Release note for DWARF v5 support

[android-x86/external-llvm.git] / docs / ReleaseNotes.rst

diff --git a/docs/ReleaseNotes.rst b/docs/ReleaseNotes.rst
index ad8b447..58fb882 100644 (file)
--- a/docs/ReleaseNotes.rst
+++ b/docs/ReleaseNotes.rst
@@ -65,7 +65,7 @@ Non-comprehensive list of changes in this release
   results for code that is relying on the undefined behavior of overflowing 
   casts. The optimization can be disabled by specifying a function attribute:
   "strict-float-cast-overflow"="false". This attribute may be created by the
-  clang option :option:`-fno-strict-float-cast-overflow`.
+  clang option ``-fno-strict-float-cast-overflow``.
   Code sanitizers can be used to detect affected patterns. The option for
   detecting this problem alone is "-fsanitize=float-cast-overflow":
 
@@ -101,6 +101,20 @@ Non-comprehensive list of changes in this release
 * Early support for UBsan, X-Ray instrumentation and libFuzzer (x86 and x86_64) for OpenBSD. Support for MSan
   (x86_64), X-Ray instrumentation and libFuzzer (x86 and x86_64) for FreeBSD.
 
+* ``SmallVector<T, 0>`` shrank from ``sizeof(void*) * 4 + sizeof(T)`` to
+  ``sizeof(void*) + sizeof(unsigned) * 2``, smaller than ``std::vector<T>`` on
+  64-bit platforms.  The maximum capacity is now restricted to ``UINT32_MAX``.
+  Since SmallVector doesn't have the exception-safety pessimizations some
+  implementations saddle std::vector with and is better at using ``realloc``,
+  it's now a better choice even on the heap (although when TinyPtrVector works,
+  it's even smaller).
+
+* Preliminary/experimental support for DWARF v5 debugging information,
+  including the new .debug_names accelerator table. DWARF emitted at ``-O0``
+  should be fully DWARF v5 compliant. Type units and split DWARF are known
+  not to be compliant, and higher optimization levels will still emit some
+  information in v4 format.
+
 * Note..
 
 .. NOTE