Build with -Wconversion produces non-viable GHC
OpenBSD people recently tried to build their ports tree with clang forcing -Wconversion. GHC 8.10.5 build on amd64 reported a number of warnings, many duplicated. More concerning is that the build didn't fail, it succefully produced broken artifacts. For example, ghci is broken:
% ./inplace/bin/ghc-stage2 --interactive
GHCi, version 8.10.5: https://www.haskell.org/ghc/ :? for help
ghc-stage2: internal error: m32_filled_page_set_next: Page not in lower 32-bits
(GHC version 8.10.5 for x86_64_unknown_openbsd)
Please report this as a GHC bug: https://www.haskell.org/ghc/reportabugTo reproduce the findings cc in PATH should be replaced with a wrapper that adds -Wconversion and removes -Werror:
#!/bin/sh
for i; do arg=$1; shift; case $arg in -Werror*) ;; *) set - "$@" "$arg" ;; esac; done
exec /usr/bin/cc -B /usr/ports/pobj/ghc-8.10.5/bin -Wconversion "$@"Some typical warnings are below, the full log is attached.
In file included from /tmp/ghc80558_0/ghc_4.c:2:0: error:
In file included from /usr/ports/pobj/ghc-8.10.5/bootstrap/lib/ghc/include/Rts.h:35:0: error:
/usr/ports/pobj/ghc-8.10.5/bootstrap/lib/ghc/include/Stg.h:515:17: error:
warning: implicit conversion changes signedness: 'StgInt64' (aka 'long long') to 'W_' (aka 'unsigned long long') [-Wsign-conversion]
p_dest[0] = src;
~ ^~~
|
515 | p_dest[0] = src;
| ^
/usr/ports/pobj/ghc-8.10.5/bootstrap/lib/ghc/include/Stg.h:520:12: error:
warning: implicit conversion changes signedness: 'W_' (aka 'unsigned long long') to 'StgInt64' (aka 'long long') [-Wsign-conversion]
return p_src[0];
~~~~~~ ^~~~~~~~
|
520 | return p_src[0];
| ^
In file included from /tmp/ghc80558_0/ghc_4.c:2:0: error:
In file included from /usr/ports/pobj/ghc-8.10.5/bootstrap/lib/ghc/include/Rts.h:208:0: error:
/usr/ports/pobj/ghc-8.10.5/bootstrap/lib/ghc/include/rts/storage/ClosureMacros.h:115:27: error:
warning: implicit conversion changes signedness: 'const StgSRTField' (aka 'const int') to 'StgHalfWord' (aka 'unsigned int') [-Wsign-conversion]
return get_itbl(con)->srt;
~~~~~~ ~~~~~~~~~~~~~~~^~~
|
115 | return get_itbl(con)->srt;
| ^
/usr/ports/pobj/ghc-8.10.5/bootstrap/lib/ghc/include/rts/storage/ClosureMacros.h:212:39: error:
warning: implicit conversion changes signedness: 'int' to 'unsigned long long' [-Wsign-conversion]
return (StgClosure*)((StgWord)p & ~TAG_MASK);
~ ^~~~~~~~~
|
212 | return (StgClosure*)((StgWord)p & ~TAG_MASK);
| ^
/usr/ports/pobj/ghc-8.10.5/bootstrap/lib/ghc/include/rts/storage/ClosureMacros.h:218:45: error:
warning: implicit conversion changes signedness: 'int' to 'unsigned long long' [-Wsign-conversion]
return (const StgClosure*)((StgWord)p & ~TAG_MASK);
~ ^~~~~~~~~
|
218 | return (const StgClosure*)((StgWord)p & ~TAG_MASK);
| ^
/usr/ports/pobj/ghc-8.10.5/bootstrap/lib/ghc/include/rts/storage/ClosureMacros.h:315:28: error:
warning: implicit conversion loses integer precision: 'StgWord' (aka 'unsigned long long') to 'uint32_t' (aka 'unsigned int') [-Wshorten-64-to-32]
|
315 | { return AP_STACK_sizeW(x->size); }
| ^
{ return AP_STACK_sizeW(x->size); }
~~~~~~~~~~~~~~ ~~~^~~~
