Commit Graph

2240 Commits

Author SHA1 Message Date
Matheus Izvekov bcd9ba2b7e
[clang] Track the templated entity in type substitution.
This is a change to how we represent type subsitution in the AST.
Instead of only storing the replaced type, we track the templated
entity we are substituting, plus an index.
We modify MLTAL to track the templated entity at each level.

Otherwise, it's much more expensive to go from the template parameter back
to the templated entity, and not possible to do in some cases, as when
we instantiate outer templates, parameters might still reference the
original entity.

This also allows us to very cheaply lookup the templated entity we saw in
the naming context and find the corresponding argument it was replaced
from, such as for implementing template specialization resugaring.

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

Differential Revision: https://reviews.llvm.org/D131858
2022-10-15 22:08:36 +02:00
Arseniy Zaostrovnykh ec6da3fb9d Fix false positive related to handling of [[noreturn]] function pointers
Before this change, the `NoReturnFunctionChecker` was missing function pointers
with a `[[noreturn]]` attribute, while `CFG` was constructed taking that into
account, which leads CSA to take impossible paths. The reason was that the
`NoReturnFunctionChecker` was looking for the attribute in the type of the
entire call expression rather than the type of the function being called.

This change makes the `[[noreturn]]` attribute of a function pointer visible
to `NoReturnFunctionChecker`. This leads to a more coherent behavior of the
CSA on the AST involving.

Reviewed By: xazax.hun

Differential Revision: https://reviews.llvm.org/D135682
2022-10-12 14:46:32 +02:00
Argyrios Kyrtzidis 371883f46d [clang/Sema] Fix non-deterministic order for certain kind of diagnostics
In the context of caching clang invocations it is important to emit diagnostics in deterministic order;
the same clang invocation should result in the same diagnostic output.

rdar://100336989

Differential Revision: https://reviews.llvm.org/D135118
2022-10-05 12:58:01 -07:00
Balazs Benics f8643a9b31 [analyzer] Prefer wrapping SymbolicRegions by ElementRegions
It turns out that in certain cases `SymbolRegions` are wrapped by
`ElementRegions`; in others, it's not. This discrepancy can cause the
analyzer not to recognize if the two regions are actually referring to
the same entity, which then can lead to unreachable paths discovered.

Consider this example:

```lang=C++
struct Node { int* ptr; };
void with_structs(Node* n1) {
  Node c = *n1; // copy
  Node* n2 = &c;
  clang_analyzer_dump(*n1); // lazy...
  clang_analyzer_dump(*n2); // lazy...
  clang_analyzer_dump(n1->ptr); // rval(n1->ptr): reg_$2<int * SymRegion{reg_$0<struct Node * n1>}.ptr>
  clang_analyzer_dump(n2->ptr); // rval(n2->ptr): reg_$1<int * Element{SymRegion{reg_$0<struct Node * n1>},0 S64b,struct Node}.ptr>
  clang_analyzer_eval(n1->ptr != n2->ptr); // UNKNOWN, bad!
  (void)(*n1);
  (void)(*n2);
}
```

The copy of `n1` will insert a new binding to the store; but for doing
that it actually must create a `TypedValueRegion` which it could pass to
the `LazyCompoundVal`. Since the memregion in question is a
`SymbolicRegion` - which is untyped, it needs to first wrap it into an
`ElementRegion` basically implementing this untyped -> typed conversion
for the sake of passing it to the `LazyCompoundVal`.
So, this is why we have `Element{SymRegion{.}, 0,struct Node}` for `n1`.

The problem appears if the analyzer evaluates a read from the expression
`n1->ptr`. The same logic won't apply for `SymbolRegionValues`, since
they accept raw `SubRegions`, hence the `SymbolicRegion` won't be
wrapped into an `ElementRegion` in that case.

Later when we arrive at the equality comparison, we cannot prove that
they are equal.

