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Add a new flag that disables symbol lookup with dlsym when set. This allows

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a JIT client to completely control symbol lookup with the LazyFunctionCreator
interface.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@52335 91177308-0d34-0410-b5e6-96231b3b80d8
This commit is contained in:
Chris Lattner 2008-06-16 17:44:14 +00:00
parent 16228c08b4
commit e846db6675
2 changed files with 48 additions and 36 deletions
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16
include/llvm/ExecutionEngine/ExecutionEngine.h
View File

@ -65,6 +65,7 @@ class ExecutionEngine {
const TargetData *TD; const TargetData *TD;
ExecutionEngineState state; ExecutionEngineState state;
bool LazyCompilationDisabled; bool LazyCompilationDisabled;
bool SymbolSearchingDisabled;
protected: protected:
/// Modules - This is a list of ModuleProvider's that we are JIT'ing from. We /// Modules - This is a list of ModuleProvider's that we are JIT'ing from. We
@ -243,13 +244,22 @@ public:
} }
/// DisableLazyCompilation - If called, the JIT will abort if lazy compilation /// DisableLazyCompilation - If called, the JIT will abort if lazy compilation
// is ever attempted. /// is ever attempted.
void DisableLazyCompilation() { void DisableLazyCompilation(bool Disabled = true) {
LazyCompilationDisabled = true; LazyCompilationDisabled = Disabled;
} }
bool isLazyCompilationDisabled() const { bool isLazyCompilationDisabled() const {
return LazyCompilationDisabled; return LazyCompilationDisabled;
} }
/// DisableSymbolSearching - If called, the JIT will not try to lookup unknown
/// symbols with dlsym. A client can still use InstallLazyFunctionCreator to
/// resolve symbols in a custom way.
void DisableSymbolSearching(bool Disabled = true) {
SymbolSearchingDisabled = Disabled;
}
bool isSymbolSearchingDisabled() const {
return SymbolSearchingDisabled;
}
/// InstallLazyFunctionCreator - If an unknown function is needed, the /// InstallLazyFunctionCreator - If an unknown function is needed, the

68
lib/ExecutionEngine/JIT/Intercept.cpp
View File

@ -91,44 +91,46 @@ static int jit_atexit(void (*Fn)(void)) {
/// for resolving library symbols, not code generated symbols. /// for resolving library symbols, not code generated symbols.
/// ///
void *JIT::getPointerToNamedFunction(const std::string &Name) { void *JIT::getPointerToNamedFunction(const std::string &Name) {
// Check to see if this is one of the functions we want to intercept. Note, if (!isSymbolSearchingDisabled()) {
// we cast to intptr_t here to silence a -pedantic warning that complains // Check to see if this is one of the functions we want to intercept. Note,
// about casting a function pointer to a normal pointer. // we cast to intptr_t here to silence a -pedantic warning that complains
if (Name == "exit") return (void*)(intptr_t)&jit_exit; // about casting a function pointer to a normal pointer.
if (Name == "atexit") return (void*)(intptr_t)&jit_atexit; if (Name == "exit") return (void*)(intptr_t)&jit_exit;
if (Name == "atexit") return (void*)(intptr_t)&jit_atexit;
const char *NameStr = Name.c_str(); const char *NameStr = Name.c_str();
// If this is an asm specifier, skip the sentinal. // If this is an asm specifier, skip the sentinal.
if (NameStr[0] == 1) ++NameStr; if (NameStr[0] == 1) ++NameStr;
// If it's an external function, look it up in the process image... // If it's an external function, look it up in the process image...
void *Ptr = sys::DynamicLibrary::SearchForAddressOfSymbol(NameStr); 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; if (Ptr) return Ptr;
}
// If it wasn't found and if it starts with an underscore ('_') character,
// darwin/ppc adds $LDBLStub suffixes to various symbols like printf. These // and has an asm specifier, try again without the underscore.
// are references to hidden visibility symbols that dlsym cannot resolve. If if (Name[0] == 1 && NameStr[0] == '_') {
// we have one of these, strip off $LDBLStub and try again. 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 $LDBLStub and try again.
#if defined(__APPLE__) && defined(__ppc__) #if defined(__APPLE__) && defined(__ppc__)
if (Name.size() > 9 && Name[Name.size()-9] == '$' && if (Name.size() > 9 && Name[Name.size()-9] == '$' &&
memcmp(&Name[Name.size()-8], "LDBLStub", 8) == 0) { memcmp(&Name[Name.size()-8], "LDBLStub", 8) == 0) {
// First try turning $LDBLStub into $LDBL128. If that fails, strip it off. // First try turning $LDBLStub into $LDBL128. If that fails, strip it off.
// This mirrors logic in libSystemStubs.a. // This mirrors logic in libSystemStubs.a.
std::string Prefix = std::string(Name.begin(), Name.end()-9); std::string Prefix = std::string(Name.begin(), Name.end()-9);
if (void *Ptr = getPointerToNamedFunction(Prefix+"$LDBL128")) if (void *Ptr = getPointerToNamedFunction(Prefix+"$LDBL128"))
return Ptr; return Ptr;
if (void *Ptr = getPointerToNamedFunction(Prefix)) if (void *Ptr = getPointerToNamedFunction(Prefix))
return Ptr; return Ptr;
} }
#endif #endif
}
/// If a LazyFunctionCreator is installed, use it to get/create the function. /// If a LazyFunctionCreator is installed, use it to get/create the function.
if (LazyFunctionCreator) if (LazyFunctionCreator)
if (void *RP = LazyFunctionCreator(Name)) if (void *RP = LazyFunctionCreator(Name))
return RP; return RP;