1), if
   you want to match against the name of a type, and you want
   the name string to be something stable, perhaps matching on
   the name of the canonical type is the better choice.

3) This patch could exposed a bug in how you get the source range of some
   TypeLoc. For some reason, a lot of code is using getLocalSourceRange(),
   which only looks at the given TypeLoc node. This patch introduces a new,
   and more common TypeLoc node which contains no source locations on itself.
   This is not an inovation here, and some other, more rare TypeLoc nodes could
   also have this property, but if you use getLocalSourceRange on them, it's not
   going to return any valid locations, because it doesn't have any. The right fix
   here is to always use getSourceRange() or getBeginLoc/getEndLoc which will dive
   into the inner TypeLoc to get the source range if it doesn't find it on the
   top level one. You can use getLocalSourceRange if you are really into
   micro-optimizations and you have some outside knowledge that the TypeLocs you are
   dealing with will always include some source location.

4) Exposed a bug somewhere in the use of the normal clang type class API, where you
   have some type, you want to see if that type is some particular kind, you try a
   `dyn_cast` such as `dyn_cast<TypedefType>` and that fails because now you have an
   ElaboratedType which has a TypeDefType inside of it, which is what you wanted to match.
   Again, like 2), this would usually have been tested poorly with some simple tests with
   no qualifications, and would have been broken had there been any other kind of type sugar,
   be it an ElaboratedType or a TemplateSpecializationType or a SubstTemplateParmType.
   The usual fix here is to use `getAs` instead of `dyn_cast`, which will look deeper
   into the type. Or use `getAsAdjusted` when dealing with TypeLocs.
   For some reason the API is inconsistent there and on TypeLocs getAs behaves like a dyn_cast.

5) It could be a bug in this patch perhaps.

Let me know if you need any help!

Signed-off-by: Matheus Izvekov <mizvekov@gmail.com>

Differential Revision: https://reviews.llvm.org/D112374
2022-07-15 04:16:55 +02:00
Ella Ma 32fe1a4be9 [analyzer] Fixing SVal::getType returns Null Type for NonLoc::ConcreteInt in boolean type
In method `TypeRetrievingVisitor::VisitConcreteInt`, `ASTContext::getIntTypeForBitwidth` is used to get the type for `ConcreteInt`s.
However, the getter in ASTContext cannot handle the boolean type with the bit width of 1, which will make method `SVal::getType` return a Null `Type`.
In this patch, a check for this case is added to fix this problem by returning the bool type directly when the bit width is 1.

Differential Revision: https://reviews.llvm.org/D129737
2022-07-14 22:00:38 +08:00
Jonas Devlieghere 3968936b92
Revert "[clang] Implement ElaboratedType sugaring for types written bare"
This reverts commit bdc6974f92 because it
breaks all the LLDB tests that import the std module.

  import-std-module/array.TestArrayFromStdModule.py
  import-std-module/deque-basic.TestDequeFromStdModule.py
  import-std-module/deque-dbg-info-content.TestDbgInfoContentDequeFromStdModule.py
  import-std-module/forward_list.TestForwardListFromStdModule.py
  import-std-module/forward_list-dbg-info-content.TestDbgInfoContentForwardListFromStdModule.py
  import-std-module/list.TestListFromStdModule.py
  import-std-module/list-dbg-info-content.TestDbgInfoContentListFromStdModule.py
  import-std-module/queue.TestQueueFromStdModule.py
  import-std-module/stack.TestStackFromStdModule.py
  import-std-module/vector.TestVectorFromStdModule.py
  import-std-module/vector-bool.TestVectorBoolFromStdModule.py
  import-std-module/vector-dbg-info-content.TestDbgInfoContentVectorFromStdModule.py
  import-std-module/vector-of-vectors.TestVectorOfVectorsFromStdModule.py

https://green.lab.llvm.org/green/view/LLDB/job/lldb-cmake/45301/
2022-07-13 09:20:30 -07:00
Kazu Hirata 53daa177f8 [clang, clang-tools-extra] Use has_value instead of hasValue (NFC) 2022-07-12 22:47:41 -07:00
Matheus Izvekov bdc6974f92
[clang] Implement ElaboratedType sugaring for types written bare
Without this patch, clang will not wrap in an ElaboratedType node types written
without a keyword and nested name qualifier, which goes against the intent that
we should produce an AST which retains enough details to recover how things are
written.

