llvm::MCStreamer

Synopsis

Declared in <llvm/MC/MCStreamer.h>

class MCStreamer;

Description

This interface is intended to provide a programmatic interface that is very similar to the level that an assembler .s file provides. It has callbacks to emit bytes, handle directives, etc. The implementation of this interface retains state to know what the current section is etc.

There are multiple implementations of this interface: one for writing out a .s file, and implementations that write out .o files of various formats.

Member Functions

Name	Description
`MCStreamer` [constructor] [deleted]	Copy constructor
`~MCStreamer` [destructor] [virtual]	Destructor
`operator=` [deleted]	Copy assignment operator
`AddComment` [virtual]	Add a textual comment.
`EnsureValidWinFrameInfo`	Retrieve the current frame info if one is available and it is not yet closed. Otherwise, issue an error and return null.
`addBlankLine` [virtual]	Emit a blank line to a .s file to pretty it up.
`addExplicitComment` [virtual]	Add explicit comment T. T is required to be a valid comment in the output and does not need to be escaped.
`beginCOFFSymbolDef` [virtual]	Start emitting COFF symbol definition
`emitAbsoluteSymbolDiff` [virtual]	Emit the absolute difference between two symbols.
`emitAbsoluteSymbolDiffAsULEB128` [virtual]	Emit the absolute difference between two symbols encoded with ULEB128.
`emitAddrsig` [virtual]
`emitAddrsigSym` [virtual]
`emitAssignment` [virtual]	Emit an assignment of `Value` to `Symbol.`
`emitBinaryData` [virtual]	Functionally identical to EmitBytes. When emitting textual assembly, this method uses .byte directives instead of .ascii or .asciz for readability.
`emitBuildVersion` [virtual]	Emit/Specify Mach-O build version command. `Platform` should be one of MachO::PlatformType.
`emitBundleAlignMode` [virtual]	Enable aligned instruction bundling with the given bundle size, from this point onward. Once enabled, bundling cannot be disabled and the bundle size cannot be changed. `Alignment` must be within [2, 2^30]. The default implementations report an error: silently emitting unbundled code would defeat the sandboxing schemes bundling exists for.
`emitBundleLock` [virtual]	The following instructions are a bundle-locked group.
`emitBundleUnlock` [virtual]	Ends a bundle-locked group.
`emitBytes` [virtual]	Emit the bytes in `Data` into the output.
`emitCFIAdjustCfaOffset` [virtual]
`emitCFIBKeyFrame` [virtual]
`emitCFIDefCfa` [virtual]
`emitCFIDefCfaOffset` [virtual]
`emitCFIDefCfaRegister` [virtual]
`emitCFIEndProc`
`emitCFIEscape` [virtual]
`emitCFIGnuArgsSize` [virtual]
`emitCFILLVMDefAspaceCfa` [virtual]
`emitCFILLVMRegisterPair` [virtual]
`emitCFILLVMSetRAState`
`emitCFILLVMVectorOffset` [virtual]
`emitCFILLVMVectorRegisterMask` [virtual]
`emitCFILLVMVectorRegisters` [virtual]
`emitCFILabel` [virtual]	When emitting an object file, create and emit a real label. When emitting textual assembly, this should do nothing to avoid polluting our output.
`emitCFILabelDirective` [virtual]
`emitCFILsda` [virtual]
`emitCFIMTETaggedFrame` [virtual]
`emitCFINegateRAState` [virtual]
`emitCFINegateRAStateWithPC` [virtual]
`emitCFIOffset` [virtual]
`emitCFIPersonality` [virtual]
`emitCFIRegister` [virtual]
`emitCFIRelOffset` [virtual]
`emitCFIRememberState` [virtual]
`emitCFIRestore` [virtual]
`emitCFIRestoreState` [virtual]
`emitCFIReturnColumn` [virtual]
`emitCFISameValue` [virtual]
`emitCFISections` [virtual]
`emitCFISignalFrame` [virtual]
`emitCFIStartProc`
`emitCFIUndefined` [virtual]
`emitCFIValOffset` [virtual]
`emitCFIWindowSave` [virtual]
`emitCGProfileEntry` [virtual]
`emitCOFFImgRel32` [virtual]	Emits a COFF image relative relocation.
`emitCOFFSafeSEH` [virtual]
`emitCOFFSecNumber` [virtual]	Emits the physical number of the section containing the given symbol as assigned during object writing (i.e., this is not a runtime relocation).
`emitCOFFSecOffset` [virtual]	Emits the offset of the symbol from the beginning of the section during object writing (i.e., this is not a runtime relocation).
`emitCOFFSecRel32` [virtual]	Emits a COFF section relative relocation.
`emitCOFFSectionIndex` [virtual]	Emits a COFF section index.
`emitCOFFSymbolIndex` [virtual]	Emits the symbol table index of a Symbol into the current section.
`emitCOFFSymbolStorageClass` [virtual]	Emit the storage class of the symbol.
`emitCOFFSymbolType` [virtual]	Emit the type of the symbol.
`emitCVDefRangeDirective`	This implements the CodeView '.cv_def_range' assembler directive.
`emitCVFPOData` [virtual]	This implements the CodeView '.cv_fpo_data' assembler directive.
`emitCVFileChecksumOffsetDirective` [virtual]	This implements the CodeView '.cv_filechecksumoffset' assembler directive.
`emitCVFileChecksumsDirective` [virtual]	This implements the CodeView '.cv_filechecksums' assembler directive.
`emitCVFileDirective` [virtual]	Associate a filename with a specified logical file number, and also specify that file's checksum information. This implements the '.cv_file 4 "foo.c"' assembler directive. Returns true on success.
`emitCVFuncIdDirective` [virtual]	Introduces a function id for use with .cv_loc.