/usr/ports/pobj/ghc-8.10.5/bootstrap/lib/ghc/include/rts/storage/ClosureMacros.h:384:16: error:
warning: implicit conversion loses integer precision: 'StgOffset' (aka 'unsigned long long') to 'uint32_t' (aka 'unsigned int') [-Wshorten-64-to-32]
return thunk_sizeW_fromITBL(info);
~~~~~~ ^~~~~~~~~~~~~~~~~~~~~~~~~~
|
384 | return thunk_sizeW_fromITBL(info);
| ^
/usr/ports/pobj/ghc-8.10.5/bootstrap/lib/ghc/include/rts/storage/ClosureMacros.h:386:16: error:
warning: implicit conversion loses integer precision: 'StgOffset' (aka 'unsigned long long') to 'uint32_t' (aka 'unsigned int') [-Wshorten-64-to-32]
return THUNK_SELECTOR_sizeW();
~~~~~~ ^~~~~~~~~~~~~~~~~~~~~~
|
386 | return THUNK_SELECTOR_sizeW();
| ^
/usr/ports/pobj/ghc-8.10.5/bootstrap/lib/ghc/include/rts/storage/ClosureMacros.h:388:16: error:
warning: implicit conversion loses integer precision: 'StgOffset' (aka 'unsigned long long') to 'uint32_t' (aka 'unsigned int') [-Wshorten-64-to-32]
return ap_stack_sizeW((StgAP_STACK *)p);
~~~~~~ ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
|
388 | return ap_stack_sizeW((StgAP_STACK *)p);
| ^
/usr/ports/pobj/ghc-8.10.5/bootstrap/lib/ghc/include/rts/storage/ClosureMacros.h:390:16: error:
warning: implicit conversion loses integer precision: 'StgOffset' (aka 'unsigned long long') to 'uint32_t' (aka 'unsigned int') [-Wshorten-64-to-32]
return ap_sizeW((StgAP *)p);
~~~~~~ ^~~~~~~~~~~~~~~~~~~~
|
390 | return ap_sizeW((StgAP *)p);
| ^
/usr/ports/pobj/ghc-8.10.5/bootstrap/lib/ghc/include/rts/storage/ClosureMacros.h:392:16: error:
warning: implicit conversion loses integer precision: 'StgOffset' (aka 'unsigned long long') to 'uint32_t' (aka 'unsigned int') [-Wshorten-64-to-32]
return pap_sizeW((StgPAP *)p);
~~~~~~ ^~~~~~~~~~~~~~~~~~~~~~
|
392 | return pap_sizeW((StgPAP *)p);
| ^
/usr/ports/pobj/ghc-8.10.5/bootstrap/lib/ghc/include/rts/storage/ClosureMacros.h:396:16: error:
warning: implicit conversion loses integer precision: 'StgOffset' (aka 'unsigned long long') to 'uint32_t' (aka 'unsigned int') [-Wshorten-64-to-32]
return arr_words_sizeW((StgArrBytes *)p);
~~~~~~ ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
|
396 | return arr_words_sizeW((StgArrBytes *)p);
| ^
/usr/ports/pobj/ghc-8.10.5/bootstrap/lib/ghc/include/rts/storage/ClosureMacros.h:401:16: error:
warning: implicit conversion loses integer precision: 'StgOffset' (aka 'unsigned long long') to 'uint32_t' (aka 'unsigned int') [-Wshorten-64-to-32]
return mut_arr_ptrs_sizeW((StgMutArrPtrs*)p);
~~~~~~ ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
|
401 | return mut_arr_ptrs_sizeW((StgMutArrPtrs*)p);
| ^
/usr/ports/pobj/ghc-8.10.5/bootstrap/lib/ghc/include/rts/storage/ClosureMacros.h:406:16: error:
warning: implicit conversion loses integer precision: 'StgOffset' (aka 'unsigned long long') to 'uint32_t' (aka 'unsigned int') [-Wshorten-64-to-32]
return small_mut_arr_ptrs_sizeW((StgSmallMutArrPtrs*)p);
~~~~~~ ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
|
406 | return small_mut_arr_ptrs_sizeW((StgSmallMutArrPtrs*)p);
| ^
/usr/ports/pobj/ghc-8.10.5/bootstrap/lib/ghc/include/rts/storage/ClosureMacros.h:410:16: error:
