[libc++] Have basic_string call basic_string_view's assume-valid constructor

.github/workflows/libcxx-build-and-test.yaml

@@ -146,6 +146,7 @@ jobs:
           'generic-no-experimental',
           'generic-no-filesystem',
           'generic-no-localization',
+          'generic-no-terminal',
           'generic-no-random_device',
           'generic-no-threads',
           'generic-no-tzdb',

bolt/lib/Core/BinaryFunctionProfile.cpp

@@ -336,7 +336,8 @@ void BinaryFunction::inferFallThroughCounts() {
       if (SuccBI.Count == 0) {
         SuccBI.Count = Inferred;
         SuccBI.MispredictedCount = BinaryBasicBlock::COUNT_INFERRED;
-        Succ->ExecutionCount += Inferred;
+        Succ->ExecutionCount =
+            std::max(Succ->getKnownExecutionCount(), Inferred);
       }
     }
   }

bolt/test/X86/end-symbol.test

@@ -1,7 +1,9 @@
 # RUN: yaml2obj %p/Inputs/plt-sec.yaml &> %t.exe
 # RUN: llvm-bolt %t.exe -o %t.out
-# RUN: (llvm-readelf --program-headers %t.out | grep LOAD | tail -n 1 ; llvm-nm %t.out) \
-# RUN:   | FileCheck %s
+
+# RUN: llvm-readelf --program-headers %t.out | grep LOAD | tail -n 1 > %t.load
+# RUN: llvm-nm %t.out >> %t.load
+# RUN: FileCheck %s < %t.load
 
 ## Check that llvm-bolt correctly updates _end symbol to match the end of the
 ## last loadable segment.

bolt/test/X86/infer-fall-throughs.s

@@ -0,0 +1,45 @@
+## Test that infer-fall-throughs would correctly infer the wrong fall-through
+## edge count in the example
+
+# RUN: llvm-mc --filetype=obj --triple x86_64-unknown-unknown %s -o %t.o
+# RUN: link_fdata %s %t.o %t.fdata
+# RUN: llvm-strip --strip-unneeded %t.o
+# RUN: %clang %cflags %t.o -o %t.exe -Wl,-q
+# RUN: llvm-bolt %t.exe -o %t.bolt \
+# RUN:         --print-estimate-edge-counts --data=%t.fdata \
+# RUN:     2>&1 | FileCheck --check-prefix=WITHOUTINFERENCE %s
+# RUN: llvm-bolt %t.exe -o %t.bolt --infer-fall-throughs \
+# RUN:         --print-estimate-edge-counts --data=%t.fdata \
+# RUN:     2>&1 | FileCheck --check-prefix=CORRECTINFERENCE %s
+
+
+# WITHOUTINFERENCE: Binary Function "main" after estimate-edge-counts
+# WITHOUTINFERENCE: {{^\.Ltmp0}}
+# WITHOUTINFERENCE: Successors: .Ltmp1 (mispreds: 0, count: 10), .LFT0 (mispreds: 0, count: 0)
+# WITHOUTINFERENCE: {{^\.LFT0}}
+# WITHOUTINFERENCE: Exec Count : 490
+
+# CORRECTINFERENCE: Binary Function "main" after estimate-edge-counts
+# CORRECTINFERENCE: {{^\.Ltmp0}}
+# CORRECTINFERENCE: Successors: .Ltmp1 (mispreds: 0, count: 10), .LFT0 (inferred count: 490)
+# CORRECTINFERENCE: {{^\.LFT0}}
+# CORRECTINFERENCE: Exec Count : 490
+
+
+        .globl  main
+        .type   main, @function
+main:
+LLmain_LLstart:
+        jmp     LLstart
+# FDATA: 1 main #LLmain_LLstart# 1 main #LLstart# 0 500
+LLstart:
+        jge     LLexit
+# FDATA: 1 main #LLstart# 1 main #LLexit# 0 10
+# FDATA: 1 main #LLstart# 1 main #LLmore# 0 0
+LLmore:
+        movl    $5, %eax
+# FDATA: 1 main #LLmore# 1 main #LLexit# 0 490
+LLexit:
+        ret
+.LLmain_end:
+        .size   main, .LLmain_end-main

