forked from OSchip/llvm-project
7943fecee8
Summary: For now I have only added support for x86_64 Linux, but other systems can be added incrementally. This is to be used for setting the default parallelism for ThinLTO backends (instead of thread::hardware_concurrency which includes hyperthreading and is too aggressive). I'll send this as a follow-on patch, and it will fall back to hardware_concurrency when the new getHostNumPhysicalCores returns -1 (when not supported for a given host system). I also added an interface to MemoryBuffer to force reading a file as a stream - this is required for /proc/cpuinfo which is a special file that looks like a normal file but appears to have 0 size. The existing readers of this file in Host.cpp are reading the first 1024 or so bytes from it, because the necessary info is near the top. But for the new functionality we need to be able to read the entire file. I can go back and change the other readers to use the new getFileAsStream as a follow-on patch since it seems much more robust. Added a unittest. Reviewers: mehdi_amini Subscribers: beanz, mgorny, llvm-commits, modocache Differential Revision: https://reviews.llvm.org/D25564 llvm-svn: 284138 |
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.. | ||
Unix | ||
Windows | ||
APFloat.cpp | ||
APInt.cpp | ||
APSInt.cpp | ||
ARMBuildAttrs.cpp | ||
ARMWinEH.cpp | ||
Allocator.cpp | ||
Atomic.cpp | ||
BlockFrequency.cpp | ||
BranchProbability.cpp | ||
CMakeLists.txt | ||
COM.cpp | ||
COPYRIGHT.regex | ||
CachePruning.cpp | ||
CommandLine.cpp | ||
Compression.cpp | ||
ConvertUTF.cpp | ||
ConvertUTFWrapper.cpp | ||
CrashRecoveryContext.cpp | ||
DAGDeltaAlgorithm.cpp | ||
DataExtractor.cpp | ||
DataStream.cpp | ||
Debug.cpp | ||
DeltaAlgorithm.cpp | ||
Dwarf.cpp | ||
DynamicLibrary.cpp | ||
Errno.cpp | ||
Error.cpp | ||
ErrorHandling.cpp | ||
FileOutputBuffer.cpp | ||
FileUtilities.cpp | ||
FoldingSet.cpp | ||
FormattedStream.cpp | ||
GraphWriter.cpp | ||
Hashing.cpp | ||
Host.cpp | ||
IntEqClasses.cpp | ||
IntervalMap.cpp | ||
IntrusiveRefCntPtr.cpp | ||
JamCRC.cpp | ||
LEB128.cpp | ||
LLVMBuild.txt | ||
LineIterator.cpp | ||
Locale.cpp | ||
LockFileManager.cpp | ||
MD5.cpp | ||
ManagedStatic.cpp | ||
MathExtras.cpp | ||
Memory.cpp | ||
MemoryBuffer.cpp | ||
MemoryObject.cpp | ||
Mutex.cpp | ||
NativeFormatting.cpp | ||
Options.cpp | ||
Path.cpp | ||
PluginLoader.cpp | ||
PrettyStackTrace.cpp | ||
Process.cpp | ||
Program.cpp | ||
README.txt.system | ||
RWMutex.cpp | ||
RandomNumberGenerator.cpp | ||
Regex.cpp | ||
SHA1.cpp | ||
ScaledNumber.cpp | ||
ScopedPrinter.cpp | ||
SearchForAddressOfSpecialSymbol.cpp | ||
Signals.cpp | ||
SmallPtrSet.cpp | ||
SmallVector.cpp | ||
SourceMgr.cpp | ||
SpecialCaseList.cpp | ||
Statistic.cpp | ||
StreamingMemoryObject.cpp | ||
StringExtras.cpp | ||
StringMap.cpp | ||
StringPool.cpp | ||
StringRef.cpp | ||
StringSaver.cpp | ||
SystemUtils.cpp | ||
TargetParser.cpp | ||
TargetRegistry.cpp | ||
ThreadLocal.cpp | ||
ThreadPool.cpp | ||
Threading.cpp | ||
TimeValue.cpp | ||
Timer.cpp | ||
ToolOutputFile.cpp | ||
Triple.cpp | ||
Twine.cpp | ||
Unicode.cpp | ||
Valgrind.cpp | ||
Watchdog.cpp | ||
YAMLParser.cpp | ||
YAMLTraits.cpp | ||
circular_raw_ostream.cpp | ||
raw_os_ostream.cpp | ||
raw_ostream.cpp | ||
regcclass.h | ||
regcname.h | ||
regcomp.c | ||
regengine.inc | ||
regerror.c | ||
regex2.h | ||
regex_impl.h | ||
regexec.c | ||
regfree.c | ||
regstrlcpy.c | ||
regutils.h | ||
xxhash.cpp |
README.txt.system
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