[clang] Fix 71315698c9 in presence of incomplete types (#114095)

Incomplete types are not considered trivially copyable by clang but we
don't want to warn about invalid argument for memcpy / memset

[clang] Fix 71315698c9 in presence of incomplete types (#114095)

Incomplete types are not considered trivially copyable by clang but we
don't want to warn about invalid argument for memcpy / memset in that
case because we cannot prove they are not Trivially Copyable.

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[clang] Warn about memset/memcpy to NonTriviallyCopyable types (#111434)

This implements a warning that's similar to what GCC does in that
context: both memcpy and memset require their first and se

[clang] Warn about memset/memcpy to NonTriviallyCopyable types (#111434)

This implements a warning that's similar to what GCC does in that
context: both memcpy and memset require their first and second operand
to be trivially copyable, let's warn if that's not the case.

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[clang] Fix crash in __builtin_strncmp and other related builtin functions

The implementation of __builtin_strncmp and other related builtins function use
getExtValue() to evaluate the size argument

[clang] Fix crash in __builtin_strncmp and other related builtin functions

The implementation of __builtin_strncmp and other related builtins function use
getExtValue() to evaluate the size argument. This can cause a crash when the
value does not fit into an int64_t value, which is can be expected since the
type of the argument is size_t.

The fix is to switch to using getZExtValue().

This fixes: https://github.com/llvm/llvm-project/issues/64876

Differential Revision: https://reviews.llvm.org/D158557

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Add extension diagnostic for linemarker directives

This adds the -Wgnu-line-marker diagnostic flag, grouped under -Wgnu,
to warn about use of the GNU linemarker preprocessor extension.

Fixes #55067

Add extension diagnostic for linemarker directives

This adds the -Wgnu-line-marker diagnostic flag, grouped under -Wgnu,
to warn about use of the GNU linemarker preprocessor extension.

Fixes #55067

Differential Revision: https://reviews.llvm.org/D124534

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Recommit: Compress formatting of array type names (int [4] -> int[4])

Based on post-commit review discussion on
2bd84938470bf2e337801faafb8a67710f46429d with Richard Smith.

Other uses of forcing Ha

Recommit: Compress formatting of array type names (int [4] -> int[4])

Based on post-commit review discussion on
2bd84938470bf2e337801faafb8a67710f46429d with Richard Smith.

Other uses of forcing HasEmptyPlaceHolder to false seem OK to me -
they're all around pointer/reference types where the pointer/reference
token will appear at the rightmost side of the left side of the type
name, so they make nested types (eg: the "int" in "int *") behave as
though there is a non-empty placeholder (because the "*" is essentially
the placeholder as far as the "int" is concerned).

This was originally committed in 277623f4d5a672d707390e2c3eaf30a9eb4b075c

Reverted in f9ad1d1c775a8e264bebc15d75e0c6e5c20eefc7 due to breakages
outside of clang - lldb seems to have some strange/strong dependence on
"char [N]" versus "char[N]" when printing strings (not due to that name
appearing in DWARF, but probably due to using clang to stringify type
names) that'll need to be addressed, plus a few other odds and ends in
other subprojects (clang-tools-extra, compiler-rt, etc).

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Revert "Compress formatting of array type names (int [4] -> int[4])"

Looks like lldb has some issues with this - somehow it causes lldb to
treat a "char[N]" type as an array of chars (prints them ou

Revert "Compress formatting of array type names (int [4] -> int[4])"

Looks like lldb has some issues with this - somehow it causes lldb to
treat a "char[N]" type as an array of chars (prints them out
individually) but a "char [N]" is printed as a string. (even though the
DWARF doesn't have this string in it - it's something to do with the
string lldb generates for itself using clang)

This reverts commit 277623f4d5a672d707390e2c3eaf30a9eb4b075c.

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Compress formatting of array type names (int [4] -> int[4])

Based on post-commit review discussion on
2bd84938470bf2e337801faafb8a67710f46429d with Richard Smith.