warning: implicit conversion loses integer precision: 'StgWord' (aka 'unsigned long long') to 'uint32_t' (aka 'unsigned int') [-Wshorten-64-to-32]
return stack_sizeW((StgStack*)p);
~~~~~~ ^~~~~~~~~~~~~~~~~~~~~~~~~
|
410 | return stack_sizeW((StgStack*)p);
| ^
/usr/ports/pobj/ghc-8.10.5/bootstrap/lib/ghc/include/rts/storage/ClosureMacros.h:412:16: error:
warning: implicit conversion loses integer precision: 'StgWord' (aka 'unsigned long long') to 'uint32_t' (aka 'unsigned int') [-Wshorten-64-to-32]
return bco_sizeW((StgBCO *)p);
~~~~~~ ^~~~~~~~~~~~~~~~~~~~~~
|
412 | return bco_sizeW((StgBCO *)p);
| ^
/usr/ports/pobj/ghc-8.10.5/bootstrap/lib/ghc/include/rts/storage/ClosureMacros.h:416:16: error:
warning: implicit conversion loses integer precision: 'StgOffset' (aka 'unsigned long long') to 'uint32_t' (aka 'unsigned int') [-Wshorten-64-to-32]
return sizeW_fromITBL(info);
~~~~~~ ^~~~~~~~~~~~~~~~~~~~
|
416 | return sizeW_fromITBL(info);
| ^
/usr/ports/pobj/ghc-8.10.5/bootstrap/lib/ghc/include/rts/storage/ClosureMacros.h:443:20: error:
warning: implicit conversion changes signedness: 'const StgHalfInt' (aka 'const int') to 'unsigned long long' [-Wsign-conversion]
return 1 + GET_LARGE_BITMAP(&info->i)->size;
^~~~~~~~~~~~~~~~~~~~~~~~~~
|
443 | return 1 + GET_LARGE_BITMAP(&info->i)->size;
| ^
/usr/ports/pobj/ghc-8.10.5/bootstrap/lib/ghc/include/rts/storage/InfoTables.h:381:58: error:
note: expanded from macro 'GET_LARGE_BITMAP'
+ (info)->layout.large_bitmap_offset))
~ ~~~~~~~~~~~~~~~^~~~~~~~~~~~~~~~~~~
|
381 | + (info)->layout.large_bitmap_offset))
| ^
In file included from /tmp/ghc80558_0/ghc_4.c:2:0: error:
In file included from /usr/ports/pobj/ghc-8.10.5/bootstrap/lib/ghc/include/Rts.h:210:0: error:
/usr/ports/pobj/ghc-8.10.5/bootstrap/lib/ghc/include/rts/storage/GC.h:248:37: error:
warning: implicit conversion loses integer precision: 'uint32_t' (aka 'unsigned int') to 'StgWord16' (aka 'unsigned short') [-Wimplicit-int-conversion]
RELAXED_STORE(&bd->gen_no, gen->no);
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~^~~
|
248 | RELAXED_STORE(&bd->gen_no, gen->no);
| ^
/usr/ports/pobj/ghc-8.10.5/bootstrap/lib/ghc/include/stg/SMP.h:477:39: error:
note: expanded from macro 'RELAXED_STORE'
|
477 | #define RELAXED_STORE(ptr,val) *ptr = val
| ^
#define RELAXED_STORE(ptr,val) *ptr = val
~ ^~~
In file included from /tmp/ghc80558_0/ghc_4.c:2:0: error:
In file included from /usr/ports/pobj/ghc-8.10.5/bootstrap/lib/ghc/include/Rts.h:210:0: error:
/usr/ports/pobj/ghc-8.10.5/bootstrap/lib/ghc/include/rts/storage/GC.h:249:39: error:
warning: implicit conversion loses integer precision: 'uint32_t' (aka 'unsigned int') to 'StgWord16' (aka 'unsigned short') [-Wimplicit-int-conversion]
RELAXED_STORE(&bd->dest_no, dest->no);
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~^~~
|
249 | RELAXED_STORE(&bd->dest_no, dest->no);
| ^
/usr/ports/pobj/ghc-8.10.5/bootstrap/lib/ghc/include/stg/SMP.h:477:39: error:
note: expanded from macro 'RELAXED_STORE'
|
477 | #define RELAXED_STORE(ptr,val) *ptr = val
| ^
#define RELAXED_STORE(ptr,val) *ptr = val
~ ^~~
20 warnings generated.