For more details check the corresponding thread on discourse:
https://discourse.llvm.org/t/are-symbolicregions-really-untyped/64406

---

In this patch, I'm eagerly wrapping each `SymbolicRegion` by an
`ElementRegion`; basically canonicalizing to this form.
It seems reasonable to do so since any object can be thought of as a single
array of that object; so this should not make much of a difference.

The tests also underpin this assumption, as only a few were broken by
this change; and actually fixed a FIXME along the way.

About the second example, which does the same copy operation - but on
the heap - it will be fixed by the next patch.

Reviewed By: martong

Differential Revision: https://reviews.llvm.org/D132142
2022-09-13 08:58:46 +02:00
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
Kazu Hirata b7a7aeee90 [clang] Qualify auto in range-based for loops (NFC) 2022-09-03 23:27:27 -07:00
Balázs Kéri d56a1c6824 [clang][analyzer] Errno modeling code refactor (NFC).
Some of the code used in StdLibraryFunctionsChecker is applicable to
other checkers, this is put into common functions. Errno related
parts of the checker are simplified and renamed. Documentations in
errno_modeling functions are updated.

This change makes it available to have more checkers that perform
modeling of some standard functions. These can set the errno state
with common functions and the bug report messages (note tags) can
look similar.

Reviewed By: steakhal, martong

Differential Revision: https://reviews.llvm.org/D131879
2022-09-01 09:05:59 +02:00
ziqingluo-90 a5e354ec4d [analyzer] Fixing a bug raising false positives of stack block object
leaking in ARC mode

When ARC (automatic reference count) is enabled, (objective-c) block
objects are automatically retained and released thus they do not leak.
Without ARC, they still can leak from an expiring stack frame like
other stack variables.
With this commit, the static analyzer now puts a block object in an
"unknown" region if ARC is enabled because it is up to the
implementation to choose whether to put the object on stack initially
(then move to heap when needed) or in heap directly under ARC.
Therefore, the `StackAddrEscapeChecker` has no need to know
specifically about ARC at all and it will not report errors on objects
in "unknown" regions.

Reviewed By: NoQ (Artem Dergachev)

Differential Revision: https://reviews.llvm.org/D131009
2022-08-26 12:19:32 -07:00
Fred Tingaud 16cb3be626 [analyzer] Deadstore static analysis: Fix false positive on C++17 assignments
Dead store detection automatically checks that an expression is a
CXXConstructor and skips it because of potential side effects. In C++17,
with guaranteed copy elision, this check can fail because we actually
receive the implicit cast of a CXXConstructor.
Most checks in the dead store analysis were already stripping all casts
and parenthesis and those that weren't were either forgotten (like the
constructor) or would not suffer from it, so this patch proposes to
factorize the stripping.
It has an impact on where the dead store warning is reported in the case
of an explicit cast, from

  auto a = static_cast<B>(A());
           ^~~~~~~~~~~~~~~~~~~

to

  auto a = static_cast<B>(A());
                          ^~~

which we think is an improvement.

Patch By: frederic-tingaud-sonarsource

Reviewed By: steakhal

Differential Revision: https://reviews.llvm.org/D126534
2022-08-23 18:33:26 +02:00
malavikasamak c74a204826 [analyzer] Fix false positive in use-after-move checker
Differential Revision: https://reviews.llvm.org/D131525
2022-08-09 17:26:30 -07:00
Fangrui Song 32197830ef [clang][clang-tools-extra] LLVM_NODISCARD => [[nodiscard]]. NFC 2022-08-09 07:11:18 +00:00
Fangrui Song 3f18f7c007 [clang] LLVM_FALLTHROUGH => [[fallthrough]]. NFC
With C++17 there is no Clang pedantic warning or MSVC C5051.

Reviewed By: aaron.ballman

Differential Revision: https://reviews.llvm.org/D131346
2022-08-08 09:12:46 -07:00
Balázs Kéri 501faaa0d6 [clang][analyzer] Add more wide-character functions to CStringChecker
Support for functions wmempcpy, wmemmove, wmemcmp is added to the checker.
The same tests are copied that exist for the non-wide versions, with
non-wide functions and character types changed to the wide version.