`emitCVInlineLinetableDirective` [virtual]	This implements the CodeView '.cv_inline_linetable' assembler directive.
`emitCVInlineSiteIdDirective` [virtual]	Introduces an inline call site id for use with .cv_loc. Includes extra information for inline line table generation.
`emitCVLinetableDirective` [virtual]	This implements the CodeView '.cv_linetable' assembler directive.
`emitCVLocDirective` [virtual]	This implements the CodeView '.cv_loc' assembler directive.
`emitCVStringTableDirective` [virtual]	This implements the CodeView '.cv_stringtable' assembler directive.
`emitCodeAlignment` [virtual]	Emit nops until the byte alignment `ByteAlignment` is reached.
`emitCommonSymbol` [virtual]	Emit a common symbol.
`emitConditionalAssignment` [virtual]	Emit an assignment of `Value` to `Symbol,` but only if `Value` is also emitted.
`emitDarwinTargetVariantBuildVersion` [virtual]
`emitDataRegion` [virtual]	Note in the output the specified region `Kind.`
`emitDwarfAdvanceLineAddr` [virtual]	If targets does not support representing debug line section by .loc/.file directives in assembly output, we need to populate debug line section with raw debug line contents.
`emitDwarfFile0Directive` [virtual]	Specify the "root" file of the compilation, using the ".file 0" extension.
`emitDwarfFileDirective`	Associate a filename with a specified logical file number. This implements the DWARF2 '.file 4 "foo.c"' assembler directive.
`emitDwarfLineEndEntry` [virtual]	Emit the debug line end entry.
`emitDwarfLineStartLabel` [virtual]	Emit the debug line start label.
`emitDwarfLocDirective` [virtual]	This implements the DWARF2 '.loc fileno lineno ...' assembler directive.
`emitDwarfLocDirectiveWithInlinedAt` [virtual]	This is same as emitDwarfLocDirective, except it has the capability to add inlined_at information.
`emitDwarfLocLabelDirective` [virtual]	This implements the '.loc_label Name' directive.
`emitDwarfUnitLength`	`emitDwarfUnitLength` overloads
`emitEHSymAttributes` [virtual]
`emitELFSize` [virtual]	Emit an ELF .size directive.
`emitELFSymverDirective` [virtual]	Emit an ELF .symver directive.
`emitExplicitComments` [virtual]	Emit added explicit comments.
`emitFileDirective`	`emitFileDirective` overloads
`emitFill`	`emitFill` overloads
`emitGNUAttribute` [virtual]	Emit a .gnu_attribute directive.
`emitIdent` [virtual]	Emit the "identifiers" directive. This implements the '.ident "version foo"' assembler directive.
`emitInstruction` [virtual]	Emit the given `Instruction` into the current section.
`emitInt16`
`emitInt32`
`emitInt64`
`emitInt8`
`emitIntValue`	Special case of EmitValue that avoids the client having to pass in a MCExpr for constant integers.
`emitIntValueInHex` [virtual]	Special case of EmitValue that avoids the client having to pass in a MCExpr for constant integers & prints in Hex format for certain modes.
`emitIntValueInHexWithPadding` [virtual]	Special case of EmitValue that avoids the client having to pass in a MCExpr for constant integers & prints in Hex format for certain modes, pads the field with leading zeros to Size width
`emitLOHDirective` [virtual]	Emit a Linker Optimization Hint (LOH) directive.
`emitLabel` [virtual]	Emit a label for `Symbol` into the current section.
`emitLineTableLabel`
`emitLinkerOptions` [virtual]	Emit the given list `Options` of strings as linker options into the output.
`emitLocalCommonSymbol` [virtual]	Emit a local common (.lcomm) symbol.
`emitNops` [virtual]
`emitPrefAlign` [virtual]
`emitPseudoProbe` [virtual]	Emit the a pseudo probe into the current section.
`emitRawComment` [virtual]	Print T and prefix it with the comment string (normally #) and optionally a tab. This prints the comment immediately, not at the end of the current line. It is basically a safe version of EmitRawText: since it only prints comments, the object streamer ignores it instead of asserting.
`emitRawText`	If this file is backed by a assembly streamer, this dumps the specified string in the output .s file. This capability is indicated by the hasRawTextSupport() predicate. By default this aborts.
`emitRelocDirective` [virtual]	Record a relocation described by the .reloc directive.
`emitSLEB128IntValue`	Special case of EmitSLEB128Value that avoids the client having to pass in a MCExpr for constant integers.
`emitSLEB128Value` [virtual]
`emitSubsectionsViaSymbols` [virtual]	Emit a .subsection_via_symbols directive.
`emitSymbolAttribute` [virtual]	Add the given `Attribute` to `Symbol.`
`emitSymbolDesc` [virtual]	Set the `DescValue` for the `Symbol.`
`emitSymbolValue`	Special case of EmitValue that avoids the client having to pass in a MCExpr for MCSymbols.
`emitSyntaxDirective` [virtual]
`emitTBSSSymbol` [virtual]	Emit a thread local bss (.tbss) symbol.
`emitTargetTriple` [virtual]
`emitULEB128IntValue`	Special case of EmitULEB128Value that avoids the client having to pass in a MCExpr for constant integers.
`emitULEB128Value` [virtual]
`emitValue`
`emitValueImpl` [virtual]	Emit the expression `Value` into the output as a native integer of the given `Size` bytes.
`emitValueToAlignment` [virtual]	Emit some number of copies of `Value` until the byte alignment `ByteAlignment` is reached.
