GHC.CmmToAsm.Dwarf.Types

Dwarf information

data DwarfInfo

Individual dwarf records. Each one will be encoded as an entry in the .debug_info section.

Constructors

DwarfCompileUnit

Fields

• dwChildren :: [DwarfInfo]
• dwName :: String
• dwProducer :: String
• dwCompDir :: String
• dwLowLabel :: CLabel
• dwHighLabel :: CLabel

DwarfSubprogram

Fields

• dwChildren :: [DwarfInfo]
• dwName :: String
• dwLabel :: CLabel
• dwParent :: Maybe CLabel

  label of DIE belonging to the parent tick

DwarfBlock

Fields

• dwChildren :: [DwarfInfo]
• dwLabel :: CLabel
• dwMarker :: Maybe CLabel

DwarfSrcNote

Fields

• dwSrcSpan :: RealSrcSpan

pprDwarfInfo :: IsDoc doc => Platform -> Bool -> DwarfInfo -> doc

Generate assembly for DWARF data

pprAbbrevDecls :: IsDoc doc => Platform -> Bool -> doc

Abbreviation declaration. This explains the binary encoding we use for representing DwarfInfo. Be aware that this must be updated along with pprDwarfInfo.

Dwarf address range table

data DwarfARange

A DWARF address range. This is used by the debugger to quickly locate which compilation unit a given address belongs to. This type assumes a non-segmented address-space.

Constructors

DwarfARange

Fields

• dwArngStartLabel :: CLabel
• dwArngEndLabel :: CLabel

pprDwarfARanges :: IsDoc doc => Platform -> [DwarfARange] -> Unique -> doc

Print assembler directives corresponding to a DWARF .debug_aranges address table entry.

Dwarf frame

data DwarfFrame

Information about unwind instructions for a procedure. This corresponds to a "Common Information Entry" (CIE) in DWARF.

Constructors

DwarfFrame

Fields

• dwCieLabel :: CLabel
• dwCieInit :: UnwindTable
• dwCieProcs :: [DwarfFrameProc]

data DwarfFrameProc

Unwind instructions for an individual procedure. Corresponds to a "Frame Description Entry" (FDE) in DWARF.

Constructors

DwarfFrameProc

Fields

• dwFdeProc :: CLabel
• dwFdeHasInfo :: Bool
• dwFdeBlocks :: [DwarfFrameBlock]

  List of blocks. Order must match asm!

data DwarfFrameBlock

Unwind instructions for a block. Will become part of the containing FDE.

Constructors

DwarfFrameBlock

Fields

• dwFdeBlkHasInfo :: Bool
• dwFdeUnwind :: [UnwindPoint]

  these unwind points must occur in the same order as they occur in the block

Instances

OutputableP Platform DwarfFrameBlock

Defined in GHC.CmmToAsm.Dwarf.Types

Methods

pdoc :: Platform -> DwarfFrameBlock -> SDoc

pprDwarfFrame :: IsDoc doc => Platform -> DwarfFrame -> doc

Header for the .debug_frame section. Here we emit the "Common Information Entry" record that establishes general call frame parameters and the default stack layout.

Utilities

pprByte :: IsDoc doc => Word8 -> doc

Assembly for a single byte of constant DWARF data

pprHalf :: IsDoc doc => Word16 -> doc

Assembly for a two-byte constant integer

pprData4' :: IsDoc doc => Line doc -> doc

Assembly for 4 bytes of dynamic DWARF data

pprDwWord :: IsDoc doc => Line doc -> doc

Assembly for a DWARF word of dynamic data. This means 32 bit, as we are generating 32 bit DWARF.

pprWord :: IsDoc doc => Platform -> Line doc -> doc

Assembly for a machine word of dynamic data. Depends on the architecture we are currently generating code for.

pprLEBWord :: IsDoc doc => Word -> doc

Prints a number in "little endian base 128" format. The idea is to optimize for small numbers by stopping once all further bytes would be 0. The highest bit in every byte signals whether there are further bytes to read.

pprLEBInt :: IsDoc doc => Int -> doc

Same as pprLEBWord, but for a signed number

wordAlign :: IsDoc doc => Platform -> doc

Align assembly at (machine) word boundary

sectionOffset :: IsDoc doc => Platform -> Line doc -> Line doc -> doc

Generate an offset into another section. This is tricky because this is handled differently depending on platform: Mac Os expects us to calculate the offset using assembler arithmetic. Linux expects us to just reference the target directly, and will figure out on their own that we actually need an offset. Finally, Windows has a special directive to refer to relative offsets. Fun.