[Git][ghc/ghc][wip/T24512] 4 commits: ghc-internal: Eliminate GHC.Internal.Data.Kind
Ben Gamari (@bgamari)
gitlab at gitlab.haskell.org
Fri Mar 8 19:38:06 UTC 2024
Ben Gamari pushed to branch wip/T24512 at Glasgow Haskell Compiler / GHC
Commits:
50454a29 by Ben Gamari at 2024-03-08T03:32:42-05:00
ghc-internal: Eliminate GHC.Internal.Data.Kind
This was simply reexporting things from `ghc-prim`. Instead reexport
these directly from `Data.Kind`. Also add build ordering dependency to
work around #23942.
- - - - -
38a4b6ab by Ben Gamari at 2024-03-08T03:33:18-05:00
rts: Fix SET_HDR initialization of retainer set
This fixes a regression in retainer set profiling introduced by
b0293f78cb6acf2540389e22bdda420d0ab874da. Prior to that commit
the heap traversal word would be initialized by `SET_HDR` using
`LDV_RECORD_CREATE`. However, the commit added a `doingLDVProfiling`
check in `LDV_RECORD_CREATE`, meaning that this initialization no longer
happened.
Given that this initialization was awkwardly indirectly anyways, I have
fixed this by explicitly initializating the heap traversal word to
`NULL` in `SET_PROF_HDR`. This is equivalent to the previous behavior,
but much more direct.
Fixes #24513.
- - - - -
dbb0be97 by Ben Gamari at 2024-03-08T14:37:41-05:00
rts/linker: Don't unload code when profiling is enabled
The heap census may contain references (e.g. `Counter.identity`) to
static data which must be available when the census is reported at the
end of execution.
Fixes #24512.
- - - - -
0c6dc060 by Ben Gamari at 2024-03-08T14:37:59-05:00
rts/linker: Don't unload native objects when dlinfo isn't available
To do so is unsafe as we have no way of identifying references to
symbols provided by the object.
Fixes #24513. Fixes #23993.
- - - - -
11 changed files:
- libraries/base/src/Data/Kind.hs
- libraries/ghc-internal/ghc-internal.cabal
- rts/CheckUnload.c
- rts/Linker.c
- rts/LinkerInternals.h
- rts/include/rts/storage/ClosureMacros.h
- rts/linker/Elf.c
- testsuite/tests/interface-stability/base-exports.stdout
- testsuite/tests/interface-stability/base-exports.stdout-javascript-unknown-ghcjs
- testsuite/tests/interface-stability/base-exports.stdout-mingw32
- testsuite/tests/interface-stability/base-exports.stdout-ws-32
Changes:
=====================================
libraries/base/src/Data/Kind.hs
=====================================
@@ -1,4 +1,4 @@
-{-# LANGUAGE Safe #-}
+{-# LANGUAGE Trustworthy #-}
-- |
--
@@ -19,4 +19,6 @@ module Data.Kind
FUN
) where
-import GHC.Internal.Data.Kind
\ No newline at end of file
+import GHC.Num.BigNat () -- for build ordering (#23942)
+import GHC.Prim (FUN)
+import GHC.Types (Type, Constraint)
=====================================
libraries/ghc-internal/ghc-internal.cabal
=====================================
@@ -120,7 +120,6 @@ Library
GHC.Internal.Data.Functor.Utils
GHC.Internal.Data.IORef
GHC.Internal.Data.Ix
- GHC.Internal.Data.Kind
GHC.Internal.Data.List
GHC.Internal.Data.Maybe
GHC.Internal.Data.Monoid
=====================================
rts/CheckUnload.c
=====================================
@@ -165,6 +165,18 @@ ObjectCode *loaded_objects;
// map static closures to their ObjectCode.
static OCSectionIndices *global_s_indices = NULL;
+// Is it safe for us to unload code?
+static bool safeToUnload(void)
+{
+ if (RtsFlags.ProfFlags.doHeapProfile != NO_HEAP_PROFILING) {
+ // We mustn't unload anything as the heap census may contain
+ // references into static data (e.g. cost centre names).
+ // See #24512.
