{-# LANGUAGE CPP #-} {-# LANGUAGE MagicHash #-} ----------------------------------------------------------------------------- -- -- Pretty-printing assembly language -- -- (c) The University of Glasgow 1993-2005 -- ----------------------------------------------------------------------------- module GHC.CmmToAsm.Ppr ( doubleToBytes, floatToBytes, pprASCII, pprString, pprFileEmbed, pprSectionHeader ) where import GHC.Prelude import GHC.Utils.Asm import GHC.Cmm.CLabel import GHC.Cmm import GHC.CmmToAsm.Config import GHC.Utils.Outputable as SDoc import GHC.Utils.Panic import GHC.Platform import qualified Data.Array.Unsafe as U ( castSTUArray ) import Data.Array.ST import Control.Monad.ST import Data.Word import Data.ByteString (ByteString) import qualified Data.ByteString as BS import GHC.Exts import GHC.Word #if !MIN_VERSION_base(4,16,0) word8ToWord# :: Word# -> Word# word8ToWord# w = w {-# INLINE word8ToWord# #-} #endif -- ----------------------------------------------------------------------------- -- Converting floating-point literals to integrals for printing -- | Get bytes of a Float representation floatToBytes :: Float -> [Word8] floatToBytes f = runST $ do arr <- newArray_ ((0::Int),3) writeArray arr 0 f let cast :: STUArray s Int Float -> ST s (STUArray s Int Word8) cast = U.castSTUArray arr <- cast arr i0 <- readArray arr 0 i1 <- readArray arr 1 i2 <- readArray arr 2 i3 <- readArray arr 3 return [i0,i1,i2,i3] -- | Get bytes of a Double representation doubleToBytes :: Double -> [Word8] doubleToBytes d = runST $ do arr <- newArray_ ((0::Int),7) writeArray arr 0 d let cast :: STUArray s Int Double -> ST s (STUArray s Int Word8) cast = U.castSTUArray arr <- cast arr i0 <- readArray arr 0 i1 <- readArray arr 1 i2 <- readArray arr 2 i3 <- readArray arr 3 i4 <- readArray arr 4 i5 <- readArray arr 5 i6 <- readArray arr 6 i7 <- readArray arr 7 return [i0,i1,i2,i3,i4,i5,i6,i7] -- --------------------------------------------------------------------------- -- Printing ASCII strings. -- -- Print as a string and escape non-printable characters. -- This is similar to charToC in GHC.Utils.Misc pprASCII :: forall doc. IsLine doc => ByteString -> doc pprASCII str -- Transform this given literal bytestring to escaped string and construct -- the literal SDoc directly. -- See #14741 -- and Note [Pretty print ASCII when AsmCodeGen] -- -- We work with a `Doc` instead of an `SDoc` because there is no need to carry -- an `SDocContext` that we don't use. It leads to nicer (STG) code. = BS.foldr f empty str where f :: Word8 -> doc -> doc f w s = do1 w <> s do1 :: Word8 -> doc do1 w | 0x09 == w = text "\\t" | 0x0A == w = text "\\n" | 0x22 == w = text "\\\"" | 0x5C == w = text "\\\\" -- ASCII printable characters range | w >= 0x20 && w <= 0x7E = char (chr' w) | otherwise = text xs where !xs = [ '\\', x0, x1, x2] -- octal !x0 = chr' (ord0 + (w `unsafeShiftR` 6) .&. 0x07) !x1 = chr' (ord0 + (w `unsafeShiftR` 3) .&. 0x07) !x2 = chr' (ord0 + w .&. 0x07) !ord0 = 0x30 -- = ord '0' -- we know that the Chars we create are in the ASCII range -- so we bypass the check in "chr" chr' :: Word8 -> Char chr' (W8# w#) = C# (chr# (word2Int# (word8ToWord# w#))) {-# SPECIALIZE pprASCII :: ByteString -> SDoc #-} {-# SPECIALIZE pprASCII :: ByteString -> HLine #-} -- see Note [SPECIALIZE to HDoc] in GHC.Utils.Outputable -- | Emit a ".string" directive pprString :: IsLine doc => ByteString -> doc pprString bs = text "\t.string " <> doubleQuotes (pprASCII bs) {-# SPECIALIZE pprString :: ByteString -> SDoc #-} {-# SPECIALIZE pprString :: ByteString -> HLine #-} -- see Note [SPECIALIZE to HDoc] in GHC.Utils.Outputable -- | Emit a ".incbin" directive -- -- A NULL byte is added after the binary data. pprFileEmbed :: IsLine doc => FilePath -> doc pprFileEmbed path = text "\t.incbin " <> pprFilePathString path -- proper escape (see #16389) <> text "\n\t.byte 0" {-# SPECIALIZE pprFileEmbed :: FilePath -> SDoc #-} {-# SPECIALIZE pprFileEmbed :: FilePath -> HLine #-} -- see Note [SPECIALIZE to HDoc] in GHC.Utils.Outputable {- Note [Embedding large binary blobs] ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ To embed a blob of binary data (e.g. an UTF-8 encoded string) into the generated code object, we have several options: 1. Generate a ".byte" directive for each byte. This is what was done in the past (see Note [Pretty print ASCII when AsmCodeGen]). 2. Generate a single ".string"/".asciz" directive for the whole sequence of bytes. Bytes in the ASCII printable range are rendered as characters and other values are escaped (e.g., "\t", "\077", etc.). 