Reviewed By: martong

Differential Revision: https://reviews.llvm.org/D130470
2022-08-05 10:32:53 +02:00
Corentin Jabot 127bf44385 [Clang][C++20] Support capturing structured bindings in lambdas
This completes the implementation of P1091R3 and P1381R1.

This patch allow the capture of structured bindings
both for C++20+ and C++17, with extension/compat warning.

In addition, capturing an anonymous union member,
a bitfield, or a structured binding thereof now has a
better diagnostic.

We only support structured bindings - as opposed to other kinds
of structured statements/blocks. We still emit an error for those.

In addition, support for structured bindings capture is entirely disabled in
OpenMP mode as this needs more investigation - a specific diagnostic indicate the feature is not yet supported there.

Note that the rest of P1091R3 (static/thread_local structured bindings) was already implemented.

at the request of @shafik, i can confirm the correct behavior of lldb wit this change.

Fixes https://github.com/llvm/llvm-project/issues/54300
Fixes https://github.com/llvm/llvm-project/issues/54300
Fixes https://github.com/llvm/llvm-project/issues/52720

Reviewed By: aaron.ballman

Differential Revision: https://reviews.llvm.org/D122768
2022-08-04 10:12:53 +02:00
Corentin Jabot a274219600 Revert "[Clang][C++20] Support capturing structured bindings in lambdas"
This reverts commit 44f2baa380.

Breaks self builds and seems to have conformance issues.
2022-08-03 21:00:29 +02:00
Corentin Jabot 44f2baa380 [Clang][C++20] Support capturing structured bindings in lambdas
This completes the implementation of P1091R3 and P1381R1.

This patch allow the capture of structured bindings
both for C++20+ and C++17, with extension/compat warning.

In addition, capturing an anonymous union member,
a bitfield, or a structured binding thereof now has a
better diagnostic.

We only support structured bindings - as opposed to other kinds
of structured statements/blocks. We still emit an error for those.

In addition, support for structured bindings capture is entirely disabled in
OpenMP mode as this needs more investigation - a specific diagnostic indicate the feature is not yet supported there.

Note that the rest of P1091R3 (static/thread_local structured bindings) was already implemented.

at the request of @shafik, i can confirm the correct behavior of lldb wit this change.

Fixes https://github.com/llvm/llvm-project/issues/54300
Fixes https://github.com/llvm/llvm-project/issues/54300
Fixes https://github.com/llvm/llvm-project/issues/52720

Reviewed By: aaron.ballman

Differential Revision: https://reviews.llvm.org/D122768
2022-08-03 20:00:01 +02:00
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
Kazu Hirata 3f3930a451 Remove redundaunt virtual specifiers (NFC)
Identified with tidy-modernize-use-override.
2022-07-25 23:00:59 -07:00
Balázs Kéri 94ca2beccc [clang][analyzer] Added partial wide character support to CStringChecker
Support for functions wmemcpy, wcslen, wcsnlen is added to the checker.
Documentation and tests are updated and extended with the new functions.

Reviewed By: martong

Differential Revision: https://reviews.llvm.org/D130091
2022-07-25 09:23:14 +02:00
Kazu Hirata a210f404da [clang] Remove redundant virtual specifies (NFC)
Identified with modernize-use-override.
2022-07-24 22:02:58 -07:00
Kazu Hirata 9e88cbcc40 Use any_of (NFC) 2022-07-24 14:48:11 -07:00
Denys Petrov bc08c3cb7f [analyzer] Add new function `clang_analyzer_value` to ExprInspectionChecker
Summary: Introduce a new function 'clang_analyzer_value'. It emits a report that in turn prints a RangeSet or APSInt associated with SVal. If there is no associated value, prints "n/a".
2022-07-15 20:07:04 +03:00
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
Kazu Hirata cb2c8f694d [clang] Use value instead of getValue (NFC) 2022-07-13 23:39:33 -07:00
einvbri 1d7e58cfad [analyzer] Fix use of length in CStringChecker
CStringChecker is using getByteLength to get the length of a string
literal. For targets where a "char" is 8-bits, getByteLength() and
getLength() will be equal for a C string, but for targets where a "char"
is 16-bits getByteLength() returns the size in octets.

