[llvm] r260733 - [WinEH] Prevent EH state numbering from skipping nested cleanup pads that never return

[Andrew Kaylor via llvm-commits]

Author: akaylor
Date: Fri Feb 12 15:10:16 2016
New Revision: 260733

URL: http://llvm.org/viewvc/llvm-project?rev=260733&view=rev
Log:
[WinEH] Prevent EH state numbering from skipping nested cleanup pads that never return

Differential Revision: http://reviews.llvm.org/D17208


Added:
    llvm/trunk/test/CodeGen/WinEH/wineh-noret-cleanup.ll
Modified:
    llvm/trunk/lib/CodeGen/WinEHPrepare.cpp

Modified: llvm/trunk/lib/CodeGen/WinEHPrepare.cpp
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/CodeGen/WinEHPrepare.cpp?rev=260733&r1=260732&r2=260733&view=diff
==============================================================================
--- llvm/trunk/lib/CodeGen/WinEHPrepare.cpp (original)
+++ llvm/trunk/lib/CodeGen/WinEHPrepare.cpp Fri Feb 12 15:10:16 2016
@@ -257,10 +257,14 @@ static void calculateCXXStateNumbers(Win
         if (auto *InnerCatchSwitch = dyn_cast<CatchSwitchInst>(UserI))
           if (InnerCatchSwitch->getUnwindDest() == CatchSwitch->getUnwindDest())
             calculateCXXStateNumbers(FuncInfo, UserI, CatchLow);
-        if (auto *InnerCleanupPad = dyn_cast<CleanupPadInst>(UserI))
-          if (getCleanupRetUnwindDest(InnerCleanupPad) ==
-              CatchSwitch->getUnwindDest())
+        if (auto *InnerCleanupPad = dyn_cast<CleanupPadInst>(UserI)) {
+          BasicBlock *UnwindDest = getCleanupRetUnwindDest(InnerCleanupPad);
+          // If a nested cleanup pad reports a null unwind destination and the
+          // enclosing catch pad doesn't it must be post-dominated by an
+          // unreachable instruction.
+          if (!UnwindDest || UnwindDest == CatchSwitch->getUnwindDest())
             calculateCXXStateNumbers(FuncInfo, UserI, CatchLow);
+        }
       }
     }
     int CatchHigh = FuncInfo.getLastStateNumber();
@@ -360,10 +364,14 @@ static void calculateSEHStateNumbers(Win
       if (auto *InnerCatchSwitch = dyn_cast<CatchSwitchInst>(UserI))
         if (InnerCatchSwitch->getUnwindDest() == CatchSwitch->getUnwindDest())
           calculateSEHStateNumbers(FuncInfo, UserI, ParentState);
-      if (auto *InnerCleanupPad = dyn_cast<CleanupPadInst>(UserI))
-        if (getCleanupRetUnwindDest(InnerCleanupPad) ==
-            CatchSwitch->getUnwindDest())
+      if (auto *InnerCleanupPad = dyn_cast<CleanupPadInst>(UserI)) {
+        BasicBlock *UnwindDest = getCleanupRetUnwindDest(InnerCleanupPad);
+        // If a nested cleanup pad reports a null unwind destination and the
+        // enclosing catch pad doesn't it must be post-dominated by an
+        // unreachable instruction.
+        if (!UnwindDest || UnwindDest == CatchSwitch->getUnwindDest())
           calculateSEHStateNumbers(FuncInfo, UserI, ParentState);
+      }
     }
   } else {
     auto *CleanupPad = cast<CleanupPadInst>(FirstNonPHI);