bolt/test/X86/instrumentation-eh_frame_hdr.cpp

@@ -6,8 +6,9 @@
 // RUN: %clangxx %cxxflags -static -Wl,-q %s -o %t.exe -Wl,--entry=_start
 // RUN: llvm-bolt %t.exe -o %t.instr -instrument \
 // RUN:   --instrumentation-file=%t.fdata -instrumentation-sleep-time=1
-// RUN: (llvm-readelf -SW %t.instr | grep -v bolt; llvm-readelf -lW %t.instr | \
-// RUN:   grep LOAD | tail -n 1) | FileCheck %s
+// RUN: llvm-readelf -SW %t.instr | grep -v bolt > %t.sections
+// RUN: llvm-readelf -lW %t.instr | grep LOAD | tail -n 1 >> %t.sections
+// RUN: FileCheck %s < %t.sections
 
 // CHECK: {{.*}} .eh_frame_hdr PROGBITS [[#%x, EH_ADDR:]]
 // CHECK: LOAD 0x[[#%x, LD_OFFSET:]] 0x[[#%x, LD_VADDR:]] 0x[[#%x, LD_FSIZE:]]

clang-tools-extra/clangd/TUScheduler.cpp

@@ -1838,7 +1838,7 @@ DebouncePolicy::compute(llvm::ArrayRef<clock::duration> History) const {
   // Base the result on the median rebuild.
   // nth_element needs a mutable array, take the chance to bound the data size.
   History = History.take_back(15);
-  llvm::SmallVector<clock::duration, 15> Recent(History.begin(), History.end());
+  llvm::SmallVector<clock::duration, 15> Recent(History);
   auto *Median = Recent.begin() + Recent.size() / 2;
   std::nth_element(Recent.begin(), Median, Recent.end());
 

clang/cmake/caches/CrossWinToARMLinux.cmake

@@ -108,9 +108,9 @@ endif()
 
 message(STATUS "Toolchain target to build: ${LLVM_TARGETS_TO_BUILD}")
 
-# Allow to override libc++ ABI version. Use 2 by default.
+# Allow to override libc++ ABI version (1 is default).
 if (NOT DEFINED LIBCXX_ABI_VERSION)
-  set(LIBCXX_ABI_VERSION 2)
+  set(LIBCXX_ABI_VERSION 1)
 endif()
 
 message(STATUS "Toolchain's Libc++ ABI version: ${LIBCXX_ABI_VERSION}")
@@ -217,6 +217,8 @@ set(RUNTIMES_${TOOLCHAIN_TARGET_TRIPLE}_LIBCXX_ENABLE_SHARED
 set(RUNTIMES_${TOOLCHAIN_TARGET_TRIPLE}_LIBCXX_ABI_VERSION                        ${LIBCXX_ABI_VERSION} CACHE STRING "")
 set(RUNTIMES_${TOOLCHAIN_TARGET_TRIPLE}_LIBCXX_CXX_ABI                            "libcxxabi" CACHE STRING "")    #!!!
 set(RUNTIMES_${TOOLCHAIN_TARGET_TRIPLE}_LIBCXX_ENABLE_NEW_DELETE_DEFINITIONS      ON CACHE BOOL "")
+# Merge libc++ and libc++abi libraries into the single libc++ library file.
+set(RUNTIMES_${TOOLCHAIN_TARGET_TRIPLE}_LIBCXX_ENABLE_STATIC_ABI_LIBRARY          ON CACHE BOOL "")
 
 # Avoid searching for the python3 interpreter during the runtimes configuration for the cross builds.
 # It starts searching the python3 package using the target's sysroot path, that usually is not compatible with the build host.

clang/docs/ClangFormatStyleOptions.rst

@@ -1617,7 +1617,7 @@ the configuration (without a prefix: ``Auto``).
 **AllowAllParametersOfDeclarationOnNextLine** (``Boolean``) :versionbadge:`clang-format 3.3` :ref:`¶ <AllowAllParametersOfDeclarationOnNextLine>`
   If the function declaration doesn't fit on a line,
   allow putting all parameters of a function declaration onto
-  the next line even if ``BinPackParameters`` is ``false``.
+  the next line even if ``BinPackParameters`` is ``OnePerLine``.
 
