+/// IsFunctionMallocLike - A function is malloc-like if it returns either null
+/// or a pointer that doesn't alias any other pointer visible to the caller.
+bool FunctionAttrs::IsFunctionMallocLike(Function *F,
+ SmallPtrSet<Function*, 8> &SCCNodes) const {
+ SmallSetVector<Value *, 8> FlowsToReturn;
+ for (Function::iterator I = F->begin(), E = F->end(); I != E; ++I)
+ if (ReturnInst *Ret = dyn_cast<ReturnInst>(I->getTerminator()))
+ FlowsToReturn.insert(Ret->getReturnValue());
+
+ for (unsigned i = 0; i != FlowsToReturn.size(); ++i) {
+ Value *RetVal = FlowsToReturn[i];
+
+ if (Constant *C = dyn_cast<Constant>(RetVal)) {
+ if (!C->isNullValue() && !isa<UndefValue>(C))
+ return false;
+
+ continue;
+ }
+
+ if (isa<Argument>(RetVal))
+ return false;
+
+ if (Instruction *RVI = dyn_cast<Instruction>(RetVal))
+ switch (RVI->getOpcode()) {
+ // Extend the analysis by looking upwards.
+ case Instruction::BitCast:
+ case Instruction::GetElementPtr:
+ case Instruction::AddrSpaceCast:
+ FlowsToReturn.insert(RVI->getOperand(0));
+ continue;
+ case Instruction::Select: {
+ SelectInst *SI = cast<SelectInst>(RVI);
+ FlowsToReturn.insert(SI->getTrueValue());
+ FlowsToReturn.insert(SI->getFalseValue());
+ continue;
+ }
+ case Instruction::PHI: {
+ PHINode *PN = cast<PHINode>(RVI);
+ for (int i = 0, e = PN->getNumIncomingValues(); i != e; ++i)
+ FlowsToReturn.insert(PN->getIncomingValue(i));
+ continue;
+ }
+
+ // Check whether the pointer came from an allocation.
+ case Instruction::Alloca:
+ break;
+ case Instruction::Call:
+ case Instruction::Invoke: {
+ CallSite CS(RVI);
+ if (CS.paramHasAttr(0, Attribute::NoAlias))
+ break;
+ if (CS.getCalledFunction() &&
+ SCCNodes.count(CS.getCalledFunction()))
+ break;
+ } // fall-through
+ default:
+ return false; // Did not come from an allocation.
+ }
+
+ if (PointerMayBeCaptured(RetVal, false, /*StoreCaptures=*/false))
+ return false;
+ }
+
+ return true;
+}
+
+/// AddNoAliasAttrs - Deduce noalias attributes for the SCC.
+bool FunctionAttrs::AddNoAliasAttrs(const CallGraphSCC &SCC) {
+ SmallPtrSet<Function*, 8> SCCNodes;
+
+ // Fill SCCNodes with the elements of the SCC. Used for quickly
+ // looking up whether a given CallGraphNode is in this SCC.
+ for (CallGraphSCC::iterator I = SCC.begin(), E = SCC.end(); I != E; ++I)
+ SCCNodes.insert((*I)->getFunction());
+
+ // Check each function in turn, determining which functions return noalias
+ // pointers.
+ for (CallGraphSCC::iterator I = SCC.begin(), E = SCC.end(); I != E; ++I) {
+ Function *F = (*I)->getFunction();
+
+ if (!F || F->hasFnAttribute(Attribute::OptimizeNone))
+ // External node or node we don't want to optimize - skip it;
+ return false;
+
+ // Already noalias.
+ if (F->doesNotAlias(0))
+ continue;
+
+ // Definitions with weak linkage may be overridden at linktime, so
+ // treat them like declarations.
+ if (F->isDeclaration() || F->mayBeOverridden())
+ return false;
+
+ // We annotate noalias return values, which are only applicable to
+ // pointer types.
+ if (!F->getReturnType()->isPointerTy())
+ continue;
+
+ if (!IsFunctionMallocLike(F, SCCNodes))
+ return false;
+ }
+
+ bool MadeChange = false;
+ for (CallGraphSCC::iterator I = SCC.begin(), E = SCC.end(); I != E; ++I) {
+ Function *F = (*I)->getFunction();
+ if (F->doesNotAlias(0) || !F->getReturnType()->isPointerTy())
+ continue;
+
+ F->setDoesNotAlias(0);
+ ++NumNoAlias;
+ MadeChange = true;
+ }
+
+ return MadeChange;
+}
+
+/// inferPrototypeAttributes - Analyze the name and prototype of the
+/// given function and set any applicable attributes. Returns true
+/// if any attributes were set and false otherwise.
