Adding support for deregistering EH frames with MCJIT.

Patch by Yaron Keren



git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@192753 91177308-0d34-0410-b5e6-96231b3b80d8
This commit is contained in:
Andrew Kaylor
2013-10-16 00:14:21 +00:00
parent 50fd83e832
commit 43507d026b
10 changed files with 118 additions and 7 deletions

View File

@@ -42,17 +42,53 @@ RTDyldMemoryManager::~RTDyldMemoryManager() {}
#if HAVE_EHTABLE_SUPPORT
extern "C" void __register_frame(void*);
extern "C" void __deregister_frame(void*);
#else
// The building compiler does not have __(de)register_frame but
// it may be found at runtime in a dynamically-loaded library.
// For example, this happens when building LLVM with Visual C++
// but using the MingW runtime.
void __register_frame(void *p) {
static bool Searched = false;
static void *rf = 0;
static const char *processFDE(const char *Entry) {
if (!Searched) {
Searched = true;
rf = llvm::sys::DynamicLibrary::SearchForAddressOfSymbol(
"__register_frame");
}
if (rf)
((void (*)(void *))rf)(p);
}
void __deregister_frame(void *p) {
static bool Searched = false;
static void *df = 0;
if (!Searched) {
Searched = true;
df = llvm::sys::DynamicLibrary::SearchForAddressOfSymbol(
"__deregister_frame");
}
if (df)
((void (*)(void *))df)(p);
}
#endif
#ifdef __APPLE__
static const char *processFDE(const char *Entry, bool isDeregister) {
const char *P = Entry;
uint32_t Length = *((const uint32_t *)P);
P += 4;
uint32_t Offset = *((const uint32_t *)P);
if (Offset != 0)
__register_frame(const_cast<char *>(Entry));
if (isDeregister)
__deregister_frame(const_cast<char *>(Entry));
else
__register_frame(const_cast<char *>(Entry));
return P + Length;
}
#endif
// This implementation handles frame registration for local targets.
// Memory managers for remote targets should re-implement this function
@@ -60,15 +96,50 @@ static const char *processFDE(const char *Entry) {
void RTDyldMemoryManager::registerEHFrames(uint8_t *Addr,
uint64_t LoadAddr,
size_t Size) {
#if HAVE_EHTABLE_SUPPORT
// On OS X OS X __register_frame takes a single FDE as an argument.
// See http://lists.cs.uiuc.edu/pipermail/llvmdev/2013-April/061768.html
const char *P = (const char *)Addr;
const char *End = P + Size;
do {
P = processFDE(P);
P = processFDE(P, false);
} while(P != End);
#endif
}
void RTDyldMemoryManager::deregisterEHFrames(uint8_t *Addr,
uint64_t LoadAddr,
size_t Size) {
const char *P = (const char *)Addr;
const char *End = P + Size;
do {
P = processFDE(P, true);
} while(P != End);
}
#else
void RTDyldMemoryManager::registerEHFrames(uint8_t *Addr,
uint64_t LoadAddr,
size_t Size) {
// On Linux __register_frame takes a single argument:
// a pointer to the start of the .eh_frame section.
// How can it find the end? Because crtendS.o is linked
// in and it has an .eh_frame section with four zero chars.
// FIXME: make sure EH frame is followed by four zero bytes.
// This should be done in the linker RuntimeDyldELF::getEHFrameSection(),
// return pointer to .eh_frame properly appended by four zero bytes.
// If the linker can not fixed, do it here.
__register_frame(Addr);
}
void RTDyldMemoryManager::deregisterEHFrames(uint8_t *Addr,
uint64_t LoadAddr,
size_t Size) {
__deregister_frame(Addr);
}
#endif
static int jit_noop() {
return 0;
}