llvm-6502

mirror of https://github.com/c64scene-ar/llvm-6502.git synced 2024-11-13 06:06:27 +00:00

History

Eli Bendersky 6b731486d4 Add backreference matching capabilities to Support/Regex, with appropriate unit tests. This change in itself is not expected to affect any functionality at this point, but it will serve as a stepping stone to improve FileCheck's variable matching capabilities. Luckily, our regex implementation already supports backreferences, although a bit of hacking is required to enable it. It supports both Basic Regular Expressions (BREs) and Extended Regular Expressions (EREs), without supporting backrefs for EREs, following POSIX strictly in this respect. And EREs is what we actually use (rightly). This is contrary to many implementations (including the default on Linux) of POSIX regexes, that do allow backrefs in EREs. Adding backref support to our EREs is a very simple change in the regcomp parsing code. I fail to think of significant cases where it would clash with existing things, and can bring more versatility to the regexes we write. There's always the danger of a backref in a specially crafted regex causing exponential matching times, but since we mainly use them for testing purposes I don't think it's a big problem. [it can also be placed behind a flag specific to FileCheck, if needed]. For more details, see: * http://lists.cs.uiuc.edu/pipermail/llvmdev/2012-November/055840.html * http://lists.cs.uiuc.edu/pipermail/llvm-commits/Week-of-Mon-20121126/156878.html git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@168802 91177308-0d34-0410-b5e6-96231b3b80d8		2012-11-28 19:00:02 +00:00
..
Unix
Windows
Allocator.cpp
APFloat.cpp
APInt.cpp
APSInt.cpp
Atomic.cpp
BlockFrequency.cpp
BranchProbability.cpp
circular_raw_ostream.cpp
CMakeLists.txt
CommandLine.cpp
ConstantRange.cpp
COPYRIGHT.regex
CrashRecoveryContext.cpp
DAGDeltaAlgorithm.cpp
DataExtractor.cpp
DataStream.cpp
Debug.cpp
DeltaAlgorithm.cpp
Disassembler.cpp
Dwarf.cpp
DynamicLibrary.cpp
Errno.cpp
ErrorHandling.cpp
FileOutputBuffer.cpp
FileUtilities.cpp
FoldingSet.cpp
FormattedStream.cpp
GraphWriter.cpp
Hashing.cpp
Host.cpp
IncludeFile.cpp
IntEqClasses.cpp
IntervalMap.cpp
IntrusiveRefCntPtr.cpp
IsInf.cpp
IsNAN.cpp
LLVMBuild.txt
Locale.cpp
LocaleGeneric.inc
LocaleWindows.inc
LocaleXlocale.inc
LockFileManager.cpp
Makefile
ManagedStatic.cpp
Memory.cpp
MemoryBuffer.cpp
MemoryObject.cpp
Mutex.cpp
Path.cpp
PathV2.cpp
PluginLoader.cpp
PrettyStackTrace.cpp
Process.cpp
Program.cpp
raw_os_ostream.cpp
raw_ostream.cpp
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	Add backreference matching capabilities to Support/Regex, with	2012-11-28 19:00:02 +00:00
regexec.c
regfree.c
regstrlcpy.c
regutils.h
RWMutex.cpp
SearchForAddressOfSpecialSymbol.cpp
Signals.cpp
SmallPtrSet.cpp
SmallVector.cpp
SourceMgr.cpp
Statistic.cpp
StreamableMemoryObject.cpp
StringExtras.cpp
StringMap.cpp
StringPool.cpp
StringRef.cpp
system_error.cpp
SystemUtils.cpp
TargetRegistry.cpp
Threading.cpp
ThreadLocal.cpp
Timer.cpp
TimeValue.cpp
ToolOutputFile.cpp
Triple.cpp
Twine.cpp
Valgrind.cpp
YAMLParser.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