+bool FunctionAttrs::inferPrototypeAttributes(Function &F) {
+ if (F.hasFnAttribute(Attribute::OptimizeNone))
+ return false;
+
+ FunctionType *FTy = F.getFunctionType();
+ LibFunc::Func TheLibFunc;
+ if (!(TLI->getLibFunc(F.getName(), TheLibFunc) && TLI->has(TheLibFunc)))
+ return false;
+
+ switch (TheLibFunc) {
+ case LibFunc::strlen:
+ if (FTy->getNumParams() != 1 || !FTy->getParamType(0)->isPointerTy())
+ return false;
+ setOnlyReadsMemory(F);
+ setDoesNotThrow(F);
+ setDoesNotCapture(F, 1);
+ break;
+ case LibFunc::strchr:
+ case LibFunc::strrchr:
+ if (FTy->getNumParams() != 2 ||
+ !FTy->getParamType(0)->isPointerTy() ||
+ !FTy->getParamType(1)->isIntegerTy())
+ return false;
+ setOnlyReadsMemory(F);
+ setDoesNotThrow(F);
+ break;
+ case LibFunc::strtol:
+ case LibFunc::strtod:
+ case LibFunc::strtof:
+ case LibFunc::strtoul:
+ case LibFunc::strtoll:
+ case LibFunc::strtold:
+ case LibFunc::strtoull:
+ if (FTy->getNumParams() < 2 ||
+ !FTy->getParamType(1)->isPointerTy())
+ return false;
+ setDoesNotThrow(F);
+ setDoesNotCapture(F, 2);
+ setOnlyReadsMemory(F, 1);
+ break;
+ case LibFunc::strcpy:
+ case LibFunc::stpcpy:
+ case LibFunc::strcat:
+ case LibFunc::strncat:
+ case LibFunc::strncpy:
+ case LibFunc::stpncpy:
+ if (FTy->getNumParams() < 2 ||
+ !FTy->getParamType(1)->isPointerTy())
+ return false;
+ setDoesNotThrow(F);
+ setDoesNotCapture(F, 2);
+ setOnlyReadsMemory(F, 2);
+ break;
+ case LibFunc::strxfrm:
+ if (FTy->getNumParams() != 3 ||
+ !FTy->getParamType(0)->isPointerTy() ||
+ !FTy->getParamType(1)->isPointerTy())
+ return false;
+ setDoesNotThrow(F);
+ setDoesNotCapture(F, 1);
+ setDoesNotCapture(F, 2);
+ setOnlyReadsMemory(F, 2);
+ break;
+ case LibFunc::strcmp: //0,1
+ case LibFunc::strspn: // 0,1
+ case LibFunc::strncmp: // 0,1
+ case LibFunc::strcspn: //0,1
+ case LibFunc::strcoll: //0,1
+ case LibFunc::strcasecmp: // 0,1
+ case LibFunc::strncasecmp: //
+ if (FTy->getNumParams() < 2 ||
+ !FTy->getParamType(0)->isPointerTy() ||
+ !FTy->getParamType(1)->isPointerTy())
+ return false;
+ setOnlyReadsMemory(F);
+ setDoesNotThrow(F);
+ setDoesNotCapture(F, 1);
+ setDoesNotCapture(F, 2);
+ break;
+ case LibFunc::strstr:
+ case LibFunc::strpbrk:
+ if (FTy->getNumParams() != 2 || !FTy->getParamType(1)->isPointerTy())
+ return false;
+ setOnlyReadsMemory(F);
+ setDoesNotThrow(F);
+ setDoesNotCapture(F, 2);
+ break;
+ case LibFunc::strtok:
+ case LibFunc::strtok_r:
+ if (FTy->getNumParams() < 2 || !FTy->getParamType(1)->isPointerTy())
+ return false;
+ setDoesNotThrow(F);
+ setDoesNotCapture(F, 2);
+ setOnlyReadsMemory(F, 2);
+ break;
+ case LibFunc::scanf:
+ if (FTy->getNumParams() < 1 || !FTy->getParamType(0)->isPointerTy())
+ return false;
+ setDoesNotThrow(F);
+ setDoesNotCapture(F, 1);
+ setOnlyReadsMemory(F, 1);
+ break;
+ case LibFunc::setbuf:
+ case LibFunc::setvbuf:
+ if (FTy->getNumParams() < 1 || !FTy->getParamType(0)->isPointerTy())
+ return false;
+ setDoesNotThrow(F);
+ setDoesNotCapture(F, 1);
+ break;
+ case LibFunc::strdup:
+ case LibFunc::strndup:
+ if (FTy->getNumParams() < 1 || !FTy->getReturnType()->isPointerTy() ||
+ !FTy->getParamType(0)->isPointerTy())
+ return false;
+ setDoesNotThrow(F);
+ setDoesNotAlias(F, 0);
+ setDoesNotCapture(F, 1);
+ setOnlyReadsMemory(F, 1);
+ break;
+ case LibFunc::stat:
+ case LibFunc::statvfs:
+ if (FTy->getNumParams() < 2 ||
+ !FTy->getParamType(0)->isPointerTy() ||
+ !FTy->getParamType(1)->isPointerTy())