This is verified in our downstream target, but we have no way to add a
test case for this case since there is no target supporting 16-bit
"char" upstream. Since this cannot have a test case, I'm asserted this
change is "correct by construction", and visually inspected to be
correct by way of the following example where this was found.

The case that shows this fails using a target with 16-bit chars is here.
getByteLength() for the string literal returns 4, which fails when
checked against "char x[4]". With the change, the string literal is
evaluated to a size of 2 which is a correct number of "char"'s for a
16-bit target.

```
void strcpy_no_overflow_2(char *y) {
  char x[4];
  strcpy(x, "12"); // with getByteLength(), returns 4 using 16-bit chars
}
```

This change exposed that embedded nulls within the string are not
handled. This is documented as a FIXME for a future fix.

```
    void strcpy_no_overflow_3(char *y) {
      char x[3];
      strcpy(x, "12\0");
    }

```

Reviewed By: martong

Differential Revision: https://reviews.llvm.org/D129269
2022-07-13 19:19:23 -05:00
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
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
Corentin Jabot 64ab2b1dcc Improve handling of static assert messages.
Instead of dumping the string literal (which
quotes it and escape every non-ascii symbol),
we can use the content of the string when it is a
8 byte string.

Wide, UTF-8/UTF-16/32 strings are still completely
escaped, until we clarify how these entities should
behave (cf https://wg21.link/p2361).

`FormatDiagnostic` is modified to escape
non printable characters and invalid UTF-8.

This ensures that unicode characters, spaces and new
lines are properly rendered in static messages.
This make clang more consistent with other implementation
and fixes this tweet
https://twitter.com/jfbastien/status/1298307325443231744 :)

Of note, `PaddingChecker` did print out new lines that were
later removed by the diagnostic printing code.
To be consistent with its tests, the new lines are removed
from the diagnostic.

Unicode tables updated to both use the Unicode definitions
and the Unicode 14.0 data.

U+00AD SOFT HYPHEN is still considered a print character
to match existing practices in terminals, in addition of
being considered a formatting character as per Unicode.

Reviewed By: aaron.ballman, #clang-language-wg

Differential Revision: https://reviews.llvm.org/D108469
2022-06-29 14:57:35 +02:00
Corentin Jabot a774ba7f60 Revert "Improve handling of static assert messages."
This reverts commit 870b6d2183.

This seems to break some libc++ tests, reverting while investigating
2022-06-29 00:03:23 +02:00
Corentin Jabot 870b6d2183 Improve handling of static assert messages.
Instead of dumping the string literal (which
quotes it and escape every non-ascii symbol),
we can use the content of the string when it is a
8 byte string.

Wide, UTF-8/UTF-16/32 strings are still completely
escaped, until we clarify how these entities should
behave (cf https://wg21.link/p2361).

`FormatDiagnostic` is modified to escape
non printable characters and invalid UTF-8.

This ensures that unicode characters, spaces and new
lines are properly rendered in static messages.
This make clang more consistent with other implementation
and fixes this tweet
https://twitter.com/jfbastien/status/1298307325443231744 :)

Of note, `PaddingChecker` did print out new lines that were
later removed by the diagnostic printing code.
To be consistent with its tests, the new lines are removed
from the diagnostic.

Unicode tables updated to both use the Unicode definitions
and the Unicode 14.0 data.

U+00AD SOFT HYPHEN is still considered a print character
to match existing practices in terminals, in addition of
being considered a formatting character as per Unicode.

