Fix inlining to not produce duplicate landingpad clauses

Before this change, inlining one "invoke" into an outer "invoke" call
site can lead to the outer landingpad's catch/filter clauses being
copied multiple times into the resulting landingpad.  This happens:

 * when the inlined function contains multiple "resume" instructions,
   because forwardResume() copies the clauses but is called multiple
   times;

 * when the inlined function contains a "resume" and a "call", because
   HandleCallsInBlockInlinedThroughInvoke() copies the clauses but is
   redundant with forwardResume().

Fix this by deduplicating the code.

This problem doesn't lead to any incorrect execution; it's only
untidy.

This change will make fixing PR17872 a little easier.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@196710 91177308-0d34-0410-b5e6-96231b3b80d8

diff --git a/lib/Transforms/Utils/InlineFunction.cpp b/lib/Transforms/Utils/InlineFunction.cpp
index 6d23af45a10ae2174d55fcb24784a03b4dd3f37e..405f77e793fdbccbd78269d5bd4e6930e53806d8 100644 (file)
--- a/lib/Transforms/Utils/InlineFunction.cpp
+++ b/lib/Transforms/Utils/InlineFunction.cpp
@@ -144,7 +144,6 @@ BasicBlock *InvokeInliningInfo::getInnerResumeDest() {
 void InvokeInliningInfo::forwardResume(ResumeInst *RI,
                                SmallPtrSet<LandingPadInst*, 16> &InlinedLPads) {
   BasicBlock *Dest = getInnerResumeDest();
-  LandingPadInst *OuterLPad = getLandingPadInst();
   BasicBlock *Src = RI->getParent();
 
   BranchInst::Create(Dest, Src);
@@ -155,16 +154,6 @@ void InvokeInliningInfo::forwardResume(ResumeInst *RI,
 
   InnerEHValuesPHI->addIncoming(RI->getOperand(0), Src);
   RI->eraseFromParent();
-
-  // Append the clauses from the outer landing pad instruction into the inlined
-  // landing pad instructions.
-  for (SmallPtrSet<LandingPadInst*, 16>::iterator I = InlinedLPads.begin(),
-         E = InlinedLPads.end(); I != E; ++I) {
-    LandingPadInst *InlinedLPad = *I;
-    for (unsigned OuterIdx = 0, OuterNum = OuterLPad->getNumClauses();
-         OuterIdx != OuterNum; ++OuterIdx)
-      InlinedLPad->addClause(OuterLPad->getClause(OuterIdx));
-  }
 }
 
 /// HandleCallsInBlockInlinedThroughInvoke - When we inline a basic block into
@@ -174,18 +163,9 @@ void InvokeInliningInfo::forwardResume(ResumeInst *RI,
 /// nodes in that block with the values specified in InvokeDestPHIValues.
 static void HandleCallsInBlockInlinedThroughInvoke(BasicBlock *BB,
                                                    InvokeInliningInfo &Invoke) {
-  LandingPadInst *LPI = Invoke.getLandingPadInst();
-
   for (BasicBlock::iterator BBI = BB->begin(), E = BB->end(); BBI != E; ) {
     Instruction *I = BBI++;
 
-    if (LandingPadInst *L = dyn_cast<LandingPadInst>(I)) {
-      unsigned NumClauses = LPI->getNumClauses();
-      L->reserveClauses(NumClauses);
-      for (unsigned i = 0; i != NumClauses; ++i)
-        L->addClause(LPI->getClause(i));
-    }
-
     // We only need to check for function calls: inlined invoke
     // instructions require no special handling.
     CallInst *CI = dyn_cast<CallInst>(I);
@@ -248,6 +228,18 @@ static void HandleInlinedInvoke(InvokeInst *II, BasicBlock *FirstNewBlock,
     if (InvokeInst *II = dyn_cast<InvokeInst>(I->getTerminator()))
       InlinedLPads.insert(II->getLandingPadInst());
 