+ return false;
+ setDoesNotThrow(F);
+ setDoesNotCapture(F, 1);
+ setDoesNotCapture(F, 2);
+ setOnlyReadsMemory(F, 1);
+ break;
+ case LibFunc::sscanf:
+ if (FTy->getNumParams() < 2 ||
+ !FTy->getParamType(0)->isPointerTy() ||
+ !FTy->getParamType(1)->isPointerTy())
+ return false;
+ setDoesNotThrow(F);
+ setDoesNotCapture(F, 1);
+ setDoesNotCapture(F, 2);
+ setOnlyReadsMemory(F, 1);
+ setOnlyReadsMemory(F, 2);
+ break;
+ case LibFunc::sprintf:
+ if (FTy->getNumParams() < 2 ||
+ !FTy->getParamType(0)->isPointerTy() ||
+ !FTy->getParamType(1)->isPointerTy())
+ return false;
+ setDoesNotThrow(F);
+ setDoesNotCapture(F, 1);
+ setDoesNotCapture(F, 2);
+ setOnlyReadsMemory(F, 2);
+ break;
+ case LibFunc::snprintf:
+ if (FTy->getNumParams() != 3 ||
+ !FTy->getParamType(0)->isPointerTy() ||
+ !FTy->getParamType(2)->isPointerTy())
+ return false;
+ setDoesNotThrow(F);
+ setDoesNotCapture(F, 1);
+ setDoesNotCapture(F, 3);
+ setOnlyReadsMemory(F, 3);
+ break;
+ case LibFunc::setitimer:
+ if (FTy->getNumParams() != 3 ||
+ !FTy->getParamType(1)->isPointerTy() ||
+ !FTy->getParamType(2)->isPointerTy())
+ return false;
+ setDoesNotThrow(F);
+ setDoesNotCapture(F, 2);
+ setDoesNotCapture(F, 3);
+ setOnlyReadsMemory(F, 2);
+ break;
+ case LibFunc::system:
+ if (FTy->getNumParams() != 1 ||
+ !FTy->getParamType(0)->isPointerTy())
+ return false;
+ // May throw; "system" is a valid pthread cancellation point.
+ setDoesNotCapture(F, 1);
+ setOnlyReadsMemory(F, 1);
+ break;
+ case LibFunc::malloc:
+ if (FTy->getNumParams() != 1 ||
+ !FTy->getReturnType()->isPointerTy())
+ return false;
+ setDoesNotThrow(F);
+ setDoesNotAlias(F, 0);
+ break;
+ case LibFunc::memcmp:
+ if (FTy->getNumParams() != 3 ||
+ !FTy->getParamType(0)->isPointerTy() ||
+ !FTy->getParamType(1)->isPointerTy())
+ return false;
+ setOnlyReadsMemory(F);
+ setDoesNotThrow(F);
+ setDoesNotCapture(F, 1);
+ setDoesNotCapture(F, 2);
+ break;
+ case LibFunc::memchr:
+ case LibFunc::memrchr:
+ if (FTy->getNumParams() != 3)
+ return false;
+ setOnlyReadsMemory(F);
+ setDoesNotThrow(F);
+ break;
+ case LibFunc::modf:
+ case LibFunc::modff:
+ case LibFunc::modfl:
+ if (FTy->getNumParams() < 2 ||
+ !FTy->getParamType(1)->isPointerTy())
+ return false;
+ setDoesNotThrow(F);
+ setDoesNotCapture(F, 2);
+ break;
+ case LibFunc::memcpy:
+ case LibFunc::memccpy:
+ case LibFunc::memmove:
+ if (FTy->getNumParams() < 2 ||
+ !FTy->getParamType(1)->isPointerTy())
+ return false;
+ setDoesNotThrow(F);
+ setDoesNotCapture(F, 2);
+ setOnlyReadsMemory(F, 2);
+ break;
+ case LibFunc::memalign:
+ if (!FTy->getReturnType()->isPointerTy())
+ return false;
+ setDoesNotAlias(F, 0);
+ break;
+ case LibFunc::mkdir:
+ if (FTy->getNumParams() == 0 ||
+ !FTy->getParamType(0)->isPointerTy())
+ return false;
+ setDoesNotThrow(F);
+ setDoesNotCapture(F, 1);
+ setOnlyReadsMemory(F, 1);
+ break;
+ case LibFunc::mktime:
+ if (FTy->getNumParams() == 0 ||
+ !FTy->getParamType(0)->isPointerTy())
+ return false;
+ setDoesNotThrow(F);
+ setDoesNotCapture(F, 1);
+ break;
+ case LibFunc::realloc:
+ if (FTy->getNumParams() != 2 ||
+ !FTy->getParamType(0)->isPointerTy() ||
+ !FTy->getReturnType()->isPointerTy())
+ return false;
+ setDoesNotThrow(F);
+ setDoesNotAlias(F, 0);
+ setDoesNotCapture(F, 1);
+ break;
+ case LibFunc::read:
+ if (FTy->getNumParams() != 3 ||
+ !FTy->getParamType(1)->isPointerTy())
+ return false;
+ // May throw; "read" is a valid pthread cancellation point.
