//===-- Intercept.cpp - System function interception routines -------------===//
-//
+//
// The LLVM Compiler Infrastructure
//
-// This file was developed by the LLVM research group and is distributed under
-// the University of Illinois Open Source License. See LICENSE.TXT for details.
-//
+// This file is distributed under the University of Illinois Open Source
+// License. See LICENSE.TXT for details.
+//
//===----------------------------------------------------------------------===//
//
// If a function call occurs to an external function, the JIT is designed to use
//===----------------------------------------------------------------------===//
#include "JIT.h"
-#include "llvm/System/DynamicLibrary.h"
-#include <iostream>
-#include <sys/stat.h>
+#include "llvm/Support/ErrorHandling.h"
+#include "llvm/Support/DynamicLibrary.h"
+#include "llvm/Config/config.h"
using namespace llvm;
// AtExitHandlers - List of functions to call when the program exits,
// strategy of making these functions work differently when inlined vs. when
// not inlined, and hiding their real definitions in a separate archive file
// that the dynamic linker can't see. For more info, search for
-// 'libc_nonshared.a' on Google, or read http://llvm.cs.uiuc.edu/PR274.
+// 'libc_nonshared.a' on Google, or read http://llvm.org/PR274.
#if defined(__linux__)
-void *FunctionPointers[] = {
- (void *) stat,
- (void *) fstat,
- (void *) lstat,
- (void *) stat64,
- (void *) fstat64,
- (void *) lstat64,
- (void *) atexit,
- (void *) mknod
+#if defined(HAVE_SYS_STAT_H)
+#include <sys/stat.h>
+#endif
+#include <fcntl.h>
+/* stat functions are redirecting to __xstat with a version number. On x86-64
+ * linking with libc_nonshared.a and -Wl,--export-dynamic doesn't make 'stat'
+ * available as an exported symbol, so we have to add it explicitly.
+ */
+namespace {
+class StatSymbols {
+public:
+ StatSymbols() {
+ sys::DynamicLibrary::AddSymbol("stat", (void*)(intptr_t)stat);
+ sys::DynamicLibrary::AddSymbol("fstat", (void*)(intptr_t)fstat);
+ sys::DynamicLibrary::AddSymbol("lstat", (void*)(intptr_t)lstat);
+ sys::DynamicLibrary::AddSymbol("stat64", (void*)(intptr_t)stat64);
+ sys::DynamicLibrary::AddSymbol("\x1stat64", (void*)(intptr_t)stat64);
+ sys::DynamicLibrary::AddSymbol("\x1open64", (void*)(intptr_t)open64);
+ sys::DynamicLibrary::AddSymbol("\x1lseek64", (void*)(intptr_t)lseek64);
+ sys::DynamicLibrary::AddSymbol("fstat64", (void*)(intptr_t)fstat64);
+ sys::DynamicLibrary::AddSymbol("lstat64", (void*)(intptr_t)lstat64);
+ sys::DynamicLibrary::AddSymbol("atexit", (void*)(intptr_t)atexit);
+ sys::DynamicLibrary::AddSymbol("mknod", (void*)(intptr_t)mknod);
+ }
};
-#endif // __linux__
-
-// __mainFunc - If the program does not have a linked in __main function, allow
-// it to run, but print a warning.
-static void __mainFunc() {
- fprintf(stderr, "WARNING: Program called __main but was not linked to "
- "libcrtend.a.\nThis probably won't hurt anything unless the "
- "program is written in C++.\n");
}
+static StatSymbols initStatSymbols;
+#endif // __linux__
// jit_exit - Used to intercept the "exit" library call.
static void jit_exit(int Status) {
}
// jit_atexit - Used to intercept the "atexit" library call.
-static int jit_atexit(void (*Fn)(void)) {
+static int jit_atexit(void (*Fn)()) {
AtExitHandlers.push_back(Fn); // Take note of atexit handler...
return 0; // Always successful
}
+static int jit_noop() {
+ return 0;
+}
+
//===----------------------------------------------------------------------===//
-//
+//
/// getPointerToNamedFunction - This method returns the address of the specified
-/// function by using the dynamic loader interface. As such it is only useful
+/// function by using the dynamic loader interface. As such it is only useful
/// for resolving library symbols, not code generated symbols.
///
-void *JIT::getPointerToNamedFunction(const std::string &Name) {
- // Check to see if this is one of the functions we want to intercept...
- if (Name == "exit") return (void*)&jit_exit;
- if (Name == "atexit") return (void*)&jit_atexit;
+void *JIT::getPointerToNamedFunction(const std::string &Name,
+ bool AbortOnFailure) {
+ if (!isSymbolSearchingDisabled()) {
+ // Check to see if this is one of the functions we want to intercept. Note,
+ // we cast to intptr_t here to silence a -pedantic warning that complains
+ // about casting a function pointer to a normal pointer.
