Cross Reference: /external/llvm/lib/Support/

Design Of lib/System
====================

The software in this directory is designed to completely shield LLVM from any
and all operating system specific functionality. It is not intended to be a
complete operating system wrapper (such as ACE), but only to provide the
functionality necessary to support LLVM.

The software located here, of necessity, has very specific and stringent design
rules. Violation of these rules means that cracks in the shield could form and
the primary goal of the library is defeated. By consistently using this library,
LLVM becomes more easily ported to new platforms since the only thing requiring
porting is this library.

Complete documentation for the library can be found in the file:
  llvm/docs/SystemLibrary.html
or at this URL:
  http://llvm.org/docs/SystemLibrary.html

While we recommend that you read the more detailed documentation, for the
impatient, here's a high level summary of the library's requirements.

 1. No system header files are to be exposed through the interface.
 2. Std C++ and Std C header files are okay to be exposed through the interface.
 3. No exposed system-specific functions.
 4. No exposed system-specific data.
 5. Data in lib/System classes must use only simple C++ intrinsic types.
 6. Errors are handled by returning "true" and setting an optional std::string
 7. Library must not throw any exceptions, period.
 8. Interface functions must not have throw() specifications.
 9. No duplicate function impementations are permitted within an operating
    system class.

To accomplish these requirements, the library has numerous design criteria that
must be satisfied. Here's a high level summary of the library's design criteria:

