The recommit ensures that the tests that failed on bots don't trigger the warning.
Xcode 10 removes support for libstdc++, but the users just get a confusing
include not file warning when including an STL header (when building for iOS6
which uses libstdc++ by default for example).
This patch adds a new warning that lets the user know that the libstdc++ include
path was not found to ensure that the user is more aware of why the error occurs.
rdar://40830462
Differential Revision: https://reviews.llvm.org/D48297
llvm-svn: 335081
Summary:
This is the second attempt of r333500 (Update NRVO logic to support early return).
The previous one was reverted for a miscompilation for an incorrect NRVO set up on templates such as:
```
struct Foo {};
template <typename T>
T bar() {
T t;
if (false)
return T();
return t;
}
```
Where, `t` is marked as non-NRVO variable before its instantiation. However, while its instantiation, it's left an NRVO candidate, turned into an NRVO variable later.
Reviewers: rsmith
Reviewed By: rsmith
Subscribers: cfe-commits
Differential Revision: https://reviews.llvm.org/D47586
llvm-svn: 335019
This is not only semantically correct but ensures that they will not
be marked as address-significant once D48155 lands.
Differential Revision: https://reviews.llvm.org/D48206
llvm-svn: 334982
Summary:
In many cases we can't devirtualize
because definition of vtable is not present. Most of the
time it is caused by inline virtual function not beeing
emitted. Forcing emitting of vtable adds a reference of these
inline virtual functions.
Note that GCC was always doing it.
Reviewers: rjmccall, rsmith, amharc, kuhar
Subscribers: llvm-commits, cfe-commits
Differential Revision: https://reviews.llvm.org/D47108
Co-authored-by: Krzysztof Pszeniczny <krzysztof.pszeniczny@gmail.com>
llvm-svn: 334600
The windows-msvc target is used for MSVC ABI compatibility, including
the exceptions model. It doesn't make sense to pair a windows-msvc
target with a non-MSVC exception model. This would previously cause an
assertion failure; explicitly error out for it in the frontend instead.
This also allows us to reduce the matrix of target/exception models a
bit (see the modified tests), and we can possibly simplify some of the
personality code in a follow-up.
Differential Revision: https://reviews.llvm.org/D47853
llvm-svn: 334243
Adding __attribute__((aligned(32))) to __m256 breaks the implementation
of _mm256_loadu_ps on Windows. On Windows, alignment attributes have
higher precedence than packing attributes.
We also might want to carefully consider the consequences of changing
our vector typedefs, since many users copy them and invent their own
new, non-Intel specific vector type names.
llvm-svn: 333958
This fixes two major problems:
- We were not capping vector alignment as desired on 32-bit ARM.
- We were using different alignments based on the AVX settings on
Intel, so we did not have a consistent ABI.
This is an ABI break, but we think we can get away with it because
vectors tend to be used mostly in inline code (which is why not having
a consistent ABI has not proven disastrous on Intel).
Intel's AVX types are specified as having 32-byte / 64-byte alignment,
so align them explicitly instead of relying on the base ABI rule.
Note that this sort of attribute is stripped from template arguments
in template substitution, so there's a possibility that code templated
over vectors will produce inadequately-aligned objects. The right
long-term solution for this is for alignment attributes to be
interpreted as true qualifiers and thus preserved in the canonical type.
llvm-svn: 333791
Summary:
clang's current wasm EH implementation is a non-MVP feature in progress.
We had a `-mexception-handling` wasm feature but were not using it. This
patch hides the non-MVP wasm EH behind a flag, so it does not affect
other code for now.
Reviewers: dschuff
Subscribers: sbc100, jgravelle-google, sunfish, cfe-commits
Differential Revision: https://reviews.llvm.org/D47614
llvm-svn: 333716
Summary:
Because wasm control flow needs to be structured, using WinEH
instructions to support wasm EH brings several benefits. This patch
makes wasm EH uses Windows EH instructions, with some changes:
1. Because wasm uses a single catch block to catch all C++ exceptions,
this merges all catch clauses into a single catchpad, within which we
test the EH selector as in Itanium EH.