Other uses of forcing HasEmptyPlac

Compress formatting of array type names (int [4] -> int[4])

Based on post-commit review discussion on
2bd84938470bf2e337801faafb8a67710f46429d with Richard Smith.

Other uses of forcing HasEmptyPlaceHolder to false seem OK to me -
they're all around pointer/reference types where the pointer/reference
token will appear at the rightmost side of the left side of the type
name, so they make nested types (eg: the "int" in "int *") behave as
though there is a non-empty placeholder (because the "*" is essentially
the placeholder as far as the "int" is concerned).

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Permit constant evaluation of mixed __builtin_memcmp between char and
char8_t.

Add documentation and testing for
2c88a485c71155c19e512f22c54e63ee337282a3.

Also extend it to cover memchr for consistency.

PR45402: Make the restrictions on constant evaluation of memcmp and
memchr consistent and comprehensible, and document them.

We previously allowed evaluation of memcmp on arrays of integers of any
s

PR45402: Make the restrictions on constant evaluation of memcmp and
memchr consistent and comprehensible, and document them.

We previously allowed evaluation of memcmp on arrays of integers of any
size, so long as the call evaluated to 0, and allowed evaluation of
memchr on any array of integral type of size 1 (including enums). The
purpose of constant-evaluating these builtins is only to support
constexpr std::char_traits, so we now consistently allow them on arrays
of (possibly signed or unsigned) char only.

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[Builtins] Treat `bcmp` as a builtin.

Summary:
This makes it consistent with `memcmp` and `__builtin_bcmp`.

Also see the discussion in https://reviews.llvm.org/D56593.

Reviewers: jyknight

Subscri

[Builtins] Treat `bcmp` as a builtin.

Summary:
This makes it consistent with `memcmp` and `__builtin_bcmp`.

Also see the discussion in https://reviews.llvm.org/D56593.

Reviewers: jyknight

Subscribers: kristina, cfe-commits

Tags: #clang

Differential Revision: https://reviews.llvm.org/D58120

llvm-svn: 354023

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[ExprConstant] Improve memchr/memcmp for type mismatch and multibyte element types

Summary:
`memchr` and `memcmp` operate upon the character units of the object
representation; that is, the `size_t`

[ExprConstant] Improve memchr/memcmp for type mismatch and multibyte element types

Summary:
`memchr` and `memcmp` operate upon the character units of the object
representation; that is, the `size_t` parameter expresses the number of
character units. The constant folding implementation is updated in this
patch to account for multibyte element types in the arrays passed to
`memchr`/`memcmp` and, in the case of `memcmp`, to account for the
possibility that the arrays may have differing element types (even when
they are byte-sized).

Actual inspection of the object representation is not implemented.
Comparisons are done only between elements with the same object size;
that is, `memchr` will fail when inspecting at least one character unit
of a multibyte element. The integer types are assumed to have two's
complement representation with 0 for `false`, 1 for `true`, and no
padding bits.

`memcmp` on multibyte elements will only be able to fold in cases where
enough elements are equal for the answer to be 0.

Various tests are added to guard against incorrect folding for cases
that miscompile on some system or other prior to this patch. At the same
time, the unsigned 32-bit `wchar_t` testing in
`test/SemaCXX/constexpr-string.cpp` is restored.

Reviewers: rsmith, aaron.ballman, hfinkel

Reviewed By: rsmith

Subscribers: cfe-commits

Differential Revision: https://reviews.llvm.org/D55510

llvm-svn: 348938

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[constexpr] Fix ICE when memcpy() is given a pointer to an incomplete array

Fix code for constant evaluation of __builtin_memcpy() and
__builtin_memmove() that would attempt to divide by zero when g

[constexpr] Fix ICE when memcpy() is given a pointer to an incomplete array

Fix code for constant evaluation of __builtin_memcpy() and
__builtin_memmove() that would attempt to divide by zero when given two
pointers to an incomplete array.