+ if (Name == "exit") return (void*)(intptr_t)&jit_exit;
+ if (Name == "atexit") return (void*)(intptr_t)&jit_atexit;
- // If the program does not have a linked in __main function, allow it to run,
- // but print a warning.
- if (Name == "__main") return (void*)&__mainFunc;
+ // We should not invoke parent's ctors/dtors from generated main()!
+ // On Mingw and Cygwin, the symbol __main is resolved to
+ // callee's(eg. tools/lli) one, to invoke wrong duplicated ctors
+ // (and register wrong callee's dtors with atexit(3)).
+ // We expect ExecutionEngine::runStaticConstructorsDestructors()
+ // is called before ExecutionEngine::runFunctionAsMain() is called.
+ if (Name == "__main") return (void*)(intptr_t)&jit_noop;
- // If it's an external function, look it up in the process image...
- void *Ptr = sys::DynamicLibrary::SearchForAddressOfSymbol(Name);
- if (Ptr) return Ptr;
-
- // If this is darwin, it has some funky issues, try to solve them here. Some
- // important symbols are marked 'private external' which doesn't allow
- // SearchForAddressOfSymbol to find them. As such, we special case them here,
- // there is only a small handful of them.
-#ifdef __APPLE__
- {
- extern void *__ashldi3; if (Name == "__ashldi3") return &__ashldi3;
- extern void *__ashrdi3; if (Name == "__ashrdi3") return &__ashrdi3;
- extern void *__cmpdi2; if (Name == "__cmpdi2") return &__cmpdi2;
- extern void *__divdi3; if (Name == "__divdi3") return &__divdi3;
- extern void *__eprintf; if (Name == "__eprintf") return &__eprintf;
- extern void *__fixdfdi; if (Name == "__fixdfdi") return &__fixdfdi;
- extern void *__fixsfdi; if (Name == "__fixsfdi") return &__fixsfdi;
- extern void *__fixunsdfdi; if (Name == "__fixunsdfdi") return &__fixunsdfdi;
- extern void *__fixunssfdi; if (Name == "__fixunssfdi") return &__fixunssfdi;
- extern void *__floatdidf; if (Name == "__floatdidf") return &__floatdidf;
- extern void *__floatdisf; if (Name == "__floatdisf") return &__floatdisf;
- extern void *__lshrdi3; if (Name == "__lshrdi3") return &__lshrdi3;
- extern void *__moddi3; if (Name == "__moddi3") return &__moddi3;
- extern void *__udivdi3; if (Name == "__udivdi3") return &__udivdi3;
- extern void *__umoddi3; if (Name == "__umoddi3") return &__umoddi3;
- }
+ const char *NameStr = Name.c_str();
+ // If this is an asm specifier, skip the sentinal.
+ if (NameStr[0] == 1) ++NameStr;
+
+ // If it's an external function, look it up in the process image...
+ void *Ptr = sys::DynamicLibrary::SearchForAddressOfSymbol(NameStr);
+ if (Ptr) return Ptr;
+
+ // If it wasn't found and if it starts with an underscore ('_') character,
+ // and has an asm specifier, try again without the underscore.
+ if (Name[0] == 1 && NameStr[0] == '_') {
+ Ptr = sys::DynamicLibrary::SearchForAddressOfSymbol(NameStr+1);
+ if (Ptr) return Ptr;
+ }
+
+ // Darwin/PPC adds $LDBLStub suffixes to various symbols like printf. These
+ // are references to hidden visibility symbols that dlsym cannot resolve.
+ // If we have one of these, strip off $LDBLStub and try again.
+#if defined(__APPLE__) && defined(__ppc__)
+ if (Name.size() > 9 && Name[Name.size()-9] == '$' &&
+ memcmp(&Name[Name.size()-8], "LDBLStub", 8) == 0) {
+ // First try turning $LDBLStub into $LDBL128. If that fails, strip it off.
+ // This mirrors logic in libSystemStubs.a.
+ std::string Prefix = std::string(Name.begin(), Name.end()-9);
+ if (void *Ptr = getPointerToNamedFunction(Prefix+"$LDBL128", false))
+ return Ptr;
+ if (void *Ptr = getPointerToNamedFunction(Prefix, false))
+ return Ptr;
+ }
#endif
+ }
+
+ /// If a LazyFunctionCreator is installed, use it to get/create the function.
+ if (LazyFunctionCreator)
+ if (void *RP = LazyFunctionCreator(Name))
+ return RP;
- std::cerr << "ERROR: Program used external function '" << Name
- << "' which could not be resolved!\n";
- abort();
+ if (AbortOnFailure) {
+ report_fatal_error("Program used external function '"+Name+
+ "' which could not be resolved!");
+ }
return 0;
}