llvm-6502/lib/Support
Argyrios Kyrtzidis 3b05d9f4db In llvm::MemoryBuffer::getFile() remove an unnecessary stat call check.
The sys::fs::is_directory() check is unnecessary because, if the filename is
a directory, the function will fail anyway with the same error code returned.
Remove the check to avoid an unnecessary stat call.

Someone needs to review on windows and see if the check is necessary there or not.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@176386 91177308-0d34-0410-b5e6-96231b3b80d8
2013-03-01 22:48:51 +00:00
..
Unix [PathV2] In llvm::sys::fs::unique_file, make sure it doesn't fall into an infinite loop by constantly trying 2013-02-28 00:38:19 +00:00
Windows Add static cast to unsigned char whenever a character classification function is called with a signed char argument, in order to avoid assertions in Windows Debug configuration. 2013-02-12 21:21:59 +00:00
Allocator.cpp as the allocator is reset zero out the number of bytes allocated, this was just 2013-02-20 23:30:56 +00:00
APFloat.cpp APFloat: Make sure that we get a well-formed x87 NaN when converting from a smaller type. 2013-01-25 17:01:00 +00:00
APInt.cpp Move part of APInt implementation from header to cpp file. These methods 2013-02-20 00:17:42 +00:00
APSInt.cpp
Atomic.cpp XLC supports the same atomic functions as GCC, use them. 2012-11-02 20:54:45 +00:00
BlockFrequency.cpp BlockFrequency: Use a smarter overflow check. 2011-10-27 16:38:50 +00:00
BranchProbability.cpp Print branch probabilities as percentages. 2011-10-23 11:32:54 +00:00
circular_raw_ostream.cpp
CMakeLists.txt Move UTF conversion routines from clang/lib/Basic to llvm/lib/Support 2013-01-30 12:05:05 +00:00
CommandLine.cpp Use the new script to sort the includes of every file under lib. 2012-12-03 16:50:05 +00:00
ConstantRange.cpp Move all of the header files which are involved in modelling the LLVM IR 2013-01-02 11:36:10 +00:00
ConvertUTF.c Move UTF conversion routines from clang/lib/Basic to llvm/lib/Support 2013-01-30 12:05:05 +00:00
ConvertUTFWrapper.cpp Move UTF conversion routines from clang/lib/Basic to llvm/lib/Support 2013-01-30 12:05:05 +00:00
COPYRIGHT.regex
CrashRecoveryContext.cpp Use the new script to sort the includes of every file under lib. 2012-12-03 16:50:05 +00:00
DAGDeltaAlgorithm.cpp Add LLVM_OVERRIDE to methods that override their base classes. 2012-09-23 02:12:10 +00:00
DataExtractor.cpp DataExtractor: Fix integer truncation issues in LEB128 extraction. 2012-08-20 10:52:11 +00:00
DataStream.cpp Use the new script to sort the includes of every file under lib. 2012-12-03 16:50:05 +00:00
Debug.cpp Fix accidental concatenation for "outputuntil" in the -debug-buffer-size option description. 2013-02-20 22:33:46 +00:00
DeltaAlgorithm.cpp Revert r171829 "Split changeset_ty using iterators instead of loops" as it breaks the VS2008 build 2013-01-14 14:13:06 +00:00
Disassembler.cpp Use the new script to sort the includes of every file under lib. 2012-12-03 16:50:05 +00:00
Dwarf.cpp Previously, parsing capability of the .debug_frame section was added 2013-02-21 22:53:19 +00:00
DynamicLibrary.cpp Remove redundant 'llvm::' qualifications 2013-01-13 16:01:15 +00:00
Errno.cpp [Support] Fix StrError on Windows to actually return the error string... 2012-11-01 00:34:09 +00:00
ErrorHandling.cpp Use the new script to sort the includes of every file under lib. 2012-12-03 16:50:05 +00:00
FileOutputBuffer.cpp [Support] Make FileOutputBuffer work on Windows. 2012-12-03 22:09:52 +00:00
FileUtilities.cpp Add static cast to unsigned char whenever a character classification function is called with a signed char argument, in order to avoid assertions in Windows Debug configuration. 2013-02-12 21:21:59 +00:00
FoldingSet.cpp Fix whitespace. No functionality change. 2012-12-25 06:13:25 +00:00
FormattedStream.cpp
GraphWriter.cpp ScheduleDAG: colorize the DOT graph and improve formatting. 2013-01-25 07:45:25 +00:00
Hashing.cpp Add the source file with trivial definitions in it that was missing from 2012-03-01 18:58:59 +00:00
Host.cpp Add support for autodetection of ADM bdver2. 2013-02-26 22:41:01 +00:00
IncludeFile.cpp
IntEqClasses.cpp
IntervalMap.cpp
IntrusiveRefCntPtr.cpp Unweaken vtables as per http://llvm.org/docs/CodingStandards.html#ll_virtual_anch 2011-12-20 02:50:00 +00:00
IsInf.cpp
IsNAN.cpp
LLVMBuild.txt LLVMBuild: Remove trailing newline, which irked me. 2011-12-12 19:48:00 +00:00
Locale.cpp platform support for counting column widths and checking isprint 2012-04-17 20:03:03 +00:00
LocaleGeneric.inc C++ has newlines at the end of files (including include files). 2012-04-17 23:46:51 +00:00
LocaleWindows.inc Switch LLVM_USE_RVALUE_REFERENCES to LLVM_HAS_RVALUE_REFERENCES. 2012-11-30 11:45:22 +00:00