+ setDoesNotCapture(F, 2);
+ break;
+ case LibFunc::rewind:
+ if (FTy->getNumParams() < 1 ||
+ !FTy->getParamType(0)->isPointerTy())
+ return false;
+ setDoesNotThrow(F);
+ setDoesNotCapture(F, 1);
+ break;
+ case LibFunc::rmdir:
+ case LibFunc::remove:
+ case LibFunc::realpath:
+ if (FTy->getNumParams() < 1 ||
+ !FTy->getParamType(0)->isPointerTy())
+ return false;
+ setDoesNotThrow(F);
+ setDoesNotCapture(F, 1);
+ setOnlyReadsMemory(F, 1);
+ break;
+ case LibFunc::rename:
+ if (FTy->getNumParams() < 2 ||
+ !FTy->getParamType(0)->isPointerTy() ||
+ !FTy->getParamType(1)->isPointerTy())
+ return false;
+ setDoesNotThrow(F);
+ setDoesNotCapture(F, 1);
+ setDoesNotCapture(F, 2);
+ setOnlyReadsMemory(F, 1);
+ setOnlyReadsMemory(F, 2);
+ break;
+ case LibFunc::readlink:
+ if (FTy->getNumParams() < 2 ||
+ !FTy->getParamType(0)->isPointerTy() ||
+ !FTy->getParamType(1)->isPointerTy())
+ return false;
+ setDoesNotThrow(F);
+ setDoesNotCapture(F, 1);
+ setDoesNotCapture(F, 2);
+ setOnlyReadsMemory(F, 1);
+ break;
+ case LibFunc::write:
+ if (FTy->getNumParams() != 3 || !FTy->getParamType(1)->isPointerTy())
+ return false;
+ // May throw; "write" is a valid pthread cancellation point.
+ setDoesNotCapture(F, 2);
+ setOnlyReadsMemory(F, 2);
+ break;
+ case LibFunc::bcopy:
+ if (FTy->getNumParams() != 3 ||
+ !FTy->getParamType(0)->isPointerTy() ||
+ !FTy->getParamType(1)->isPointerTy())
+ return false;
+ setDoesNotThrow(F);
+ setDoesNotCapture(F, 1);
+ setDoesNotCapture(F, 2);
+ setOnlyReadsMemory(F, 1);
+ break;
+ case LibFunc::bcmp:
+ if (FTy->getNumParams() != 3 ||
+ !FTy->getParamType(0)->isPointerTy() ||
+ !FTy->getParamType(1)->isPointerTy())
+ return false;
+ setDoesNotThrow(F);
+ setOnlyReadsMemory(F);
+ setDoesNotCapture(F, 1);
+ setDoesNotCapture(F, 2);
+ break;
+ case LibFunc::bzero:
+ if (FTy->getNumParams() != 2 || !FTy->getParamType(0)->isPointerTy())
+ return false;
+ setDoesNotThrow(F);
+ setDoesNotCapture(F, 1);
+ break;
+ case LibFunc::calloc:
+ if (FTy->getNumParams() != 2 ||
+ !FTy->getReturnType()->isPointerTy())
+ return false;
+ setDoesNotThrow(F);
+ setDoesNotAlias(F, 0);
+ break;
+ case LibFunc::chmod:
+ case LibFunc::chown:
+ if (FTy->getNumParams() == 0 || !FTy->getParamType(0)->isPointerTy())
+ return false;
+ setDoesNotThrow(F);
+ setDoesNotCapture(F, 1);
+ setOnlyReadsMemory(F, 1);
+ break;
+ case LibFunc::ctermid:
+ case LibFunc::clearerr:
+ case LibFunc::closedir:
+ if (FTy->getNumParams() == 0 || !FTy->getParamType(0)->isPointerTy())
+ return false;
+ setDoesNotThrow(F);
+ setDoesNotCapture(F, 1);
+ break;
+ case LibFunc::atoi:
+ case LibFunc::atol:
+ case LibFunc::atof:
+ case LibFunc::atoll:
+ if (FTy->getNumParams() != 1 || !FTy->getParamType(0)->isPointerTy())
+ return false;
+ setDoesNotThrow(F);
+ setOnlyReadsMemory(F);
+ setDoesNotCapture(F, 1);
+ break;
+ case LibFunc::access:
+ if (FTy->getNumParams() != 2 || !FTy->getParamType(0)->isPointerTy())
+ return false;
+ setDoesNotThrow(F);
+ setDoesNotCapture(F, 1);
+ setOnlyReadsMemory(F, 1);
+ break;
+ case LibFunc::fopen:
+ if (FTy->getNumParams() != 2 ||
+ !FTy->getReturnType()->isPointerTy() ||
+ !FTy->getParamType(0)->isPointerTy() ||
+ !FTy->getParamType(1)->isPointerTy())
+ return false;
+ setDoesNotThrow(F);
+ setDoesNotAlias(F, 0);
+ setDoesNotCapture(F, 1);
+ setDoesNotCapture(F, 2);
+ setOnlyReadsMemory(F, 1);
+ setOnlyReadsMemory(F, 2);
+ break;
+ case LibFunc::fdopen:
+ if (FTy->getNumParams() != 2 ||
+ !FTy->getReturnType()->isPointerTy() ||
+ !FTy->getParamType(1)->isPointerTy())
+ return false;
+ setDoesNotThrow(F);
+ setDoesNotAlias(F, 0);
+ setDoesNotCapture(F, 2);
+ setOnlyReadsMemory(F, 2);
+ break;
+ case LibFunc::feof:
+ case LibFunc::free:
+ case LibFunc::fseek:
+ case LibFunc::ftell:
+ case LibFunc::fgetc:
+ case LibFunc::fseeko:
+ case LibFunc::ftello:
+ case LibFunc::fileno:
+ case LibFunc::fflush:
+ case LibFunc::fclose:
+ case LibFunc::fsetpos:
+ case LibFunc::flockfile:
+ case LibFunc::funlockfile:
+ case LibFunc::ftrylockfile:
+ if (FTy->getNumParams() == 0 || !FTy->getParamType(0)->isPointerTy())
+ return false;
+ setDoesNotThrow(F);
+ setDoesNotCapture(F, 1);
+ break;
+ case LibFunc::ferror:
+ if (FTy->getNumParams() != 1 || !FTy->getParamType(0)->isPointerTy())
+ return false;
+ setDoesNotThrow(F);
+ setDoesNotCapture(F, 1);
+ setOnlyReadsMemory(F);
+ break;
+ case LibFunc::fputc:
+ case LibFunc::fstat:
+ case LibFunc::frexp:
+ case LibFunc::frexpf:
+ case LibFunc::frexpl:
+ case LibFunc::fstatvfs:
+ if (FTy->getNumParams() != 2 || !FTy->getParamType(1)->isPointerTy())
+ return false;
+ setDoesNotThrow(F);
+ setDoesNotCapture(F, 2);
+ break;
+ case LibFunc::fgets:
+ if (FTy->getNumParams() != 3 ||
+ !FTy->getParamType(0)->isPointerTy() ||
+ !FTy->getParamType(2)->isPointerTy())
+ return false;
+ setDoesNotThrow(F);
+ setDoesNotCapture(F, 3);
+ break;
+ case LibFunc::fread:
+ if (FTy->getNumParams() != 4 ||
+ !FTy->getParamType(0)->isPointerTy() ||
+ !FTy->getParamType(3)->isPointerTy())
+ return false;
+ setDoesNotThrow(F);
+ setDoesNotCapture(F, 1);
+ setDoesNotCapture(F, 4);
+ break;
+ case LibFunc::fwrite:
+ if (FTy->getNumParams() != 4 ||
+ !FTy->getParamType(0)->isPointerTy() ||
+ !FTy->getParamType(3)->isPointerTy())
+ return false;
+ setDoesNotThrow(F);
+ setDoesNotCapture(F, 1);
+ setDoesNotCapture(F, 4);
+ break;
+ case LibFunc::fputs:
+ if (FTy->getNumParams() < 2 ||
+ !FTy->getParamType(0)->isPointerTy() ||
+ !FTy->getParamType(1)->isPointerTy())
+ return false;
+ setDoesNotThrow(F);
+ setDoesNotCapture(F, 1);
+ setDoesNotCapture(F, 2);
+ setOnlyReadsMemory(F, 1);
+ break;
+ case LibFunc::fscanf:
+ case LibFunc::fprintf:
+ if (FTy->getNumParams() < 2 ||
+ !FTy->getParamType(0)->isPointerTy() ||
+ !FTy->getParamType(1)->isPointerTy())
+ return false;
+ setDoesNotThrow(F);
+ setDoesNotCapture(F, 1);
+ setDoesNotCapture(F, 2);
+ setOnlyReadsMemory(F, 2);
+ break;
+ case LibFunc::fgetpos:
+ if (FTy->getNumParams() < 2 ||
+ !FTy->getParamType(0)->isPointerTy() ||
+ !FTy->getParamType(1)->isPointerTy())
+ return false;
+ setDoesNotThrow(F);
+ setDoesNotCapture(F, 1);
+ setDoesNotCapture(F, 2);
+ break;
+ case LibFunc::getc:
+ case LibFunc::getlogin_r:
+ case LibFunc::getc_unlocked:
+ if (FTy->getNumParams() == 0 || !FTy->getParamType(0)->isPointerTy())
+ return false;
+ setDoesNotThrow(F);
+ setDoesNotCapture(F, 1);
+ break;
+ case LibFunc::getenv:
