Commit Graph

72 Commits

Author SHA1 Message Date
Shafik Yaghmour 9f6b3199d3 [Clang] Fix lambda CheckForDefaultedFunction(...) so that it checks the CXXMethodDecl is not deleted before attempting to call DefineDefaultedFunction(...)
I discovered this additional bug at the end of working on D132906

In Sema::CheckCompletedCXXClass(...)  uses a lambda CheckForDefaultedFunction to
verify each CXXMethodDecl holds to the expected invariants before passing them
on to CheckForDefaultedFunction.

It is currently missing a check that it is not deleted, this adds that check and
a test that crashed without this check.

This fixes: https://github.com/llvm/llvm-project/issues/57516

Differential Revision: https://reviews.llvm.org/D133177
2022-09-02 18:59:15 -07:00
Shafik Yaghmour b9f7678846 [Clang] Fix lambda CheckForDefaultedFunction(...) so that it checks the CXXMethodDecl is a special member function before attempting to call DefineDefaultedFunction(...)
In Sema::CheckCompletedCXXClass(...) It used a lambda CheckForDefaultedFunction
the CXXMethodDecl passed to CheckForDefaultedFunction may not be a special
member function and so before attempting to apply functions that only apply to
special member functions it needs to check. It fails to do this before calling
DefineDefaultedFunction(...). This PR adds that check and test to verify we no
longer crash.

This fixes https://github.com/llvm/llvm-project/issues/57431

Differential Revision: https://reviews.llvm.org/D132906
2022-08-30 18:08:44 -07:00
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
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
Shivam Gupta 48e1829874 [Diagnostics] Fix inconsistent shift-overflow warnings in C++20
This fixes https://github.com/llvm/llvm-project/issues/52873.
Don't warn in C++2A mode (and newer), as signed left shifts
always wrap and never overflow. Ref. -
https://www.open-std.org/jtc1/sc22/wg21/docs/papers/2018/p1236r1.html.
2022-06-14 20:19:46 +05:30
Richard Smith 30baa5d2a4 PR45879: Fix assert when constant evaluating union assignment.
Consider the form of the first operand of a class assignment not the
second operand when implicitly starting the lifetimes of union members.
Also add a missing check that the assignment call actually came from a
syntactic assignment, not from a direct call to `operator=`.
2022-02-02 17:02:47 -08:00
David Blaikie aee4925507 Recommit: Compress formatting of array type names (int [4] -> int[4])
Based on post-commit review discussion on
2bd8493847 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 277623f4d5

Reverted in f9ad1d1c77 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).
2021-10-21 11:34:43 -07:00
David Blaikie f9ad1d1c77 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 277623f4d5.
2021-10-14 14:49:25 -07:00
David Blaikie 277623f4d5 Compress formatting of array type names (int [4] -> int[4])
Based on post-commit review discussion on
2bd8493847 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).
2021-10-14 14:23:32 -07:00
Yuanfang Chen 27a972a699 Diagnose -Wunused-value based on CFG reachability
(This relands 59337263ab and makes sure comma operator
 diagnostics are suppressed in a SFINAE context.)

While at it, add the diagnosis message "left operand of comma operator has no effect" (used by GCC) for comma operator.

This also makes Clang diagnose in the constant evaluation context which aligns with GCC/MSVC behavior. (https://godbolt.org/z/7zxb8Tx96)

Reviewed By: aaron.ballman

Differential Revision: https://reviews.llvm.org/D103938
2021-09-28 10:00:15 -07:00
Yuanfang Chen 59337263ab Revert "Diagnose -Wunused-value based on CFG reachability"
This reverts commit cbbf2e8c8a.
It seems causing diagnoses in SFINAE context.
2021-09-23 11:12:00 -07:00
Yuanfang Chen cbbf2e8c8a Diagnose -Wunused-value based on CFG reachability
While at it, add the diagnosis message "left operand of comma operator has no effect" (used by GCC) for comma operator.

