main.mm   [plain text]

// BUILD: $CC missing.m -dynamiclib -o $TEMP_DIR/libmissing.dylib -install_name $BUILD_DIR/libmissing.dylib -lobjc
// BUILD: $CC lib1.m -dynamiclib -o $BUILD_DIR/liblinked1.dylib -install_name $RUN_DIR/liblinked1.dylib -lobjc
// BUILD: $CC lib2.m -dynamiclib -o $BUILD_DIR/liblinked2.dylib -install_name $RUN_DIR/liblinked2.dylib -lobjc $TEMP_DIR/libmissing.dylib
// BUILD: $CC main.mm -o $BUILD_DIR/_dyld_for_each_objc_class-missing-weak.exe -lobjc $BUILD_DIR/liblinked1.dylib $BUILD_DIR/liblinked2.dylib $TEMP_DIR/libmissing.dylib -lc++

// RUN: ./_dyld_for_each_objc_class-missing-weak.exe

// liblinked2 weakly links libmissing and so has a missing weak superclass.
// This means we should not see classes from liblinked be returned from _dyld_for_each_objc_class
// liblinked1 itself has classes which are fine so shoud be in the map.
// At runtime, objc is going to walk the images in reverse load order so will see the classes in liblinked2 first
// which are the ones we couldn't optimize. But objc should then check the closure class map and choose the class
// from liblinked

#include <mach-o/dyld_priv.h>

#import <Foundation/Foundation.h>

// All the libraries have a copy of DyldClass
@interface DyldClass : NSObject
@end

@implementation DyldClass
@end

// Only the main executable has DyldMainClass
@interface DyldMainClass : NSObject
@end

@implementation DyldMainClass
@end

extern Class OBJC_CLASS_$_DyldClass;
extern Class OBJC_CLASS_$_DyldMainClass;

Class getMainDyldClass() {
return (Class)&OBJC_CLASS_$_DyldClass;
}

Class getMainDyldMainClass() {
return (Class)&OBJC_CLASS_$_DyldMainClass;
}

extern "C" int printf(const char*, ...);

extern "C" id objc_getClass(const char *name);

// Get the DyldClass from liblinked1.dylib
extern "C" id getLinked1DyldClass();

// Get the DyldLinkedClass from liblinked1.dylib
extern "C" id getLinked1DyldLinkedClass();

// Get the DyldLinkedClass from liblinked.dylib
extern "C" id getLinked2DyldLinkedClass();

// Get the DyldClass from libmissing.dylib
// Note, this is weak_import and missing so this must fail
__attribute__((weak_import))
extern "C" id getMissingDyldClass();

static bool gotDyldClassMain = false;
static bool gotDyldClassLinked1 = false;

int main() {
printf("[BEGIN] _dyld_for_each_objc_class-missing-weak\n");

// This API is only available with dyld3 and shared caches. If we have dyld2 then don't do anything
const char* testDyldMode = getenv("TEST_DYLD_MODE");
assert(testDyldMode);

size_t unusedCacheLen;
bool haveSharedCache = _dyld_get_shared_cache_range(&unusedCacheLen) != 0;
if (!strcmp(testDyldMode, "2") || !haveSharedCache) {
__block bool sawClass = false;
_dyld_for_each_objc_class("DyldClass", ^(void* classPtr, bool isLoaded, bool* stop) {
sawClass = true;
});
if (sawClass) {
printf("[FAIL] _dyld_for_each_objc_class: dyld2 shouldn't see any classes\n");
return 0;
}
printf("[PASS] _dyld_for_each_objc_class (dyld2 or no shared cache)\n");
return 0;
}

// Make sure libmissing.dylib is actually missing
if (&getMissingDyldClass != nil) {
printf("[FAIL] _dyld_for_each_objc_class-missing-weak: libmissing needs to be missing\n");
return 0;
}

// DyldClass in liblinked1 should exist as its superclass is just NSObject
if (getLinked1DyldClass() == nil) {
printf("[FAIL] _dyld_for_each_objc_class-missing-weak: liblinked1 DyldClass should exist\n");
return 0;
}

// DyldLinkedClass in liblinked1 should exist as its superclass is just NSObject
if (getLinked1DyldLinkedClass() == nil) {
printf("[FAIL] _dyld_for_each_objc_class-missing-weak: liblinked1 DyldLinkedClass should exist\n");
return 0;
}