   .. code-block:: c++
 
@@ -2067,20 +2067,41 @@ the configuration (without a prefix: ``Auto``).
 
 .. _BinPackParameters:
 
-**BinPackParameters** (``Boolean``) :versionbadge:`clang-format 3.7` :ref:`¶ <BinPackParameters>`
-  If ``false``, a function declaration's or function definition's
-  parameters will either all be on the same line or will have one line each.
+**BinPackParameters** (``BinPackParametersStyle``) :versionbadge:`clang-format 3.7` :ref:`¶ <BinPackParameters>`
+  The bin pack parameters style to use.
 
-  .. code-block:: c++
+  Possible values:
+
+  * ``BPPS_BinPack`` (in configuration: ``BinPack``)
+    Bin-pack parameters.
+
+    .. code-block:: c++
+
+       void f(int a, int bbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbb,
+              int ccccccccccccccccccccccccccccccccccccccccccc);
+
+  * ``BPPS_OnePerLine`` (in configuration: ``OnePerLine``)
+    Put all parameters on the current line if they fit.
+    Otherwise, put each one on its own line.
+
+    .. code-block:: c++
+
+       void f(int a, int b, int c);
+
+       void f(int a,
+              int b,
+              int ccccccccccccccccccccccccccccccccccccc);
+
+  * ``BPPS_AlwaysOnePerLine`` (in configuration: ``AlwaysOnePerLine``)
+    Always put each parameter on its own line.
+
+    .. code-block:: c++
+
+       void f(int a,
+              int b,
+              int c);
 
-    true:
-    void f(int aaaaaaaaaaaaaaaaaaaa, int aaaaaaaaaaaaaaaaaaaa,
-           int aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa) {}
 
-    false:
-    void f(int aaaaaaaaaaaaaaaaaaaa,
-           int aaaaaaaaaaaaaaaaaaaa,
-           int aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa) {}
 
 .. _BitFieldColonSpacing:
 
@@ -4817,7 +4838,7 @@ the configuration (without a prefix: ``Auto``).
   items into as few lines as possible when they go over ``ColumnLimit``.
 
   If ``Auto`` (the default), delegates to the value in
-  ``BinPackParameters``. If that is ``true``, bin-packs Objective-C
+  ``BinPackParameters``. If that is ``BinPack``, bin-packs Objective-C
   protocol conformance list items into as few lines as possible
   whenever they go over ``ColumnLimit``.
 
@@ -4831,13 +4852,13 @@ the configuration (without a prefix: ``Auto``).
 
   .. code-block:: objc
 
-     Always (or Auto, if BinPackParameters=true):
+     Always (or Auto, if BinPackParameters==BinPack):
      @interface ccccccccccccc () <
          ccccccccccccc, ccccccccccccc,
          ccccccccccccc, ccccccccccccc> {
      }
 
-     Never (or Auto, if BinPackParameters=false):
+     Never (or Auto, if BinPackParameters!=BinPack):
      @interface ddddddddddddd () <
          ddddddddddddd,
          ddddddddddddd,

clang/docs/RealtimeSanitizer.rst

@@ -0,0 +1,85 @@
+=================
+RealtimeSanitizer
+=================
+
+.. contents::
+   :local:
+
+Introduction
+============
+RealtimeSanitizer (a.k.a. RTSan) is a real-time safety testing tool for C and C++
+projects. RTSan can be used to detect real-time violations, i.e. calls to methods
+that are not safe for use in functions with deterministic runtime requirements.
+RTSan considers any function marked with the ``[[clang::nonblocking]]`` attribute
+to be a real-time function. If RTSan detects a call to ``malloc``, ``free``,
+``pthread_mutex_lock``, or anything else that could have a non-deterministic
+execution time in a function marked ``[[clang::nonblocking]]``
+RTSan raises an error.
+
+The runtime slowdown introduced by RealtimeSanitizer is negligible.
+
+How to build
+============
+
+Build LLVM/Clang with `CMake <https://llvm.org/docs/CMake.html>` and enable the
+``compiler-rt`` runtime. An example CMake configuration that will allow for the
+use/testing of RealtimeSanitizer:
+
+.. code-block:: console
+
+   $ cmake -DCMAKE_BUILD_TYPE=Release -DLLVM_ENABLE_PROJECTS="clang" -DLLVM_ENABLE_RUNTIMES="compiler-rt" <path to source>/llvm
+
+Usage
+=====
+
+There are two requirements:
+
+1. The code must be compiled with the ``-fsanitize=realtime`` flag.
+2. Functions that are subject to real-time constraints must be marked
+   with the ``[[clang::nonblocking]]`` attribute.
+
+Typically, these attributes should be added onto the functions that are entry
+points for threads with real-time priority. These threads are subject to a fixed
+callback time, such as audio callback threads or rendering loops in video game
+code.
+
+.. code-block:: console
+
+   % cat example_realtime_violation.cpp
+   #include <vector>
+
+   void violation() [[clang::nonblocking]]{
+     std::vector<float> v;
+     v.resize(100);
+   }
+
+   int main() {
+     violation();
+     return 0;
+   }
+   # Compile and link
+   % clang++ -fsanitize=realtime -g example_realtime_violation.cpp
+
+If a real-time safety violation is detected in a ``[[clang::nonblocking]]``
+context, or any function invoked by that function, the program will exit with a
+non-zero exit code.
+
+.. code-block:: console
+
+   % clang++ -fsanitize=realtime -g example_realtime_violation.cpp
+   % ./a.out
+   Real-time violation: intercepted call to real-time unsafe function `malloc` in real-time context! Stack trace:
+    #0 0x000102893034 in __rtsan::PrintStackTrace() rtsan_stack.cpp:45
+    #1 0x000102892e64 in __rtsan::Context::ExpectNotRealtime(char const*) rtsan_context.cpp:78
+    #2 0x00010289397c in malloc rtsan_interceptors.cpp:286
+    #3 0x000195bd7bd0 in operator new(unsigned long)+0x1c (libc++abi.dylib:arm64+0x16bd0)
+    #4 0x5c7f00010230f07c  (<unknown module>)
+    #5 0x00010230f058 in std::__1::__libcpp_allocate[abi:ue170006](unsigned long, unsigned long) new:324
+    #6 0x00010230effc in std::__1::allocator<float>::allocate[abi:ue170006](unsigned long) allocator.h:114
+    ... snip ...
+    #10 0x00010230e4bc in std::__1::vector<float, std::__1::allocator<float>>::__append(unsigned long) vector:1162
+    #11 0x00010230dcdc in std::__1::vector<float, std::__1::allocator<float>>::resize(unsigned long) vector:1981
+    #12 0x00010230dc28 in violation() main.cpp:5
+    #13 0x00010230dd64 in main main.cpp:9
+    #14 0x0001958960dc  (<unknown module>)
+    #15 0x2f557ffffffffffc  (<unknown module>)

clang/docs/ReleaseNotes.rst

@@ -107,19 +107,6 @@ C++ Language Changes
   constant expression. Supports the `V.xyzw` syntax and other tidbits
   as seen in OpenCL. Selecting multiple elements is left as a future work.
 