2. Generates a call to `__clang_call_terminate` in case a cleanup
throws. Wasm does not have a runtime to handle this.
3. In case there is no catch-all clause, inserts a call to
`__cxa_rethrow` at the end of a catchpad in order to unwind to an
enclosing EH scope.
Reviewers: majnemer, dschuff
Subscribers: jfb, sbc100, jgravelle-google, sunfish, cfe-commits
Differential Revision: https://reviews.llvm.org/D44931
llvm-svn: 333703
Ensure latest MPT decl has a MSInheritanceAttr when instantiating
templates, to avoid null MSInheritanceAttr deref in
CXXRecordDecl::getMSInheritanceModel().
See PR#37399 for repo / details.
Patch by Andrew Rogers!
Differential Revision: https://reviews.llvm.org/D46664
llvm-svn: 333680
Summary:
The previous implementation misses an opportunity to apply NRVO (Named Return Value
Optimization) below. That discourages user to write early return code.
```
struct Foo {};
Foo f(bool b) {
if (b)
return Foo();
Foo oo;
return oo;
}
```
That is, we can/should apply RVO for a local variable if:
* It's directly returned by at least one return statement.
* And, all reachable return statements in its scope returns the variable directly.
While, the previous implementation disables the RVO in a scope if there are multiple return
statements that refers different variables.
On the new algorithm, local variables are in NRVO_Candidate state at first, and a return
statement changes it to NRVO_Disabled for all visible variables but the return statement refers.
Then, at the end of the function AST traversal, NRVO is enabled for variables in NRVO_Candidate
state and refers from at least one return statement.
Reviewers: rsmith
Reviewed By: rsmith
Subscribers: xbolva00, Quuxplusone, arthur.j.odwyer, cfe-commits
Differential Revision: https://reviews.llvm.org/D47067
llvm-svn: 333500
This helps especially when the collision is for a template specialization,
where the template arguments are not available from anywhere else in the
diagnostic, and are likely relevant to the problem.
llvm-svn: 333489
initialization functions to 'cxx_fast_tlscc'.
This fixes a bug where instructions calling initialization functions for
thread-local static members of c++ template classes were using calling
convention 'cxx_fast_tlscc' while the called functions weren't annotated
with the calling convention.
rdar://problem/40447463
Differential Revision: https://reviews.llvm.org/D47354
llvm-svn: 333447
It caused asserts, see PR37560.
> Use zeroinitializer for (trailing zero portion of) large array initializers
> more reliably.
>
> Clang has two different ways it emits array constants (from InitListExprs and
> from APValues), and both had some ability to emit zeroinitializer, but neither
> was able to catch all cases where we could use zeroinitializer reliably. In
> particular, emitting from an APValue would fail to notice if all the explicit
> array elements happened to be zero. In addition, for large arrays where only an
> initial portion has an explicit initializer, we would emit the complete
> initializer (which could be huge) rather than emitting only the non-zero
> portion. With this change, when the element would have a suffix of more than 8
> zero elements, we emit the array constant as a packed struct of its initial
> portion followed by a zeroinitializer constant for the trailing zero portion.
>
> In passing, I found a bug where SemaInit would sometimes walk the entire array
> when checking an initializer that only covers the first few elements; that's
> fixed here to unblock testing of the rest.
>
> Differential Revision: https://reviews.llvm.org/D47166
llvm-svn: 333067
more reliably.
Clang has two different ways it emits array constants (from InitListExprs and
from APValues), and both had some ability to emit zeroinitializer, but neither
was able to catch all cases where we could use zeroinitializer reliably. In
particular, emitting from an APValue would fail to notice if all the explicit
array elements happened to be zero. In addition, for large arrays where only an
initial portion has an explicit initializer, we would emit the complete
initializer (which could be huge) rather than emitting only the non-zero
portion. With this change, when the element would have a suffix of more than 8
zero elements, we emit the array constant as a packed struct of its initial
portion followed by a zeroinitializer constant for the trailing zero portion.
In passing, I found a bug where SemaInit would sometimes walk the entire array
when checking an initializer that only covers the first few elements; that's
fixed here to unblock testing of the rest.
