Lang Hames f9bddc40cd [ADT] Add a fallible_iterator wrapper. ... A fallible iterator is one whose increment or decrement operations may fail. This would usually be supported by replacing the ++ and -- operators with methods that return error: class MyFallibleIterator { public: // ... Error inc(); Errro dec(); // ... }; The downside of this style is that it no longer conforms to the C++ iterator concept, and can not make use of standard algorithms and features such as range-based for loops. The fallible_iterator wrapper takes an iterator written in the style above and adapts it to (mostly) conform with the C++ iterator concept. It does this by providing standard ++ and -- operator implementations, returning any errors generated via a side channel (an Error reference passed into the wrapper at construction time), and immediately jumping the iterator to a known 'end' value upon error. It also marks the Error as checked any time an iterator is compared with a known end value and found to be inequal, allowing early exit from loops without redundant error checking*. Usage looks like: MyFallibleIterator I = ..., E = ...; Error Err = Error::success(); for (auto &Elem : make_fallible_range(I, E, Err)) { // Loop body is only entered when safe. // Early exits from loop body permitted without checking Err. if (SomeCondition) return; } if (Err) // Handle error. * Since failure causes a fallible iterator to jump to end, testing that a fallible iterator is not an end value implicitly verifies that the error is a success value, and so is equivalent to an error check. Reviewers: dblaikie, rupprecht Subscribers: mgorny, dexonsmith, kristina, llvm-commits Tags: #llvm Differential Revision: https://reviews.llvm.org/D57618 llvm-svn: 353237		2019-02-05 23:17:11 +00:00
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Archive.cpp	[ADT] Add a fallible_iterator wrapper.	2019-02-05 23:17:11 +00:00
ArchiveWriter.cpp	Update the file headers across all of the LLVM projects in the monorepo	2019-01-19 08:50:56 +00:00
Binary.cpp	Update the file headers across all of the LLVM projects in the monorepo	2019-01-19 08:50:56 +00:00
CMakeLists.txt
COFFImportFile.cpp	Update the file headers across all of the LLVM projects in the monorepo	2019-01-19 08:50:56 +00:00
COFFModuleDefinition.cpp	Update the file headers across all of the LLVM projects in the monorepo	2019-01-19 08:50:56 +00:00
COFFObjectFile.cpp	[COFF] Add new relocation types.	2019-01-27 19:53:36 +00:00
Decompressor.cpp	Update the file headers across all of the LLVM projects in the monorepo	2019-01-19 08:50:56 +00:00
ELF.cpp	Update the file headers across all of the LLVM projects in the monorepo	2019-01-19 08:50:56 +00:00
ELFObjectFile.cpp	Update the file headers across all of the LLVM projects in the monorepo	2019-01-19 08:50:56 +00:00
Error.cpp	Update the file headers across all of the LLVM projects in the monorepo	2019-01-19 08:50:56 +00:00
IRObjectFile.cpp	Update the file headers across all of the LLVM projects in the monorepo	2019-01-19 08:50:56 +00:00
IRSymtab.cpp	Update the file headers across all of the LLVM projects in the monorepo	2019-01-19 08:50:56 +00:00
LLVMBuild.txt	Update the file headers across all of the LLVM projects in the monorepo	2019-01-19 08:50:56 +00:00
MachOObjectFile.cpp	Limit dyld image suffixes guessed by guessLibraryShortName()	2019-01-24 20:59:44 +00:00
MachOUniversal.cpp	Update the file headers across all of the LLVM projects in the monorepo	2019-01-19 08:50:56 +00:00
ModuleSymbolTable.cpp	Update the file headers across all of the LLVM projects in the monorepo	2019-01-19 08:50:56 +00:00
Object.cpp	Update the file headers across all of the LLVM projects in the monorepo	2019-01-19 08:50:56 +00:00
ObjectFile.cpp	Update the file headers across all of the LLVM projects in the monorepo	2019-01-19 08:50:56 +00:00
RecordStreamer.cpp	[AsmPrinter] Remove hidden flag -print-schedule.	2019-02-04 12:51:26 +00:00
RecordStreamer.h	[AsmPrinter] Remove hidden flag -print-schedule.	2019-02-04 12:51:26 +00:00
SymbolicFile.cpp	Update the file headers across all of the LLVM projects in the monorepo	2019-01-19 08:50:56 +00:00
SymbolSize.cpp	Update the file headers across all of the LLVM projects in the monorepo	2019-01-19 08:50:56 +00:00
WasmObjectFile.cpp	[WebAssembly] Object: Remove redundant method. NFC.	2019-02-05 16:30:21 +00:00
WindowsResource.cpp	Update the file headers across all of the LLVM projects in the monorepo	2019-01-19 08:50:56 +00:00