Added: llvm/trunk/test/CodeGen/WinEH/wineh-noret-cleanup.ll
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/test/CodeGen/WinEH/wineh-noret-cleanup.ll?rev=260733&view=auto
==============================================================================
--- llvm/trunk/test/CodeGen/WinEH/wineh-noret-cleanup.ll (added)
+++ llvm/trunk/test/CodeGen/WinEH/wineh-noret-cleanup.ll Fri Feb 12 15:10:16 2016
@@ -0,0 +1,80 @@
+; RUN: sed -e s/.Cxx:// %s | llc -mtriple=x86_64-pc-windows-msvc | FileCheck %s --check-prefix=CXX
+; RUN: sed -e s/.Seh:// %s | llc -mtriple=x86_64-pc-windows-msvc | FileCheck %s --check-prefix=SEH
+
+declare i32 @__CxxFrameHandler3(...)
+declare i32 @__C_specific_handler(...)
+declare void @dummy_filter()
+
+declare void @f(i32)
+
+;Cxx: define void @test() personality i32 (...)* @__CxxFrameHandler3 {
+;Seh: define void @test() personality i32 (...)* @__C_specific_handler {
+entry:
+  invoke void @f(i32 1)
+          to label %invoke.cont unwind label %catch.dispatch
+
+catch.dispatch:
+  %cs1 = catchswitch within none [label %catch.body] unwind label %catch.dispatch.2
+
+catch.body:
+;Cxx: %catch = catchpad within %cs1 [i8* null, i32 u0x40, i8* null]
+;Seh: %catch = catchpad within %cs1 [void ()* @dummy_filter]
+  invoke void @f(i32 2) [ "funclet"(token %catch) ]
+          to label %unreachable unwind label %terminate
+
+terminate:
+  %cleanup = cleanuppad within %catch []
+  call void @f(i32 3) [ "funclet"(token %cleanup) ]
+  unreachable
+
+unreachable:
+  unreachable
+
+invoke.cont:
+  ret void
+
+catch.dispatch.2:
+  %cs2 = catchswitch within none [label %catch.body.2] unwind to caller
+
+catch.body.2:
+;Cxx: %catch2 = catchpad within %cs2 [i8* null, i32 u0x40, i8* null]
+;Seh: %catch2 = catchpad within %cs2 [void ()* @dummy_filter]
+  unreachable
+}
+
+; CXX-LABEL: test:
+; CXX-LABEL: $ip2state$test:
+; CXX-NEXT:   .long   .Lfunc_begin0 at IMGREL
+; CXX-NEXT:   .long   -1
+; CXX-NEXT:   .long   .Ltmp0 at IMGREL+1
+; CXX-NEXT:   .long   1
+; CXX-NEXT:   .long   .Ltmp1 at IMGREL+1
+; CXX-NEXT:   .long   -1
+; CXX-NEXT:   .long   "?catch$3@?0?test at 4HA"@IMGREL
+; CXX-NEXT:   .long   2
+; CXX-NEXT:   .long   .Ltmp2 at IMGREL+1
+; CXX-NEXT:   .long   3
+; CXX-NEXT:   .long   .Ltmp3 at IMGREL+1
+; CXX-NEXT:   .long   2
+; CXX-NEXT:   .long   "?catch$5@?0?test at 4HA"@IMGREL
+; CXX-NEXT:   .long   4
+
+; SEH-LABEL: test:
+; SEH-LABEL: .Llsda_begin0:
+; SEH-NEXT:    .long   .Ltmp0 at IMGREL+1
+; SEH-NEXT:    .long   .Ltmp1 at IMGREL+1
+; SEH-NEXT:    .long   dummy_filter at IMGREL
+; SEH-NEXT:    .long   .LBB0_3 at IMGREL
+; SEH-NEXT:    .long   .Ltmp0 at IMGREL+1
+; SEH-NEXT:    .long   .Ltmp1 at IMGREL+1
+; SEH-NEXT:    .long   dummy_filter at IMGREL
+; SEH-NEXT:    .long   .LBB0_5 at IMGREL
+; SEH-NEXT:    .long   .Ltmp2 at IMGREL+1
+; SEH-NEXT:    .long   .Ltmp3 at IMGREL+1
+; SEH-NEXT:    .long   "?dtor$2@?0?test at 4HA"@IMGREL
+; SEH-NEXT:    .long   0
+; SEH-NEXT:    .long   .Ltmp2 at IMGREL+1
+; SEH-NEXT:    .long   .Ltmp3 at IMGREL+1
+; SEH-NEXT:    .long   dummy_filter at IMGREL
+; SEH-NEXT:    .long   .LBB0_5 at IMGREL
+; SEH-NEXT:  .Llsda_end0: