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gottesmmgottesmm
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[sil-deserialization] Implement cache invalidation for all serialized SIL entities and use it to properly invalidate global variables/witness tables when we delete them.
Otherwise, one runs into memory corruption. I ran into this while enabling ossa on the stdlib for non-Darwin platforms. Hopefully we do not regress on this again when someone adds more optzns that eliminate these since I added a big NOTE to warn people to do it and implemented support even for the entities we do not support deleting at the SIL level... yet.
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+267
-26
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5 files changed

+267
-26
lines changed

‎include/swift/Serialization/SerializedSILLoader.h

Lines changed: 11 additions & 4 deletions
Original file line numberDiff line numberDiff line change
@@ -29,6 +29,7 @@ class ModuleDecl;
2929
class SILDeserializer;
3030
class SILFunction;
3131
class SILGlobalVariable;
32+
class SILProperty;
3233
class SILModule;
3334
class SILVTable;
3435
class SILWitnessTable;
@@ -69,10 +70,16 @@ class SerializedSILLoader {
6970
SILDifferentiabilityWitness *
7071
lookupDifferentiabilityWitness(SILDifferentiabilityWitnessKey key);
7172

72-
/// Invalidate the cached entries for deserialized SILFunctions.
73-
void invalidateCaches();
74-
75-
bool invalidateFunction(SILFunction *F);
73+
/// Invalidate the cached entries for deserialized state. Must be
74+
/// called when erasing deserialized state in the SILModule.
75+
void invalidateAllCaches();
76+
bool invalidateFunction(SILFunction *f);
77+
bool invalidateGlobalVariable(SILGlobalVariable *gv);
78+
bool invalidateVTable(SILVTable *vt);
79+
bool invalidateWitnessTable(SILWitnessTable *wt);
80+
bool invalidateDefaultWitnessTable(SILDefaultWitnessTable *wt);
81+
bool invalidateProperty(SILProperty *p);
82+
bool invalidateDifferentiabilityWitness(SILDifferentiabilityWitness *w);
7683

7784
/// Deserialize all SILFunctions, VTables, and WitnessTables for
7885
/// a given Module.

‎lib/SIL/IR/SILModule.cpp

Lines changed: 6 additions & 4 deletions
Original file line numberDiff line numberDiff line change
@@ -320,6 +320,7 @@ SILModule::createDefaultWitnessTableDeclaration(const ProtocolDecl *Protocol,
320320
void SILModule::deleteWitnessTable(SILWitnessTable *Wt) {
321321
auto Conf = Wt->getConformance();
322322
assert(lookUpWitnessTable(Conf, false) == Wt);
323+
getSILLoader()->invalidateWitnessTable(Wt);
323324
WitnessTableMap.erase(Conf);
324325
witnessTables.erase(Wt);
325326
}
@@ -474,7 +475,7 @@ bool SILModule::hasFunction(StringRef Name) {
474475
}
475476

476477
void SILModule::invalidateSILLoaderCaches() {
477-
getSILLoader()->invalidateCaches();
478+
getSILLoader()->invalidateAllCaches();
478479
}
479480

480481
SILFunction *SILModule::removeFromZombieList(StringRef Name) {
@@ -526,9 +527,10 @@ void SILModule::invalidateFunctionInSILCache(SILFunction *F) {
526527
}
527528

528529
/// Erase a global SIL variable from the module.
529-
void SILModule::eraseGlobalVariable(SILGlobalVariable *G) {
530-
GlobalVariableMap.erase(G->getName());
531-
getSILGlobalList().erase(G);
530+
void SILModule::eraseGlobalVariable(SILGlobalVariable *gv) {
531+
getSILLoader()->invalidateGlobalVariable(gv);
532+
GlobalVariableMap.erase(gv->getName());
533+
getSILGlobalList().erase(gv);
532534
}
533535

534536
SILVTable *SILModule::lookUpVTable(const ClassDecl *C,

‎lib/Serialization/DeserializeSIL.cpp

Lines changed: 133 additions & 8 deletions
Original file line numberDiff line numberDiff line change
@@ -28,6 +28,7 @@
2828
#include "swift/SIL/SILBuilder.h"
2929
#include "swift/SIL/SILDebugScope.h"
3030
#include "swift/SIL/SILModule.h"
31+
#include "swift/SIL/SILProperty.h"
3132
#include "swift/SIL/SILUndef.h"
3233

