diff options
| -rw-r--r-- | rts/Linker.c | 75 | ||||
| -rw-r--r-- | rts/include/rts/Linker.h | 1 |
2 files changed, 61 insertions, 15 deletions
diff --git a/rts/Linker.c b/rts/Linker.c index 383f68abc8..cac82891ae 100644 --- a/rts/Linker.c +++ b/rts/Linker.c @@ -98,11 +98,11 @@ Note [runtime-linker-phases] ~~~~~~~~~~~~~~~~~~~~~~~~~~~~ Broadly the behavior of the runtime linker can be - split into the following four phases: + split into the following five phases: - Indexing (e.g. ocVerifyImage and ocGetNames) - - Initialization (e.g. ocResolve and ocRunInit) - - Resolve (e.g. resolveObjs()) + - Initialization (e.g. ocResolve) + - RunInit (e.g. ocRunInit) - Lookup (e.g. lookupSymbol) This is to enable lazy loading of symbols. Eager loading is problematic @@ -132,14 +132,22 @@ * During resolve we attempt to resolve all the symbols needed for the initial link. This essentially means, that for any ObjectCode given - directly to the command-line we perform lookupSymbols on the required - symbols. lookupSymbols may trigger the loading of additional ObjectCode - if required. + directly to the command-line we perform lookupSymbol on the required + symbols. lookupSymbol may trigger the loading of additional ObjectCode + if required. After resolving an object we mark its text as executable and + not writable. This phase will produce ObjectCode with status `OBJECT_RESOLVED` if the previous status was `OBJECT_NEEDED`. - * lookupSymbols is used to lookup any symbols required, both during initial + * During RunInit we run the initializers ("constructors") of the objects + that are in `OBJECT_RESOLVED` state and move them to `OBJECT_READY` state. + This must be in a separate phase since we must ensure that all needed + objects have been fully resolved before we can run their initializers. + This is particularly tricky in the presence of cyclic dependencies (see + #21253). + + * lookupSymbol is used to lookup any symbols required, both during initial link and during statement and expression compilations in the REPL. Declaration of e.g. a foreign import, will eventually call lookupSymbol which will either fail (symbol unknown) or succeed (and possibly trigger a @@ -170,8 +178,11 @@ StrHashTable *symhash; Mutex linker_mutex; #endif -/* Generic wrapper function to try and Resolve and RunInit oc files */ -int ocTryLoad( ObjectCode* oc ); +/* Generic wrapper function to try and resolve oc files */ +static int ocTryLoad( ObjectCode* oc ); +/* Run initializers */ +static int ocRunInit( ObjectCode* oc ); +static int runPendingInitializers (void); static void ghciRemoveSymbolTable(StrHashTable *table, const SymbolName* key, ObjectCode *owner) @@ -282,6 +293,7 @@ int ghciInsertSymbolTable( return 1; } else if ( pinfo->owner + && pinfo->owner->status != OBJECT_READY && pinfo->owner->status != OBJECT_RESOLVED && pinfo->owner->status != OBJECT_NEEDED) { @@ -296,7 +308,9 @@ int ghciInsertSymbolTable( This is essentially emulating the behavior of a linker wherein it will always link in object files that are .o file arguments, but only take object files from archives as needed. */ - if (owner && (owner->status == OBJECT_NEEDED || owner->status == OBJECT_RESOLVED)) { + if (owner && (owner->status == OBJECT_NEEDED + || owner->status == OBJECT_RESOLVED + || owner->status == OBJECT_READY)) { pinfo->value = data; pinfo->owner = owner; pinfo->strength = strength; @@ -991,6 +1005,10 @@ SymbolAddr* lookupSymbol( SymbolName* lbl ) IF_DEBUG(linker, printLoadedObjects()); fflush(stderr); } + + if (!runPendingInitializers()) { + errorBelch("lookupSymbol: Failed to run initializers."); + } RELEASE_LOCK(&linker_mutex); return r; } @@ -1622,12 +1640,24 @@ int ocTryLoad (ObjectCode* oc) { m32_allocator_flush(oc->rw_m32); #endif - // run init/init_array/ctors/mod_init_func + IF_DEBUG(linker, ocDebugBelch(oc, "resolved\n")); + oc->status = OBJECT_RESOLVED; + + return 1; +} + +// run init/init_array/ctors/mod_init_func +int ocRunInit(ObjectCode *oc) +{ + if (oc->status != OBJECT_RESOLVED) { + return 1; + } IF_DEBUG(linker, ocDebugBelch(oc, "running initializers\n")); // See Note [Tracking foreign exports] in ForeignExports.c foreignExportsLoadingObject(oc); + int r; #if defined(OBJFORMAT_ELF) r = ocRunInit_ELF ( oc ); #elif defined(OBJFORMAT_PEi386) @@ -1640,10 +1670,22 @@ int ocTryLoad (ObjectCode* oc) { foreignExportsFinishedLoadingObject(); if (!r) { return r; } + oc->status = OBJECT_READY; - IF_DEBUG(linker, ocDebugBelch(oc, "resolved\n")); - oc->status = OBJECT_RESOLVED; + return 1; +} +int runPendingInitializers (void) +{ + for (ObjectCode *oc = objects; oc; oc = oc->next) { + int r = ocRunInit(oc); + if (!r) { + errorBelch("Could not run initializers of Object Code %" PATH_FMT ".\n", OC_INFORMATIVE_FILENAME(oc)); + IF_DEBUG(linker, printLoadedObjects()); + fflush(stderr); + return r; + } + } return 1; } @@ -1658,8 +1700,7 @@ static HsInt resolveObjs_ (void) for (ObjectCode *oc = objects; oc; oc = oc->next) { int r = ocTryLoad(oc); - if (!r) - { + if (!r) { errorBelch("Could not load Object Code %" PATH_FMT ".\n", OC_INFORMATIVE_FILENAME(oc)); IF_DEBUG(linker, printLoadedObjects()); fflush(stderr); @@ -1667,6 +1708,10 @@ static HsInt resolveObjs_ (void) } } + if (!runPendingInitializers()) { + return 0; + } + #if defined(PROFILING) // collect any new cost centres & CCSs that were defined during runInit refreshProfilingCCSs(); diff --git a/rts/include/rts/Linker.h b/rts/include/rts/Linker.h index 143f1328d5..ae463bc05e 100644 --- a/rts/include/rts/Linker.h +++ b/rts/include/rts/Linker.h @@ -52,6 +52,7 @@ typedef enum { OBJECT_LOADED, OBJECT_NEEDED, OBJECT_RESOLVED, + OBJECT_READY, OBJECT_UNLOADED, OBJECT_DONT_RESOLVE, OBJECT_NOT_LOADED /* The object was either never loaded or has been |