`emitValueToOffset` [virtual]	Emit some number of copies of `Value` until the byte offset `Offset` is reached.
`emitVersionForTarget`
`emitVersionMin` [virtual]	Specify the Mach-O minimum deployment target version.
`emitWeakReference` [virtual]	Emit an weak reference from `Alias` to `Symbol.`
`emitWinCFIAllocStack` [virtual]
`emitWinCFIBeginEpilogue` [virtual]
`emitWinCFIEndEpilogue` [virtual]
`emitWinCFIEndProc` [virtual]
`emitWinCFIEndProlog` [virtual]
`emitWinCFIFuncletOrFuncEnd` [virtual]	This is used on platforms, such as Windows on ARM64, that require function or funclet sizes to be emitted in .xdata before the End marker is emitted for the frame. We cannot use the End marker, as it is not set at the point of emitting .xdata, in order to indicate that the frame is active.
`emitWinCFIPush2Regs` [virtual]
`emitWinCFIPushFrame` [virtual]
`emitWinCFIPushReg` [virtual]
`emitWinCFISaveReg` [virtual]
`emitWinCFISaveXMM` [virtual]
`emitWinCFISetFrame` [virtual]
`emitWinCFISplitChained` [virtual]
`emitWinCFIStartProc` [virtual]
`emitWinCFIUnwindV2Start` [virtual]
`emitWinCFIUnwindVersion` [virtual]
`emitWinEHHandler` [virtual]
`emitWinEHHandlerData` [virtual]
`emitXCOFFCInfoSym` [virtual]	Emit a C_INFO symbol with XCOFF embedded metadata to the .info section.
`emitXCOFFExceptDirective` [virtual]	Emit an XCOFF .except directive which adds information about a trap instruction to the object file exception section
`emitXCOFFLocalCommonSymbol` [virtual]	Emits an lcomm directive with XCOFF csect information.
`emitXCOFFRefDirective` [virtual]	Emit a XCOFF .ref directive which creates R_REF type entry in the relocation table for one or more symbols.
`emitXCOFFRenameDirective` [virtual]	Emit a XCOFF .rename directive which creates a synonym for an illegal or undesirable name.
`emitXCOFFSymbolLinkageWithVisibility` [virtual]	Emit a symbol's linkage and visibility with a linkage directive for XCOFF.
`emitZerofill` [virtual]	Emit the zerofill section and an optional symbol.
`emitZeros`	Emit NumBytes worth of zeros. This function properly handles data in virtual sections.
`endCOFFSymbolDef` [virtual]	Marks the end of the symbol definition.
`endSection`
`finish`	Finish emission of machine code.
`finishImpl` [virtual]	Streamer specific finalization.
`getAllowAutoPadding`
`getAssemblerPtr` [virtual]
`getAssociatedPDataSection`	Get the .pdata section used for the given section. Typically the given section is either the main .text section or some other COMDAT .text section, but it may be any section containing code.
`getAssociatedXDataSection`	Get the .xdata section used for the given section.
`getCommentOS` [virtual]	Return a raw_ostream that comments can be written to. Unlike AddComment, you are required to terminate comments with if you use this method.
`getContext`
`getCurFragSize`
`getCurrentFragment`
`getCurrentSection`	Return the current section that the streamer is emitting code to.
`getCurrentSectionOnly`
`getCurrentWinEpilog`
`getDefaultWinCFIUnwindVersion`
`getDwarfFrameInfos`
`getDwarfLineTableSymbol` [virtual]
`getLFIRewriter`
`getMnemonic` [virtual]	Returns the mnemonic for `MI,` if the streamer has access to a instruction printer and returns an empty string otherwise.
`getNumFrameInfos`
`getNumWinFrameInfos`
`getPreviousSection`	Return the previous section that the streamer is emitting code to.
`getStartTokLoc`
`getTargetStreamer`
`getUseAssemblerInfoForParsing`
`getWinFrameInfos`
`hasRawTextSupport` [virtual]	Return true if this asm streamer supports emitting unformatted text to the .s file with EmitRawText.
`hasUnfinishedDwarfFrameInfo`
`initSections` [virtual]	Create the default sections and set the initial one.
`isInEpilogCFI`
`isIntegratedAssemblerRequired` [virtual]	Is the integrated assembler required for this streamer to function correctly?
`isObj`
`isVerboseAsm` [virtual]	Return true if this streamer supports verbose assembly and if it is enabled.
`isWinCFIPrologEnded`	Returns true if a WinCFI prolog has been completed (.seh_endprologue) in the current frame.
`mayHaveInstructions` [virtual]
`maybeEmitDwarf64Mark`	Emit a special value of 0xffffffff if producing 64-bit debugging info.
`popSection` [virtual]	Restore the current and previous section from the section stack. Calls changeSection as needed.
`pushSection`	Save the current and previous section on the section stack.
`reset` [virtual]	State management
`setAllowAutoPadding`
`setDefaultWinCFIUnwindVersion`	Set the default unwind version for new WinCFI frames.
`setLFIRewriter`
`setStartTokLocPtr`
`setTargetStreamer`
`setUseAssemblerInfoForParsing`
`switchSection`	Set the current section where code is being emitted to `Section.` This is required to update CurSection.
`switchSectionNoPrint`	Similar to switchSection, but does not print the section directive.
`tryEmitDwarfFileDirective` [virtual]	Associate a filename with a specified logical file number. Also associate a directory, optional checksum, and optional source text with the logical file. This implements the DWARF2 '.file 4 "dir/foo.c"' assembler directive, and the DWARF5 '.file 4 "dir/foo.c" md5 "..." source "..."' assembler directive.
`visitUsedExpr`
`visitUsedSymbol` [virtual]