// DyldLinkedClass in liblinked2 should exist as its superclass is just NSObject
if (getLinked2DyldLinkedClass() == nil) {
printf("[FAIL] _dyld_for_each_objc_class-missing-weak: liblinked2 DyldLinkedClass should exist\n");
return 0;
}

// Check that DyldMainClass comes main.exe as that is its only definition
id runtimeDyldMainClass = objc_getClass("DyldMainClass");
if (runtimeDyldMainClass != getMainDyldMainClass()) {
printf("[FAIL] _dyld_for_each_objc_class-missing-weak: DyldMainClass should have come from main.exe\n");
return 0;
}

// Check that DyldClass comes liblinked1 as it should be missing from liblinked2
id runtimeDyldClass = objc_getClass("DyldClass");
if (runtimeDyldClass != getLinked1DyldClass()) {
printf("[FAIL] _dyld_for_each_objc_class-missing-weak: DyldClass should have come from liblinked1\n");
return 0;
}

// Check that DyldLinkedClass comes from liblinked2
// Note, this changes once the objc runtime has adopted our changes. Don't test it for now
#if 0
id runtimeDyldLinkedClass = objc_getClass("DyldLinkedClass");
if (runtimeDyldLinkedClass != getLinked2DyldLinkedClass()) {
printf("[FAIL] _dyld_for_each_objc_class-missing-weak: DyldLinkedClass should have come from liblinked2\n");
return 0;
}
#endif

_dyld_for_each_objc_class("DyldClass", ^(void* classPtr, bool isLoaded, bool* stop) {
// We should walk these in the order liblinked, main exe
if (!gotDyldClassLinked1) {
if (classPtr != getLinked1DyldClass()) {
printf("[FAIL] _dyld_for_each_objc_class-missing-weak: DyldClass should have come from liblinked1\n");
*stop = true;
return;
}
if (!isLoaded) {
printf("[FAIL] _dyld_for_each_objc_class-missing-weak: DyldClass isLoaded should have been set on liblinked1\n");
*stop = true;
return;
}
gotDyldClassLinked1 = true;
return;
}
if (!gotDyldClassMain) {
if (classPtr != getMainDyldClass()) {
printf("[FAIL] _dyld_for_each_objc_class-missing-weak: DyldClass should have come from main exe\n");
*stop = true;
return;
}
if (!isLoaded) {
printf("[FAIL] _dyld_for_each_objc_class-missing-weak: DyldClass isLoaded should have been set on main exe\n");
*stop = true;
return;
}
gotDyldClassMain = true;
return;
}
printf("[FAIL] _dyld_for_each_objc_class-missing-weak: Unexpected DyldClass\n");
return;
});

if (!gotDyldClassLinked1) {
printf("[FAIL] _dyld_for_each_objc_class-missing-weak: _dyld_for_each_objc_class should have seen DyldClass in liblinked1\n");
return 0;
}

if (!gotDyldClassMain) {
printf("[FAIL] _dyld_for_each_objc_class-missing-weak: _dyld_for_each_objc_class should have seen DyldClass in main.exe\n");
return 0;
}

// Visit again, and return liblinked1's DyldClass
// Visit again, and return liblinked2's DyldClass
__block void* dyldClassImpl = nil;
_dyld_for_each_objc_class("DyldClass", ^(void* classPtr, bool isLoaded, bool* stop) {
dyldClassImpl = classPtr;
*stop = true;
});
if (dyldClassImpl != getLinked1DyldClass()) {
printf("[FAIL] _dyld_for_each_objc_class-missing-weak: _dyld_for_each_objc_class should have returned DyldClass from liblinked1\n");
return 0;
}

// Visit again, and return liblinked1's DyldClass
dyldClassImpl = nil;
_dyld_for_each_objc_class("DyldClass", ^(void* classPtr, bool isLoaded, bool* stop) {
// We should walk these in the order liblinked, main exe
// And return the one from main.exe
if (classPtr == getLinked1DyldClass())
return;
dyldClassImpl = classPtr;
*stop = true;
});
if (dyldClassImpl != getMainDyldClass()) {
printf("[FAIL] _dyld_for_each_objc_class-missing-weak: _dyld_for_each_objc_class should have returned DyldClass from main.exe\n");
return 0;
}

printf("[PASS] _dyld_for_each_objc_class-missing-weak\n");

return 0;
}