The lack of this sugar is incompatible with the intent of the type printer
default policy, which is to print types as written, but to fall back and print
them fully qualified when they are desugared.

An ElaboratedTypeLoc without keyword / NNS uses no storage by itself, but still
requires pointer alignment due to pre-existing bug in the TypeLoc buffer
handling.

Signed-off-by: Matheus Izvekov <mizvekov@gmail.com>

Differential Revision: https://reviews.llvm.org/D112374
2022-07-13 02:10:09 +02:00
Alexandre Ganea 0880b9d526 [Clang][unittests] Silence trucation warning with MSVC 2022
Differential Revision: https://reviews.llvm.org/D129152
2022-07-05 20:31:54 -04:00
Kazu Hirata 3b7c3a654c Revert "Don't use Optional::hasValue (NFC)"
This reverts commit aa8feeefd3.
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
Sam McCall 4cec789c17 [Testing] Drop clangTesting from clang's public library interface
This was probably not particularly intended to be public, and disallows deps
on gtest which are useful in test helpers.

https://discourse.llvm.org/t/stop-exporting-clangtesting-library/61672

Differential Revision: https://reviews.llvm.org/D123610
2022-04-20 13:28:44 +02:00
Denys Petrov e37726beb2 [analyzer] Implemented RangeSet::Factory::castTo function to perform promotions, truncations and conversions.
Summary: Handle casts for ranges working similarly to APSIntType::apply function but for the whole range set. Support promotions, truncations and conversions.
Example:
promotion: char [0, 42] -> short [0, 42] -> int [0, 42] -> llong [0, 42]
truncation: llong [4295033088, 4295033130] -> int [65792, 65834] -> short [256, 298] -> char [0, 42]
conversion: char [-42, 42] -> uint [0, 42]U[4294967254, 4294967295] -> short[-42, 42]

Differential Revision: https://reviews.llvm.org/D103094
2022-04-19 22:34:03 +03:00
Kristóf Umann 32ac21d049 [NFC][analyzer] Allow CallDescriptions to be matched with CallExprs
Since CallDescriptions can only be matched against CallEvents that are created
during symbolic execution, it was not possible to use it in syntactic-only
contexts. For example, even though InnerPointerChecker can check with its set of
CallDescriptions whether a function call is interested during analysis, its
unable to check without hassle whether a non-analyzer piece of code also calls
such a function.

The patch adds the ability to use CallDescriptions in syntactic contexts as
well. While we already have that in Signature, we still want to leverage the
ability to use dynamic information when we have it (function pointers, for
example). This could be done with Signature as well (StdLibraryFunctionsChecker
does it), but it makes it even less of a drop-in replacement.

Differential Revision: https://reviews.llvm.org/D119004
2022-03-01 17:13:04 +01:00
Balazs Benics abc873694f [analyzer] Restrict CallDescription fuzzy builtin matching
`CallDescriptions` for builtin functions relaxes the match rules
somewhat, so that the `CallDescription` will match for calls that have
some prefix or suffix. This was achieved by doing a `StringRef::contains()`.
However, this is somewhat problematic for builtins that are substrings
of each other.

Consider the following:

`CallDescription{ builtin, "memcpy"}` will match for
`__builtin_wmemcpy()` calls, which is unfortunate.

This patch addresses/works around the issue by checking if the
characters around the function's name are not part of the 'name'
semantically. In other words, to accept a match for `"memcpy"` the call
should not have alphanumeric (`[a-zA-Z]`) characters around the 'match'.

So, `CallDescription{ builtin, "memcpy"}` will not match on:

 - `__builtin_wmemcpy: there is a `w` alphanumeric character before the match.
 - `__builtin_memcpyFOoBar_inline`: there is a `F` character after the match.
 - `__builtin_memcpyX_inline`: there is an `X` character after the match.

