#include <unistd.h>
#include <assert.h>
+#include <iostream>
+#include <sstream>
#include <string>
#include <map>
#include <set>
// HACK, I can't find a way to pass values in the compare classes (e.g. ContentFuncs)
// so use global variable to pass info.
static ld::IndirectBindingTable* _s_indirectBindingTable = NULL;
-bool SymbolTable::_s_doDemangle = false;
SymbolTable::SymbolTable(const Options& opts, std::vector<const ld::Atom*>& ibt)
- : _options(opts), _cstringTable(6151), _indirectBindingTable(ibt), _hasExternalTentativeDefinitions(false)
+ : _options(opts), _cstringTable(6151), _indirectBindingTable(ibt), _hasExternalTentativeDefinitions(false)
{
_s_indirectBindingTable = this;
- _s_doDemangle = _options.demangleSymbols();
}
}
+void SymbolTable::addDuplicateSymbol(const char *name, const ld::Atom *atom)
+{
+ // Look up or create the file list for name.
+ DuplicateSymbols::iterator symbolsIterator = _duplicateSymbols.find(name);
+ DuplicatedSymbolAtomList *atoms = NULL;
+ if (symbolsIterator != _duplicateSymbols.end()) {
+ atoms = symbolsIterator->second;
+ } else {
+ atoms = new std::vector<const ld::Atom *>;
+ _duplicateSymbols.insert(std::pair<const char *, DuplicatedSymbolAtomList *>(name, atoms));
+ }
+
+ // check if file is already in the list, add it if not
+ bool found = false;
+ for (DuplicatedSymbolAtomList::iterator it = atoms->begin(); !found && it != atoms->end(); it++)
+ if (strcmp((*it)->file()->path(), atom->file()->path()) == 0)
+ found = true;
+ if (!found)
+ atoms->push_back(atom);
+}
-bool SymbolTable::addByName(const ld::Atom& newAtom, bool ignoreDuplicates)
+void SymbolTable::checkDuplicateSymbols() const
{
- bool useNew = true;
- bool checkVisibilityMismatch = false;
- assert(newAtom.name() != NULL);
- const char* name = newAtom.name();
- IndirectBindingSlot slot = this->findSlotForName(name);
- const ld::Atom* existingAtom = _indirectBindingTable[slot];
- //fprintf(stderr, "addByName(%p) name=%s, slot=%u, existing=%p\n", &newAtom, newAtom.name(), slot, existingAtom);
- if ( existingAtom != NULL ) {
- assert(&newAtom != existingAtom);
- switch ( existingAtom->definition() ) {
- case ld::Atom::definitionRegular:
- switch ( newAtom.definition() ) {
- case ld::Atom::definitionRegular:
- if ( existingAtom->combine() == ld::Atom::combineByName ) {
- if ( newAtom.combine() == ld::Atom::combineByName ) {
- // <rdar://problem/9183821> always choose mach-o over llvm bit code, otherwise LTO may eliminate the llvm atom
- const bool existingIsLTO = (existingAtom->contentType() == ld::Atom::typeLTOtemporary);
- const bool newIsLTO = (newAtom.contentType() == ld::Atom::typeLTOtemporary);
- if ( existingIsLTO != newIsLTO ) {
- useNew = existingIsLTO;
- }
- else {
- // both weak, prefer non-auto-hide one
- if ( newAtom.autoHide() != existingAtom->autoHide() ) {
- // <rdar://problem/6783167> support auto hidden weak symbols: .weak_def_can_be_hidden
- useNew = existingAtom->autoHide();
- // don't check for visibility mismatch
- }
- else if ( newAtom.autoHide() && existingAtom->autoHide() ) {
- // both have auto-hide, so use one with greater alignment
- useNew = ( newAtom.alignment().trailingZeros() > existingAtom->alignment().trailingZeros() );
- }
- else {
- // neither auto-hide, check visibility
- if ( newAtom.scope() != existingAtom->scope() ) {
