sbv-0.9.17: Data/SBV/Compilers/C.hs
-----------------------------------------------------------------------------
-- |
-- Module : Data.SBV.Compilers.C
-- Copyright : (c) Levent Erkok
-- License : BSD3
-- Maintainer : erkokl@gmail.com
-- Stability : experimental
-- Portability : portable
--
-- Compilation of symbolic programs to C
-----------------------------------------------------------------------------
{-# LANGUAGE PatternGuards #-}
module Data.SBV.Compilers.C(compileToC, compileToC') where
import Data.Char(isSpace)
import Data.Maybe(isJust)
import qualified Data.Foldable as F (toList)
import Text.PrettyPrint.HughesPJ
import System.Random
import Data.SBV.BitVectors.Data
import Data.SBV.BitVectors.PrettyNum(shex)
import Data.SBV.Compilers.CodeGen
-- token for the target language
data SBVToC = SBVToC
instance SBVTarget SBVToC where
targetName _ = "C"
translate _ = cgen
-- Unexpected input, or things we will probably never support
die :: String -> a
die msg = error $ "SBV->C: Unexpected: " ++ msg
-- Unsupported features, or features TBD
tbd :: String -> a
tbd msg = error $ "SBV->C: Not yet supported: " ++ msg
-- | Given a symbolic computation, render it as an equivalent C program.
--
-- * First argument: States whether run-time-checks should be inserted for index-out-of-bounds or shifting-by-large values etc.
-- If `False`, such checks are ignored, gaining efficiency, at the cost of potential undefined behavior.
--
-- * Second argument is an optional directory name under which the files will be saved. If `Nothing`, the result
-- will be written to stdout. Use @`Just` \".\"@ for creating files in the current directory.
--
-- * The third argument is name of the function, which also forms the names of the C and header files.
--
-- * The fourth argument are the names of the arguments to be used and the names of the outputs, if any.
-- Provide as many arguments as you like, SBV will make up ones if you don't pass enough.
--
-- * The fifth and the final argument is the computation to be compiled.
--
-- Compilation will also generate a @Makefile@ and a sample driver program, which executes the program over random
-- input values.
compileToC :: SymExecutable f => Bool -> Maybe FilePath -> String -> [String] -> f -> IO ()
compileToC rtc mbDir fn extraNames f = do rands <- newStdGen >>= return . randoms
codeGen SBVToC rands rtc mbDir fn extraNames f
-- | Alternative interface for generating C. The output driver program uses the specified values (first argument) instead of random values.
-- Also this version returns the generated files for further manipulation. (Useful mainly for generating regression tests.)
compileToC' :: SymExecutable f => [Integer] -> Bool -> String -> [String] -> f -> IO CgPgmBundle
compileToC' dvals = codeGen' SBVToC (dvals ++ repeat 0)
cgen :: [Integer] -> Bool -> String -> [String] -> Result -> CgPgmBundle
cgen randVals rtc nm extraNames sbvProg@(Result ins _ _ _ _ _ _ outs) = CgPgmBundle
[ ("Makefile", genMake nm nmd)
, (nm ++ ".h", genHeader nm sig)
, (nmd ++ ".c", genDriver randVals nm typ)
, (nm ++ ".c", genCProg rtc nm sig sbvProg (map fst outputVars))
]
where nmd = nm ++ "_driver"
typ@(CType (_, outputVars)) = mkCType extraNames ins outs
sig = pprCFunHeader nm typ
-- | A simple representation of C types for functions
-- sufficient enough to represent SBV generated functions
newtype CType = CType ([(String, (Bool, Int))], [(String, (Bool, Int))])
mkCType :: [String] -> [NamedSymVar] -> [SW] -> CType
mkCType extraNames ins outs = CType (map mkVar ins, map mkVar (zip outs outNames))
where outNames = extraNames ++ ["out" ++ show i | i <- [length extraNames ..]]
mkVar (sw, n) = (n, (hasSign sw, sizeOf sw))
-- | Pretty print a functions type. If there is only one output, we compile it
-- as a function that returns that value. Otherwise, we compile it as a void function
-- that takes return values as pointers to be updated.