+ if (FTy->getNumParams() != 1 || !FTy->getParamType(0)->isPointerTy())
+ return false;
+ setDoesNotThrow(F);
+ setOnlyReadsMemory(F);
+ setDoesNotCapture(F, 1);
+ break;
+ case LibFunc::gets:
+ case LibFunc::getchar:
+ setDoesNotThrow(F);
+ break;
+ case LibFunc::getitimer:
+ if (FTy->getNumParams() != 2 || !FTy->getParamType(1)->isPointerTy())
+ return false;
+ setDoesNotThrow(F);
+ setDoesNotCapture(F, 2);
+ break;
+ case LibFunc::getpwnam:
+ if (FTy->getNumParams() != 1 || !FTy->getParamType(0)->isPointerTy())
+ return false;
+ setDoesNotThrow(F);
+ setDoesNotCapture(F, 1);
+ setOnlyReadsMemory(F, 1);
+ break;
+ case LibFunc::ungetc:
+ if (FTy->getNumParams() != 2 || !FTy->getParamType(1)->isPointerTy())
+ return false;
+ setDoesNotThrow(F);
+ setDoesNotCapture(F, 2);
+ break;
+ case LibFunc::uname:
+ if (FTy->getNumParams() != 1 || !FTy->getParamType(0)->isPointerTy())
+ return false;
+ setDoesNotThrow(F);
+ setDoesNotCapture(F, 1);
+ break;
+ case LibFunc::unlink:
+ if (FTy->getNumParams() != 1 || !FTy->getParamType(0)->isPointerTy())
+ return false;
+ setDoesNotThrow(F);
+ setDoesNotCapture(F, 1);
+ setOnlyReadsMemory(F, 1);
+ break;
+ case LibFunc::unsetenv:
+ if (FTy->getNumParams() != 1 || !FTy->getParamType(0)->isPointerTy())
+ return false;
+ setDoesNotThrow(F);
+ setDoesNotCapture(F, 1);
+ setOnlyReadsMemory(F, 1);
+ break;
+ case LibFunc::utime:
+ case LibFunc::utimes:
+ if (FTy->getNumParams() != 2 ||
+ !FTy->getParamType(0)->isPointerTy() ||
+ !FTy->getParamType(1)->isPointerTy())
+ return false;
+ setDoesNotThrow(F);
+ setDoesNotCapture(F, 1);
+ setDoesNotCapture(F, 2);
+ setOnlyReadsMemory(F, 1);
+ setOnlyReadsMemory(F, 2);
+ break;
+ case LibFunc::putc:
+ if (FTy->getNumParams() != 2 || !FTy->getParamType(1)->isPointerTy())
+ return false;
+ setDoesNotThrow(F);
+ setDoesNotCapture(F, 2);
+ break;
+ case LibFunc::puts:
+ case LibFunc::printf:
+ case LibFunc::perror:
+ if (FTy->getNumParams() != 1 || !FTy->getParamType(0)->isPointerTy())
+ return false;
+ setDoesNotThrow(F);
+ setDoesNotCapture(F, 1);
+ setOnlyReadsMemory(F, 1);
+ break;
+ case LibFunc::pread:
+ if (FTy->getNumParams() != 4 || !FTy->getParamType(1)->isPointerTy())
+ return false;
+ // May throw; "pread" is a valid pthread cancellation point.
+ setDoesNotCapture(F, 2);
+ break;
+ case LibFunc::pwrite:
+ if (FTy->getNumParams() != 4 || !FTy->getParamType(1)->isPointerTy())
+ return false;
+ // May throw; "pwrite" is a valid pthread cancellation point.
+ setDoesNotCapture(F, 2);
+ setOnlyReadsMemory(F, 2);
+ break;
+ case LibFunc::putchar:
+ setDoesNotThrow(F);
+ break;
+ case LibFunc::popen:
+ if (FTy->getNumParams() != 2 ||
+ !FTy->getReturnType()->isPointerTy() ||
+ !FTy->getParamType(0)->isPointerTy() ||
+ !FTy->getParamType(1)->isPointerTy())
+ return false;
+ setDoesNotThrow(F);
+ setDoesNotAlias(F, 0);
+ setDoesNotCapture(F, 1);
+ setDoesNotCapture(F, 2);
+ setOnlyReadsMemory(F, 1);
+ setOnlyReadsMemory(F, 2);
+ break;
+ case LibFunc::pclose:
+ if (FTy->getNumParams() != 1 || !FTy->getParamType(0)->isPointerTy())
+ return false;
+ setDoesNotThrow(F);
+ setDoesNotCapture(F, 1);
+ break;
+ case LibFunc::vscanf:
+ if (FTy->getNumParams() != 2 || !FTy->getParamType(1)->isPointerTy())
+ return false;
+ setDoesNotThrow(F);
+ setDoesNotCapture(F, 1);
+ setOnlyReadsMemory(F, 1);
+ break;
+ case LibFunc::vsscanf:
+ if (FTy->getNumParams() != 3 ||
+ !FTy->getParamType(1)->isPointerTy() ||
+ !FTy->getParamType(2)->isPointerTy())
+ return false;
+ setDoesNotThrow(F);
+ setDoesNotCapture(F, 1);
+ setDoesNotCapture(F, 2);
+ setOnlyReadsMemory(F, 1);
+ setOnlyReadsMemory(F, 2);
+ break;
+ case LibFunc::vfscanf:
+ if (FTy->getNumParams() != 3 ||
+ !FTy->getParamType(1)->isPointerTy() ||
+ !FTy->getParamType(2)->isPointerTy())
+ return false;
+ setDoesNotThrow(F);
+ setDoesNotCapture(F, 1);
+ setDoesNotCapture(F, 2);
+ setOnlyReadsMemory(F, 2);
+ break;
+ case LibFunc::valloc:
+ if (!FTy->getReturnType()->isPointerTy())
+ return false;
+ setDoesNotThrow(F);
+ setDoesNotAlias(F, 0);
+ break;
+ case LibFunc::vprintf:
+ if (FTy->getNumParams() != 2 || !FTy->getParamType(0)->isPointerTy())
+ return false;
+ setDoesNotThrow(F);
+ setDoesNotCapture(F, 1);
+ setOnlyReadsMemory(F, 1);
+ break;
+ case LibFunc::vfprintf:
+ case LibFunc::vsprintf:
+ if (FTy->getNumParams() != 3 ||
+ !FTy->getParamType(0)->isPointerTy() ||
+ !FTy->getParamType(1)->isPointerTy())
+ return false;
+ setDoesNotThrow(F);
+ setDoesNotCapture(F, 1);
+ setDoesNotCapture(F, 2);
+ setOnlyReadsMemory(F, 2);
+ break;
+ case LibFunc::vsnprintf:
+ if (FTy->getNumParams() != 4 ||
+ !FTy->getParamType(0)->isPointerTy() ||
+ !FTy->getParamType(2)->isPointerTy())
+ return false;
+ setDoesNotThrow(F);
+ setDoesNotCapture(F, 1);
+ setDoesNotCapture(F, 3);
+ setOnlyReadsMemory(F, 3);
+ break;
+ case LibFunc::open:
+ if (FTy->getNumParams() < 2 || !FTy->getParamType(0)->isPointerTy())
+ return false;
+ // May throw; "open" is a valid pthread cancellation point.
+ setDoesNotCapture(F, 1);
+ setOnlyReadsMemory(F, 1);
+ break;
+ case LibFunc::opendir:
+ if (FTy->getNumParams() != 1 ||
+ !FTy->getReturnType()->isPointerTy() ||
+ !FTy->getParamType(0)->isPointerTy())
+ return false;
+ setDoesNotThrow(F);
+ setDoesNotAlias(F, 0);
+ setDoesNotCapture(F, 1);
+ setOnlyReadsMemory(F, 1);
+ break;
+ case LibFunc::tmpfile:
+ if (!FTy->getReturnType()->isPointerTy())
+ return false;
+ setDoesNotThrow(F);
+ setDoesNotAlias(F, 0);
+ break;
+ case LibFunc::times:
+ if (FTy->getNumParams() != 1 || !FTy->getParamType(0)->isPointerTy())
+ return false;
+ setDoesNotThrow(F);
+ setDoesNotCapture(F, 1);
+ break;
+ case LibFunc::htonl:
+ case LibFunc::htons:
+ case LibFunc::ntohl:
+ case LibFunc::ntohs:
+ setDoesNotThrow(F);
+ setDoesNotAccessMemory(F);
+ break;
+ case LibFunc::lstat:
+ if (FTy->getNumParams() != 2 ||
+ !FTy->getParamType(0)->isPointerTy() ||
+ !FTy->getParamType(1)->isPointerTy())
+ return false;
+ setDoesNotThrow(F);
+ setDoesNotCapture(F, 1);
+ setDoesNotCapture(F, 2);
+ setOnlyReadsMemory(F, 1);
+ break;
+ case LibFunc::lchown:
+ if (FTy->getNumParams() != 3 || !FTy->getParamType(0)->isPointerTy())
+ return false;
+ setDoesNotThrow(F);
+ setDoesNotCapture(F, 1);
+ setOnlyReadsMemory(F, 1);
+ break;
+ case LibFunc::qsort:
+ if (FTy->getNumParams() != 4 || !FTy->getParamType(3)->isPointerTy())
+ return false;
+ // May throw; places call through function pointer.