-C++17 Feature Support
-^^^^^^^^^^^^^^^^^^^^^
-
-C++14 Feature Support
-^^^^^^^^^^^^^^^^^^^^^
-
-C++20 Feature Support
-^^^^^^^^^^^^^^^^^^^^^
-
-C++23 Feature Support
-^^^^^^^^^^^^^^^^^^^^^
-- Removed the restriction to literal types in constexpr functions in C++23 mode.
-
 C++2c Feature Support
 ^^^^^^^^^^^^^^^^^^^^^
 
@@ -131,6 +118,16 @@ C++2c Feature Support
 
 - Implemented `P2893R3 Variadic Friends <https://wg21.link/P2893>`_
 
+- Implemented `P2747R2 constexpr placement new <https://wg21.link/P2747R2>`_.
+
+C++23 Feature Support
+^^^^^^^^^^^^^^^^^^^^^
+- Removed the restriction to literal types in constexpr functions in C++23 mode.
+
+C++20 Feature Support
+^^^^^^^^^^^^^^^^^^^^^
+
+
 Resolutions to C++ Defect Reports
 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
 
@@ -152,6 +149,9 @@ Resolutions to C++ Defect Reports
 - ``nullptr`` is now promoted to ``void*`` when passed to a C-style variadic function.
   (`CWG722: Can nullptr be passed to an ellipsis? <https://cplusplus.github.io/CWG/issues/722.html>`_)
 
+- Allow ``void{}`` as a prvalue of type ``void``.
+  (`CWG2351: void{} <https://cplusplus.github.io/CWG/issues/2351.html>`_).
+
 C Language Changes
 ------------------
 
@@ -177,8 +177,6 @@ Deprecated Compiler Flags
 Modified Compiler Flags
 -----------------------
 
-- The compiler flag `-fbracket-depth` default value is increased from 256 to 2048.
-
 - The ``-ffp-model`` option has been updated to enable a more limited set of
   optimizations when the ``fast`` argument is used and to accept a new argument,
   ``aggressive``. The behavior of ``-ffp-model=aggressive`` is equivalent
@@ -236,6 +234,10 @@ Improvements to Clang's diagnostics
 
 - Clang now diagnoses when the result of a [[nodiscard]] function is discarded after being cast in C. Fixes #GH104391.
 
+- Don't emit duplicated dangling diagnostics. (#GH93386).
+
+- Improved diagnostic when trying to befriend a concept. (#GH45182).
+
 Improvements to Clang's time-trace
 ----------------------------------
 
@@ -287,6 +289,10 @@ Bug Fixes to C++ Support
 - Clang now properly handles the order of attributes in `extern` blocks. (#GH101990).
 - Fixed an assertion failure by preventing null explicit object arguments from being deduced. (#GH102025).
 - Correctly check constraints of explicit instantiations of member functions. (#GH46029)
+- Fixed an assertion failure about a constraint of a friend function template references to a value with greater
+  template depth than the friend function template. (#GH98258)
+- Clang now rebuilds the template parameters of out-of-line declarations and specializations in the context
+  of the current instantiation in all cases.
 
 Bug Fixes to AST Handling
 ^^^^^^^^^^^^^^^^^^^^^^^^^
@@ -305,6 +311,12 @@ Miscellaneous Clang Crashes Fixed
 - Fixed a crash caused by long chains of ``sizeof`` and other similar operators
   that can be followed by a non-parenthesized expression. (#GH45061)
 
+- Fixed an crash when compiling ``#pragma STDC FP_CONTRACT DEFAULT`` with
+  ``-ffp-contract=fast-honor-pragmas``. (#GH104830)
+
+- Fixed a crash when function has more than 65536 parameters.
+  Now a diagnostic is emitted. (#GH35741)
+
 OpenACC Specific Changes
 ------------------------
 
@@ -437,6 +449,11 @@ Moved checkers
 
 Sanitizers
 ----------
+- Introduced Realtime Sanitizer, activated by using the -fsanitize=realtime
+  flag. This sanitizer detects unsafe system library calls, such as memory
+  allocations and mutex locks. If any such function is called during invocation
+  of a function marked with the ``[[clang::nonblocking]]`` attribute, an error
+  is printed to the console and the process exits non-zero.
 
 - Added the ``-fsanitize-undefined-ignore-overflow-pattern`` flag which can be
   used to disable specific overflow-dependent code patterns. The supported