But it will still match for:
 - `memcpy`: exact match
 - `__builtin_memcpy`: there is an _ before the match
 - `__builtin_memcpy_inline`: there is an _ after the match
 - `memcpy_inline_builtinFooBar`: there is an _ after the match

Reviewed By: NoQ

Differential Revision: https://reviews.llvm.org/D118388
2022-02-11 10:45:18 +01:00
Balazs Benics 881b6a009f [analyzer][NFC] Re-enable skipped SValTests by relaxing expectations
Some tests were skipped in D114454 to resolve test failures on some
platforms, where the pointers have different bitwidth than expected.
This patch re-enables these tests, by relaxing the requirements on the
types of the SVal.

The issue:
There is no way to reconstruct the type of the `SVal` perfectly
accurately, since there could be multiple types having the required
bitwidth and signedness.
Consider platforms where `int` and `long` have the same bitwidth.
Additionally, we need to be careful about casting a pointer to an
integral representation, because we don't know what smallest integral
type can represent that.

To workaround these issues, I propose enforcing a type that has the
same signedness and bitwidth as the expected type, instead of perfect
equality.

In the `GetLocAsIntType` test, in case of pointer-to-integral casts
I'm using the widest standard integral type (long long) to make sure
that the pointer can be represented by the type without losing
precision. This won't affect the test in any meaningful way, since the
type of the `lvalue` remained the same.

In one case, I had to replace `getUIntPtrType()` with `UnsignedLongTy`
because on some platforms `getUIntPtrType()` is different then `long
int`.

In this patch, I also enforce that the tests must compile without
errors, to prevent narrowing conversions in the future.

Reviewed By: stevewan

Differential Revision: https://reviews.llvm.org/D115349
2022-01-19 15:16:18 +01:00
Denys Petrov 6a399bf4b3 [analyzer] Implemented RangeSet::Factory::unite function to handle intersections and adjacency
Summary: Handle intersected and adjacent ranges uniting them into a single one.
Example:
intersection [0, 10] U [5, 20] = [0, 20]
adjacency [0, 10] U [11, 20] = [0, 20]

Differential Revision: https://reviews.llvm.org/D99797
2021-12-10 18:48:02 +02:00
Steven Wan 9c4d194f44 [analyzer]Skip unstable CSA tests failing on several platforms
Clang static analyzer uses bitwidth to infer the integer value type, that is, any 32-bit integer is considered of type `int`, and any 64-bit integer is considered of type `long`. This isn't always true, for instance, in ILP32 (e.g., 32-bit AIX), 32-bit could be `long`, and in LP64 (e.g., 64-bit wasm64), 64-bit could be `long long`.

Reviewed By: steakhal

Differential Revision: https://reviews.llvm.org/D114454
2021-12-02 18:30:14 -05:00
Balazs Benics f18da190b0 [analyzer][NFC] Switch to using CallDescription::matches() instead of isCalled()
This patch replaces each use of the previous API with the new one.
In variadic cases, it will use the ADL `matchesAny(Call, CDs...)`
variadic function.
Also simplifies some code involving such operations.

Reviewed By: martong, xazax.hun

Differential Revision: https://reviews.llvm.org/D113591
2021-11-19 18:32:13 +01:00
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 9b5c9c469d [analyzer] Dump checker name if multiple checkers evaluate the same call
Previously, if accidentally multiple checkers `eval::Call`-ed the same
`CallEvent`, in debug builds the analyzer detected this and crashed
with the message stating this. Unfortunately, the message did not state
the offending checkers violating this invariant.
This revision addresses this by printing a more descriptive message
before aborting.

Reviewed By: martong

Differential Revision: https://reviews.llvm.org/D112889
2021-11-02 14:42:14 +01:00
Balazs Benics 72d04d7b2b [analyzer] Allow matching non-CallExprs using CallDescriptions
Fallback to stringification and string comparison if we cannot compare
the `IdentifierInfo`s, which is the case for C++ overloaded operators,
constructors, destructors, etc.