+ setDoesNotCapture(F, 4);
+ break;
+ case LibFunc::dunder_strdup:
+ case LibFunc::dunder_strndup:
+ if (FTy->getNumParams() < 1 ||
+ !FTy->getReturnType()->isPointerTy() ||
+ !FTy->getParamType(0)->isPointerTy())
+ return false;
+ setDoesNotThrow(F);
+ setDoesNotAlias(F, 0);
+ setDoesNotCapture(F, 1);
+ setOnlyReadsMemory(F, 1);
+ break;
+ case LibFunc::dunder_strtok_r:
+ if (FTy->getNumParams() != 3 ||
+ !FTy->getParamType(1)->isPointerTy())
+ return false;
+ setDoesNotThrow(F);
+ setDoesNotCapture(F, 2);
+ setOnlyReadsMemory(F, 2);
+ break;
+ case LibFunc::under_IO_getc:
+ if (FTy->getNumParams() != 1 || !FTy->getParamType(0)->isPointerTy())
+ return false;
+ setDoesNotThrow(F);
+ setDoesNotCapture(F, 1);
+ break;
+ case LibFunc::under_IO_putc:
+ if (FTy->getNumParams() != 2 || !FTy->getParamType(1)->isPointerTy())
+ return false;
+ setDoesNotThrow(F);
+ setDoesNotCapture(F, 2);
+ break;
+ case LibFunc::dunder_isoc99_scanf:
+ if (FTy->getNumParams() < 1 ||
+ !FTy->getParamType(0)->isPointerTy())
+ return false;
+ setDoesNotThrow(F);
+ setDoesNotCapture(F, 1);
+ setOnlyReadsMemory(F, 1);
+ break;
+ case LibFunc::stat64:
+ case LibFunc::lstat64:
+ case LibFunc::statvfs64:
+ if (FTy->getNumParams() < 1 ||
+ !FTy->getParamType(0)->isPointerTy() ||
+ !FTy->getParamType(1)->isPointerTy())
+ return false;
+ setDoesNotThrow(F);
+ setDoesNotCapture(F, 1);
+ setDoesNotCapture(F, 2);
+ setOnlyReadsMemory(F, 1);
+ break;
+ case LibFunc::dunder_isoc99_sscanf:
+ if (FTy->getNumParams() < 1 ||
+ !FTy->getParamType(0)->isPointerTy() ||
+ !FTy->getParamType(1)->isPointerTy())
+ return false;
+ setDoesNotThrow(F);
+ setDoesNotCapture(F, 1);
+ setDoesNotCapture(F, 2);
+ setOnlyReadsMemory(F, 1);
+ setOnlyReadsMemory(F, 2);
+ break;
+ case LibFunc::fopen64:
+ if (FTy->getNumParams() != 2 ||
+ !FTy->getReturnType()->isPointerTy() ||
+ !FTy->getParamType(0)->isPointerTy() ||
+ !FTy->getParamType(1)->isPointerTy())
+ return false;
+ setDoesNotThrow(F);
+ setDoesNotAlias(F, 0);
+ setDoesNotCapture(F, 1);
+ setDoesNotCapture(F, 2);
+ setOnlyReadsMemory(F, 1);
+ setOnlyReadsMemory(F, 2);
+ break;
+ case LibFunc::fseeko64:
+ case LibFunc::ftello64:
+ if (FTy->getNumParams() == 0 || !FTy->getParamType(0)->isPointerTy())
+ return false;
+ setDoesNotThrow(F);
+ setDoesNotCapture(F, 1);
+ break;
+ case LibFunc::tmpfile64:
+ if (!FTy->getReturnType()->isPointerTy())
+ return false;
+ setDoesNotThrow(F);
+ setDoesNotAlias(F, 0);
+ break;
+ case LibFunc::fstat64:
+ case LibFunc::fstatvfs64:
+ if (FTy->getNumParams() != 2 || !FTy->getParamType(1)->isPointerTy())
+ return false;
+ setDoesNotThrow(F);
+ setDoesNotCapture(F, 2);
+ break;
+ case LibFunc::open64:
+ if (FTy->getNumParams() < 2 || !FTy->getParamType(0)->isPointerTy())
+ return false;
+ // May throw; "open" is a valid pthread cancellation point.
+ setDoesNotCapture(F, 1);
+ setOnlyReadsMemory(F, 1);
+ break;
+ case LibFunc::gettimeofday:
+ if (FTy->getNumParams() != 2 || !FTy->getParamType(0)->isPointerTy() ||
+ !FTy->getParamType(1)->isPointerTy())
+ return false;
+ // Currently some platforms have the restrict keyword on the arguments to
+ // gettimeofday. To be conservative, do not add noalias to gettimeofday's
+ // arguments.
+ setDoesNotThrow(F);
+ setDoesNotCapture(F, 1);
+ setDoesNotCapture(F, 2);
+ break;
+ default:
+ // Didn't mark any attributes.
+ return false;
+ }
+
+ return true;
+}
+
+/// annotateLibraryCalls - Adds attributes to well-known standard library
+/// call declarations.
+bool FunctionAttrs::annotateLibraryCalls(const CallGraphSCC &SCC) {
+ bool MadeChange = false;
+
+ // Check each function in turn annotating well-known library function
+ // declarations with attributes.
+ for (CallGraphSCC::iterator I = SCC.begin(), E = SCC.end(); I != E; ++I) {
+ Function *F = (*I)->getFunction();
+
+ if (F && F->isDeclaration())
+ MadeChange |= inferPrototypeAttributes(*F);
+ }
+
+ return MadeChange;
+}
+
+bool FunctionAttrs::runOnSCC(CallGraphSCC &SCC) {
+ AA = &getAnalysis<AliasAnalysis>();
+ TLI = &getAnalysis<TargetLibraryInfoWrapperPass>().getTLI();
+
+ bool Changed = annotateLibraryCalls(SCC);
+ Changed |= AddReadAttrs(SCC);
+ Changed |= AddArgumentAttrs(SCC);
+ Changed |= AddNoAliasAttrs(SCC);