Protected Member Functions

Name	Description
`MCStreamer` [constructor]	Construct from `MCContext`
`addFragment`
`changeSection` [virtual]	This is called by popSection and switchSection, if the current section changes.
`checkCVLocSection`	Returns true if the .cv_loc directive is in the right section.
`emitCFIEndProcImpl` [virtual]
`emitCFIStartProcImpl` [virtual]
`emitRawTextImpl` [virtual]
`emitWindowsUnwindTables`
`getCurrentWinFrameInfo`

Protected Data Members

Name
`CurFrag`
`CurrentWinEpilog`
`DwarfFrameInfos`
`IsObj`
`LFIRewriter`

Non-Member Functions

Name	Description
`createAsmStreamer`	Create a machine code streamer which will print out assembly for the native target, suitable for compiling with a native assembler.
`createNullStreamer`	Create a dummy machine code streamer, which does nothing. This is useful for timing the assembler front end.

Derived Classes

Name	Description
`CFIFunctionFrameStreamer`	This class is an `MCStreamer` implementation that watches for machine instructions and CFI directives. It cuts the stream into function frames and channels them to `CFIFunctionFrameReceiver`. A function frame is the machine instructions and CFI directives that are between `.cfi_startproc` and `.cfi_endproc` directives.
`MCAsmBaseStreamer`
`MCObjectStreamer`	Streaming object file generation interface.