LLVM: llvm::EHStreamer Class Reference (original) (raw)

Emits exception handling directives. More...

#include "[CodeGen/AsmPrinter/EHStreamer.h](EHStreamer%5F8h%5Fsource.html)"

Emits exception handling directives.

Definition at line 30 of file EHStreamer.h.

◆ RangeMapType

◆ ~EHStreamer()

◆ callToNoUnwindFunction()

Return ‘true’ if this is a call to a function marked ‘nounwind’.

Return ‘false’ otherwise.

References MI.

Referenced by computeCallSiteTable().

◆ computeActionsTable()

Compute the actions table and gather the first action index for each landing pad site.

Definition at line 51 of file EHStreamer.cpp.

References Asm, assert(), llvm::getSLEB128Size(), llvm::getULEB128Size(), isFilterEHSelector(), llvm::Offset, llvm::SmallVectorTemplateBase< T, bool >::push_back(), llvm::SmallVectorImpl< T >::reserve(), sharedTypeIDs(), llvm::SmallVectorTemplateCommon< T, typename >::size(), and llvm::LandingPadInfo::TypeIds.

Referenced by emitExceptionTable().

◆ computeCallSiteTable()

Compute the call-site table and the call-site ranges.

Compute the call-site table.

The entry for an invoke has a try-range containing the call, a non-zero landing pad and an appropriate action. The entry for an ordinary call has a try-range containing the call and zero for the landing pad and the action. Calls marked 'nounwind' have no entry and must not be contained in the try-range of any entry - they form gaps in the table. Entries must be ordered by try-range address. CallSiteRanges vector is only populated for Itanium exception handling.

The entry for an invoke has a try-range containing the call, a non-zero landing pad, and an appropriate action. The entry for an ordinary call has a try-range containing the call and zero for the landing pad and the action. Calls marked 'nounwind' have no entry and must not be contained in the try-range of any entry - they form gaps in the table. Entries must be ordered by try-range address.

Call-sites are split into one or more call-site ranges associated with different sections of the function.

• Without -basic-block-sections, all call-sites are grouped into one call-site-range corresponding to the function section.
• With -basic-block-sections, one call-site range is created for each section, with its FragmentBeginLabel and FragmentEndLabel respectively

Reimplemented in llvm::WasmException.

Definition at line 229 of file EHStreamer.cpp.

References llvm::EHStreamer::CallSiteEntry::Action, llvm::AIX, Asm, assert(), llvm::SmallVectorTemplateCommon< T, typename >::back(), llvm::LandingPadInfo::BeginLabels, callToNoUnwindFunction(), computePadMap(), llvm::DenseMapBase< DerivedT, KeyT, ValueT, KeyInfoT, BucketT >::end(), llvm::EHStreamer::CallSiteEntry::EndLabel, llvm::LandingPadInfo::EndLabels, llvm::DenseMapBase< DerivedT, KeyT, ValueT, KeyInfoT, BucketT >::find(), llvm::LandingPadInfo::LandingPadLabel, llvm::EHStreamer::CallSiteEntry::LPad, MBB, MI, P, llvm::SmallVectorTemplateBase< T, bool >::push_back(), Range, llvm::SmallVectorImpl< T >::resize(), llvm::SmallVectorTemplateCommon< T, typename >::size(), and llvm::SjLj.

Referenced by emitExceptionTable().

◆ computePadMap()

Definition at line 186 of file EHStreamer.cpp.

References assert(), llvm::LandingPadInfo::BeginLabels, llvm::DenseMapBase< DerivedT, KeyT, ValueT, KeyInfoT, BucketT >::count(), llvm::MCSymbol::isDefined(), N, P, and llvm::SmallVectorTemplateCommon< T, typename >::size().

Referenced by computeCallSiteTable().

◆ emitExceptionTable()

Emit landing pads and actions.

The general organization of the table is complex, but the basic concepts are easy. First there is a header which describes the location and organization of the three components that follow.

1. The landing pad site information describes the range of code covered by the try. In our case it's an accumulation of the ranges covered by the invokes in the try. There is also a reference to the landing pad that handles the exception once processed. Finally an index into the actions table.
2. The action table, in our case, is composed of pairs of type ids and next action offset. Starting with the action index from the landing pad site, each type Id is checked for a match to the current exception. If it matches then the exception and type id are passed on to the landing pad. Otherwise the next action is looked up. This chain is terminated with a next action of zero. If no type id is found the frame is unwound and handling continues.
3. Type id table contains references to all the C++ typeinfo for all catches in the function. This tables is reversed indexed base 1.

Returns the starting symbol of an exception table.

The general organization of the table is complex, but the basic concepts are easy. First there is a header which describes the location and organization of the three components that follow.

1. The landing pad site information describes the range of code covered by the try. In our case it's an accumulation of the ranges covered by the invokes in the try. There is also a reference to the landing pad that handles the exception once processed. Finally an index into the actions table.
2. The action table, in our case, is composed of pairs of type IDs and next action offset. Starting with the action index from the landing pad site, each type ID is checked for a match to the current exception. If it matches then the exception and type id are passed on to the landing pad. Otherwise the next action is looked up. This chain is terminated with a next action of zero. If no type id is found then the frame is unwound and handling continues.
3. Type ID table contains references to all the C++ typeinfo for all catches in the function. This tables is reverse indexed base 1.

Returns the starting symbol of an exception table.

Definition at line 379 of file EHStreamer.cpp.

References llvm::EHStreamer::CallSiteEntry::Action, Asm, assert(), llvm::SmallVectorTemplateCommon< T, typename >::back(), llvm::SmallVectorTemplateCommon< T, typename >::begin(), llvm::EHStreamer::CallSiteEntry::BeginLabel, llvm::EHStreamer::CallSiteRange::CallSiteBeginIdx, llvm::EHStreamer::CallSiteRange::CallSiteEndIdx, computeActionsTable(), computeCallSiteTable(), llvm::MCSymbolRefExpr::create(), llvm::MCBinaryExpr::createSub(), llvm::dwarf::DW_EH_PE_absptr, llvm::dwarf::DW_EH_PE_omit, llvm::dwarf::DW_EH_PE_pcrel, llvm::dwarf::DW_EH_PE_udata4, emitTypeInfos(), llvm::SmallVectorTemplateCommon< T, typename >::end(), llvm::EHStreamer::CallSiteEntry::EndLabel, llvm::EHStreamer::CallSiteRange::FragmentBeginLabel, llvm::MachineFunction::getFilterIds(), llvm::MachineFunction::getFunction(), llvm::MachineFunction::getLandingPads(), llvm::MCSymbol::getName(), llvm::getSLEB128Size(), llvm::MachineFunction::getTypeInfos(), llvm::getULEB128Size(), I, llvm::isUInt(), llvm::LandingPadInfo::LandingPadLabel, llvm::EHStreamer::CallSiteEntry::LPad, llvm::SmallVectorTemplateBase< T, bool >::push_back(), llvm::report_fatal_error(), llvm::SmallVectorImpl< T >::reserve(), llvm::SmallVectorTemplateCommon< T, typename >::size(), llvm::SjLj, llvm::sort(), and llvm::Wasm.

Referenced by llvm::AIXException::endFunction(), llvm::ARMException::endFunction(), llvm::DwarfCFIException::endFunction(), llvm::WasmException::endFunction(), and llvm::WinException::endFunction().

◆ emitTypeInfos()

◆ isCatchEHSelector()

◆ isCleanupEHSelector()

◆ isFilterEHSelector()

◆ sharedTypeIDs()

◆ Asm

Target of directive emission.

Definition at line 33 of file EHStreamer.h.

Referenced by llvm::DwarfCFIException::beginBasicBlockSection(), llvm::WinException::beginFunclet(), llvm::ARMException::beginFunction(), llvm::DwarfCFIException::beginFunction(), llvm::WinException::beginFunction(), computeActionsTable(), computeCallSiteTable(), llvm::WasmException::computeCallSiteTable(), EHStreamer(), emitExceptionTable(), emitTypeInfos(), llvm::DwarfCFIException::endBasicBlockSection(), llvm::WinException::endFunclet(), llvm::AIXException::endFunction(), llvm::ARMException::endFunction(), llvm::WasmException::endFunction(), llvm::WinException::endFunction(), llvm::DwarfCFIException::endModule(), llvm::WinException::endModule(), llvm::ARMException::markFunctionEnd(), llvm::WinException::markFunctionEnd(), and llvm::WinException::WinException().

◆ MMI

The documentation for this class was generated from the following files:

• lib/CodeGen/AsmPrinter/EHStreamer.h
• lib/CodeGen/AsmPrinter/EHStreamer.cpp