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[Runtime] NULL/availability check shared cache calls.

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Avoid a dynamic linker failure if the calls aren't available at runtime.

rdar://74965969
This commit is contained in:
Mike Ash
2021-03-03 15:31:45 -05:00
parent 109a33cf2b
commit e06c978cf8
1 changed files with 48 additions and 37 deletions
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85
stdlib/public/runtime/ProtocolConformance.cpp
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@@ -291,6 +291,10 @@ struct ConformanceState {
auto uintPtr = reinterpret_cast<uintptr_t>(ptr);
return dyldSharedCacheStart <= uintPtr && uintPtr < dyldSharedCacheEnd;
}
bool sharedCacheOptimizationsActive() { return dyldSharedCacheStart != 0; }
#else
bool sharedCacheOptimizationsActive() { return false; }
#endif
ConformanceState() {
@@ -298,22 +302,28 @@ struct ConformanceState {
runtime::bincompat::workaroundProtocolConformanceReverseIteration();
#if USE_DYLD_SHARED_CACHE_CONFORMANCE_TABLES
if (_dyld_swift_optimizations_version() ==
DYLD_EXPECTED_SWIFT_OPTIMIZATIONS_VERSION) {
size_t length;
dyldSharedCacheStart = (uintptr_t)_dyld_get_shared_cache_range(&length);
dyldSharedCacheEnd =
dyldSharedCacheStart ? dyldSharedCacheStart + length : 0;
validateSharedCacheResults = runtime::environment::
SWIFT_DEBUG_VALIDATE_SHARED_CACHE_PROTOCOL_CONFORMANCES();
SHARED_CACHE_LOG("Shared cache range is %#lx-%#lx", dyldSharedCacheStart,
dyldSharedCacheEnd);
} else {
SHARED_CACHE_LOG("Disabling shared cache optimizations due to unknown "
"optimizations version %u",
_dyld_swift_optimizations_version());
dyldSharedCacheStart = 0;
dyldSharedCacheEnd = 0;
if (__builtin_available(macOS 9999, iOS 9999, tvOS 9999, watchOS 9999, *)) {
if (&_dyld_swift_optimizations_version) {
if (_dyld_swift_optimizations_version() ==
DYLD_EXPECTED_SWIFT_OPTIMIZATIONS_VERSION) {
size_t length;
dyldSharedCacheStart =
(uintptr_t)_dyld_get_shared_cache_range(&length);
dyldSharedCacheEnd =
dyldSharedCacheStart ? dyldSharedCacheStart + length : 0;
validateSharedCacheResults = runtime::environment::
SWIFT_DEBUG_VALIDATE_SHARED_CACHE_PROTOCOL_CONFORMANCES();
SHARED_CACHE_LOG("Shared cache range is %#lx-%#lx",
dyldSharedCacheStart, dyldSharedCacheEnd);
} else {
SHARED_CACHE_LOG(
"Disabling shared cache optimizations due to unknown "
"optimizations version %u",
_dyld_swift_optimizations_version());
dyldSharedCacheStart = 0;
dyldSharedCacheEnd = 0;
}
}
}
#endif
@@ -570,7 +580,7 @@ static void validateSharedCacheResults(
const WitnessTable *dyldCachedWitnessTable,
const ProtocolConformanceDescriptor *dyldCachedConformanceDescriptor) {
#if USE_DYLD_SHARED_CACHE_CONFORMANCE_TABLES
if (!C.validateSharedCacheResults)
if (!C.sharedCacheOptimizationsActive() || !C.validateSharedCacheResults)
return;
llvm::SmallVector<const ProtocolConformanceDescriptor *, 8> conformances;
@@ -726,29 +736,30 @@ swift_conformsToProtocolImpl(const Metadata *const type,
// Search the shared cache tables for a conformance for this type, and for
// superclasses (if it's a class).
const Metadata *dyldSearchType = type;
do {
bool definitiveFailure;
std::tie(dyldCachedWitnessTable, dyldCachedConformanceDescriptor,
definitiveFailure) =
findSharedCacheConformance(C, dyldSearchType, protocol);
if (C.sharedCacheOptimizationsActive()) {
const Metadata *dyldSearchType = type;
do {
bool definitiveFailure;
std::tie(dyldCachedWitnessTable, dyldCachedConformanceDescriptor,
definitiveFailure) =
findSharedCacheConformance(C, dyldSearchType, protocol);
if (definitiveFailure)
return nullptr;
if (definitiveFailure)
return nullptr;
dyldSearchType = _swift_class_getSuperclass(dyldSearchType);
} while (dyldSearchType && !dyldCachedWitnessTable &&
!dyldCachedConformanceDescriptor);
dyldSearchType = _swift_class_getSuperclass(dyldSearchType);
} while (dyldSearchType && !dyldCachedWitnessTable &&
!dyldCachedConformanceDescriptor);
validateSharedCacheResults(C, type, protocol, dyldCachedWitnessTable,
dyldCachedConformanceDescriptor);
// Return a cached result if we got a witness table. We can't do this if
// scanSectionsBackwards is set, since a scanned conformance can override a
// cached result in that case.
if (!C.scanSectionsBackwards)
if (dyldCachedWitnessTable)
return dyldCachedWitnessTable;
validateSharedCacheResults(C, type, protocol, dyldCachedWitnessTable,
dyldCachedConformanceDescriptor);
// Return a cached result if we got a witness table. We can't do this if
// scanSectionsBackwards is set, since a scanned conformance can override a
// cached result in that case.
if (!C.scanSectionsBackwards)
if (dyldCachedWitnessTable)
return dyldCachedWitnessTable;
}
// See if we have an authoritative cached conformance. The
// ConcurrentReadableHashMap data structure allows us to search the map