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[Reflection] Fail gracefully when objc_debug_taggedpointer_obfuscator isn't present. #22956

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Merged
merged 2 commits into from
Feb 27, 2019
Merged

[Reflection] Fail gracefully when objc_debug_taggedpointer_obfuscator isn't present. #22956

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f85d87f
[Reflection] Fail gracefully when objc_debug_taggedpointer_obfuscator…
mikeash Feb 27, 2019
dd17039
[Reflection] Add some (disabled by default) debug logging in swift-re…
mikeash Feb 27, 2019
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9 changes: 7 additions & 2 deletions include/swift/Remote/MetadataReader.h
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Original file line number Diff line number Diff line change
Expand Up @@ -2472,8 +2472,13 @@ class MetadataReader {
TaggedPointerExtendedClasses =
TaggedPointerExtendedClassesAddr.getAddressData();

tryFindAndReadSymbol(TaggedPointerObfuscator,
"objc_debug_taggedpointer_obfuscator");
// The tagged pointer obfuscator is not present on older OSes, in
// which case we can treat it as zero.
TaggedPointerObfuscator = 0;
auto TaggedPointerObfuscatorAddr = Reader->getSymbolAddress(
"objc_debug_taggedpointer_obfuscator");
if (TaggedPointerObfuscatorAddr)
tryReadSymbol(TaggedPointerObfuscatorAddr, TaggedPointerObfuscator);

# undef tryFindSymbol
# undef tryReadSymbol
Expand Down
16 changes: 16 additions & 0 deletions stdlib/tools/swift-reflection-test/swift-reflection-test.c
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Original file line number Diff line number Diff line change
Expand Up @@ -66,6 +66,14 @@ static void errnoAndExit(const char *message) {
abort();
}

#if 0
#include <inttypes.h>
#define DEBUG_LOG(fmt, ...) fprintf(stderr, "%s: " fmt "\n",\
__func__, __VA_ARGS__)
#else
#define DEBUG_LOG(fmt, ...) (void)0
#endif

static const size_t ReadEnd = 0;
static const size_t WriteEnd = 1;

Expand Down Expand Up @@ -143,6 +151,8 @@ const void *PipeMemoryReader_readBytes(void *Context, swift_addr_t Address,
const PipeMemoryReader *Reader = (const PipeMemoryReader *)Context;
uintptr_t TargetAddress = Address;
size_t TargetSize = (size_t)Size;
DEBUG_LOG("Requesting read of %zu bytes from 0x%" PRIxPTR,
TargetSize, TargetAddress);
int WriteFD = PipeMemoryReader_getParentWriteFD(Reader);
write(WriteFD, REQUEST_READ_BYTES, 2);
write(WriteFD, &TargetAddress, sizeof(TargetAddress));
Expand All @@ -162,12 +172,14 @@ swift_addr_t PipeMemoryReader_getSymbolAddress(void *Context,
uint64_t Length) {
const PipeMemoryReader *Reader = (const PipeMemoryReader *)Context;
uintptr_t Address = 0;
DEBUG_LOG("Requesting address of symbol %s", SymbolName);
int WriteFD = PipeMemoryReader_getParentWriteFD(Reader);
write(WriteFD, REQUEST_SYMBOL_ADDRESS, 2);
write(WriteFD, SymbolName, Length);
write(WriteFD, "\n", 1);
PipeMemoryReader_collectBytesFromPipe(Reader, (uint8_t*)&Address,
sizeof(Address));
DEBUG_LOG("Address of %s is 0x%" PRIxPTR, SymbolName, Address);
return (uintptr_t)Address;
}

Expand All @@ -177,6 +189,7 @@ PipeMemoryReader_receiveInstanceKind(const PipeMemoryReader *Reader) {
write(WriteFD, REQUEST_INSTANCE_KIND, 2);
uint8_t KindValue = 0;
PipeMemoryReader_collectBytesFromPipe(Reader, &KindValue, sizeof(KindValue));
DEBUG_LOG("Requested instance kind is %u", KindValue);
return KindValue;
}

Expand All @@ -187,6 +200,7 @@ PipeMemoryReader_receiveInstanceAddress(const PipeMemoryReader *Reader) {
uintptr_t InstanceAddress = 0;
PipeMemoryReader_collectBytesFromPipe(Reader, (uint8_t *)&InstanceAddress,
sizeof(InstanceAddress));
DEBUG_LOG("Requested instance address is 0x%" PRIxPTR, InstanceAddress);
return InstanceAddress;
}

Expand Down Expand Up @@ -222,6 +236,7 @@ PipeMemoryReader_receiveImages(SwiftReflectionContextRef RC,
size_t NumReflectionInfos;
PipeMemoryReader_collectBytesFromPipe(Reader, &NumReflectionInfos,
sizeof(NumReflectionInfos));
DEBUG_LOG("Receiving %z images from child", NumReflectionInfos);

if (NumReflectionInfos == 0)
return;
Expand All @@ -232,6 +247,7 @@ PipeMemoryReader_receiveImages(SwiftReflectionContextRef RC,
NumReflectionInfos * sizeof(*Images));

for (size_t i = 0; i < NumReflectionInfos; ++i) {
DEBUG_LOG("Adding image at 0x%" PRIxPTR, Images[i].Start);
swift_reflection_addImage(RC, Images[i].Start);
}

Expand Down