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| author | Sylvain Henry <sylvain@haskus.fr> | 2020-06-08 18:33:41 +0200 |
|---|---|---|
| committer | Marge Bot <ben+marge-bot@smart-cactus.org> | 2020-06-23 22:48:18 -0400 |
| commit | 2636794d1a1d0c4c2666d5afb002b0ba73600f8a (patch) | |
| tree | 9ef784b387e5bfe1afebc1d028b8f4379612be30 /compiler/GHC/Cmm/Parser.y | |
| parent | 7750bd456f32c3e91b9165587fe290122b9c2444 (diff) | |
| download | haskell-2636794d1a1d0c4c2666d5afb002b0ba73600f8a.tar.gz | |
CmmToC: don't add extern decl to parsed Cmm data
Previously, if a .cmm file *not in the RTS* contained something like:
```cmm
section "rodata" { msg : bits8[] "Test\n"; }
```
It would get compiled by CmmToC into:
```c
ERW_(msg);
const char msg[] = "Test\012";
```
and fail with:
```
/tmp/ghc32129_0/ghc_4.hc:5:12: error:
error: conflicting types for \u2018msg\u2019
const char msg[] = "Test\012";
^~~
In file included from /tmp/ghc32129_0/ghc_4.hc:3:0: error:
/tmp/ghc32129_0/ghc_4.hc:4:6: error:
note: previous declaration of \u2018msg\u2019 was here
ERW_(msg);
^
/builds/hsyl20/ghc/_build/install/lib/ghc-8.11.0.20200605/lib/../lib/x86_64-linux-ghc-8.11.0.20200605/rts-1.0/include/Stg.h:253:46: error:
note: in definition of macro \u2018ERW_\u2019
#define ERW_(X) extern StgWordArray (X)
^
```
See the rationale for this on https://gitlab.haskell.org/ghc/ghc/-/wikis/commentary/compiler/backends/ppr-c#prototypes
Now we don't generate these extern declarations (ERW_, etc.) for
top-level data. It shouldn't change anything for the RTS (the only place
we use .cmm files) as it is already special cased in
`GHC.Cmm.CLabel.needsCDecl`. And hand-written Cmm can use explicit
extern declarations when needed.
Note that it allows `cgrun069` test to pass with CmmToC (cf #15467).
Diffstat (limited to 'compiler/GHC/Cmm/Parser.y')
| -rw-r--r-- | compiler/GHC/Cmm/Parser.y | 4 |
1 files changed, 2 insertions, 2 deletions
diff --git a/compiler/GHC/Cmm/Parser.y b/compiler/GHC/Cmm/Parser.y index e3d7e93486..7bf60f58da 100644 --- a/compiler/GHC/Cmm/Parser.y +++ b/compiler/GHC/Cmm/Parser.y @@ -399,7 +399,7 @@ cmmdata :: { CmmParse () } data_label :: { CmmParse CLabel } : NAME ':' {% liftP . withHomeUnitId $ \pkg -> - return (mkCmmDataLabel pkg $1) } + return (mkCmmDataLabel pkg (NeedExternDecl False) $1) } statics :: { [CmmParse [CmmStatic]] } : {- empty -} { [] } @@ -1176,7 +1176,7 @@ staticClosure :: UnitId -> FastString -> FastString -> [CmmLit] -> CmmParse () staticClosure pkg cl_label info payload = do dflags <- getDynFlags let lits = mkStaticClosure dflags (mkCmmInfoLabel pkg info) dontCareCCS payload [] [] [] - code $ emitDataLits (mkCmmDataLabel pkg cl_label) lits + code $ emitDataLits (mkCmmDataLabel pkg (NeedExternDecl True) cl_label) lits foreignCall :: String |