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
diff --git a/lib/ExecutionEngine/RTDyldMemoryManager.cpp b/lib/ExecutionEngine/RTDyldMemoryManager.cpp
index 9926576..11a5ec7 100644
--- a/lib/ExecutionEngine/RTDyldMemoryManager.cpp
+++ b/lib/ExecutionEngine/RTDyldMemoryManager.cpp
@@ -42,17 +42,53 @@
#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 @@
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;
}