- // <rdar://problem/8304984> use more visible weak def symbol
- useNew = (newAtom.scope() == ld::Atom::scopeGlobal);
- }
- else {
- // both have same visibility, use one with greater alignment
- useNew = ( newAtom.alignment().trailingZeros() > existingAtom->alignment().trailingZeros() );
- }
- }
- }
- }
- else {
- // existing weak, new is not-weak
- useNew = true;
- }
+ bool foundDuplicate = false;
+ for (DuplicateSymbols::const_iterator symbolIt = _duplicateSymbols.begin(); symbolIt != _duplicateSymbols.end(); symbolIt++) {
+ DuplicatedSymbolAtomList *atoms = symbolIt->second;
+ bool reportDuplicate;
+ if (_options.deadCodeStrip()) {
+ // search for a live atom
+ reportDuplicate = false;
+ for (DuplicatedSymbolAtomList::iterator it = atoms->begin(); !reportDuplicate && it != atoms->end(); it++) {
+ if ((*it)->live())
+ reportDuplicate = true;
+ }
+ } else {
+ reportDuplicate = true;
+ }
+ if (reportDuplicate) {
+ foundDuplicate = true;
+ fprintf(stderr, "duplicate symbol %s in:\n", symbolIt->first);
+ for (DuplicatedSymbolAtomList::iterator atomIt = atoms->begin(); atomIt != atoms->end(); atomIt++) {
+ fprintf(stderr, " %s\n", (*atomIt)->file()->path());
+ }
+ }
+ }
+ if (foundDuplicate)
+ throwf("%d duplicate symbol%s", (int)_duplicateSymbols.size(), _duplicateSymbols.size()==1?"":"s");
+}
+
+// AtomPicker encapsulates the logic for picking which atom to use when adding an atom by name results in a collision
+class NameCollisionResolution {
+public:
+ NameCollisionResolution(const ld::Atom& a, const ld::Atom& b, bool ignoreDuplicates, const Options& options) : _atomA(a), _atomB(b), _options(options), _reportDuplicate(false), _ignoreDuplicates(ignoreDuplicates) {
+ pickAtom();
+ }
+
+ // Returns which atom to use
+ const ld::Atom& chosen() { return *_chosen; }
+ bool choseAtom(const ld::Atom& atom) { return _chosen == &atom; }
+
+ // Returns true if the two atoms should be reported as a duplicate symbol
+ bool reportDuplicate() { return _reportDuplicate; }
+
+private:
+ const ld::Atom& _atomA;
+ const ld::Atom& _atomB;
+ const Options& _options;
+ const ld::Atom* _chosen;
+ bool _reportDuplicate;
+ bool _ignoreDuplicates;
+
+ void pickAtom(const ld::Atom& atom) { _chosen = &atom; } // primitive to set which atom is picked
+ void pickAtomA() { pickAtom(_atomA); } // primitive to pick atom A
+ void pickAtomB() { pickAtom(_atomB); } // primitive to pick atom B
+
+ // use atom A if pickA, otherwise use atom B
+ void pickAOrB(bool pickA) { if (pickA) pickAtomA(); else pickAtomB(); }
+
+ void pickHigherOrdinal() {
+ pickAOrB(_atomA.file()->ordinal() < _atomB.file()->ordinal());
+ }
+
+ void pickLowerOrdinal() {
+ pickAOrB(_atomA.file()->ordinal() > _atomB.file()->ordinal());
+ }
+
+ void pickLargerSize() {
+ if (_atomA.size() == _atomB.size())
+ pickLowerOrdinal();
+ else
+ pickAOrB(_atomA.size() > _atomB.size());
+ }
+
+ void pickGreaterAlignment() {
+ pickAOrB(_atomA.alignment().trailingZeros() > _atomB.alignment().trailingZeros());
+ }
+
+ void pickBetweenRegularAtoms() {
+ if ( _atomA.combine() == ld::Atom::combineByName ) {
+ if ( _atomB.combine() == ld::Atom::combineByName ) {
+ // <rdar://problem/9183821> always choose mach-o over llvm bit code, otherwise LTO may eliminate the llvm atom