LocaleXlocale.inc Use the new script to sort the includes of every file under lib. 2012-12-03 16:50:05 +00:00
LockFileManager.cpp Provide a "None" value for convenience when using Optional<T>() 2013-02-21 00:27:28 +00:00
Makefile Don't explicitly require RTTI and EH. 2012-10-26 12:15:29 +00:00
ManagedStatic.cpp Add support for tsan annotations (thread sanitizer, a valgrind-based tool). 2011-11-14 20:50:16 +00:00
Memory.cpp Use the new script to sort the includes of every file under lib. 2012-12-03 16:50:05 +00:00
MemoryBuffer.cpp In llvm::MemoryBuffer::getFile() remove an unnecessary stat call check. 2013-03-01 22:48:51 +00:00
MemoryObject.cpp Make MemoryObject accessor members const again 2012-02-29 01:09:06 +00:00
Mutex.cpp Add support for the OpenBSD for Bitrig. 2012-08-06 20:52:18 +00:00
Path.cpp Remove duplicate includes. 2012-12-21 17:06:44 +00:00
PathV2.cpp Add static cast to unsigned char whenever a character classification function is called with a signed char argument, in order to avoid assertions in Windows Debug configuration. 2013-02-12 21:21:59 +00:00
PluginLoader.cpp Use the new script to sort the includes of every file under lib. 2012-12-03 16:50:05 +00:00
PrettyStackTrace.cpp Use the new script to sort the includes of every file under lib. 2012-12-03 16:50:05 +00:00
Process.cpp Add time getters to the process interface for requesting the elapsed 2013-01-04 23:19:55 +00:00
Program.cpp Support/Program: Make Change<stream>ToBinary return error_code. 2011-12-13 23:16:49 +00:00
raw_os_ostream.cpp
raw_ostream.cpp Add static cast to unsigned char whenever a character classification function is called with a signed char argument, in order to avoid assertions in Windows Debug configuration. 2013-02-12 21:21:59 +00:00
README.txt.system
regcclass.h
regcname.h
regcomp.c Add backreference matching capabilities to Support/Regex, with 2012-11-28 19:00:02 +00:00
regengine.inc
regerror.c
regex2.h
regex_impl.h
Regex.cpp Use the new script to sort the includes of every file under lib. 2012-12-03 16:50:05 +00:00
regexec.c Fix integer undefined behavior due to signed left shift overflow in LLVM. 2012-08-24 23:29:28 +00:00
regfree.c
regstrlcpy.c
regutils.h
RWMutex.cpp Remove dead code. 2012-01-15 01:09:13 +00:00
SearchForAddressOfSpecialSymbol.cpp
Signals.cpp
SmallPtrSet.cpp SmallPtrSet: Reuse DenseMapInfo's pointer hash function instead of inventing a bad one ourselves. 2012-04-18 10:37:32 +00:00
SmallVector.cpp Reduce alignment of SmallVector<T> to the required amount, rather than forcing 16-byte alignment. This fixes misaligned SmallVector accesses via ExtractValueInst's SmallVector data member. 2012-08-22 00:11:07 +00:00
SourceMgr.cpp Make helpers static. Add missing include so LLVMInitializeObjCARCOpts gets C linkage. 2013-02-15 12:30:38 +00:00
Statistic.cpp Use the new script to sort the includes of every file under lib. 2012-12-03 16:50:05 +00:00
StreamableMemoryObject.cpp Add LLVM_OVERRIDE to methods that override their base classes. 2012-09-23 02:12:10 +00:00
StringExtras.cpp Move the implementation of StringRef::split out of StringExtras.cpp 2012-02-21 12:00:25 +00:00
StringMap.cpp Add some __builtin_expect magic to StringMap. 2012-08-29 22:57:04 +00:00
StringPool.cpp
StringRef.cpp Use the new script to sort the includes of every file under lib. 2012-12-03 16:50:05 +00:00
system_error.cpp Use the new script to sort the includes of every file under lib. 2012-12-03 16:50:05 +00:00
SystemUtils.cpp
TargetRegistry.cpp Fix it so llvm-objdump -arch does accept x86 and x86-64 as valid arch names. 2012-05-08 23:38:45 +00:00
Threading.cpp Use the new script to sort the includes of every file under lib. 2012-12-03 16:50:05 +00:00
ThreadLocal.cpp Fix ThreadLocalImpl::getInstance for --disable-threads. 2012-06-26 17:13:58 +00:00
Timer.cpp Use the new script to sort the includes of every file under lib. 2012-12-03 16:50:05 +00:00
TimeValue.cpp Fix initialization-order bug in llvm::Support::TimeValue. TimeValue::now() is explicitly called during module initialization of lib/Support/Process.cpp. It reads the field of global object PosixZeroTime, which is not guaranteed to be initialized at this point. Found by AddressSanitizer with -fsanitize=init-order option. 2013-02-19 11:35:39 +00:00
ToolOutputFile.cpp
Triple.cpp Add AArch64 as an experimental target. 2013-01-31 12:12:40 +00:00
Twine.cpp
Valgrind.cpp Don't define these unless we plan to use them. 2011-11-28 22:14:02 +00:00
YAMLParser.cpp Use the new script to sort the includes of every file under lib. 2012-12-03 16:50:05 +00:00
YAMLTraits.cpp Fix memory leak in YAML I/O. 2013-01-08 21:04:44 +00:00

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