pprCFunHeader :: String -> CType -> Doc
pprCFunHeader fn (CType (ins, outs)) = retType <+> text fn <> parens (fsep (punctuate comma (map mkParam ins ++ os)))
where (retType, os) = case outs of
[(_, bs)] -> (pprCWord False bs, [])
_ -> (text "void", map mkPParam outs)
mkParam, mkPParam :: (String, (Bool, Int)) -> Doc
mkParam (n, bs) = pprCWord True bs <+> text n
mkPParam (n, bs) = pprCWord False bs <+> text "*" <> text n
-- | Renders as "const SWord8 s0", etc. the first parameter is the width of the typefield
declSW :: Int -> SW -> Doc
declSW w sw@(SW sgsz _) = text "const" <+> pad (showCType sgsz) <+> text (show sw)
where pad s = text $ s ++ take (w - length s) (repeat ' ')
-- | Renders as "s0", etc, or the corresponding constant
showSW :: [(SW, CW)] -> SW -> Doc
showSW consts sw
| sw == falseSW = text "0"
| sw == trueSW = text "1"
| Just cw <- sw `lookup` consts = showConst cw
| True = text $ show sw
-- | Words as it would be defined in the standard header stdint.h
pprCWord :: Bool -> (Bool, Int) -> Doc
pprCWord cnst sgsz = (if cnst then text "const" else empty) <+> text (showCType sgsz)
showCType :: (Bool, Int) -> String
showCType (False, 1) = "SBool"
showCType (s, sz)
| sz `elem` [8, 16, 32, 64] = t
| True = die $ "Non-regular bitvector type: " ++ t
where t = (if s then "SInt" else "SWord") ++ show sz
-- | The printf specifier for the type
specifier :: (Bool, Int) -> Doc
specifier (False, 1) = text "%d"
specifier (False, 8) = text "%\"PRIu8\""
specifier (True, 8) = text "%\"PRId8\""
specifier (False, 16) = text "0x%04\"PRIx16\"U"
specifier (True, 16) = text "%\"PRId16\""
specifier (False, 32) = text "0x%08\"PRIx32\"UL"
specifier (True, 32) = text "%\"PRId32\"L"
specifier (False, 64) = text "0x%016\"PRIx64\"ULL"
specifier (True, 64) = text "%\"PRId64\"LL"
specifier (s, sz) = die $ "Format specifier at type " ++ (if s then "SInt" else "SWord") ++ show sz
-- | Make a constant value of the given type. We don't check for out of bounds here, as it should not be needed.
-- There are many options here, using binary, decimal, etc. We simply
-- 8-bit or less constants using decimal; otherwise we use hex.
-- Note that this automatically takes care of the boolean (1-bit) value problem, since it
-- shows the result as an integer, which is OK as far as C is concerned.
mkConst :: Integer -> (Bool, Int) -> Doc
mkConst i (False, 1) = integer i
mkConst i t@(False, 8) = text (shex False True t i)
mkConst i t@(True, 8) = text (shex False True t i)
mkConst i t@(False, 16) = text (shex False True t i) <> text "U"
mkConst i t@(True, 16) = text (shex False True t i)
mkConst i t@(False, 32) = text (shex False True t i) <> text "UL"
mkConst i t@(True, 32) = text (shex False True t i) <> text "L"
mkConst i t@(False, 64) = text (shex False True t i) <> text "ULL"
mkConst i t@(True, 64) = text (shex False True t i) <> text "LL"
mkConst i (True, 1) = die $ "Signed 1-bit value " ++ show i
mkConst i (s, sz) = die $ "Constant " ++ show i ++ " at type " ++ (if s then "SInt" else "SWord") ++ show sz
-- | Show a constant
showConst :: CW -> Doc
showConst cw = mkConst (cwVal cw) (hasSign cw, sizeOf cw)
-- | Generate a makefile for ease of experimentation..
genMake :: String -> String -> Doc
genMake fn dn =
text "# Makefile for" <+> nm <> text ". Automatically generated by SBV. Do not edit!"