Differential Revision: https://reviews.llvm.org/D47166
llvm-svn: 333044
Introduced CreateMemTempWithoutCast and CreateTemporaryAllocaWithoutCast to emit alloca
without casting to default addr space.
ActiveFlag is a temporary variable emitted for clean up. It is defined as AllocaInst* type and there is
a cast to AlllocaInst in SetActiveFlag. An alloca casted to generic pointer causes assertion in
SetActiveFlag.
Since there is only load/store of ActiveFlag, it is safe to use the original alloca, therefore use
CreateMemTempWithoutCast is called.
Differential Revision: https://reviews.llvm.org/D47099
llvm-svn: 332982
This change will help Visual Studio resolve forward references to C++ lambda
routines used by captured variables.
Differential Revision: https://reviews.llvm.org/D45438
llvm-svn: 332975
If a variable has an initializer, codegen tries to build its value. If
the variable is large in size, building its value requires substantial
resources. It causes strange behavior from user viewpoint: compilation
of huge zero initialized arrays like:
char data_1[2147483648u] = { 0 };
consumes enormous amount of time and memory.
With this change codegen tries to determine if variable initializer is
equivalent to zero initializer. In this case variable value is not
constructed.
This change fixes PR18978.
Differential Revision: https://reviews.llvm.org/D46241
llvm-svn: 332847
The first version of the patch (r332228) was flawed because it was
putting structors into C5/D5 comdats very eagerly. This is correct only
if we can ensure the comdat contains all required versions of the
structor (which wasn't the case). This version uses a more nuanced
approach:
- for local structor symbols we use an alias because we don't have to
worry about comdats or other compilation units.
- linkonce symbols are emitted separately, as we cannot guarantee we
will have all symbols we need to form a comdat (they are emitted
lazily, only when referenced).
- available_externally symbols are also emitted separately, as the code
seemed to be worried about emitting an alias in this case.
- other linkage types are not affected by the optimization level. They
either get put into a comdat (weak) or get aliased (external).
Reviewers: rjmccall, aprantl
Subscribers: cfe-commits
Differential Revision: https://reviews.llvm.org/D46685
llvm-svn: 332839
When a lambda capture captures a __block in the same statement, the compiler asserts out because isCapturedBy assumes that an Expr can only be a BlockExpr, StmtExpr, or if it's a Stmt then all the statement's children are expressions. That's wrong, we need to visit all sub-statements even if they're not expressions to see if they also capture.
Fix this issue by pulling out the isCapturedBy logic to use RecursiveASTVisitor.
<rdar://problem/39926584>
llvm-svn: 332801
lifetime.start/end expects pointer argument in alloca address space.
However in C++ a temporary variable is in default address space.
This patch changes API CreateMemTemp and CreateTempAlloca to
get the original alloca instruction and pass it lifetime.start/end.
It only affects targets with non-zero alloca address space.
Differential Revision: https://reviews.llvm.org/D45900
llvm-svn: 332593
Some targets have constant address space (e.g. amdgcn). For them string literal should be
emitted in constant address space then casted to default address space.
Differential Revision: https://reviews.llvm.org/D46643
llvm-svn: 332279
Summary:
Removing the full structor and replacing all usages with the base one
can degrade debug quality as it will leave the debugger unable to locate
the full object structor. This is apparent when evaluating an expression
in the debugger which requires constructing an object of class which has
had this optimization applied to it. When compiling the expression, we
pretend that the class and its methods have been defined in another
compilation unit, so the expression compiler assumes the structor
definition must be available. This didn't use to be the case for
structors with internal linkage. Less aggressive optimizations like
emitting the full structor as an alias remain in place, as they do not
cause the structor symbol to disappear completely.
This improves debug quality on non-darwin platforms (darwin does not
have -mconstructor-aliases on by default, so it is spared these
problems) and enable us to remove some workarounds from LLDB which attempt to
mitigate this issue.
Reviewers: rjmccall, aprantl
Subscribers: cfe-commits
Differential Revision: https://reviews.llvm.org/D46685
llvm-svn: 332228
The PS4 requires clang ABI version 6 for compatibility reasons. This change forces this and if the user specifies a different version when the PS4 target is specified, the compiler emits a warning that the specified version is being ignored.
