[llvm] r337018 - Revert "CallGraphSCCPass: iterate over all functions."
Evgeniy Stepanov via llvm-commits
llvm-commits at lists.llvm.org
Fri Jul 13 09:32:31 PDT 2018
Author: eugenis
Date: Fri Jul 13 09:32:31 2018
New Revision: 337018
URL: http://llvm.org/viewvc/llvm-project?rev=337018&view=rev
Log:
Revert "CallGraphSCCPass: iterate over all functions."
This reverts commit r336419: use-after-free on CallGraph::FunctionMap elements
due to the use of a stale iterator in CGPassManager::runOnModule.
The iterator may be invalidated if a pass removes a function, ex.:
llvm::LegacyInlinerBase::inlineCalls
inlineCallsImpl
llvm::CallGraph::removeFunctionFromModule
Modified:
llvm/trunk/include/llvm/ADT/SCCIterator.h
llvm/trunk/lib/Analysis/CallGraphSCCPass.cpp
llvm/trunk/test/Transforms/Inline/always-inline.ll
Modified: llvm/trunk/include/llvm/ADT/SCCIterator.h
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/include/llvm/ADT/SCCIterator.h?rev=337018&r1=337017&r2=337018&view=diff
==============================================================================
--- llvm/trunk/include/llvm/ADT/SCCIterator.h (original)
+++ llvm/trunk/include/llvm/ADT/SCCIterator.h Fri Jul 13 09:32:31 2018
@@ -90,7 +90,6 @@ class scc_iterator : public iterator_fac
/// Compute the next SCC using the DFS traversal.
void GetNextSCC();
-public:
scc_iterator(NodeRef entryN) : visitNum(0) {
DFSVisitOne(entryN);
GetNextSCC();
@@ -99,6 +98,12 @@ public:
/// End is when the DFS stack is empty.
scc_iterator() = default;
+public:
+ static scc_iterator begin(const GraphT &G) {
+ return scc_iterator(GT::getEntryNode(G));
+ }
+ static scc_iterator end(const GraphT &) { return scc_iterator(); }
+
/// Direct loop termination test which is more efficient than
/// comparison with \c end().
bool isAtEnd() const {
@@ -217,25 +222,16 @@ bool scc_iterator<GraphT, GT>::hasLoop()
return false;
}
-/// Construct the begin iterator for a deduced graph type T, starting from its
-/// entry node.
+/// Construct the begin iterator for a deduced graph type T.
template <class T> scc_iterator<T> scc_begin(const T &G) {
- return scc_iterator<T>(GraphTraits<T>::getEntryNode(G));
+ return scc_iterator<T>::begin(G);
}
-/// Construct the begin iterator for a graph type T, starting from the specified
-/// node.
-template <class T, class U = GraphTraits<T>>
-scc_iterator<T, U> scc_begin(typename U::NodeRef N) {
- return scc_iterator<T>(N);
-}
-
- /// Construct the end iterator for a deduced graph type T.
+/// Construct the end iterator for a deduced graph type T.
template <class T> scc_iterator<T> scc_end(const T &G) {
- return scc_iterator<T>();
+ return scc_iterator<T>::end(G);
}
-
} // end namespace llvm
#endif // LLVM_ADT_SCCITERATOR_H
Modified: llvm/trunk/lib/Analysis/CallGraphSCCPass.cpp
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/Analysis/CallGraphSCCPass.cpp?rev=337018&r1=337017&r2=337018&view=diff
==============================================================================
--- llvm/trunk/lib/Analysis/CallGraphSCCPass.cpp (original)
+++ llvm/trunk/lib/Analysis/CallGraphSCCPass.cpp Fri Jul 13 09:32:31 2018
@@ -17,7 +17,6 @@
#include "llvm/Analysis/CallGraphSCCPass.h"
#include "llvm/ADT/DenseMap.h"
-#include "llvm/ADT/DenseSet.h"
#include "llvm/ADT/SCCIterator.h"
#include "llvm/ADT/Statistic.h"
#include "llvm/Analysis/CallGraph.h"
@@ -64,10 +63,6 @@ public:
/// whether any of the passes modifies the module, and if so, return true.
bool runOnModule(Module &M) override;
- /// Execute all of the passes scheduled for execution on a given SCC. Return
- /// true if any passes modify the module.
- bool runOnSCC(CallGraphSCC &SCC, CallGraph &CG);
-
using ModulePass::doInitialization;
using ModulePass::doFinalization;
@@ -453,78 +448,51 @@ bool CGPassManager::RunAllPassesOnSCC(Ca
bool CGPassManager::runOnModule(Module &M) {
CallGraph &CG = getAnalysis<CallGraphWrapperPass>().getCallGraph();
bool Changed = doInitialization(CG);
+
+ // Walk the callgraph in bottom-up SCC order.
+ scc_iterator<CallGraph*> CGI = scc_begin(&CG);
- DenseSet<const Function *> Visited;
-
- CallGraph::iterator INext;
- for (auto I = CG.begin(), E = CG.end(); I != E;) {
- // Walk the callgraph in bottom-up SCC order.
- auto CGI = scc_begin<CallGraph *>(I->second.get());
-
- CallGraphSCC CurSCC(CG, &CGI);
- while (!CGI.isAtEnd()) {
- const std::vector<CallGraphNode *> &NodeVec = *CGI;
-
- // Record that we've seen this set of functions so we don't run the pass
- // twice.
- for (auto *Elt : NodeVec)
- Visited.insert(Elt->getFunction());
-
- // Copy the current SCC and increment past it so that the pass can hack
- // on the SCC if it wants to without invalidating our iterator.
- CurSCC.initialize(NodeVec);
- ++CGI;
-
- // If we've got all functions reachable from our chosen initial node,
- // calculate the next node we need to search from now before parts of the
- // graph are invalidated.
- if (CGI.isAtEnd()) {
- do
- ++I;
- while (I != E && Visited.count(I->first));
- }
+ CallGraphSCC CurSCC(CG, &CGI);
+ while (!CGI.isAtEnd()) {
+ // Copy the current SCC and increment past it so that the pass can hack
+ // on the SCC if it wants to without invalidating our iterator.
+ const std::vector<CallGraphNode *> &NodeVec = *CGI;
+ CurSCC.initialize(NodeVec);
+ ++CGI;
+
+ // At the top level, we run all the passes in this pass manager on the
+ // functions in this SCC. However, we support iterative compilation in the
+ // case where a function pass devirtualizes a call to a function. For
+ // example, it is very common for a function pass (often GVN or instcombine)
+ // to eliminate the addressing that feeds into a call. With that improved
+ // information, we would like the call to be an inline candidate, infer
+ // mod-ref information etc.
+ //
+ // Because of this, we allow iteration up to a specified iteration count.
+ // This only happens in the case of a devirtualized call, so we only burn
+ // compile time in the case that we're making progress. We also have a hard
+ // iteration count limit in case there is crazy code.
+ unsigned Iteration = 0;
+ bool DevirtualizedCall = false;
+ do {
+ LLVM_DEBUG(if (Iteration) dbgs()
+ << " SCCPASSMGR: Re-visiting SCC, iteration #" << Iteration
+ << '\n');
+ DevirtualizedCall = false;
+ Changed |= RunAllPassesOnSCC(CurSCC, CG, DevirtualizedCall);
+ } while (Iteration++ < MaxIterations && DevirtualizedCall);
+
+ if (DevirtualizedCall)
+ LLVM_DEBUG(dbgs() << " CGSCCPASSMGR: Stopped iteration after "
+ << Iteration
+ << " times, due to -max-cg-scc-iterations\n");
- Changed |= runOnSCC(CurSCC, CG);
- }
+ MaxSCCIterations.updateMax(Iteration);
}
-
Changed |= doFinalization(CG);
return Changed;
}
-bool CGPassManager::runOnSCC(CallGraphSCC &CurSCC, CallGraph &CG) {
- bool Changed = false;
-
- // At the top level, we run all the passes in this pass manager on the
- // functions in this SCC. However, we support iterative compilation in the
- // case where a function pass devirtualizes a call to a function. For
- // example, it is very common for a function pass (often GVN or instcombine)
- // to eliminate the addressing that feeds into a call. With that improved
- // information, we would like the call to be an inline candidate, infer
- // mod-ref information etc.
- //
- // Because of this, we allow iteration up to a specified iteration count.
- // This only happens in the case of a devirtualized call, so we only burn
- // compile time in the case that we're making progress. We also have a hard
- // iteration count limit in case there is crazy code.
- unsigned Iteration = 0;
- bool DevirtualizedCall = false;
- do {
- LLVM_DEBUG(if (Iteration) dbgs()
- << " SCCPASSMGR: Re-visiting SCC, iteration #" << Iteration
- << '\n');
- DevirtualizedCall = false;
- Changed |= RunAllPassesOnSCC(CurSCC, CG, DevirtualizedCall);
- } while (Iteration++ < MaxIterations && DevirtualizedCall);
-
- if (DevirtualizedCall)
- LLVM_DEBUG(dbgs() << " CGSCCPASSMGR: Stopped iteration after " << Iteration
- << " times, due to -max-cg-scc-iterations\n");
-
- MaxSCCIterations.updateMax(Iteration);
- return Changed;
-}
-
/// Initialize CG
bool CGPassManager::doInitialization(CallGraph &CG) {
bool Changed = false;
Modified: llvm/trunk/test/Transforms/Inline/always-inline.ll
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/test/Transforms/Inline/always-inline.ll?rev=337018&r1=337017&r2=337018&view=diff
==============================================================================
--- llvm/trunk/test/Transforms/Inline/always-inline.ll (original)
+++ llvm/trunk/test/Transforms/Inline/always-inline.ll Fri Jul 13 09:32:31 2018
@@ -316,10 +316,3 @@ define void @outer14() {
call void @inner14()
ret void
}
-
-define internal i32 @outer15() {
-; CHECK-LABEL: @outer15
-; CHECK: ret i32 1
- %res = call i32 @inner1()
- ret i32 %res
-}
More information about the llvm-commits
mailing list