 1. No unused functionality (only what LLVM needs)
 2. High-Level Interfaces
 3. Use Opaque Classes
 4. Common Implementations
 5. Multiple Implementations
 6. Minimize Memory Allocation
 7. No Virtual Methods
Name	Date	Size
..	12-Mar-2015	4 KiB
Allocator.cpp	12-Mar-2015	1.5 KiB
Android.mk	12-Mar-2015	2.4 KiB
APFloat.cpp	12-Mar-2015	115.1 KiB
APInt.cpp	12-Mar-2015	87.3 KiB
APSInt.cpp	12-Mar-2015	779
ARMBuildAttrs.cpp	12-Mar-2015	4 KiB
ARMWinEH.cpp	12-Mar-2015	1 KiB
Atomic.cpp	12-Mar-2015	3 KiB
BlockFrequency.cpp	12-Mar-2015	1.9 KiB
BranchProbability.cpp	12-Mar-2015	2 KiB
circular_raw_ostream.cpp	12-Mar-2015	1.3 KiB
CMakeLists.txt	12-Mar-2015	3 KiB
CommandLine.cpp	12-Mar-2015	62.4 KiB
Compression.cpp	12-Mar-2015	3.3 KiB
ConvertUTF.c	12-Mar-2015	26.4 KiB
ConvertUTFWrapper.cpp	12-Mar-2015	4.4 KiB
COPYRIGHT.regex	12-Mar-2015	2.7 KiB
CrashRecoveryContext.cpp	12-Mar-2015	11 KiB
DAGDeltaAlgorithm.cpp	12-Mar-2015	12.7 KiB
DataExtractor.cpp	12-Mar-2015	4.9 KiB
DataStream.cpp	12-Mar-2015	2.7 KiB
Debug.cpp	12-Mar-2015	4.6 KiB
DeltaAlgorithm.cpp	12-Mar-2015	3.4 KiB
Disassembler.cpp	12-Mar-2015	1.7 KiB
Dwarf.cpp	12-Mar-2015	42.1 KiB
DynamicLibrary.cpp	12-Mar-2015	5.1 KiB
Errno.cpp	12-Mar-2015	2.1 KiB
ErrorHandling.cpp	12-Mar-2015	7.8 KiB
FileOutputBuffer.cpp	12-Mar-2015	3.1 KiB
FileUtilities.cpp	12-Mar-2015	8.6 KiB
FoldingSet.cpp	12-Mar-2015	14.2 KiB
FormattedStream.cpp	12-Mar-2015	3.4 KiB
GraphWriter.cpp	12-Mar-2015	7.2 KiB
Hashing.cpp	12-Mar-2015	1.1 KiB
Host.cpp	12-Mar-2015	26.3 KiB
IncludeFile.cpp	12-Mar-2015	707
IntEqClasses.cpp	12-Mar-2015	2.1 KiB
IntervalMap.cpp	12-Mar-2015	4.3 KiB
IntrusiveRefCntPtr.cpp	12-Mar-2015	445
IsInf.cpp	12-Mar-2015	1.5 KiB
IsNAN.cpp	12-Mar-2015	914
LEB128.cpp	12-Mar-2015	1.2 KiB
LineIterator.cpp	12-Mar-2015	1.9 KiB
LLVMBuild.txt	12-Mar-2015	669
Locale.cpp	12-Mar-2015	837
LockFileManager.cpp	12-Mar-2015	7.3 KiB
Makefile	12-Mar-2015	699
ManagedStatic.cpp	12-Mar-2015	2.6 KiB
MD5.cpp	12-Mar-2015	9 KiB
Memory.cpp	12-Mar-2015	802
MemoryBuffer.cpp	12-Mar-2015	14.1 KiB
MemoryObject.cpp	12-Mar-2015	850
Mutex.cpp	12-Mar-2015	3.2 KiB
Path.cpp	12-Mar-2015	29.5 KiB
PluginLoader.cpp	12-Mar-2015	1.6 KiB
PrettyStackTrace.cpp	12-Mar-2015	4.6 KiB
Process.cpp	12-Mar-2015	3.9 KiB
Program.cpp	12-Mar-2015	2.3 KiB
RandomNumberGenerator.cpp	12-Mar-2015	1.8 KiB
raw_os_ostream.cpp	12-Mar-2015	967
raw_ostream.cpp	12-Mar-2015	22.8 KiB
README.txt.system	12-Mar-2015	1.9 KiB
regcclass.h	12-Mar-2015	2.9 KiB
regcname.h	12-Mar-2015	4.2 KiB
regcomp.c	12-Mar-2015	35.8 KiB
regengine.inc	12-Mar-2015	26.5 KiB
regerror.c	12-Mar-2015	4.4 KiB
Regex.cpp	12-Mar-2015	5.3 KiB
regex2.h	12-Mar-2015	6.8 KiB
regex_impl.h	12-Mar-2015	3.6 KiB
regexec.c	12-Mar-2015	5.7 KiB
regfree.c	12-Mar-2015	2.5 KiB
regstrlcpy.c	12-Mar-2015	1.6 KiB
regutils.h	12-Mar-2015	2.3 KiB
RWMutex.cpp	12-Mar-2015	3.2 KiB
ScaledNumber.cpp	12-Mar-2015	8.8 KiB
SearchForAddressOfSpecialSymbol.cpp	12-Mar-2015	1.7 KiB
Signals.cpp	12-Mar-2015	1.1 KiB
SmallPtrSet.cpp	12-Mar-2015	10.9 KiB
SmallVector.cpp	12-Mar-2015	1.5 KiB
SourceMgr.cpp	12-Mar-2015	16 KiB
SpecialCaseList.cpp	12-Mar-2015	5.7 KiB
Statistic.cpp	12-Mar-2015	5.1 KiB
StreamableMemoryObject.cpp	12-Mar-2015	4.3 KiB
StringExtras.cpp	12-Mar-2015	2.3 KiB
StringMap.cpp	12-Mar-2015	8.5 KiB
StringPool.cpp	12-Mar-2015	978
StringRef.cpp	12-Mar-2015	14.2 KiB
StringRefMemoryObject.cpp	12-Mar-2015	946
SystemUtils.cpp	12-Mar-2015	1.2 KiB
TargetRegistry.cpp	12-Mar-2015	4.7 KiB
Threading.cpp	12-Mar-2015	3.2 KiB
ThreadLocal.cpp	12-Mar-2015	2.7 KiB
Timer.cpp	12-Mar-2015	12 KiB
TimeValue.cpp	12-Mar-2015	1.8 KiB
ToolOutputFile.cpp	12-Mar-2015	1.6 KiB
Triple.cpp	12-Mar-2015	28.9 KiB
Twine.cpp	12-Mar-2015	4 KiB
Unicode.cpp	12-Mar-2015	20.1 KiB
Unix/	12-Mar-2015	4 KiB
Valgrind.cpp	12-Mar-2015	2.6 KiB
Watchdog.cpp	12-Mar-2015	712
Windows/	12-Mar-2015	4 KiB
YAMLParser.cpp	12-Mar-2015	60.8 KiB
YAMLTraits.cpp	12-Mar-2015	21.8 KiB