Reviewers: probinson
Subscribers: cfe-commits
Differential Revision: https://reviews.llvm.org/D46767
llvm-svn: 332160
Summary:
The Itanium ABI requires that the type info for pointer-to-incomplete types to have internal linkage, so that it doesn't interfere with the type info once completed. Currently it also marks the type info name as internal as well. However, this causes a bug with the STL implementations, which use the type info name pointer to perform ordering and hashing of type infos.
For example:
```
// header.h
struct T;
extern std::type_info const& Info;
// tu_one.cpp
#include "header.h"
std::type_info const& Info = typeid(T*);
// tu_two.cpp
#include "header.h"
struct T {};
int main() {
auto &TI1 = Info;
auto &TI2 = typeid(T*);
assert(TI1 == TI2); // Fails
assert(TI1.hash_code() == TI2.hash_code()); // Fails
}
```
This patch fixes the STL bug by emitting the type info name as linkonce_odr when the type-info is for a pointer-to-incomplete type.
Note that libc++ could fix this without a compiler change, but the quality of fix would be poor. The library would either have to:
(A) Always perform strcmp/string hashes.
(B) Determine if we have a pointer-to-incomplete type, and only do strcmp then. This would require an ABI break for libc++.
Reviewers: rsmith, rjmccall, majnemer, vsapsai
Reviewed By: rjmccall
Subscribers: smeenai, cfe-commits
Differential Revision: https://reviews.llvm.org/D46665
llvm-svn: 332028
Summary:
The Itanium ABI requires that the type info for pointer-to-incomplete types to have internal linkage, so that it doesn't interfere with the type info once completed. Currently it also marks the type info name as internal as well. However, this causes a bug with the STL implementations, which use the type info name pointer to perform ordering and hashing of type infos.
For example:
```
// header.h
struct T;
extern std::type_info const& Info;
// tu_one.cpp
#include "header.h"
std::type_info const& Info = typeid(T*);
// tu_two.cpp
#include "header.h"
struct T {};
int main() {
auto &TI1 = Info;
auto &TI2 = typeid(T*);
assert(TI1 == TI2); // Fails
assert(TI1.hash_code() == TI2.hash_code()); // Fails
}
```
This patch fixes the STL bug by emitting the type info name as linkonce_odr when the type-info is for a pointer-to-incomplete type.
Note that libc++ could fix this without a compiler change, but the quality of fix would be poor. The library would either have to:
(A) Always perform strcmp/string hashes.
(B) Determine if we have a pointer-to-incomplete type, and only do strcmp then. This would require an ABI break for libc++.
Reviewers: rsmith, rjmccall, majnemer, vsapsai
Reviewed By: rjmccall
Subscribers: smeenai, cfe-commits
Differential Revision: https://reviews.llvm.org/D46665
llvm-svn: 331957
Summary:
This patch tackles long hanging fruit for the builtin operator<=> expressions. It is currently needs some cleanup before landing, but I want to get some initial feedback.
The main changes are:
* Lookup, build, and store the required standard library types and expressions in `ASTContext`. By storing them in ASTContext we don't need to store (and duplicate) the required expressions in the BinaryOperator AST nodes.
* Implement [expr.spaceship] checking, including diagnosing narrowing conversions.
* Implement `ExprConstant` for builtin spaceship operators.
* Implement builitin operator<=> support in `CodeGenAgg`. Initially I emitted the required comparisons using `ScalarExprEmitter::VisitBinaryOperator`, but this caused the operand expressions to be emitted once for every required cmp.
* Implement [builtin.over] with modifications to support the intent of P0946R0. See the note on `BuiltinOperatorOverloadBuilder::addThreeWayArithmeticOverloads` for more information about the workaround.
Reviewers: rsmith, aaron.ballman, majnemer, rnk, compnerd, rjmccall
Reviewed By: rjmccall
Subscribers: rjmccall, rsmith, aaron.ballman, junbuml, mgorny, cfe-commits
Differential Revision: https://reviews.llvm.org/D45476
llvm-svn: 331677
Reid Kleckner