$$ text ""
$$ text "CC=gcc"
$$ text "CCFLAGS=-Wall -O3 -DNDEBUG -fomit-frame-pointer"
$$ text ""
$$ text "all:" <+> nmd
$$ text ""
$$ nmo <> text ":" <+> hsep [nmc, nmh]
$$ text "\t${CC} ${CCFLAGS}" <+> text "-c" <+> nmc <+> text "-o" <+> nmo
$$ text ""
$$ nmdo <> text ":" <+> nmdc
$$ text "\t${CC} ${CCFLAGS}" <+> text "-c" <+> nmdc <+> text "-o" <+> nmdo
$$ text ""
$$ nmd <> text ":" <+> hsep [nmo, nmdo]
$$ text "\t${CC} ${CCFLAGS}" <+> nmo <+> nmdo <+> text "-o" <+> nmd
$$ text ""
$$ text "clean:"
$$ text "\trm -f" <+> nmdo <+> nmo
$$ text ""
$$ text "veryclean: clean"
$$ text "\trm -f" <+> nmd
$$ text ""
where nm = text fn
nmd = text dn
nmh = nm <> text ".h"
nmc = nm <> text ".c"
nmo = nm <> text ".o"
nmdc = nmd <> text ".c"
nmdo = nmd <> text ".o"
-- | Generate the header
genHeader :: String -> Doc -> Doc
genHeader fn signature =
text "/* Header file for" <+> nm <> text ". Automatically generated by SBV. Do not edit! */"
$$ text ""
$$ text "#ifndef" <+> tag
$$ text "#define" <+> tag
$$ text ""
$$ text "#include <inttypes.h>"
$$ text "#include <stdint.h>"
$$ text ""
$$ text "/* Unsigned bit-vectors */"
$$ text "typedef uint8_t SBool ;"
$$ text "typedef uint8_t SWord8 ;"
$$ text "typedef uint16_t SWord16;"
$$ text "typedef uint32_t SWord32;"
$$ text "typedef uint64_t SWord64;"
$$ text ""
$$ text "/* Signed bit-vectors */"
$$ text "typedef int8_t SInt8 ;"
$$ text "typedef int16_t SInt16;"
$$ text "typedef int32_t SInt32;"
$$ text "typedef int64_t SInt64;"
$$ text ""
$$ text "/* Entry point prototype: */"
$$ signature <> semi
$$ text ""
$$ text "#endif /*" <+> tag <+> text "*/"
$$ text ""
where nm = text fn
tag = text "__" <> nm <> text "__HEADER_INCLUDED__"
sepIf :: Bool -> Doc
sepIf b = if b then text "" else empty
-- | Generate an example driver program
genDriver :: [Integer] -> String -> CType -> Doc
genDriver randVals fn (CType (inps, outs)) =
text "/* Example driver program for" <+> nm <> text ". */"
$$ text "/* Automatically generated by SBV. Edit as you see fit! */"
$$ text ""
$$ text "#include <inttypes.h>"
$$ text "#include <stdint.h>"
$$ text "#include <stdio.h>"
$$ text "#include" <+> doubleQuotes (nm <> text ".h")
$$ text ""
$$ text "int main(void)"
$$ text "{"
$$ text ""
$$ nest 2 ( vcat (map (\ (n, bs) -> pprCWord False bs <+> text n <> semi) (if singleOut then [] else outs))
$$ sepIf (not singleOut)
$$ call
$$ text ""
$$ (case outs of
[(n, bsz)] -> text "printf" <> parens (printQuotes (fcall <+> text "=" <+> specifier bsz <> text "\\n") <> comma <+> text n) <> semi
_ -> text "printf" <> parens (printQuotes (fcall <+> text "->\\n")) <> semi
$$ vcat (map display outs))
$$ text ""
$$ text "return 0" <> semi)
$$ text "}"
$$ text ""
where nm = text fn
singleOut = case outs of
[_] -> True
_ -> False
call = case outs of
[(n, bs)] -> pprCWord True bs <+> text n <+> text "=" <+> fcall <> semi
_ -> fcall <> semi
mkCVal (_, bsz@(b, sz)) r
| not b = mkConst (abs r `mod` (2^sz)) bsz
| True = mkConst ((abs r `mod` (2^sz)) - (2^(sz-1))) bsz
fcall = case outs of
[_] -> nm <> parens (fsep (punctuate comma (zipWith mkCVal inps randVals)))
_ -> nm <> parens (fsep (punctuate comma (zipWith mkCVal inps randVals ++ map (\ (n, _) -> text "&" <> text n) outs)))
display (s, bsz) = text "printf" <> parens (printQuotes (text " " <+> text s <+> text "=" <+> specifier bsz <> text "\\n") <> comma <+> text s) <> semi
-- | Generate the C program
genCProg :: Bool -> String -> Doc -> Result -> [String] -> Doc
genCProg rtc fn proto (Result inps preConsts tbls arrs uints axms asgns outs) outputVars