Reviewed By: aaron.ballman, #clang-language-wg

Differential Revision: https://reviews.llvm.org/D108469
2022-06-28 22:26:00 +02:00
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 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
Balázs Kéri 7dc81c6244 [clang][analyzer] Fix StdLibraryFunctionsChecker 'mkdir' return value.
The functions 'mkdir', 'mknod', 'mkdirat', 'mknodat' return 0 on success
and -1 on failure. The checker modeled these functions with a >= 0
return value on success which is changed to 0 only. This fix makes
ErrnoChecker work better for these functions.

Reviewed By: steakhal

Differential Revision: https://reviews.llvm.org/D127277
2022-06-23 11:27:26 +02:00
Balázs Kéri 957014da2d [clang][Analyzer] Add errno state to standard functions modeling.
This updates StdLibraryFunctionsChecker to set the state of 'errno'
by using the new errno_modeling functionality.
The errno value is set in the PostCall callback. Setting it in call::Eval
did not work for some reason and then every function should be
EvalCallAsPure which may be bad to do. Now the errno value and state
is not allowed to be checked in any PostCall checker callback because
it is unspecified if the errno was set already or will be set later
by this checker.

Reviewed By: martong, steakhal

Differential Revision: https://reviews.llvm.org/D125400
2022-06-21 08:56:41 +02:00
Kazu Hirata ca4af13e48 [clang] Don't use Optional::getValue (NFC) 2022-06-20 22:59:26 -07:00
Kazu Hirata 064a08cd95 Don't use Optional::hasValue (NFC) 2022-06-20 20:05:16 -07:00
Kazu Hirata 452db157c9 [clang] Don't use Optional::hasValue (NFC) 2022-06-20 10:51:34 -07:00
Balázs Kéri 60f3b07118 [clang][analyzer] Add checker for bad use of 'errno'.
Extend checker 'ErrnoModeling' with a state of 'errno' to indicate
the importance of the 'errno' value and how it should be used.
Add a new checker 'ErrnoChecker' that observes use of 'errno' and
finds possible wrong uses, based on the "errno state".
The "errno state" should be set (together with value of 'errno')
by other checkers (that perform modeling of the given function)
in the future. Currently only a test function can set this value.
The new checker has no user-observable effect yet.

Reviewed By: martong, steakhal

Differential Revision: https://reviews.llvm.org/D122150
2022-06-20 10:07:31 +02:00
Kazu Hirata 06decd0b41 [clang] Use value_or instead of getValueOr (NFC) 2022-06-18 23:21:34 -07:00
Balazs Benics f4fc3f6ba3 [analyzer] Treat system globals as mutable if they are not const
Previously, system globals were treated as immutable regions, unless it
was the `errno` which is known to be frequently modified.

D124244 wants to add a check for stores to immutable regions.
It would basically turn all stores to system globals into an error even
though we have no reason to believe that those mutable sys globals
should be treated as if they were immutable. And this leads to
false-positives if we apply D124244.

In this patch, I'm proposing to treat mutable sys globals actually
mutable, hence allocate them into the `GlobalSystemSpaceRegion`, UNLESS
they were declared as `const` (and a primitive arithmetic type), in
which case, we should use `GlobalImmutableSpaceRegion`.

In any other cases, I'm using the `GlobalInternalSpaceRegion`, which is
no different than the previous behavior.

---

In the tests I added, only the last `expected-warning` was different, compared to the baseline.
Which is this:
```lang=C++
void test_my_mutable_system_global_constraint() {
  assert(my_mutable_system_global > 2);
  clang_analyzer_eval(my_mutable_system_global > 2); // expected-warning {{TRUE}}
  invalidate_globals();
  clang_analyzer_eval(my_mutable_system_global > 2); // expected-warning {{UNKNOWN}} It was previously TRUE.
}
void test_my_mutable_system_global_assign(int x) {
  my_mutable_system_global = x;
  clang_analyzer_eval(my_mutable_system_global == x); // expected-warning {{TRUE}}
  invalidate_globals();
  clang_analyzer_eval(my_mutable_system_global == x); // expected-warning {{UNKNOWN}} It was previously TRUE.
}
```

---

Unfortunately, the taint checker will be also affected.
The `stdin` global variable is a pointer, which is assumed to be a taint
source, and the rest of the taint propagation rules will propagate from
it.
However, since mutable variables are no longer treated immutable, they
also get invalidated, when an opaque function call happens, such as the
first `scanf(stdin, ...)`. This would effectively remove taint from the
pointer, consequently disable all the rest of the taint propagations
down the line from the `stdin` variable.