Examples:
  { "std", "basic_string", "basic_string", 2} // match the 2 param std::string constructor
  { "std", "basic_string", "~basic_string" }  // match the std::string destructor
  { "aaa", "bbb", "operator int" } // matches the struct bbb conversion operator to int

Reviewed By: martong

Differential Revision: https://reviews.llvm.org/D111535
2021-10-18 14:57:24 +02:00
Balazs Benics 5644d15257 [analyzer][NFC] Add unittests for CallDescription and split the old ones
This NFC change accomplishes three things:
1) Splits up the single unittest into reasonable segments.
2) Extends the test infra using a template to select the AST-node
   from which it is supposed to construct a `CallEvent`.
3) Adds a *lot* of different tests, documenting the current
   capabilities of the `CallDescription`. The corresponding tests are
   marked with `FIXME`s, where the current behavior should be different.

Both `CXXMemberCallExpr` and `CXXOperatorCallExpr` are derived from
`CallExpr`, so they are matched by using the default template parameter.
On the other hand, `CXXConstructExpr` is not derived from `CallExpr`.
In case we want to match for them, we need to pass the type explicitly
to the `CallDescriptionAction`.

About destructors:
They have no AST-node, but they are generated in the CFG machinery in
the analyzer. Thus, to be able to match against them, we would need to
construct a CFG and walk on that instead of simply walking the AST.

I'm also relaxing the `EXPECT`ation in the
`CallDescriptionConsumer::performTest()`, to check the `LookupResult`
only if we matched for the `CallDescription`.
This is necessary to allow tests in which we expect *no* matches at all.

Reviewed By: martong

Differential Revision: https://reviews.llvm.org/D111794
2021-10-18 14:57:24 +02:00
Kristóf Umann fb4d590a62 Fix a unittest file after D108695 when Z3 is enabled 2021-09-14 16:11:11 +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 a375bfb5b7.

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 7d0e62bfb7.
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
Balázs Kéri b0d38ad0bc [clang][Analyzer] Add symbol uninterestingness to bug report.
`PathSensitiveBughReport` has a function to mark a symbol as interesting but
it was not possible to clear this flag. This can be useful in some cases,
so the functionality is added.

Reviewed By: NoQ

Differential Revision: https://reviews.llvm.org/D105637
2021-07-15 10:02:18 +02:00
Valeriy Savchenko b2842298ce [analyzer] Fix SValTest for LocAsInt test 2021-06-29 13:01:41 +03:00
Valeriy Savchenko 159024ce23 [analyzer] Implement getType for SVal
This commit adds a function to the top-class of SVal hierarchy to
provide type information about the value.  That can be extremely
useful when this is the only piece of information that the user is
actually caring about.

Additionally, this commit introduces a testing framework for writing
unit-tests for symbolic values.

Differential Revision: https://reviews.llvm.org/D104550
2021-06-29 12:11:19 +03:00
Simon Pilgrim 61cdaf66fe [ADT] Remove APInt/APSInt toString() std::string variants
<string> is currently the highest impact header in a clang+llvm build:

https://commondatastorage.googleapis.com/chromium-browser-clang/llvm-include-analysis.html

One of the most common places this is being included is the APInt.h header, which needs it for an old toString() implementation that returns std::string - an inefficient method compared to the SmallString versions that it actually wraps.

This patch replaces these APInt/APSInt methods with a pair of llvm::toString() helpers inside StringExtras.h, adjusts users accordingly and removes the <string> from APInt.h - I was hoping that more of these users could be converted to use the SmallString methods, but it appears that most end up creating a std::string anyhow. I avoided trying to use the raw_ostream << operators as well as I didn't want to lose having the integer radix explicit in the code.

Differential Revision: https://reviews.llvm.org/D103888
2021-06-11 13:19:15 +01:00
Balazs Benics 3febf0b507 [analyzer][Z3][NFC] Use GTEST_SKIP instead of hacks
Since @bkramer bumped gtest to 1.10.0 I think it's a good time to clean
up some of my hacks.