+ const bool aIsLTO = (_atomA.contentType() == ld::Atom::typeLTOtemporary);
+ const bool bIsLTO = (_atomB.contentType() == ld::Atom::typeLTOtemporary);
+ // <rdar://problem/9183821> always choose mach-o over llvm bit code, otherwise LTO may eliminate the llvm atom
+ if ( aIsLTO != bIsLTO ) {
+ pickAOrB(!aIsLTO);
+ }
+ else {
+ // both weak, prefer non-auto-hide one
+ if ( _atomA.autoHide() != _atomB.autoHide() ) {
+ // <rdar://problem/6783167> support auto hidden weak symbols: .weak_def_can_be_hidden
+ pickAOrB(!_atomA.autoHide());
+ }
+ else if ( _atomA.autoHide() && _atomB.autoHide() ) {
+ // both have auto-hide, so use one with greater alignment
+ pickGreaterAlignment();
+ }
+ else {
+ // neither auto-hide, check visibility
+ if ( _atomA.scope() != _atomB.scope() ) {
+ // <rdar://problem/8304984> use more visible weak def symbol
+ pickAOrB(_atomA.scope() == ld::Atom::scopeGlobal);
}
else {
- if ( newAtom.combine() == ld::Atom::combineByName ) {
- // existing not-weak, new is weak
- useNew = false;
- }
- else {
- // existing not-weak, new is not-weak
- if ( newAtom.section().type() == ld::Section::typeMachHeader ) {
- warning("ignoring override of built-in symbol %s from %s", newAtom.name(), existingAtom->file()->path());
- useNew = true;
- }
- else if ( existingAtom->section().type() == ld::Section::typeMachHeader ) {
- warning("ignoring override of built-in symbol %s from %s", newAtom.name(), newAtom.file()->path());
- useNew = false;
- }
- else {
- if ( ignoreDuplicates ) {
- useNew = false;
- static bool fullWarning = false;
- if ( ! fullWarning ) {
- warning("-dead_strip with lazy loaded static (library) archives "
- "has resulted in a duplicate symbol. You can change your "
- "source code to rename symbols to avoid the collision. "
- "This will be an error in a future linker.");
- fullWarning = true;
- }
- warning("duplicate symbol %s originally in %s now lazily loaded from %s",
- SymbolTable::demangle(name), existingAtom->file()->path(), newAtom.file()->path());
- }
- else {
- throwf("duplicate symbol %s in %s and %s",
- SymbolTable::demangle(name), newAtom.file()->path(), existingAtom->file()->path());
- }
- }
- }
+ // both have same visibility, use one with greater alignment
+ pickGreaterAlignment();
}
+ }
+ }
+ }
+ else {
+ pickAtomB(); // pick not-weak
+
+ }
+ }
+ else {
+ if ( _atomB.combine() == ld::Atom::combineByName ) {
+ pickAtomA(); // pick not-weak
+
+ }
+ else {
+ // both are not-weak
+ if ( _atomA.section().type() == ld::Section::typeMachHeader ) {
+ pickAtomA();
+ }
+ else if ( _atomB.section().type() == ld::Section::typeMachHeader ) {
+ pickAtomB();
+ }
+ else {
+ if ( _ignoreDuplicates ) {
+ pickLowerOrdinal();
+ }
+ else {
+ _reportDuplicate = true;
+ }
+ }
+ }
+ }
+ }
+
+ void pickCommonsMode(const ld::Atom& dylib, const ld::Atom& proxy) {
+ assert(dylib.definition() == ld::Atom::definitionTentative);
+ assert(proxy.definition() == ld::Atom::definitionProxy);
+ switch ( _options.commonsMode() ) {
+ case Options::kCommonsIgnoreDylibs:
+ if ( _options.warnCommons() )
+ warning("using common symbol %s from %s and ignoring defintion from dylib %s",
+ proxy.name(), proxy.file()->path(), dylib.file()->path());
+ pickAtom(dylib);
+ break;
+ case Options::kCommonsOverriddenByDylibs:
+ if ( _options.warnCommons() )