3334
#include "llvm/ADT/Statistic.h"
@@ -2937,11 +2938,11 @@ SILGlobalVariable *SILDeserializer::readGlobalVar(StringRef Name) {
29372938

29382939
assert(VId <= GlobalVars.size() && "invalid GlobalVar ID");
29392940
auto &globalVarOrOffset = GlobalVars[VId-1];
2940-
if (globalVarOrOffset.isComplete())
2941-
return globalVarOrOffset;
2941+
if (globalVarOrOffset.isFullyDeserialized())
2942+
return globalVarOrOffset.get();
29422943

29432944
BCOffsetRAII restoreOffset(SILCursor);
2944-
if (llvm::Error Err = SILCursor.JumpToBit(globalVarOrOffset))
2945+
if (llvm::Error Err = SILCursor.JumpToBit(globalVarOrOffset.getOffset()))
29452946
MF->fatal(std::move(Err));
29462947
llvm::Expected<llvm::BitstreamEntry> maybeEntry =
29472948
SILCursor.advance(AF_DontPopBlockAtEnd);
@@ -2988,7 +2989,7 @@ SILGlobalVariable *SILDeserializer::readGlobalVar(StringRef Name) {
29882989
None,
29892990
dID ? cast<VarDecl>(MF->getDecl(dID)): nullptr);
29902991
v->setLet(IsLet);
2991-
globalVarOrOffset = v;
2992+
globalVarOrOffset.set(v, true /*isFullyDeserialized*/);
29922993
v->setDeclaration(IsDeclaration);
29932994

29942995
if (Callback)
@@ -3087,11 +3088,11 @@ SILVTable *SILDeserializer::readVTable(DeclID VId) {
30873088
assert(VId <= VTables.size() && "invalid VTable ID");
30883089
auto &vTableOrOffset = VTables[VId-1];
30893090

3090-
if (vTableOrOffset.isComplete())
3091-
return vTableOrOffset;
3091+
if (vTableOrOffset.isFullyDeserialized())
3092+
return vTableOrOffset.get();
30923093

30933094
BCOffsetRAII restoreOffset(SILCursor);
3094-
if (llvm::Error Err = SILCursor.JumpToBit(vTableOrOffset))
3095+
if (llvm::Error Err = SILCursor.JumpToBit(vTableOrOffset.getOffset()))
30953096
MF->fatal(std::move(Err));
30963097
llvm::Expected<llvm::BitstreamEntry> maybeEntry =
30973098
SILCursor.advance(AF_DontPopBlockAtEnd);
@@ -3188,7 +3189,7 @@ SILVTable *SILDeserializer::readVTable(DeclID VId) {
31883189
SILMod, theClass,
31893190
Serialized ? IsSerialized : IsNotSerialized,
31903191
vtableEntries);
3191-
vTableOrOffset = vT;
3192+
vTableOrOffset.set(vT, true /*isFullyDeserialized*/);
31923193

