llvm-project/clang/lib/CodeGen
Naomi Musgrave 866af2d6d1 Refactored dtor sanitizing into EHScopeStack
Summary:
Dtor sanitization handled amidst other dtor cleanups,
between cleaning bases and fields. Sanitizer call pushed onto
stack of cleanup operations.

Reviewers: eugenis, kcc

Differential Revision: http://reviews.llvm.org/D12022

Refactoring dtor sanitizing emission order.

- Support multiple inheritance by poisoning after
 member destructors are invoked, and before base
 class destructors are invoked.
- Poison for virtual destructor and virtual bases.
- Repress dtor aliasing when sanitizing in dtor.
- CFE test for dtor aliasing, and repression of aliasing in dtor
 code generation.
- Poison members on field-by-field basis, with collective poisoning
 of trivial members when possible.
- Check msan flags and existence of fields, before dtor sanitizing,
 and when determining if aliasing is allowed.
- Testing sanitizing bit fields.

llvm-svn: 246815
2015-09-03 23:02:30 +00:00
..
ABIInfo.h [MIPS] Re-land the change r238200 to fix extension of integer types 2015-05-26 21:07:19 +00:00
BackendUtil.cpp Convert SampleProfile pass into a Module pass. 2015-08-25 15:25:13 +00:00
CGAtomic.cpp Add missing atomic libcall support. 2015-08-05 16:57:36 +00:00
CGBlocks.cpp Devirtualize EHScopeStack::Cleanup's dtor because it's never destroyed polymorphically 2015-08-18 22:40:54 +00:00
CGBlocks.h Revert r240270 ("Fixed/added namespace ending comments using clang-tidy"). 2015-06-22 23:07:51 +00:00
CGBuilder.h Wdeprecated: CGBuilderInserter is copy constructed in some contexts - remove the unnecessarily disabling copy assignment to enable this 2015-08-12 23:16:55 +00:00
CGBuiltin.cpp [WebAssembly] Initial WebAssembly support in clang 2015-09-03 22:51:53 +00:00
CGCUDANV.cpp Revert r240270 ("Fixed/added namespace ending comments using clang-tidy"). 2015-06-22 23:07:51 +00:00
CGCUDARuntime.cpp Pass expressions instead of argument ranges to EmitCall/EmitCXXConstructorCall. 2014-08-21 20:26:47 +00:00
CGCUDARuntime.h Revert r240270 ("Fixed/added namespace ending comments using clang-tidy"). 2015-06-22 23:07:51 +00:00
CGCXX.cpp Refactored dtor sanitizing into EHScopeStack 2015-09-03 23:02:30 +00:00
CGCXXABI.cpp [CodeGen] Rename EmitMemberPointer to EmitMemberFunctionPointer 2015-06-23 07:31:01 +00:00
CGCXXABI.h Revert r246214 and r246213 2015-08-28 07:14:10 +00:00
CGCall.cpp Migrate the target attribute parsing code to returning an instance 2015-09-02 20:40:12 +00:00
CGCall.h Revert r245879. Speculative, might have caused crbug.com/524604 2015-08-25 18:43:32 +00:00
CGClass.cpp Refactored dtor sanitizing into EHScopeStack 2015-09-03 23:02:30 +00:00
CGCleanup.cpp [WinEH] Update to new EH pad/ret signatures (with tokens required) 2015-08-23 00:26:48 +00:00
CGCleanup.h [MS ABI] Hook clang up to the new EH instructions 2015-07-31 17:58:45 +00:00
CGDebugInfo.cpp CGDebugInfo: Instead of uniquing RetainedTypes, just refrain from retaining 2015-08-27 22:56:46 +00:00
CGDebugInfo.h CGDebugInfo: Factor out a getOrCreateStandaloneType() method. 2015-08-27 21:21:19 +00:00
CGDecl.cpp Devirtualize EHScopeStack::Cleanup's dtor because it's never destroyed polymorphically 2015-08-18 22:40:54 +00:00
CGDeclCXX.cpp Avoid clearing an empty PrioritizedCXXGlobalInits, NFC 2015-06-20 15:51:52 +00:00
CGException.cpp [WinEH] Update to new EH pad/ret signatures (with tokens required) 2015-08-23 00:26:48 +00:00
CGExpr.cpp [OPENMP 4.0] Codegen for array sections. 2015-08-31 07:32:19 +00:00
CGExprAgg.cpp Implementing C99 partial re-initialization behavior (DR-253) 2015-06-10 00:27:52 +00:00
CGExprCXX.cpp Devirtualize EHScopeStack::Cleanup's dtor because it's never destroyed polymorphically 2015-08-18 22:40:54 +00:00
CGExprComplex.cpp Propagate SourceLocations through to get a Loc on float_cast_overflow 2015-08-11 04:19:28 +00:00
CGExprConstant.cpp [CodeGen] Rename EmitMemberPointer to EmitMemberFunctionPointer 2015-06-23 07:31:01 +00:00
CGExprScalar.cpp Propagate SourceLocations through to get a Loc on float_cast_overflow 2015-08-11 04:19:28 +00:00
CGLoopInfo.cpp Add new llvm.loop.unroll.enable metadata for use with "#pragma unroll". 2015-08-10 17:29:39 +00:00
CGLoopInfo.h Add new llvm.loop.unroll.enable metadata for use with "#pragma unroll". 2015-08-10 17:29:39 +00:00