+ warning("replacing common symbol %s from %s with true definition from dylib %s",
+ proxy.name(), proxy.file()->path(), dylib.file()->path());
+ pickAtom(proxy);
+ break;
+ case Options::kCommonsConflictsDylibsError:
+ throwf("common symbol %s from %s conflicts with defintion from dylib %s",
+ proxy.name(), proxy.file()->path(), dylib.file()->path());
+ }
+ }
+
+ void pickProxyAtom() {
+ // both atoms are definitionProxy
+ // <rdar://problem/5137732> ld should keep looking when it finds a weak definition in a dylib
+ if ( _atomA.combine() == ld::Atom::combineByName ) {
+ pickAtomB();
+ } else if ( _atomB.combine() == ld::Atom::combineByName ) {
+ pickAtomA();
+ } else {
+ throwf("symbol %s exported from both %s and %s\n", _atomA.name(), _atomA.file()->path(), _atomB.file()->path());
+ }
+ }
+
+ void pickAtom() {
+ // First, discriminate by definition
+ switch (_atomA.definition()) {
+ case ld::Atom::definitionRegular:
+ switch (_atomB.definition()) {
+ case ld::Atom::definitionRegular:
+ pickBetweenRegularAtoms();
break;
case ld::Atom::definitionTentative:
- // ignore new tentative atom, because we already have a regular one
- useNew = false;
- checkVisibilityMismatch = true;
- if ( newAtom.size() > existingAtom->size() ) {
- warning("for symbol %s tentative definition of size %llu from %s is "
- "is smaller than the real definition of size %llu from %s",
- newAtom.name(), newAtom.size(), newAtom.file()->path(),
- existingAtom->size(), existingAtom->file()->path());
- }
+ pickAtomA();
break;
case ld::Atom::definitionAbsolute:
- throwf("duplicate symbol %s in %s and %s", name, newAtom.file()->path(), existingAtom->file()->path());
+ _reportDuplicate = true;
+ pickHigherOrdinal();
+ break;
case ld::Atom::definitionProxy:
- // ignore external atom, because we already have a one
- useNew = false;
+ pickAtomA();
break;
}
break;
case ld::Atom::definitionTentative:
- switch ( newAtom.definition() ) {
+ switch (_atomB.definition()) {
case ld::Atom::definitionRegular:
- // replace existing tentative atom with regular one
- if ( newAtom.section().type() == ld::Section::typeMachHeader ) {
- // silently replace tentative __dso_handle with real linker created symbol
- useNew = true;
- }
- else if ( existingAtom->section().type() == ld::Section::typeMachHeader ) {
- // silently replace tentative __dso_handle with real linker created symbol
- useNew = false;
- }
- else {
- checkVisibilityMismatch = true;
- if ( newAtom.size() < existingAtom->size() ) {
- warning("for symbol %s tentative definition of size %llu from %s is "
- "being replaced by a real definition of size %llu from %s",
- newAtom.name(), existingAtom->size(), existingAtom->file()->path(),
- newAtom.size(), newAtom.file()->path());
- }
- if ( newAtom.section().type() == ld::Section::typeCode ) {
- warning("for symbol %s tentative (data) defintion from %s is "
- "being replaced by code from %s", newAtom.name(), existingAtom->file()->path(),
- newAtom.file()->path());
- }
- }
+ pickAtomB();
break;
case ld::Atom::definitionTentative:
- // new and existing are both tentative definitions, use largest
- checkVisibilityMismatch = true;
- if ( newAtom.size() < existingAtom->size() ) {
- useNew = false;
- }
- else {
- if ( newAtom.alignment().trailingZeros() < existingAtom->alignment().trailingZeros() )