This also makes Clang diagnose in the constant evaluation context which aligns with GCC/MSVC behavior. (https://godbolt.org/z/7zxb8Tx96)

Reviewed By: aaron.ballman

Differential Revision: https://reviews.llvm.org/D103938
2021-09-22 14:38:06 -07:00
Aaron Ballman 73a8bcd789 Revert "Diagnose -Wunused-value based on CFG reachability"
This reverts commit 63e0d038fc.

It causes test failures:

http://lab.llvm.org:8011/#/builders/119/builds/5612
https://logs.chromium.org/logs/fuchsia/buildbucket/cr-buildbucket/8835548361443044001/+/u/clang/test/stdout
2021-09-21 12:25:13 -04:00
Yuanfang Chen 63e0d038fc Diagnose -Wunused-value based on CFG reachability
While at it, add the diagnosis message "left operand of comma operator has no effect" (used by GCC) for comma operator.

This also makes Clang diagnose in the constant evaluation context which aligns with GCC/MSVC behavior. (https://godbolt.org/z/7zxb8Tx96)

Reviewed By: aaron.ballman

Differential Revision: https://reviews.llvm.org/D103938
2021-09-20 10:43:34 -07:00
Zequan Wu 96fb49c3ff [AST] Update LVal before evaluating lambda decl fields.
Differential Revision: https://reviews.llvm.org/D96092
2021-02-04 17:01:09 -08:00
Richard Smith 9dbb0886ea Perform lvalue conversions on the left of a pseudo-destructor call 'p->~T()'.
Previously we failed to convert 'p' from array/function to pointer type,
and to represent the load of 'p' in the AST. The latter causes problems
for constant evaluation.
2020-10-14 22:09:01 -07:00
Richard Smith f7f2e4261a PR47805: Use a single object for a function parameter in the caller and
callee in constant evaluation.

We previously made a deep copy of function parameters of class type when
passing them, resulting in the destructor for the parameter applying to
the original argument value, ignoring any modifications made in the
function body. This also meant that the 'this' pointer of the function
parameter could be observed changing between the caller and the callee.

This change completely reimplements how we model function parameters
during constant evaluation. We now model them roughly as if they were
variables living in the caller, albeit with an artificially reduced
scope that covers only the duration of the function call, instead of
modeling them as temporaries in the caller that we partially "reparent"
into the callee at the point of the call. This brings some minor
diagnostic improvements, as well as significantly reduced stack usage
during constant evaluation.
2020-10-14 17:43:51 -07:00
Richard Smith 69f7c006ff Revert "PR47805: Use a single object for a function parameter in the caller and"
Breaks a clangd unit test.

This reverts commit 8f8b9f2cca.
2020-10-13 19:32:03 -07:00
Richard Smith 8f8b9f2cca PR47805: Use a single object for a function parameter in the caller and
callee in constant evaluation.

We previously made a deep copy of function parameters of class type when
passing them, resulting in the destructor for the parameter applying to
the original argument value, ignoring any modifications made in the
function body. This also meant that the 'this' pointer of the function
parameter could be observed changing between the caller and the callee.

This change completely reimplements how we model function parameters
during constant evaluation. We now model them roughly as if they were
variables living in the caller, albeit with an artificially reduced
scope that covers only the duration of the function call, instead of
modeling them as temporaries in the caller that we partially "reparent"
into the callee at the point of the call. This brings some minor
diagnostic improvements, as well as significantly reduced stack usage
during constant evaluation.
2020-10-13 18:50:46 -07:00
Richard Smith ab870f3030 Revert "PR47805: Use a single object for a function parameter in the caller and"
The buildbots are displeased.

This reverts commit 8d03a972ce.
2020-10-13 15:59:00 -07:00
Richard Smith 8d03a972ce PR47805: Use a single object for a function parameter in the caller and
callee in constant evaluation.

We previously made a deep copy of function parameters of class type when
passing them, resulting in the destructor for the parameter applying to
the original argument value, ignoring any modifications made in the
function body. This also meant that the 'this' pointer of the function
parameter could be observed changing between the caller and the callee.

This change completely reimplements how we model function parameters
during constant evaluation. We now model them roughly as if they were
variables living in the caller, albeit with an artificially reduced
scope that covers only the duration of the function call, instead of
modeling them as temporaries in the caller that we partially "reparent"
into the callee at the point of the call. This brings some minor
diagnostic improvements, as well as significantly reduced stack usage
during constant evaluation.
2020-10-13 15:45:04 -07:00
Richard Smith bd08e0cf1c PR47143: Don't crash while constant-evaluating value-initialization of
an array of unknown bound as the initializer of an array new expression.
2020-08-12 16:53:45 -07:00
Richard Smith 9a7eda1bec PR45350: Handle unsized array CXXConstructExprs in constant evaluation
of array new expressions with runtime bound.
2020-03-29 19:33:56 -07:00
Richard Smith e7a811b319 PR45133: Don't crash if the active member of a union changes while it's
in the process of being initialized.
2020-03-17 20:37:14 -07:00
Richard Smith 061f3a50dd P0593R6: Pseudo-destructor expressions end object lifetimes.
This only has an observable effect on constant evaluation.
2020-02-18 18:41:03 -08:00
Richard Smith e28d9bae4b PR44958: Allow member calls and typeid / dynamic_cast on mutable objects
and objects with mutable subobjects.

The standard wording doesn't really cover these cases; accepting all
such cases seems most in line with what we do in other cases and what
other compilers do. (Essentially this means we're assuming that objects
external to the evaluation are always in-lifetime.)
2020-02-18 14:57:13 -08:00
Richard Smith f495de43bd [c++20] P1959R0: Remove support for std::*_equality. 2019-12-16 17:49:45 -08:00
Richard Smith 4e9f1379b9 If constant evaluation fails due to an unspecified pointer comparison,
produce a note saying that rather than the default "evaluation failed"
note.
2019-12-16 17:49:45 -08:00
Elizabeth Andrews 878a24ee24 Reapply "Fix crash on switch conditions of non-integer types in templates"
This patch reapplies commit 759948467e. Patch was reverted due to a
clang-tidy test fail on Windows. The test has been modified. There
are no additional code changes.

Patch was tested with ninja check-all on Windows and Linux.

Summary of code changes:

Clang currently crashes for switch statements inside a template when the
condition is a non-integer field member because contextual implicit
conversion is skipped when parsing the condition. This conversion is
however later checked in an assert when the case statement is handled.
The conversion is skipped when parsing the condition because
the field member is set as type-dependent based on its containing class.
This patch sets the type dependency based on the field's type instead.

This patch fixes Bug 40982.
2019-12-03 15:27:19 -08:00
Melanie Blower d0b3e73175 Revert "Reapply "Fix crash on switch conditions of non-integer types in templates""
This reverts commit 759948467e.
There were build bot failures in clang-tidy
2019-11-08 14:18:15 -08:00
Melanie Blower 759948467e Reapply "Fix crash on switch conditions of non-integer types in templates"
This patch reapplies commit 76945821b9. The first version broke
buildbots due to clang-tidy test fails. The fails are because some
errors in templates are now diagnosed earlier (does not wait till
instantiation). I have modified the tests to add checks for these
diagnostics/prevent these diagnostics. There are no additional code
changes.

Summary of code changes:

Clang currently crashes for switch statements inside a template when the
condition is a non-integer field member because contextual implicit
conversion is skipped when parsing the condition. This conversion is
however later checked in an assert when the case statement is handled.
The conversion is skipped when parsing the condition because
the field member is set as type-dependent based on its containing class.
This patch sets the type dependency based on the field's type instead.

This patch fixes Bug 40982.

Reviewers: rnk, gribozavr2

Patch by: Elizabeth Andrews (eandrews)

Differential revision: https://reviews.llvm.org/D69950
2019-11-08 10:17:06 -08:00
Richard Smith faee39baa8 PR43762: when implicitly changing the active union member for an
assignment during constant evaluation, only start the lifetime of
trivially-default-constructible union members.
2019-10-27 12:31:16 -07:00
Richard Smith df3761f6dc [c++20] Check for a class-specific operator delete when deleting an
object of class type with a virtual destructor.

llvm-svn: 373875
2019-10-07 03:14:28 +00:00
Richard Smith 5e18f4db08 Fix crash on constant-evaluation of pseudo-destruction of a pointer.
We got confused and thought we might be pseudo-destroying the pointee
instead.

llvm-svn: 373418
2019-10-02 01:13:57 +00:00
Richard Smith 3b69bcc363 During constant evaluation, handle CXXBindTemporaryExprs for
array-of-class types, not just for class types.

llvm-svn: 373279
2019-10-01 00:41:16 +00:00
Richard Smith 9a84dc0b36 [c++20] Fix crash when constant-evaluating an assignment with a
reference member access on its left-hand side.

llvm-svn: 373276
2019-10-01 00:07:14 +00:00
Richard Smith 63e8a0f55f Fix crash on value-dependent delete-expressions.
We used to miscompute the 'value-dependent' bit, and would crash if we
tried to evaluate a delete expression that should be value-dependent.

llvm-svn: 373272
2019-09-30 22:55:27 +00:00
Richard Smith 00966d1791 Don't crash if a variable with a constexpr destructor has a
value-dependent initializer.

llvm-svn: 373173
2019-09-29 20:30:13 +00:00
Richard Smith 1e8c0850b1 For now, disallow lifetime-extended temporaries with non-trivial (but
constexpr) destructors from being used in the values of constexpr
variables.

The standard rules here are unclear at best, so rejecting the
problematic cases seems prudent. Prior to this change, we would fail to
run the destructors for these temporaries, even if they had
side-effects, which is certainly not the right behavior.

llvm-svn: 373161
2019-09-29 06:22:54 +00:00
Richard Smith 61422f9665 For P0784R7: add support for explicit destructor calls and
pseudo-destructor calls in constant evaluation.

llvm-svn: 373122
2019-09-27 20:24:36 +00:00
Richard Smith 62a95568ef For P0784R7: add support for new (std::nothrow).
llvm-svn: 373037
2019-09-27 01:26:49 +00:00
Richard Smith da1b4347e4 For P0784R7: Add support for dynamic allocation with new / delete during
constant evaluation.

llvm-svn: 373036
2019-09-27 01:26:47 +00:00
Richard Smith 457226e02a For P0784R7: add support for constexpr destructors, and call them as
appropriate during constant evaluation.

Note that the evaluator is sometimes invoked on incomplete expressions.
In such cases, if an object is constructed but we never reach the point
where it would be destroyed (and it has non-trivial destruction), we
treat the expression as having an unmodeled side-effect.

llvm-svn: 372538
2019-09-23 03:48:44 +00:00
Richard Smith 397a686762 Fix assertion failure when constant evaluation of a switch jumps over an
uninitialized variable in an init-statement of a 'for' or 'if'.

llvm-svn: 372437
2019-09-20 23:08:59 +00:00
Richard Smith c667cdc850 [c++20] P1331R2: Allow transient use of uninitialized objects in
constant evaluation.

llvm-svn: 372237
2019-09-18 17:37:44 +00:00
Roman Lebedev 2c9f83cfab Revert "[Clang Interpreter] Initial patch for the constexpr interpreter"
Breaks BUILD_SHARED_LIBS build, introduces cycles in library dependency
graphs. (clangInterp depends on clangAST which depends on clangInterp)

This reverts r370839, which is an yet another recommit of D64146.

llvm-svn: 370874
2019-09-04 10:57:06 +00:00
Nandor Licker 32f82c9cba [Clang Interpreter] Initial patch for the constexpr interpreter
Summary:
This patch introduces the skeleton of the constexpr interpreter,
capable of evaluating a simple constexpr functions consisting of
if statements. The interpreter is described in more detail in the
RFC. Further patches will add more features.

Reviewers: Bigcheese, jfb, rsmith

Subscribers: bruno, uenoku, ldionne, Tyker, thegameg, tschuett, dexonsmith, mgorny, cfe-commits

Tags: #clang

Differential Revision: https://reviews.llvm.org/D64146

llvm-svn: 370839
2019-09-04 05:49:41 +00:00