+  // Append the clauses from the outer landing pad instruction into the inlined
+  // landing pad instructions.
+  LandingPadInst *OuterLPad = Invoke.getLandingPadInst();
+  for (SmallPtrSet<LandingPadInst*, 16>::iterator I = InlinedLPads.begin(),
+         E = InlinedLPads.end(); I != E; ++I) {
+    LandingPadInst *InlinedLPad = *I;
+    unsigned OuterNum = OuterLPad->getNumClauses();
+    InlinedLPad->reserveClauses(OuterNum);
+    for (unsigned OuterIdx = 0; OuterIdx != OuterNum; ++OuterIdx)
+      InlinedLPad->addClause(OuterLPad->getClause(OuterIdx));
+  }
+
   for (Function::iterator BB = FirstNewBlock, E = Caller->end(); BB != E; ++BB){
     if (InlinedCodeInfo.ContainsCalls)
       HandleCallsInBlockInlinedThroughInvoke(BB, Invoke);

diff --git a/test/Transforms/Inline/inline_invoke.ll b/test/Transforms/Inline/inline_invoke.ll
index c3941388f9378589f5e7c3ffd44bff63f600a6cb..c53bb5aa17be8ecbf8d0de3af6f9ef572e3f48a1 100644 (file)
--- a/test/Transforms/Inline/inline_invoke.ll
+++ b/test/Transforms/Inline/inline_invoke.ll
@@ -96,7 +96,6 @@ eh.resume:
 ; CHECK:      landingpad { i8*, i32 } personality i32 (...)* @__gxx_personality_v0
 ; CHECK-NEXT:    cleanup
 ; CHECK-NEXT:    catch i8* bitcast (i8** @_ZTIi to i8*)
-; CHECK-NEXT:    catch i8* bitcast (i8** @_ZTIi to i8*)
 ; CHECK-NEXT: invoke void @_ZN1AD1Ev(%struct.A* [[A]])
 ; CHECK-NEXT:   to label %[[LBL:[^\s]+]] unwind
 ; CHECK: [[LBL]]:
@@ -167,7 +166,6 @@ eh.resume:
 ; CHECK-NEXT: [[LPADVAL1:%.*]] = landingpad { i8*, i32 } personality i32 (...)* @__gxx_personality_v0
 ; CHECK-NEXT:    cleanup
 ; CHECK-NEXT:    catch i8* bitcast (i8** @_ZTIi to i8*)
-; CHECK-NEXT:    catch i8* bitcast (i8** @_ZTIi to i8*)
 ; CHECK-NEXT: invoke void @_ZN1AD1Ev(%struct.A* [[A1]])
 ; CHECK-NEXT:   to label %[[RESUME1:[^\s]+]] unwind
 ; CHECK: [[RESUME1]]:
@@ -187,7 +185,6 @@ eh.resume:
 ; CHECK-NEXT: [[LPADVAL2:%.*]] = landingpad { i8*, i32 } personality i32 (...)* @__gxx_personality_v0
 ; CHECK-NEXT:   cleanup
 ; CHECK-NEXT:   catch i8* bitcast (i8** @_ZTIi to i8*)
-; CHECK-NEXT:   catch i8* bitcast (i8** @_ZTIi to i8*)
 ; CHECK-NEXT: invoke void @_ZN1AD1Ev(%struct.A* [[A2]])
 ; CHECK-NEXT:   to label %[[RESUME2:[^\s]+]] unwind
 ; CHECK: [[RESUME2]]:
@@ -275,7 +272,6 @@ lpad.cont:
 ; CHECK:      landingpad { i8*, i32 } personality i32 (...)* @__gxx_personality_v0
 ; CHECK-NEXT:    cleanup
 ; CHECK-NEXT:    catch i8* bitcast (i8** @_ZTIi to i8*)
-; CHECK-NEXT:    catch i8* bitcast (i8** @_ZTIi to i8*)
 ; CHECK-NEXT: invoke void @_ZN1AD1Ev(
 ; CHECK-NEXT:   to label %[[L:[^\s]+]] unwind
 ; CHECK:    [[L]]:
@@ -322,7 +318,6 @@ terminate:
 ; CHECK:      landingpad { i8*, i32 } personality i32 (...)* @__gxx_personality_v0
 ; CHECK-NEXT:    cleanup
 ; CHECK-NEXT:    catch i8* bitcast (i8** @_ZTIi to i8*)
-; CHECK-NEXT:    catch i8* bitcast (i8** @_ZTIi to i8*)
 ; CHECK-NEXT: invoke void @_ZN1AD1Ev(
 ; CHECK-NEXT:   to label %[[L:[^\s]+]] unwind
 ; CHECK:    [[L]]:

diff --git a/test/Transforms/Inline/invoke-combine-clauses.ll b/test/Transforms/Inline/invoke-combine-clauses.ll
new file mode 100644 (file)
index 0000000..5f06039
--- /dev/null
+++ b/test/Transforms/Inline/invoke-combine-clauses.ll
@@ -0,0 +1,117 @@
+; RUN: opt %s -inline -S | FileCheck %s
+
+declare void @external_func()
+declare void @abort()
+
+@exception_inner = external global i8
+@exception_outer = external global i8
+@condition = external global i1
+
+
+; Check for a bug in which multiple "resume" instructions in the
+; inlined function caused "catch i8* @exception_outer" to appear
+; multiple times in the resulting landingpad.
+
+define internal void @inner_multiple_resume() {
+  invoke void @external_func()
+      to label %cont unwind label %lpad
+cont:
+  ret void
+lpad:
+  %lp = landingpad i32 personality i8* null
+      catch i8* @exception_inner
+  %cond = load i1* @condition
+  br i1 %cond, label %resume1, label %resume2
+resume1:
+  resume i32 1
+resume2:
+  resume i32 2
+}
+
+define void @outer_multiple_resume() {
+  invoke void @inner_multiple_resume()
+      to label %cont unwind label %lpad
+cont:
+  ret void
+lpad:
+  %lp = landingpad i32 personality i8* null
+      catch i8* @exception_outer
+  resume i32 %lp
+}
+; CHECK: define void @outer_multiple_resume()
+; CHECK: %lp.i = landingpad
+; CHECK-NEXT: catch i8* @exception_inner
+; CHECK-NEXT: catch i8* @exception_outer
+; Check that there isn't another "catch" clause:
+; CHECK-NEXT: load
+
+
+; Check for a bug in which having a "resume" and a "call" in the
+; inlined function caused "catch i8* @exception_outer" to appear
+; multiple times in the resulting landingpad.
+
+define internal void @inner_resume_and_call() {
+  call void @external_func()
+  invoke void @external_func()
+      to label %cont unwind label %lpad
+cont:
+  ret void
+lpad:
+  %lp = landingpad i32 personality i8* null
+      catch i8* @exception_inner
+  resume i32 %lp
+}
+
+define void @outer_resume_and_call() {
+  invoke void @inner_resume_and_call()
+      to label %cont unwind label %lpad
+cont:
+  ret void
+lpad:
+  %lp = landingpad i32 personality i8* null
+      catch i8* @exception_outer
+  resume i32 %lp
+}
+; CHECK: define void @outer_resume_and_call()
+; CHECK: %lp.i = landingpad
+; CHECK-NEXT: catch i8* @exception_inner
+; CHECK-NEXT: catch i8* @exception_outer
+; Check that there isn't another "catch" clause:
+; CHECK-NEXT: br
+
+
+; Check what happens if the inlined function contains an "invoke" but
+; no "resume".  In this case, the inlined landingpad does not need to
+; include the "catch i8* @exception_outer" clause from the outer
+; function (since the outer function's landingpad will not be
+; reachable), but it's OK to include this clause.
+
+define internal void @inner_no_resume_or_call() {
+  invoke void @external_func()
+      to label %cont unwind label %lpad
+cont:
+  ret void
+lpad:
+  %lp = landingpad i32 personality i8* null
+      catch i8* @exception_inner
+  ; A landingpad might have no "resume" if a C++ destructor aborts.
+  call void @abort() noreturn nounwind
+  unreachable
+}
+
+define void @outer_no_resume_or_call() {
+  invoke void @inner_no_resume_or_call()
+      to label %cont unwind label %lpad
+cont:
+  ret void
+lpad:
+  %lp = landingpad i32 personality i8* null
+      catch i8* @exception_outer
+  resume i32 %lp
+}
+; CHECK: define void @outer_no_resume_or_call()
+; CHECK: %lp.i = landingpad
+; CHECK-NEXT: catch i8* @exception_inner
+; CHECK-NEXT: catch i8* @exception_outer
+; Check that there isn't another "catch" clause:
+; CHECK-NEXT: call void @abort()