Reviewed By: Szelethus

Differential Revision: https://reviews.llvm.org/D102643
2021-05-21 11:35:24 +02:00
Benjamin Kramer 05de4b4139 Put back the trailing commas on TYPED_TEST_SUITE
This avoids a -pedantic warning:
warning: ISO C++11 requires at least one argument for the "..." in a variadic macro

See also https://github.com/google/googletest/issues/2271
2021-05-17 14:14:13 +02:00
Benjamin Kramer d4d80a2903 Bump googletest to 1.10.0 2021-05-14 19:16:31 +02:00
Dmitri Gribenko 9cd7c41306 [analyzer] Don't include private gtest headers 2021-03-22 13:31:38 +01:00
Valeriy Savchenko 02b51e5316 [analyzer][solver] Redesign constraint ranges data structure
ImmutableSet doesn't seem like the perfect fit for the RangeSet
data structure.  It is good for saving memory in a persistent
setting, but not for the case when the population of the container
is tiny.  This commit replaces RangeSet implementation and
redesigns the most common operations to be more efficient.

Differential Revision: https://reviews.llvm.org/D86465
2021-03-22 13:52:35 +03:00
Adam Balogh facad21b29 [Analyzer] Fix for `ExprEngine::computeObjectUnderConstruction()` for base and delegating consturctor initializers
For /C++/ constructor initializers `ExprEngine:computeUnderConstruction()`
asserts that they are all member initializers. This is not neccessarily
true when this function is used to get the return value for the
construction context thus attempts to fetch return values of base and
delegating constructor initializers result in assertions. This small
patch fixes this issue.

Differential Revision: https://reviews.llvm.org/D85351
2020-09-25 13:28:22 +02:00
Balazs Benics 63d3aeb529 [analyzer] Fix out-of-tree only clang build by not relaying on private header
It turned out that the D78704 included a private LLVM header, which is excluded
from the LLVM install target.
I'm substituting that `#include` with the public one by moving the necessary
`#define` into that. There was a discussion about this at D78704 and on the
cfe-dev mailing list.

I'm also placing a note to remind others of this pitfall.

Reviewed By: mgorny

Differential Revision: https://reviews.llvm.org/D84929
2020-07-31 10:28:14 +02:00
Kirstóf Umann 690ff37a28 [analyzer] Force dependency checkers to be hidden
Since strong dependencies aren't user-facing (its hardly ever legal to disable
them), lets enforce that they are hidden. Modeling checkers that aren't
dependencies are of course not impacted, but there is only so much you can do
against developers shooting themselves in the foot :^)

I also made some changes to the test files, reversing the "test" package for,
well, testing.

Differential Revision: https://reviews.llvm.org/D81761
2020-07-06 13:05:45 +02:00
Kirstóf Umann b6cbe6cb03 [analyzer][NFC] Move the data structures from CheckerRegistry to the Core library
If you were around the analyzer for a while now, you must've seen a lot of
patches that awkwardly puts code from one library to the other:

* D75360 moves the constructors of CheckerManager, which lies in the Core
  library, to the Frontend library. Most the patch itself was a struggle along
  the library lines.
* D78126 had to be reverted because dependency information would be utilized
  in the Core library, but the actual data lied in the frontend.
  D78126#inline-751477 touches on this issue as well.

This stems from the often mentioned problem: the Frontend library depends on
Core and Checkers, Checkers depends on Core. The checker registry functions
(`registerMallocChecker`, etc) lie in the Checkers library in order to keep each
checker its own module. What this implies is that checker registration cannot
take place in the Core, but the Core might still want to use the data that
results from it (which checker/package is enabled, dependencies, etc).

D54436 was the patch that initiated this. Back in the days when CheckerRegistry
was super dumb and buggy, it implemented a non-documented solution to this
problem by keeping the data in the Core, and leaving the logic in the Frontend.
At the time when the patch landed, the merger to the Frontend made sense,
because the data hadn't been utilized anywhere, and the whole workaround without
any documentation made little sense to me.

So, lets put the data back where it belongs, in the Core library. This patch
introduces `CheckerRegistryData`, and turns `CheckerRegistry` into a short lived
wrapper around this data that implements the logic of checker registration. The
data is tied to CheckerManager because it is required to parse it.

Side note: I can't help but cringe at the fact how ridiculously awkward the
library lines are. I feel like I'm thinking too much inside the box, but I guess
this is just the price of keeping the checkers so modularized.

Differential Revision: https://reviews.llvm.org/D82585
2020-07-04 12:31:51 +02:00
Balazs Benics de361df3f6 [analyzer][Z3-refutation] Fix a refutation BugReporterVisitor bug
FalsePositiveRefutationBRVisitor had a bug where the constraints were not
properly collected thus crosschecked with Z3.
This patch demonstratest and fixes that bug.

Bug:
The visitor wanted to collect all the constraints on a BugPath.
Since it is a visitor, it stated the visitation of the BugPath with the node
before the ErrorNode. As a final step, it visited the ErrorNode explicitly,
before it processed the collected constraints.

In principle, the ErrorNode should have visited before every other node.
Since the constraints were collected into a map, mapping each symbol to its
RangeSet, if the map already had a mapping with the symbol, then it was skipped.

This behavior was flawed if:
We already had a constraint on a symbol, but at the end in the ErrorNode we have
a tighter constraint on that. Therefore, this visitor would not utilize that
tighter constraint during the crosscheck validation.

Differential Revision: https://reviews.llvm.org/D78457
2020-06-29 18:51:24 +02:00
Balazs Benics fe0a555aa3 [analyzer][NFC] Add unittest for FalsePositiveRefutationBRVisitor
Adds the test infrastructure for testing the FalsePositiveRefutationBRVisitor.
It will be extended in the D78457 patch, which demonstrates and fixes a bug in
the visitor.

Differential Revision: https://reviews.llvm.org/D78704
2020-06-29 18:18:43 +02:00
Dmitri Gribenko a44425f25b Revert "[analyzer][NFC] Add unittest for FalsePositiveRefutationBRVisitor"
This reverts commit e22cae32c5. It broke
the build:

FalsePositiveRefutationBRVisitorTest.cpp:112:3: error: use of undeclared identifier 'LLVM_WITH_Z3'
2020-06-29 17:00:15 +02:00
Balazs Benics e22cae32c5 [analyzer][NFC] Add unittest for FalsePositiveRefutationBRVisitor
Adds the test infrastructure for testing the FalsePositiveRefutationBRVisitor.
It will be extended in the D78457 patch, which demonstrates and fixes a bug in
the visitor.

Differential Revision: https://reviews.llvm.org/D78704
2020-06-29 16:54:17 +02:00
Adam Balogh b2a37cfe2b [Analyzer] Replace `assert` with `ASSERT_TRUE` in a unit test to silence warnings 2020-06-12 17:09:34 +02:00
Kirstóf Umann e22f1c02a2 [analyzer] Introduce weak dependencies to express *preferred* checker callback evaluation order
Checker dependencies were added D54438 to solve a bug where the checker names
were incorrectly registered, for example, InnerPointerChecker would incorrectly
emit diagnostics under the name MallocChecker, or vice versa [1]. Since the
system over the course of about a year matured, our expectations of what a role
of a dependency and a dependent checker should be crystallized a bit more --
D77474 and its summary, as well as a variety of patches in the stack
demonstrates how we try to keep dependencies to play a purely modeling role. In
fact, D78126 outright forbids diagnostics under a dependency checkers name.

These dependencies ensured the registration order and enabling only when all
dependencies are satisfied. This was a very "strong" contract however, that
doesn't fit the dependency added in D79420. As its summary suggests, this
relation is directly in between diagnostics, not modeling -- we'd prefer a more
specific warning over a general one.

To support this, I added a new dependency kind, weak dependencies. These are not
as strict of a contract, they only express a preference in registration order.
If a weak dependency isn't satisfied, the checker may still be enabled, but if
it is, checker registration, and transitively, checker callback evaluation order
is ensured.

If you are not familiar with the TableGen changes, a rather short description
can be found in the summary of D75360. A lengthier one is in D58065.

[1] https://www.youtube.com/watch?v=eqKeqHRAhQM

Differential Revision: https://reviews.llvm.org/D80905
2020-06-12 14:08:38 +02:00
Kirstóf Umann d61b1f8534 [analyzer][NFC] Change checker dependency unit tests to check for the registration order
Exactly what it says on the tin! "Strong" dependencies are mentioned in contrast
to a new kind of dependency introduced in a followup patch.

Differential Revision: https://reviews.llvm.org/D80901
2020-06-12 12:43:56 +02:00
Simon Pilgrim 948b206fc2 Add missing lambda capture from rGf529c0a8a149. 2020-06-11 13:57:39 +01:00