Differential Revision: https://reviews.llvm.org/D51855

llvm-svn: 343761

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Fix crash on call to __builtin_memcpy with a null pointer to an
incomplete type.

Also improve the diagnostics for similar situations.

llvm-svn: 342192

[constexpr] Support for constant evaluation of __builtin_memcpy and
__builtin_memmove (in non-type-punning cases).

This is intended to permit libc++ to make std::copy etc constexpr
without sacrifici

[constexpr] Support for constant evaluation of __builtin_memcpy and
__builtin_memmove (in non-type-punning cases).

This is intended to permit libc++ to make std::copy etc constexpr
without sacrificing the optimization that uses memcpy on
trivially-copyable types.

__builtin_strcpy and __builtin_wcscpy are not handled by this change.
They'd be straightforward to add, but we haven't encountered a need for
them just yet.

This reinstates r338455, reverted in r338602, with a fix to avoid trying
to constant-evaluate a memcpy call if either pointer operand has an
invalid designator.

llvm-svn: 338941

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Revert r338455 "[constexpr] Support for constant evaluation of __builtin_memcpy and __builtin_memmove (in non-type-punning cases)."

It caused asserts during Chromium builds, see reply on the cfe-com

Revert r338455 "[constexpr] Support for constant evaluation of __builtin_memcpy and __builtin_memmove (in non-type-punning cases)."

It caused asserts during Chromium builds, see reply on the cfe-commits thread.

> This is intended to permit libc++ to make std::copy etc constexpr
> without sacrificing the optimization that uses memcpy on
> trivially-copyable types.
>
> __builtin_strcpy and __builtin_wcscpy are not handled by this change.
> They'd be straightforward to add, but we haven't encountered a need for
> them just yet.

llvm-svn: 338602

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[constexpr] Support for constant evaluation of __builtin_memcpy and
__builtin_memmove (in non-type-punning cases).

This is intended to permit libc++ to make std::copy etc constexpr
without sacrifici

[constexpr] Support for constant evaluation of __builtin_memcpy and
__builtin_memmove (in non-type-punning cases).

This is intended to permit libc++ to make std::copy etc constexpr
without sacrificing the optimization that uses memcpy on
trivially-copyable types.

__builtin_strcpy and __builtin_wcscpy are not handled by this change.
They'd be straightforward to add, but we haven't encountered a need for
them just yet.

llvm-svn: 338455

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[AST] Another attempt at fixing the ARM bots.

llvm-svn: 330690

[AST] Use a bit of trickery to make test pass on platforms where wchar_t is unsigned.

llvm-svn: 330689

[AST] strcmp/memcmp always compares unsigned chars.

This makes it return the right result in a couple of edge cases. The
wide versions always do the comparison on the underlying wchar_t type.

llvm-

[AST] strcmp/memcmp always compares unsigned chars.

This makes it return the right result in a couple of edge cases. The
wide versions always do the comparison on the underlying wchar_t type.

llvm-svn: 330656

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P0426: Make the library implementation of constexpr char_traits a little easier
by providing a memchr builtin that returns char* instead of void*.

Also add a __has_feature flag to indicate the prese

P0426: Make the library implementation of constexpr char_traits a little easier
by providing a memchr builtin that returns char* instead of void*.

Also add a __has_feature flag to indicate the presence of constexpr forms of
the relevant <string> functions.

llvm-svn: 292555

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Support constant expression evaluation for wchar_t versions of simple string
functions, in order to support constexpr std::char_traits<wchar_t>.

llvm-svn: 288193

[c++1z] Support constant folding for __builtin_strchr and __builtin_memchr.

llvm-svn: 286699

[c++1z] Add constant-folding support for strcmp, strncmp, and memcmp, to
support constexpr char_traits.

llvm-svn: 286678