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发帖数: 1034 | 1 by Jeff Martin on Jun 26, 2014 | Discuss
Details continue to emerge from Microsoft as to how the support for standard
C will be improved in Visual Studio “14”. Improving C99 compliance is a
top priority, but complementing that effort is a redesign of the familiar
mscorlib DLL. Microsoft’s James McNellis announced that the company is
splitting up Windows’ C runtime (CRT) into three distinct runtimes to
better support the needs of the various platforms that applications are
targeting.
The refactoring also improves the ability of Microsoft to maintain the
existing runtime while making additions easier to implement. For example,
McNellis notes that the CRT offers 142 variations of printf, and that until
the refactor the supporting code was spread over hundreds of conditionally
compiled regions.
VCRuntime – Process startup, exception handling, stuff closely coupled
to the compiler. Note that breaking changes may be made in the future.
AppCRT – Functionality that is used on all platforms. Backward
compatibility will be maintained.
DesktopCRT – Desktop specific functionality, not bundled in on Windows
Phones, etc. Backward compatibility will be maintained.
Visual Studio “14” has taken the first step in adopting the new layout by
producing vcruntime140.dll, appcrt140.dll, and desktop140.dll. Since the
work to divide the runtime across these 3 files is still ongoing, all 3 are
still required the CTP regardless of the application type being targeted.
When the refactor is completed (prior to the official release of “14”),
the version numbers will be removed from the filenames of AppCRT and
DesktopCRT. At that time, Windows Store and Windows Phone apps will be able
to utilize VCRuntime and AppCRT while desktop apps can also use DesktopCRT.
In the scenario of a future release of the runtimes, the newest version
would take precedence and replace any older versions. So an app requiring
the theoretical “VCRuntime16” would install the necessary runtime, and “
VCRuntime14” would be replaced.
As the effort to split the runtime into these 3 parts continues, news as to
the specifics of C99 have also been released by McNellis. Confusingly he
writes that “14” has full C99 compliance—but that is tempered by the
immediate qualifier that such compliance only applies if a given feature
doesn’t require something unsupported by the Visual C++ compiler. | k**********g
发帖数: 989 | 2 The printf thing is getting funny. Let's see if Microsoft will create a
Windows-only Y2K Problem by adding C99 compliance into VCRT14. |
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