- warning("alignment lost in merging tentative definition %s", newAtom.name());
- }
+ pickLargerSize();
break;
case ld::Atom::definitionAbsolute:
- // replace tentative with absolute
- useNew = true;
+ pickHigherOrdinal();
break;
case ld::Atom::definitionProxy:
- // a tentative definition and a dylib definition, so commons-mode decides how to handle
- switch ( _options.commonsMode() ) {
- case Options::kCommonsIgnoreDylibs:
- if ( _options.warnCommons() )
- warning("using common symbol %s from %s and ignoring defintion from dylib %s",
- existingAtom->name(), existingAtom->file()->path(), newAtom.file()->path());
- useNew = false;
- break;
- case Options::kCommonsOverriddenByDylibs:
- if ( _options.warnCommons() )
- warning("replacing common symbol %s from %s with true definition from dylib %s",
- existingAtom->name(), existingAtom->file()->path(), newAtom.file()->path());
- break;
- case Options::kCommonsConflictsDylibsError:
- throwf("common symbol %s from %s conflicts with defintion from dylib %s",
- existingAtom->name(), existingAtom->file()->path(), newAtom.file()->path());
- }
+ pickCommonsMode(_atomA, _atomB);
break;
}
break;
case ld::Atom::definitionAbsolute:
- switch ( newAtom.definition() ) {
+ switch (_atomB.definition()) {
case ld::Atom::definitionRegular:
- throwf("duplicate symbol %s in %s and %s", name, newAtom.file()->path(), existingAtom->file()->path());
+ _reportDuplicate = true;
+ pickHigherOrdinal();
+ break;
case ld::Atom::definitionTentative:
- // ignore new tentative atom, because we already have a regular one
- useNew = false;
+ pickAtomA();
break;
case ld::Atom::definitionAbsolute:
- throwf("duplicate symbol %s in %s and %s", name, newAtom.file()->path(), existingAtom->file()->path());
+ _reportDuplicate = true;
+ pickHigherOrdinal();
+ break;
case ld::Atom::definitionProxy:
- // ignore external atom, because we already have a one
- useNew = false;
+ pickAtomA();
break;
}
break;
case ld::Atom::definitionProxy:
- switch ( newAtom.definition() ) {
+ switch (_atomB.definition()) {
case ld::Atom::definitionRegular:
- // replace external atom with regular one
- useNew = true;
+ pickAtomB();
break;
case ld::Atom::definitionTentative:
- // a tentative definition and a dylib definition, so commons-mode decides how to handle
- switch ( _options.commonsMode() ) {
- case Options::kCommonsIgnoreDylibs:
- if ( _options.warnCommons() )
- warning("using common symbol %s from %s and ignoring defintion from dylib %s",
- newAtom.name(), newAtom.file()->path(), existingAtom->file()->path());
- break;
- case Options::kCommonsOverriddenByDylibs:
- if ( _options.warnCommons() )
- warning("replacing defintion of %s from dylib %s with common symbol from %s",
- newAtom.name(), existingAtom->file()->path(), newAtom.file()->path());
- useNew = false;
- break;
- case Options::kCommonsConflictsDylibsError:
- throwf("common symbol %s from %s conflicts with defintion from dylib %s",
- newAtom.name(), newAtom.file()->path(), existingAtom->file()->path());
- }
+ pickCommonsMode(_atomB, _atomA);
break;
case ld::Atom::definitionAbsolute:
- // replace external atom with absolute one
- useNew = true;
+ pickAtomB();
break;
case ld::Atom::definitionProxy:
- // <rdar://problem/5137732> ld should keep looking when it finds a weak definition in a dylib