All that said, I decided to look through `DerivedSymbol`s as well, to
acquire the memregion in that case as well. This should preserve the
previously existing taint reports.

Reviewed By: martong

Differential Revision: https://reviews.llvm.org/D127306
2022-06-15 17:08:27 +02:00
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 481f860324 [analyzer][NFC] Remove dead field of UnixAPICheckers
Initially, I thought there is some fundamental bug here by not using the
bool fields, but it turns out D55425 split this checker into two
separate ones; making these fields dead.

Depends on D127836, which uncovered this issue.

Reviewed By: martong

Differential Revision: https://reviews.llvm.org/D127838
2022-06-15 16:50:12 +02:00
Balazs Benics 6c4f9998ae [analyzer] Fix StreamErrorState hash bug
The `Profile` function was incorrectly implemented.
The `StreamErrorState` has an implicit `bool` conversion operator, which
will result in a different hash than faithfully hashing the raw value of
the enum.

I don't have a test for it, since it seems difficult to find one.
Even if we would have one, any change in the hashing algorithm would
have a chance of breaking it, so I don't think it would justify the
effort.

Depends on D127836, which uncovered this issue by marking the related
`Profile` function dead.

Reviewed By: martong, balazske

Differential Revision: https://reviews.llvm.org/D127839
2022-06-15 16:50:12 +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 de6ba9704d [analyzer][Casting] Support isa, cast, dyn_cast of SVals
This change specializes the LLVM RTTI mechanism for SVals.
After this change, we can use the well-known `isa`, `cast`, `dyn_cast`.

Examples:

  // SVal V = ...;
  // Loc MyLoc = ...;

  bool IsInteresting = isa<loc::MemRegionVal, loc::GotoLabel>(MyLoc);
  auto MRV = cast<loc::MemRegionVal>(MyLoc);
  Optional<loc::MemRegionVal> MaybeMRV = dyn_cast<loc::MemRegionVal>(V)

The current `SVal::getAs` and `castAs` member functions are redundant at
this point, but I believe that they are still handy.

The member function version is terse and reads left-to-right, which IMO
is a great plus. However, we should probably add a variadic `isa` member
function version to have the same casting API in both cases.

Thanks for the extensive TMP help @bzcheeseman!

Reviewed By: bzcheeseman

Differential Revision: https://reviews.llvm.org/D125709
2022-06-14 13:43:04 +02:00
Vince Bridgers c7fa4e8a8b [analyzer] Fix null pointer deref in CastValueChecker
A crash was seen in CastValueChecker due to a null pointer dereference.

The fix uses QualType::getAsString to avoid the null dereference
when a CXXRecordDecl cannot be obtained. A small reproducer is added,
and cast value notes LITs are updated for the new debug messages.

Reviewed By: steakhal

Differential Revision: https://reviews.llvm.org/D127105
2022-06-07 13:34:06 -04:00
Balazs Benics 7d24641f89 [llvm][analyzer][NFC] Introduce SFINAE for specializing FoldingSetTraits
Reviewed By: martong

Differential Revision: https://reviews.llvm.org/D126803
2022-06-02 19:46:38 +02:00
Balazs Benics cf1f1b7240 [analyzer][NFC] Uplift checkers after D126801
Reviewed By: martong

Differential Revision: https://reviews.llvm.org/D126802
2022-06-02 19:46:38 +02:00