Background: Clang has a set of base headers distributed with the compiler
that contain things like vector operations, stddef.h, and tgmath.h.
Swift also needs these headers in order to import C and Objective-C (not
really a surprise), so we symlink to them from lib/swift/clang/. When we
build installable packages, we actually copy them in.
Now the tricky part. Clang's headers are actually at a path like
"include/clang/3.6.0/include/tgmath.h". That "3.6.0" is the Clang version,
which allows multiple Clangs to be installed on a single system. Swift
currently links to the top-level directory, but of course it's only
guaranteed to work with a specific version of the Clang headers. So the
version number here is always the version of Clang we use to build Swift.
Rather than leave the (relatively meaningless) version number here, just
make the symlink point at the "3.6.0" directory rather than the "clang"
directory. This means Swift doesn't have to think about the version number
here at all.
rdar://problem/23223066
In cases where our major version of clang is different than the
installed clang this allows us to install the builtin headers ourselves.
This should be used judiciously, since it installs to a path 'owned' by
clang.
Swift SVN r32696
Revert "Add test cases to exercise the native String vs cocoa buffer String path."
Revert "stdlib: Add back a test I removed"
Revert "stdlib: Fix hasPrefix,hasSuffix tests"
Revert "stdlib: Add documentation for the cached ascii collation tables"
This reverts commit 31493, 31492, 31491, 31490, 31489.
There are linking errors in SwiftExternalProjects (we probably have to link
against libicucore somewhere).
Swift SVN r31543
Reapply of 31474 with a fix in _compareCocoaBuffer to use the bufferSizeRhs
variable instead of bufferSizeLhs for the right hand side buffer.
We no longer create intermediate NSString copies to compare and hash swift
Strings. Instead we call directly into the ICU library.
I measured a 1.2 to 2x improvement on dictionary benchmarks as a result of this.
The SuperChars benchmark is also about 1.2x faster because of this.
Pure ASCII comparison has gotten a little bit slower (20% on a pure comparison
micro-benchmark) because we no longer do a memcmp. Doing a memcmp on ASCII is
not the same as the default unicode collation. Instead we have to a string scan.
The default unicode collation does not order like ASCII does and ignores
characters (for example the \0 character).
rdar://18992510
Swift SVN r31489
Revert "stdlib: Add back a test I removed"
Revert "Add test cases to exercise the native String vs cocoa buffer String path."
Revert "stdlib: Move the darwin String implementation over to use the ICU library."
This reverts commit r31477, r31476, r31475, r31474.
Commit r31474 broke the ASAN build.
Swift SVN r31488
We no longer create intermediate NSString copies to compare and hash swift
Strings. Instead we call directly into the ICU library.
I measured a 1.2 to 2x improvement on dictionary benchmarks as a result of this.
The SuperChars benchmark is also about 1.2x faster because of this.
Pure ASCII comparison has gotten a little bit slower (20% on a pure comparison
micro-benchmark) because we no longer do a memcmp. Doing a memcmp on ASCII is
not the same as the default unicode collation. Instead we have to a string scan.
The default unicode collation does not order like ASCII does and ignores
characters (for example the \0 character).
rdar://18992510
Swift SVN r31474
The standard library has grown significantly, and we need a new
directory structure that clearly reflects the role of the APIs, and
allows future growth.
See stdlib/{public,internal,private}/README.txt for more information.
Swift SVN r25876