| not (null arrs) = tbd "User specified arrays"
| not (null uints) = tbd "Uninterpreted constants"
| not (null axms) = tbd "User given axioms"
| True
= text "/* File:" <+> doubleQuotes (nm <> text ".c") <> text ". Automatically generated by SBV. Do not edit! */"
$$ text ""
$$ text "#include <inttypes.h>"
$$ text "#include <stdint.h>"
$$ text "#include" <+> doubleQuotes (nm <> text ".h")
$$ text ""
$$ proto
$$ text "{"
$$ text ""
$$ nest 2 ( vcat (map genInp inps)
$$ vcat (merge (map genTbl tbls) (map genAsgn assignments))
$$ sepIf (not (null assignments) || not (null tbls))
$$ genOuts outs)
$$ text "}"
$$ text ""
where nm = text fn
assignments = F.toList asgns
typeWidth = getMax 0 [len (hasSign s, sizeOf s) | (s, _) <- assignments]
where len (False, 1) = 5 -- SBool
len (False, n) = 5 + length (show n) -- SWordN
len (True, n) = 4 + length (show n) -- SIntN
getMax 7 _ = 7 -- 7 is the max we can get with SWord64, so don't bother looking any further
getMax m [] = m
getMax m (x:xs) = getMax (m `max` x) xs
consts = (falseSW, falseCW) : (trueSW, trueCW) : preConsts
isConst s = isJust (lookup s consts)
genInp :: NamedSymVar -> Doc
genInp (sw, n)
| show sw == n = empty -- no aliasing, so no need to assign
| True = declSW typeWidth sw <+> text "=" <+> text n <> semi
genTbl :: ((Int, (Bool, Int), (Bool, Int)), [SW]) -> (Int, Doc)
genTbl ((i, _, (sg, sz)), elts) = (location, static <+> mkParam ("table" ++ show i, (sg, sz)) <> text "[] = {"
$$ nest 4 (fsep (punctuate comma (align (map (showSW consts) elts))))
$$ text "};")
where static = if location == -1 then text "static" else empty
location = maximum (-1 : map getNodeId elts)
getNodeId s@(SW _ (NodeId n)) | isConst s = -1
| True = n
genAsgn :: (SW, SBVExpr) -> (Int, Doc)
genAsgn (sw, n) = (getNodeId sw, declSW typeWidth sw <+> text "=" <+> ppExpr rtc consts n <> semi)
genOuts :: [SW] -> Doc
genOuts [sw] = text "return" <+> showSW consts sw <> semi
genOuts os
| length os /= length outputVars = die $ "Mismatched outputs: " ++ show (os, outputVars)
| True = vcat (zipWith assignOut outputVars os)
where assignOut v sw = text "*" <> text v <+> text "=" <+> showSW consts sw <> semi
-- merge tables intermixed with assignments, paying attention to putting tables as
-- early as possible.. Note that the assignment list (second argument) is sorted on its order
merge :: [(Int, Doc)] -> [(Int, Doc)] -> [Doc]
merge [] as = map snd as
merge ts [] = map snd ts
merge ts@((i, t):trest) as@((i', a):arest)
| i < i' = t : merge trest as
| True = a : merge ts arest
-- Align a bunch of docs to occupy the exact same length by padding in the left by space
-- this is ugly and inefficient, but easy to code..
align :: [Doc] -> [Doc]
align ds = map (text . pad) ss
where ss = map render ds
l = maximum (0 : map length ss)
pad s = take (l - length s) (repeat ' ') ++ s
ppExpr :: Bool -> [(SW, CW)] -> SBVExpr -> Doc
ppExpr rtc consts (SBVApp op opArgs) = p op (map (showSW consts) opArgs)
where cBinOps = [ (Plus, "+"), (Times, "*"), (Minus, "-"), (Quot, "/"), (Rem, "%")
, (Equal, "=="), (NotEqual, "!=")
, (LessThan, "<"), (GreaterThan, ">"), (LessEq, "<="), (GreaterEq, ">=")
, (And, "&"), (Or, "|"), (XOr, "^")
]
p (ArrRead _) _ = tbd $ "User specified arrays (ArrRead)"
p (ArrEq _ _) _ = tbd $ "User specified arrays (ArrEq)"
p (Uninterpreted s) _ = tbd $ "Uninterpreted constants (" ++ show s ++ ")"
p (Extract i j) [a] = extract i j (let s = head opArgs in (hasSign s, sizeOf s)) a
p Join [a, b] = join (let (s1 : s2 : _) = opArgs in ((hasSign s1, sizeOf s1), (hasSign s2, sizeOf s2), a, b))
