Dramatically improves C++ demangling performance by introducing a new…

… implementation that is much faster than the existing demangler. While not yet complete, the new demangler will fail gracefully when it encounters symbols it isn’t prepared to deal with. In these cases LLDB will fall back to using the full demangler to prevent a loss in functionality. On sizable code bases the fast path succeeds 95% of the time, providing a significant net win.

The new implementation is located in source/Core/FastDemangle.cpp.  It’s fairly straightforward C code with a few basic C++ extensions.  It should compile with little or no change on a variety of platforms, but of course it is still only useful for symbols that comply with the Itanium ABI mangling spec (plus a few Clang extensions.)

<rdar://problem/15397553> <rdar://problem/15794867>



git-svn-id: https://llvm.org/svn/llvm-project/lldb/trunk@213671 91177308-0d34-0410-b5e6-96231b3b80d8

lldb.xcodeproj/project.pbxproj

@@ -580,6 +580,7 @@
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 		26FFC19D14FC072100087D58 /* DynamicLoaderPOSIXDYLD.cpp in Sources */ = {isa = PBXBuildFile; fileRef = 26FFC19714FC072100087D58 /* DynamicLoaderPOSIXDYLD.cpp */; };
 		26FFC19E14FC072100087D58 /* DynamicLoaderPOSIXDYLD.h in Headers */ = {isa = PBXBuildFile; fileRef = 26FFC19814FC072100087D58 /* DynamicLoaderPOSIXDYLD.h */; };
+		449ACC98197DEA0B008D175E /* FastDemangle.cpp in Sources */ = {isa = PBXBuildFile; fileRef = 449ACC96197DE9EC008D175E /* FastDemangle.cpp */; };
 		490A36C0180F0E6F00BA31F8 /* PlatformWindows.cpp in Sources */ = {isa = PBXBuildFile; fileRef = 490A36BD180F0E6F00BA31F8 /* PlatformWindows.cpp */; };
 		490A36C2180F0E9300BA31F8 /* PlatformWindows.h in Headers */ = {isa = PBXBuildFile; fileRef = 490A36BE180F0E6F00BA31F8 /* PlatformWindows.h */; };
 		490A966B1628C3BF00F0002E /* SBDeclaration.h in Headers */ = {isa = PBXBuildFile; fileRef = 9452573816262CEF00325455 /* SBDeclaration.h */; settings = {ATTRIBUTES = (Public, ); }; };
@@ -1710,6 +1711,7 @@
 		26FFC19614FC072100087D58 /* DYLDRendezvous.h */ = {isa = PBXFileReference; fileEncoding = 4; lastKnownFileType = sourcecode.c.h; path = DYLDRendezvous.h; sourceTree = "<group>"; };
 		26FFC19714FC072100087D58 /* DynamicLoaderPOSIXDYLD.cpp */ = {isa = PBXFileReference; fileEncoding = 4; lastKnownFileType = sourcecode.cpp.cpp; path = DynamicLoaderPOSIXDYLD.cpp; sourceTree = "<group>"; };
 		26FFC19814FC072100087D58 /* DynamicLoaderPOSIXDYLD.h */ = {isa = PBXFileReference; fileEncoding = 4; lastKnownFileType = sourcecode.c.h; path = DynamicLoaderPOSIXDYLD.h; sourceTree = "<group>"; };
+		449ACC96197DE9EC008D175E /* FastDemangle.cpp */ = {isa = PBXFileReference; fileEncoding = 4; lastKnownFileType = sourcecode.cpp.cpp; name = FastDemangle.cpp; path = source/Core/FastDemangle.cpp; sourceTree = "<group>"; };
 		4906FD4012F2255300A2A77C /* ASTDumper.cpp */ = {isa = PBXFileReference; fileEncoding = 4; lastKnownFileType = sourcecode.cpp.cpp; name = ASTDumper.cpp; path = source/Expression/ASTDumper.cpp; sourceTree = "<group>"; };
 		4906FD4412F2257600A2A77C /* ASTDumper.h */ = {isa = PBXFileReference; fileEncoding = 4; lastKnownFileType = sourcecode.c.h; name = ASTDumper.h; path = include/lldb/Expression/ASTDumper.h; sourceTree = "<group>"; };
 		490A36BD180F0E6F00BA31F8 /* PlatformWindows.cpp */ = {isa = PBXFileReference; fileEncoding = 4; lastKnownFileType = sourcecode.cpp.cpp; path = PlatformWindows.cpp; sourceTree = "<group>"; };
@@ -3074,6 +3076,7 @@
 				26BC7E7810F1B85900F91463 /* Error.cpp */,
 				26BC7D6110F1B77400F91463 /* Event.h */,
 				26BC7E7910F1B85900F91463 /* Event.cpp */,
+				449ACC96197DE9EC008D175E /* FastDemangle.cpp */,
 				26BD407D135D2AC400237D80 /* FileLineResolver.h */,
 				26BD407E135D2ADF00237D80 /* FileLineResolver.cpp */,
 				26BC7D6310F1B77400F91463 /* FileSpecList.h */,
@@ -4649,6 +4652,7 @@
 				2689000113353DB600698AC0 /* BreakpointResolverAddress.cpp in Sources */,
 				2689000313353DB600698AC0 /* BreakpointResolverFileLine.cpp in Sources */,
 				26474CA818D0CB070073DEBA /* RegisterContextFreeBSD_i386.cpp in Sources */,
+				449ACC98197DEA0B008D175E /* FastDemangle.cpp in Sources */,
 				94CD705216F8F5BC00CF1E42 /* LibCxxMap.cpp in Sources */,
 				2689000513353DB600698AC0 /* BreakpointResolverName.cpp in Sources */,
 				2689000713353DB600698AC0 /* BreakpointSite.cpp in Sources */,

source/Core/CMakeLists.txt

@@ -25,6 +25,7 @@ add_lldb_library(lldbCore
   EmulateInstruction.cpp
   Error.cpp
   Event.cpp
+  FastDemangle.cpp
   FileLineResolver.cpp
   FileSpecList.cpp
   History.cpp