31933194
if (Callback) Callback->didDeserialize(MF->getAssociatedModule(), vT);
31943195
return vT;
@@ -3819,3 +3820,127 @@ bool SILDeserializer::invalidateFunction(SILFunction *F) {
38193820
}
38203821
return false;
38213822
}
3823+
3824+
// Invalidate all cached SILGlobalVariable.
3825+
void SILDeserializer::invalidateGlobalVariableCache() {
3826+
for (auto &entry : GlobalVars) {
3827+
if (entry.isDeserialized()) {
3828+
entry.reset();
3829+
}
3830+
}
3831+
}
3832+
3833+
// Invalidate a specific cached GlobalVariable.
3834+
bool SILDeserializer::invalidateGlobalVariable(SILGlobalVariable *gv) {
3835+
for (auto &entry : GlobalVars) {
3836+
if (entry.isDeserialized() && entry.get() == gv) {
3837+
entry.reset();
3838+
return true;
3839+
}
3840+
}
3841+
3842+
return false;
3843+
}
3844+
3845+
// Invalidate all cached SILVTable.
3846+
void SILDeserializer::invalidateVTableCache() {
3847+
for (auto &entry : VTables) {
3848+
if (entry.isDeserialized()) {
3849+
entry.reset();
3850+
}
3851+
}
3852+
}
3853+
3854+
// Invalidate a specific cached SILVTable.
3855+
bool SILDeserializer::invalidateVTable(SILVTable *v) {
3856+
for (auto &entry : VTables) {
3857+
if (entry.isDeserialized() && entry.get() == v) {
3858+
entry.reset();
3859+
return true;
3860+
}
3861+
}
3862+
3863+
return false;
3864+
}
3865+
3866+
// Invalidate all cached SILWitnessTable.
3867+
void SILDeserializer::invalidateWitnessTableCache() {
3868+
for (auto &entry : WitnessTables) {
3869+
if (entry.isDeserialized()) {
3870+
entry.reset();
3871+
}
3872+
}
3873+
}
3874+
3875+
// Invalidate a specific cached SILWitnessTable.
3876+
bool SILDeserializer::invalidateWitnessTable(SILWitnessTable *wt) {
3877+
for (auto &entry : WitnessTables) {
3878+
if (entry.isDeserialized() && entry.get() == wt) {
3879+
entry.reset();
3880+
return true;
3881+
}
3882+
}
3883+
return false;
3884+
}
3885+
3886+
// Invalidate all cached SILDefaultWitnessTable.
3887+
void SILDeserializer::invalidateDefaultWitnessTableCache() {
3888+
for (auto &entry : DefaultWitnessTables) {
3889+
if (entry.isDeserialized()) {
3890+
entry.reset();
3891+
}
3892+
}
3893+
}
3894+
3895+
// Invalidate a specific cached SILDefaultWitnessTable.
3896+
bool SILDeserializer::invalidateDefaultWitnessTable(
3897+
SILDefaultWitnessTable *wt) {
3898+
for (auto &entry : DefaultWitnessTables) {
3899+
if (entry.isDeserialized() && entry.get() == wt) {
3900+
entry.reset();
3901+
return true;
3902+
}
3903+
}
3904+
return false;
3905+
}
3906+
3907+
// Invalidate all cached SILProperty.
3908+
void SILDeserializer::invalidatePropertyCache() {
3909+
for (auto &entry : Properties) {
3910+
if (entry.isDeserialized()) {
3911+
entry.reset();
3912+
}
3913+
}
3914+
}
3915+
3916+
// Invalidate a specific cached SILProperty.
3917+
bool SILDeserializer::invalidateProperty(SILProperty *p) {
3918+
for (auto &entry : Properties) {
3919+
if (entry.isDeserialized() && entry.get() == p) {
3920+
entry.reset();
3921+
return true;
3922+
}
3923+
}
3924+
return false;
3925+
}
3926+
3927+
// Invalidate all cached SILDifferentiabilityWitness.
3928+
void SILDeserializer::invalidateDifferentiabilityWitnessCache() {
3929+
for (auto &entry : DifferentiabilityWitnesses) {
3930+
if (entry.isDeserialized()) {
3931+
entry.reset();
3932+
}
3933+
}
3934+
}
3935+
3936+
// Invalidate a specific cached SILDifferentiabilityWitness.
3937+
bool SILDeserializer::invalidateDifferentiabilityWitness(
3938+
SILDifferentiabilityWitness *w) {
3939+
for (auto &entry : DifferentiabilityWitnesses) {
3940+
if (entry.isDeserialized() && entry.get() == w) {
3941+
entry.reset();
3942+
return true;
3943+
}
3944+
}
3945+
return false;
3946+
}

‎lib/Serialization/DeserializeSIL.h

Lines changed: 67 additions & 4 deletions
Original file line numberDiff line numberDiff line change
@@ -38,14 +38,24 @@ namespace swift {
3838
using SerializedFuncTable =
3939
llvm::OnDiskIterableChainedHashTable<FuncTableInfo>;
4040

