[Git][ghc/ghc][wip/bump-images] 4 commits: base: Advertise linear time of readFloat
Matthew Pickering (@mpickering)
gitlab at gitlab.haskell.org
Tue Sep 19 08:38:16 UTC 2023
Matthew Pickering pushed to branch wip/bump-images at Glasgow Haskell Compiler / GHC
Commits:
7ca0240e by Ben Gamari at 2023-09-18T15:16:48-04:00
base: Advertise linear time of readFloat
As noted in #23538, `readFloat` has runtime that scales nonlinearly in
the size of its input. Consequently, its use on untrusted input can
be exploited as a denial-of-service vector. Point this out and suggest
use of `read` instead.
See #23538.
- - - - -
f3f58f13 by Simon Peyton Jones at 2023-09-18T15:17:24-04:00
Remove dead code GHC.CoreToStg.Prep.canFloat
This function never fires, so we can delete it: #23965.
- - - - -
ccab5b15 by Ben Gamari at 2023-09-18T15:18:02-04:00
base/changelog: Move fix for #23907 to 9.8.1 section
Since the fix was backported to 9.8.1
- - - - -
5ab81cae by Matthew Pickering at 2023-09-19T09:38:02+01:00
Bump ci-images to use updated version of Alex
Fixes #23977
- - - - -
4 changed files:
- .gitlab-ci.yml
- compiler/GHC/CoreToStg/Prep.hs
- libraries/base/Numeric.hs
- libraries/base/changelog.md
Changes:
=====================================
.gitlab-ci.yml
=====================================
@@ -2,7 +2,7 @@ variables:
GIT_SSL_NO_VERIFY: "1"
# Commit of ghc/ci-images repository from which to pull Docker images
- DOCKER_REV: 653b899f026f84c8043c76c014a5355d28cda24a
+ DOCKER_REV: 8035736da0a70f09bd9b63a696cf2eb7977694ec
# Sequential version number of all cached things.
# Bump to invalidate GitLab CI cache.
=====================================
compiler/GHC/CoreToStg/Prep.hs
=====================================
@@ -657,9 +657,6 @@ cpePair top_lvl is_rec dmd is_unlifted env bndr rhs
| allLazyTop floats
= return (floats, rhs)
- | Just floats <- canFloat floats rhs
- = return floats
-
| otherwise
= dontFloat floats rhs
@@ -1954,32 +1951,6 @@ deFloatTop (Floats _ floats)
---------------------------------------------------------------------------
-canFloat :: Floats -> CpeRhs -> Maybe (Floats, CpeRhs)
-canFloat (Floats ok_to_spec fs) rhs
- | OkToSpec <- ok_to_spec -- Worth trying
- , Just fs' <- go nilOL (fromOL fs)
- = Just (Floats OkToSpec fs', rhs)
- | otherwise
- = Nothing
- where
- go :: OrdList FloatingBind -> [FloatingBind]
- -> Maybe (OrdList FloatingBind)
-
- go (fbs_out) [] = Just fbs_out
-
- go fbs_out (fb@(FloatLet _) : fbs_in)
- = go (fbs_out `snocOL` fb) fbs_in
-
- go fbs_out (fb at FloatString{} : fbs_in)
- -- See Note [ANF-ising literal string arguments]
- = go (fbs_out `snocOL` fb) fbs_in
-
- go fbs_out (ft at FloatTick{} : fbs_in)
- = go (fbs_out `snocOL` ft) fbs_in
-
- go _ (FloatCase{} : _) = Nothing
-
-
wantFloatNested :: RecFlag -> Demand -> Bool -> Floats -> CpeRhs -> Bool
wantFloatNested is_rec dmd rhs_is_unlifted floats rhs
= isEmptyFloats floats
=====================================
libraries/base/Numeric.hs
=====================================
@@ -117,6 +117,14 @@ readHex = readP_to_S L.readHexP
-- | Reads an /unsigned/ 'RealFrac' value,
-- expressed in decimal scientific notation.
+--
+-- Note that this function takes time linear in the magnitude of its input
+-- which can scale exponentially with input size (e.g. @"1e100000000"@ is a
+-- very large number while having a very small textual form).
+-- For this reason, users should take care to avoid using this function on
+-- untrusted input. Users needing to parse floating point values
+-- (e.g. 'Float') are encouraged to instead use 'read', which does
+-- not suffer from this issue.
readFloat :: RealFrac a => ReadS a
readFloat = readP_to_S readFloatP
=====================================
libraries/base/changelog.md
=====================================
@@ -4,7 +4,6 @@
* Export `foldl'` from `Prelude` ([CLC proposal #167](https://github.com/haskell/core-libraries-committee/issues/167))
* Add a `RULE` to `Prelude.lookup`, allowing it to participate in list fusion ([CLC proposal #174](https://github.com/haskell/core-libraries-committee/issues/175))
* The `Enum Int64` and `Enum Word64` instances now use native operations on 32-bit platforms, increasing performance by up to 1.5x on i386 and up to 5.6x with the JavaScript backend. ([CLC proposal #187](https://github.com/haskell/core-libraries-committee/issues/187))
- * Add rewrite rules for conversion between Int64/Word64 and Float/Double on 64-bit architectures ([CLC proposal #203](https://github.com/haskell/core-libraries-committee/issues/203)).
* Update to [Unicode 15.1.0](https://www.unicode.org/versions/Unicode15.1.0/).
## 4.19.0.0 *TBA*
@@ -44,6 +43,7 @@
* Deprecate `Data.List.NonEmpty.unzip` ([CLC proposal #86](https://github.com/haskell/core-libraries-committee/issues/86))
* Fixed exponent overflow/underflow bugs in the `Read` instances for `Float` and `Double` ([CLC proposal #192](https://github.com/haskell/core-libraries-committee/issues/192))
* Implement `copyBytes`, `fillBytes`, `moveBytes` and `stimes` for `Data.Array.Byte.ByteArray` using primops ([CLC proposal #188](https://github.com/haskell/core-libraries-committee/issues/188))
+ * Add rewrite rules for conversion between Int64/Word64 and Float/Double on 64-bit architectures ([CLC proposal #203](https://github.com/haskell/core-libraries-committee/issues/203)).
## 4.18.0.0 *March 2023*
* Shipped with GHC 9.6.1
View it on GitLab: https://gitlab.haskell.org/ghc/ghc/-/compare/4c6fad053944c5460502cb989cbfaf0f5f4a6bc3...5ab81cae6acf6f2e6264f4a6c2b76abbf539611d
--
View it on GitLab: https://gitlab.haskell.org/ghc/ghc/-/compare/4c6fad053944c5460502cb989cbfaf0f5f4a6bc3...5ab81cae6acf6f2e6264f4a6c2b76abbf539611d
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