CGObjC.cpp Devirtualize EHScopeStack::Cleanup's dtor because it's never destroyed polymorphically 2015-08-18 22:40:54 +00:00
CGObjCGNU.cpp Replace push_back(Constructor(foo)) with emplace_back(foo) for non-trivial types 2015-05-29 19:42:19 +00:00
CGObjCMac.cpp Devirtualize EHScopeStack::Cleanup's dtor because it's never destroyed polymorphically 2015-08-18 22:40:54 +00:00
CGObjCRuntime.cpp Devirtualize EHScopeStack::Cleanup's dtor because it's never destroyed polymorphically 2015-08-18 22:40:54 +00:00
CGObjCRuntime.h Revert r240270 ("Fixed/added namespace ending comments using clang-tidy"). 2015-06-22 23:07:51 +00:00
CGOpenCLRuntime.cpp [C++11] Use 'nullptr'. CodeGen edition. 2014-05-21 05:09:00 +00:00
CGOpenCLRuntime.h Revert r240270 ("Fixed/added namespace ending comments using clang-tidy"). 2015-06-22 23:07:51 +00:00
CGOpenMPRuntime.cpp [OpenMP] Make helper functoin static. NFC. 2015-09-02 15:31:05 +00:00
CGOpenMPRuntime.h [OPENMP 4.0] Codegen for 'omp cancel' directive. 2015-07-06 05:50:32 +00:00
CGRecordLayout.h Respect alignment of nested bitfields 2015-07-10 17:30:00 +00:00
CGRecordLayoutBuilder.cpp Respect alignment of nested bitfields 2015-07-10 17:30:00 +00:00
CGStmt.cpp Use CGLoopInfo to emit metadata for loop hint pragmas. 2015-07-27 20:10:20 +00:00
CGStmtOpenMP.cpp [OPENMP 4.1] Codegen for extended format of 'if' clause. 2015-09-03 08:45:56 +00:00
CGVTT.cpp Remove and forbid raw_svector_ostream::flush() calls. 2015-08-13 18:12:56 +00:00
CGVTables.cpp Revert r246214 and r246213 2015-08-28 07:14:10 +00:00
CGVTables.h Header guard canonicalization, clang part. 2014-08-13 16:25:19 +00:00
CGValue.h [opaque pointer type] Update for GEP API changes in LLVM 2015-04-02 18:55:21 +00:00
CMakeLists.txt [CMake] Fill up required libs, corresponding to r241653. 2015-07-08 02:06:21 +00:00
CodeGenABITypes.cpp LLVM API Change: the Module always owns the DataLayout 2015-07-24 16:04:29 +00:00
CodeGenAction.cpp Initialize the AST consumer as soon as we have both an ASTConsumer and an 2015-08-18 20:39:29 +00:00
CodeGenFunction.cpp add __builtin_unpredictable and convert to metadata 2015-09-02 20:01:30 +00:00
CodeGenFunction.h [WebAssembly] Initial WebAssembly support in clang 2015-09-03 22:51:53 +00:00
CodeGenModule.cpp [WebAssembly] Initial WebAssembly support in clang 2015-09-03 22:51:53 +00:00
CodeGenModule.h Refactored dtor sanitizing into EHScopeStack 2015-09-03 23:02:30 +00:00
CodeGenPGO.cpp Switch users of the 'for (StmtRange range = stmt->children(); range; ++range)‘ pattern to range for loops. 2015-07-02 21:03:14 +00:00
CodeGenPGO.h InstrProf: Cede ownership of createProfileWeights to CGF 2015-05-02 05:00:55 +00:00
CodeGenTBAA.cpp Remove and forbid raw_svector_ostream::flush() calls. 2015-08-13 18:12:56 +00:00
CodeGenTBAA.h Header guard canonicalization, clang part. 2014-08-13 16:25:19 +00:00
CodeGenTypes.cpp LLVM API Change: the Module always owns the DataLayout 2015-07-24 16:04:29 +00:00
CodeGenTypes.h Remove superfluous private:, TypeCache is private by default. 2015-08-13 07:12:03 +00:00
CoverageMappingGen.cpp Use llvm::reverse to make a bunch of loops use foreach. NFC. 2015-07-30 17:22:52 +00:00
CoverageMappingGen.h [cleanup] Re-sort *all* #include lines with llvm/utils/sort_includes.py 2015-01-14 11:29:14 +00:00
EHScopeStack.h Devirtualize EHScopeStack::Cleanup's dtor because it's never destroyed polymorphically 2015-08-18 22:40:54 +00:00
ItaniumCXXABI.cpp [WebAssembly] Initial WebAssembly support in clang 2015-09-03 22:51:53 +00:00
Makefile
MicrosoftCXXABI.cpp Revert r246214 and r246213 2015-08-28 07:14:10 +00:00
ModuleBuilder.cpp Rename DescriptionString -> DataLayoutString as it matches the actual 2015-08-05 23:48:05 +00:00
ObjectFilePCHContainerOperations.cpp Add a -gmodules option to the driver and a -dwarf-ext-refs to cc1 2015-08-27 19:46:20 +00:00
README.txt
SanitizerMetadata.cpp [ASan] Initial support for Kernel AddressSanitizer 2015-06-19 12:19:07 +00:00
SanitizerMetadata.h Removing LLVM_DELETED_FUNCTION, as MSVC 2012 was the last reason for requiring the macro. NFC; Clang edition. 2015-02-15 22:54:08 +00:00
TargetInfo.cpp [WebAssembly] Initial WebAssembly support in clang 2015-09-03 22:51:53 +00:00
TargetInfo.h [OPENMP] Introduced type trait "__builtin_omp_required_simd_align" for default simd alignment. 2015-07-02 03:40:19 +00:00

README.txt

IRgen optimization opportunities.

//===---------------------------------------------------------------------===//

The common pattern of
--
short x; // or char, etc
(x == 10)
--
generates an zext/sext of x which can easily be avoided.

//===---------------------------------------------------------------------===//

Bitfields accesses can be shifted to simplify masking and sign
extension. For example, if the bitfield width is 8 and it is
appropriately aligned then is is a lot shorter to just load the char
directly.

//===---------------------------------------------------------------------===//

It may be worth avoiding creation of alloca's for formal arguments
for the common situation where the argument is never written to or has
its address taken. The idea would be to begin generating code by using
the argument directly and if its address is taken or it is stored to
then generate the alloca and patch up the existing code.

In theory, the same optimization could be a win for block local
variables as long as the declaration dominates all statements in the
block.

NOTE: The main case we care about this for is for -O0 -g compile time
performance, and in that scenario we will need to emit the alloca
anyway currently to emit proper debug info. So this is blocked by
being able to emit debug information which refers to an LLVM
temporary, not an alloca.

//===---------------------------------------------------------------------===//

We should try and avoid generating basic blocks which only contain
jumps. At -O0, this penalizes us all the way from IRgen (malloc &
instruction overhead), all the way down through code generation and
assembly time.

On 176.gcc:expr.ll, it looks like over 12% of basic blocks are just
direct branches!

//===---------------------------------------------------------------------===//