41+
//-----
42+
// Deserialization Caches
43+
//
44+
// NOTE: When adding more serialized tables to the deserializer,
45+
// always add invalidate methods and make sure SILModule always
46+
// invalidates the deserializer appropriately when it erases a
47+
// value that we deserialized here. Otherwise, memory corruption
48+
// may result.
49+
4150
std::unique_ptr<SerializedFuncTable> FuncTable;
4251
MutableArrayRef<ModuleFile::PartiallySerialized<SILFunction*>> Funcs;
4352

44-
std::unique_ptr<SerializedFuncTable> VTableList;
45-
MutableArrayRef<ModuleFile::Serialized<SILVTable*>> VTables;
46-
4753
std::unique_ptr<SerializedFuncTable> GlobalVarList;
48-
MutableArrayRef<ModuleFile::Serialized<SILGlobalVariable*>> GlobalVars;
54+
MutableArrayRef<ModuleFile::PartiallySerialized<SILGlobalVariable *>>
55+
GlobalVars;
56+
57+
std::unique_ptr<SerializedFuncTable> VTableList;
58+
MutableArrayRef<ModuleFile::PartiallySerialized<SILVTable *>> VTables;
4959

5060
std::unique_ptr<SerializedFuncTable> WitnessTableList;
5161
MutableArrayRef<ModuleFile::PartiallySerialized<SILWitnessTable *>>
@@ -63,6 +73,12 @@ namespace swift {
6373
ModuleFile::PartiallySerialized<SILDifferentiabilityWitness *>>
6474
DifferentiabilityWitnesses;
6575

76+
//-----
77+
// End Deserialization Caches
78+
//
79+
// Before adding a new cache here, please read the comment at the
80+
// beginning of the deserialization cache section.
81+
6682
/// A declaration will only
6783
llvm::DenseMap<NormalProtocolConformance *, SILWitnessTable *>
6884
ConformanceToWitnessTableMap;
@@ -176,6 +192,53 @@ namespace swift {
176192
/// Invalidate a specific cached SILFunction.
177193
bool invalidateFunction(SILFunction *F);
178194

195+
/// Invalidate all cached SILGlobalVariable.
196+
void invalidateGlobalVariableCache();
197+
198+
/// Invalidate a specific cached GlobalVariable.
199+
bool invalidateGlobalVariable(SILGlobalVariable *gv);
200+
201+
/// Invalidate all cached SILVTable.
202+
void invalidateVTableCache();
203+
204+
/// Invalidate a specific cached SILVTable.
205+
bool invalidateVTable(SILVTable *v);
206+
207+
/// Invalidate all cached SILWitnessTable.
208+
void invalidateWitnessTableCache();
209+
210+
/// Invalidate a specific cached SILWitnessTable.
211+
bool invalidateWitnessTable(SILWitnessTable *v);
212+
213+
/// Invalidate all cached SILDefaultWitnessTable.
214+
void invalidateDefaultWitnessTableCache();
215+
216+
/// Invalidate a specific cached SILDefaultWitnessTable.
217+
bool invalidateDefaultWitnessTable(SILDefaultWitnessTable *v);
218+
219+
/// Invalidate all cached SILProperty.
220+
void invalidatePropertyCache();
221+
222+
/// Invalidate a specific cached SILProperty.
223+
bool invalidateProperty(SILProperty *v);
224+
225+
/// Invalidate all cached SILDifferentiabilityWitness.
226+
void invalidateDifferentiabilityWitnessCache();
227+
228+
/// Invalidate a specific cached SILDifferentiabilityWitness.
229+
bool invalidateDifferentiabilityWitness(SILDifferentiabilityWitness *v);
230+
231+
/// Invalidate all caches in this deserializer.
232+
void invalidateAllCaches() {
233+
invalidateFunctionCache();
234+
invalidateGlobalVariableCache();
235+
invalidateVTableCache();
236+
invalidateWitnessTableCache();
237+
invalidateDefaultWitnessTableCache();
238+
invalidatePropertyCache();
239+
invalidateDifferentiabilityWitnessCache();
240+
}
241+
179242
/// Deserialize all SILFunctions, VTables, WitnessTables, and
180243
/// DefaultWitnessTables inside the module, and add them to SILMod.
181244
///

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