- if ( newAtom.combine() == ld::Atom::combineByName ) {
- useNew = false;
- }
- else {
- if ( existingAtom->combine() == ld::Atom::combineByName )
- useNew = true;
- else
- throwf("symbol %s exported from both %s and %s\n", name, newAtom.file()->path(), existingAtom->file()->path());
- }
+ pickProxyAtom();
break;
}
break;
- }
+ }
}
- if ( (existingAtom != NULL) && checkVisibilityMismatch && (newAtom.scope() != existingAtom->scope()) ) {
- warning("%s has different visibility (%s) in %s and (%s) in %s",
- SymbolTable::demangle(newAtom.name()), (newAtom.scope() == 1 ? "hidden" : "default"), newAtom.file()->path(), (existingAtom->scope() == 1 ? "hidden" : "default"), existingAtom->file()->path());
+};
+
+bool SymbolTable::addByName(const ld::Atom& newAtom, bool ignoreDuplicates)
+{
+ bool useNew = true;
+ assert(newAtom.name() != NULL);
+ const char* name = newAtom.name();
+ IndirectBindingSlot slot = this->findSlotForName(name);
+ const ld::Atom* existingAtom = _indirectBindingTable[slot];
+ //fprintf(stderr, "addByName(%p) name=%s, slot=%u, existing=%p\n", &newAtom, newAtom.name(), slot, existingAtom);
+ if ( existingAtom != NULL ) {
+ assert(&newAtom != existingAtom);
+ NameCollisionResolution picker(newAtom, *existingAtom, ignoreDuplicates, _options);
+ if (picker.reportDuplicate()) {
+ addDuplicateSymbol(name, existingAtom);
+ addDuplicateSymbol(name, &newAtom);
+ }
+ useNew = picker.choseAtom(newAtom);
}
if ( useNew ) {
_indirectBindingTable[slot] = &newAtom;
if ( existingAtom != NULL ) {
markCoalescedAway(existingAtom);
-// if ( fOwner.fInitialLoadsDone ) {
-// //fprintf(stderr, "existing %p %s overridden by %p\n", existingAtom, existingAtom->name(), &newAtom);
-// fOwner.fAtomsOverriddenByLateLoads.insert(existingAtom);
-// }
}
if ( newAtom.scope() == ld::Atom::scopeGlobal ) {
if ( newAtom.definition() == ld::Atom::definitionTentative ) {
}
+
+struct StrcmpSorter {
+ bool operator() (const char* i,const char* j) {
+ if (i==NULL)
+ return true;
+ if (j==NULL)
+ return false;
+ return strcmp(i, j)<0;}
+};
+
void SymbolTable::undefines(std::vector<const char*>& undefs)
{
// return all names in _byNameTable that have no associated atom
undefs.push_back(it->first);
}
// sort so that undefines are in a stable order (not dependent on hashing functions)
- std::sort(undefs.begin(), undefs.end());
+ struct StrcmpSorter strcmpSorter;
+ std::sort(undefs.begin(), undefs.end(), strcmpSorter);
}
return _indirectBindingTable[slot];
}
-extern "C" char* __cxa_demangle (const char* mangled_name,
- char* buf,
- size_t* n,
- int* status);
-
-const char* SymbolTable::demangle(const char* sym)
-{
- // only try to demangle symbols if -demangle on command line
- if ( !_s_doDemangle )
- return sym;
-
- // only try to demangle symbols that look like C++ symbols
- if ( strncmp(sym, "__Z", 3) != 0 )
- return sym;
-
- static size_t size = 1024;
- static char* buff = (char*)malloc(size);
- int status;
-
- char* result = __cxa_demangle(&sym[1], buff, &size, &status);
- if ( result != NULL ) {
- // if demangling succesful, keep buffer for next demangle
- buff = result;
- return buff;
- }
- return sym;
-}
-
-
void SymbolTable::printStatistics()
{
// fprintf(stderr, "cstring table size: %lu, bucket count: %lu, hash func called %u times\n",
projects / apple / ld64.git / blobdiff