3. Create a temporary file into which we dump the binary data and generate a single ".incbin" directive. The assembler will include the binary file for us in the generated output object. Now the code generator uses either (2) or (3), depending on the binary blob size. Using (3) for small blobs adds too much overhead (see benchmark results in #16190), so we only do it when the size is above a threshold (500K at the time of writing). The threshold is configurable via the `-fbinary-blob-threshold` flag. -} {- Note [Pretty print ASCII when AsmCodeGen] ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ Previously, when generating assembly code, we created SDoc with `(ptext . sLit)` for every bytes in literal bytestring, then combine them using `hcat`. When handling literal bytestrings with millions of bytes, millions of SDoc would be created and to combine, leading to high memory usage. Now we escape the given bytestring to string directly and construct SDoc only once. This improvement could dramatically decrease the memory allocation from 4.7GB to 1.3GB when embedding a 3MB literal string in source code. See #14741 for profiling results. -} -- ---------------------------------------------------------------------------- -- Printing section headers. -- -- If -split-section was specified, include the suffix label, otherwise just -- print the section type. For Darwin, where subsections-for-symbols are -- used instead, only print section type. -- -- For string literals, additional flags are specified to enable merging of -- identical strings in the linker. With -split-sections each string also gets -- a unique section to allow strings from unused code to be GC'd. pprSectionHeader :: IsLine doc => NCGConfig -> Section -> doc pprSectionHeader config (Section t suffix) = case platformOS (ncgPlatform config) of OSAIX -> pprXcoffSectionHeader t OSDarwin -> pprDarwinSectionHeader t _ -> pprGNUSectionHeader config t suffix {-# SPECIALIZE pprSectionHeader :: NCGConfig -> Section -> SDoc #-} {-# SPECIALIZE pprSectionHeader :: NCGConfig -> Section -> HLine #-} -- see Note [SPECIALIZE to HDoc] in GHC.Utils.Outputable pprGNUSectionHeader :: IsLine doc => NCGConfig -> SectionType -> CLabel -> doc pprGNUSectionHeader config t suffix = hcat [text ".section ", header, subsection, flags] where sep | OSMinGW32 <- platformOS platform = char '$' | otherwise = char '.' platform = ncgPlatform config splitSections = ncgSplitSections config subsection | splitSections = sep <> pprAsmLabel platform suffix | otherwise = empty header = case t of Text -> text ".text" Data -> text ".data" ReadOnlyData | OSMinGW32 <- platformOS platform -> text ".rdata" | otherwise -> text ".rodata" RelocatableReadOnlyData | OSMinGW32 <- platformOS platform -- Concept does not exist on Windows, -- So map these to R/O data. -> text ".rdata$rel.ro" | otherwise -> text ".data.rel.ro" UninitialisedData -> text ".bss" InitArray | OSMinGW32 <- platformOS platform -> text ".ctors" | otherwise -> text ".init_array" FiniArray | OSMinGW32 <- platformOS platform -> text ".dtors" | otherwise -> text ".fini_array" CString | OSMinGW32 <- platformOS platform -> text ".rdata" | otherwise -> text ".rodata.str" OtherSection _ -> panic "PprBase.pprGNUSectionHeader: unknown section type" flags = case t of CString | OSMinGW32 <- platformOS platform -> empty | otherwise -> text ",\"aMS\"," <> sectionType platform "progbits" <> text ",1" _ -> empty {-# SPECIALIZE pprGNUSectionHeader :: NCGConfig -> SectionType -> CLabel -> SDoc #-} {-# SPECIALIZE pprGNUSectionHeader :: NCGConfig -> SectionType -> CLabel -> HLine #-} -- see Note [SPECIALIZE to HDoc] in GHC.Utils.Outputable -- XCOFF doesn't support relocating label-differences, so we place all -- RO sections into .text[PR] sections pprXcoffSectionHeader :: IsLine doc => SectionType -> doc pprXcoffSectionHeader t = case t of Text -> text ".csect .text[PR]" Data -> text ".csect .data[RW]" ReadOnlyData -> text ".csect .text[PR] # ReadOnlyData" RelocatableReadOnlyData -> text ".csect .text[PR] # RelocatableReadOnlyData" CString -> text ".csect .text[PR] # CString" UninitialisedData -> text ".csect .data[BS]" _ -> panic "pprXcoffSectionHeader: unknown section type" {-# SPECIALIZE pprXcoffSectionHeader :: SectionType -> SDoc #-} {-# SPECIALIZE pprXcoffSectionHeader :: SectionType -> HLine #-} -- see Note [SPECIALIZE to HDoc] in GHC.Utils.Outputable pprDarwinSectionHeader :: IsLine doc => SectionType -> doc pprDarwinSectionHeader t = case t of Text -> text ".text" Data -> text ".data" ReadOnlyData -> text ".const" RelocatableReadOnlyData -> text ".const_data" UninitialisedData -> text ".data" InitArray -> text ".section\t__DATA,__mod_init_func,mod_init_funcs" FiniArray -> panic "pprDarwinSectionHeader: fini not supported" CString -> text ".section\t__TEXT,__cstring,cstring_literals" OtherSection _ -> panic "pprDarwinSectionHeader: unknown section type" {-# SPECIALIZE pprDarwinSectionHeader :: SectionType -> SDoc #-} {-# SPECIALIZE pprDarwinSectionHeader :: SectionType -> HLine #-} -- see Note [SPECIALIZE to HDoc] in GHC.Utils.Outputable