+ return false;
+ }
+ return true;
+}
+
static OCSectionIndices *createOCSectionIndices(void)
{
// TODO (osa): Maybe initialize as empty (without allocation) and allocate
@@ -457,6 +469,8 @@ void checkUnload(void)
{
if (global_s_indices == NULL) {
return;
+ } else if (!safeToUnload()) {
+ return;
}
// At this point we've marked all dynamically loaded static objects
@@ -478,8 +492,6 @@ void checkUnload(void)
next = oc->next;
ASSERT(oc->status == OBJECT_UNLOADED);
- removeOCSectionIndices(s_indices, oc);
-
// Symbols should be removed by unloadObj_.
// NB (osa): If this assertion doesn't hold then freeObjectCode below
// will corrupt symhash as keys of that table live in ObjectCodes. If
@@ -487,8 +499,17 @@ void checkUnload(void)
// RTS) then it's probably because this assertion did not hold.
ASSERT(oc->symbols == NULL);
- freeObjectCode(oc);
- n_unloaded_objects -= 1;
+ if (oc->unloadable) {
+ removeOCSectionIndices(s_indices, oc);
+ freeObjectCode(oc);
+ n_unloaded_objects -= 1;
+ } else {
+ // If we don't have enough information to
+ // accurately determine the reachability of
+ // the object then hold onto it.
+ oc->next = objects;
+ objects = oc;
+ }
}
old_objects = NULL;
=====================================
rts/Linker.c
=====================================
@@ -1385,6 +1385,7 @@ mkOc( ObjectType type, pathchar *path, char *image, int imageSize,
oc->prev = NULL;
oc->next_loaded_object = NULL;
oc->mark = object_code_mark_bit;
+ oc->unloadable = false;
oc->dependencies = allocHashSet();
#if defined(NEED_M32)
@@ -1527,6 +1528,12 @@ preloadObjectFile (pathchar *path)
/* FIXME (AP): =mapped= parameter unconditionally set to true */
oc = mkOc(STATIC_OBJECT, path, image, fileSize, true, NULL, misalignment);
+ /* assume that static objects are safely unloadable since
+ * we have know of all references to symbols provided by
+ * the object. These are tracked by lookupDependentSymbol.
+ */
+ oc->unloadable = true;
+
#if defined(OBJFORMAT_MACHO)
if (ocVerifyImage_MachO( oc ))
ocInit_MachO( oc );
=====================================
rts/LinkerInternals.h
=====================================
@@ -313,8 +313,14 @@ struct _ObjectCode {
struct _ObjectCode *next_loaded_object;
// Mark bit
+ // N.B. This is a full word as we CAS it.
StgWord mark;
+ // Can this object be safely unloaded? Not true for
+ // dynamic objects when dlinfo is not available as
+ // we cannot determine liveness.
+ bool unloadable;
+
// Set of dependencies (ObjectCode*) of the object file. Traverse
// dependencies using `iterHashTable`.
//
@@ -376,7 +382,9 @@ struct _ObjectCode {
/* handle returned from dlopen */
void *dlopen_handle;
- /* virtual memory ranges of loaded code */
+ /* virtual memory ranges of loaded code. NULL if no range information is
+ * available (e.g. if dlinfo is unavailable on the current platform).
+ */
NativeCodeRange *nc_ranges;
};
=====================================
rts/include/rts/storage/ClosureMacros.h
=====================================
@@ -147,17 +147,10 @@ EXTERN_INLINE StgHalfWord GET_TAG(const StgClosure *con)
#if defined(PROFILING)
/*
The following macro works for both retainer profiling and LDV profiling. For
- retainer profiling, 'era' remains 0, so by setting the 'ldvw' field we also set
- 'rs' to zero.
-
- Note that we don't have to bother handling the 'flip' bit properly[1] since the
- retainer profiling code will just set 'rs' to NULL upon visiting a closure with
- an invalid 'flip' bit anyways.
-
- See Note [Profiling heap traversal visited bit] for details.
-
- [1]: Technically we should set 'rs' to `NULL | flip`.
+ retainer profiling, we set 'trav' to 0, which is an invalid
+ RetainerSet.
*/
+
/*
MP: Various other places use the check era > 0 to check whether LDV profiling
is enabled. The use of these predicates here is the reason for including RtsFlags.h in
@@ -168,17 +161,14 @@ EXTERN_INLINE StgHalfWord GET_TAG(const StgClosure *con)
*/
#define SET_PROF_HDR(c, ccs_) \
{ \
- (c)->header.prof.ccs = ccs_; \
- if (doingLDVProfiling()) { \
- LDV_RECORD_CREATE((c)); \
- } \
-\
- if (doingRetainerProfiling()) { \
- LDV_RECORD_CREATE((c)); \
- }; \
- if (doingErasProfiling()){ \
- ERA_RECORD_CREATE((c)); \
- }; \
+ (c)->header.prof.ccs = ccs_; \
+ if (doingLDVProfiling()) { \
+ LDV_RECORD_CREATE((c)); \
+ } else if (doingRetainerProfiling()) { \
+ (c)->header.prof.hp.trav = 0; \
+ } else if (doingErasProfiling()){ \
+ ERA_RECORD_CREATE((c)); \
+ } \
}
#else
=====================================
rts/linker/Elf.c
=====================================
@@ -2190,6 +2190,10 @@ void * loadNativeObj_ELF (pathchar *path, char **errmsg)
copyErrmsg(errmsg, "dl_iterate_phdr failed to find obj");
goto dl_iterate_phdr_fail;
}
+ nc->unloadable = true;
+#else
+ nc->nc_ranges = NULL;
+ nc->unloadable = false;
#endif /* defined (HAVE_DLINFO) */
insertOCSectionIndices(nc);
=====================================
testsuite/tests/interface-stability/base-exports.stdout
=====================================
@@ -1276,7 +1276,7 @@ module Data.Ix where
{-# MINIMAL range, (index | GHC.Internal.Ix.unsafeIndex), inRange #-}
module Data.Kind where
- -- Safety: Safe
+ -- Safety: Trustworthy
type Constraint :: *
type Constraint = GHC.Prim.CONSTRAINT GHC.Types.LiftedRep
type role FUN nominal representational representational
=====================================
testsuite/tests/interface-stability/base-exports.stdout-javascript-unknown-ghcjs
=====================================
@@ -1276,7 +1276,7 @@ module Data.Ix where
{-# MINIMAL range, (index | GHC.Internal.Ix.unsafeIndex), inRange #-}
module Data.Kind where
- -- Safety: Safe
+ -- Safety: Trustworthy
type Constraint :: *
type Constraint = GHC.Prim.CONSTRAINT GHC.Types.LiftedRep
type role FUN nominal representational representational
=====================================
testsuite/tests/interface-stability/base-exports.stdout-mingw32
=====================================
@@ -1276,7 +1276,7 @@ module Data.Ix where
{-# MINIMAL range, (index | GHC.Internal.Ix.unsafeIndex), inRange #-}
module Data.Kind where
- -- Safety: Safe
+ -- Safety: Trustworthy
type Constraint :: *
type Constraint = GHC.Prim.CONSTRAINT GHC.Types.LiftedRep
type role FUN nominal representational representational
=====================================
testsuite/tests/interface-stability/base-exports.stdout-ws-32
=====================================
@@ -1276,7 +1276,7 @@ module Data.Ix where
{-# MINIMAL range, (index | GHC.Internal.Ix.unsafeIndex), inRange #-}
module Data.Kind where
- -- Safety: Safe
+ -- Safety: Trustworthy
type Constraint :: *
type Constraint = GHC.Prim.CONSTRAINT GHC.Types.LiftedRep
type role FUN nominal representational representational
View it on GitLab: https://gitlab.haskell.org/ghc/ghc/-/compare/7d3edc79eb17250515550344f3d75cf897eae880...0c6dc060c39a14e4eb4679aab655c2bcd32a87df
--
View it on GitLab: https://gitlab.haskell.org/ghc/ghc/-/compare/7d3edc79eb17250515550344f3d75cf897eae880...0c6dc060c39a14e4eb4679aab655c2bcd32a87df
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