p (Rol i) [a] = rotate True i a (let s = head opArgs in (hasSign s, sizeOf s))
p (Ror i) [a] = rotate False i a (let s = head opArgs in (hasSign s, sizeOf s))
p (Shl i) [a] = shift True i a (let s = head opArgs in (hasSign s, sizeOf s))
p (Shr i) [a] = shift False i a (let s = head opArgs in (hasSign s, sizeOf s))
p Not [a] = text "~" <> a
p Ite [a, b, c] = a <+> text "?" <+> b <+> text ":" <+> c
p (LkUp (t, (as, at), _, len) ind def) []
| not rtc = lkUp -- ignore run-time-checks per user request
| needsCheckL && needsCheckR = cndLkUp checkBoth
| needsCheckL = cndLkUp checkLeft
| needsCheckR = cndLkUp checkRight
| True = lkUp
where [index, defVal] = map (showSW consts) [ind, def]
lkUp = text "table" <> int t <> brackets (showSW consts ind)
cndLkUp cnd = cnd <+> text "?" <+> defVal <+> text ":" <+> lkUp
checkLeft = index <+> text "< 0"
checkRight = index <+> text ">=" <+> int len
checkBoth = parens (checkLeft <+> text "||" <+> checkRight)
(needsCheckL, needsCheckR) | as = (True, (2::Integer)^(at-1)-1 >= (fromIntegral len))
| True = (False, (2::Integer)^(at) -1 >= (fromIntegral len))
p o [a, b]
| Just co <- lookup o cBinOps
= a <+> text co <+> b
p o args = die $ "Received operator " ++ show o ++ " applied to " ++ show args
shift toLeft i a (sg, sz)
| i < 0 = shift (not toLeft) (-i) a (sg, sz)
| i == 0 = a
| i >= sz = mkConst 0 (sg, sz)
| True = a <+> text cop <+> int i
where cop | toLeft = "<<"
| True = ">>"
rotate toLeft i a (True, sz)
= tbd $ "Rotation of signed words at size " ++ show (toLeft, i, a, sz)
rotate toLeft i a (False, sz)
| i < 0 = rotate (not toLeft) (-i) a (False, sz)
| i == 0 = a
| i >= sz = rotate toLeft (i `mod` sz) a (False, sz)
| True = parens (a <+> text cop <+> int i)
<+> text "|"
<+> parens (a <+> text cop' <+> int (sz - i))
where (cop, cop') | toLeft = ("<<", ">>")
| True = (">>", "<<")
-- TBD: below we only support the values that SBV actually currently generates.
-- we would need to add new ones if we generate others. (Check instances in Data/SBV/BitVectors/Splittable.hs).
extract 63 32 (False, 64) a = text "(SWord32)" <+> (parens (a <+> text ">> 32"))
extract 31 0 (False, 64) a = text "(SWord32)" <+> a
extract 31 16 (False, 32) a = text "(SWord16)" <+> (parens (a <+> text ">> 16"))
extract 15 0 (False, 32) a = text "(SWord16)" <+> a
extract 15 8 (False, 16) a = text "(SWord8)" <+> (parens (a <+> text ">> 8"))
extract 7 0 (False, 16) a = text "(SWord8)" <+> a
extract i j (sg, sz) _ = tbd $ "extract with " ++ show (i, j, (sg, sz))
-- TBD: ditto here for join, just like extract above
join ((False, 8), (False, 8), a, b) = parens ((parens (text "(SWord16)" <+> a)) <+> text "<< 8") <+> text "|" <+> parens (text "(SWord16)" <+> b)
join ((False, 16), (False, 16), a, b) = parens ((parens (text "(SWord32)" <+> a)) <+> text "<< 16") <+> text "|" <+> parens (text "(SWord32)" <+> b)
join ((False, 32), (False, 32), a, b) = parens ((parens (text "(SWord64)" <+> a)) <+> text "<< 32") <+> text "|" <+> parens (text "(SWord64)" <+> b)
join (sgsz1, sgsz2, _, _) = tbd $ "join with " ++ show (sgsz1, sgsz2)
-- same as doubleQuotes, except we have to make sure there are no line breaks..
-- Otherwise breaks the generated code.. sigh
printQuotes :: Doc -> Doc
printQuotes d = text $ '"' : ppSameLine d ++ "\""
-- Remove newlines.. Useful when generating Makefile and such
ppSameLine :: Doc -> String
ppSameLine = trim . render
where trim "" = ""
trim ('\n':cs) = ' ' : trim (dropWhile isSpace cs)
trim (c:cs) = c : trim cs