Update of 94055 to track the IR level call site information via an intrinsic.

This allows code gen and the exception table writer to cooperate to make sure
landing pads are associated with the correct invoke locations.



git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@94726 91177308-0d34-0410-b5e6-96231b3b80d8

docs/ExceptionHandling.html

@@ -39,6 +39,7 @@
   	<li><a href="#llvm_eh_sjlj_setjmp"><tt>llvm.eh.sjlj.setjmp</tt></a></li>
   	<li><a href="#llvm_eh_sjlj_longjmp"><tt>llvm.eh.sjlj.longjmp</tt></a></li>
   	<li><a href="#llvm_eh_sjlj_lsda"><tt>llvm.eh.sjlj.lsda</tt></a></li>
+  	<li><a href="#llvm_eh_sjlj_callsite"><tt>llvm.eh.sjlj.callsite</tt></a></li>
   </ol></li>
   <li><a href="#asm">Asm Table Formats</a>
   <ol>
@@ -508,6 +509,24 @@
 
 </div>
 
+<!-- ======================================================================= -->
+<div class="doc_subsubsection">
+  <a name="llvm_eh_sjlj_callsite">llvm.eh.sjlj.callsite</a>
+</div>
+
+<div class="doc_text">
+
+<pre>
+  void %<a href="#llvm_eh_sjlj_callsite">llvm.eh.sjlj.callsite</a>(i32)
+</pre>
+
+<p>For SJLJ based exception handling, the <a href="#llvm_eh_sjlj_callsite">
+  <tt>llvm.eh.sjlj.callsite</tt></a> intrinsic identifies the callsite value
+  associated with the following invoke instruction. This is used to ensure
+  that landing pad entries in the LSDA are generated in the matching order.</p>
+
+</div>
+
 <!-- ======================================================================= -->
 <div class="doc_section">
   <a name="asm">Asm Table Formats</a>

include/llvm/CodeGen/MachineModuleInfo.h

@@ -113,7 +113,14 @@ class MachineModuleInfo : public ImmutablePass {
   // LandingPads - List of LandingPadInfo describing the landing pad information
   // in the current function.
   std::vector<LandingPadInfo> LandingPads;
-  
+
+  // Map of invoke call site index values to associated begin EH_LABEL for
+  // the current function.
+  DenseMap<unsigned, unsigned> CallSiteMap;
+
+  // The current call site index being processed, if any. 0 if none.
+  unsigned CurCallSite;
+
   // TypeInfos - List of C++ TypeInfo used in the current function.
   //
   std::vector<GlobalVariable *> TypeInfos;
@@ -294,7 +301,26 @@ public:
   const std::vector<LandingPadInfo> &getLandingPads() const {
     return LandingPads;
   }
-  
+
+  /// setCallSiteBeginLabel - Map the begin label for a call site
+  void setCallSiteBeginLabel(unsigned BeginLabel, unsigned Site) {
+    CallSiteMap[BeginLabel] = Site;
+  }
+
+  /// getCallSiteBeginLabel - Get the call site number for a begin label
+  unsigned getCallSiteBeginLabel(unsigned BeginLabel) {
+    assert(CallSiteMap.count(BeginLabel) &&
+           "Missing call site number for EH_LABEL!");
+    return CallSiteMap[BeginLabel];
+  }
+
+  /// setCurrentCallSite - Set the call site currently being processed.
+  void setCurrentCallSite(unsigned Site) { CurCallSite = Site; }
+
+  /// getCurrentCallSite - Get the call site currently being processed, if any.
+  /// return zero if none.
+  unsigned getCurrentCallSite(void) { return CurCallSite; }
+
   /// getTypeInfos - Return a reference to the C++ typeinfo for the current
   /// function.
   const std::vector<GlobalVariable *> &getTypeInfos() const {

include/llvm/Intrinsics.td

@@ -309,6 +309,7 @@ let Properties = [IntrNoMem] in {
   def int_eh_sjlj_setjmp  : Intrinsic<[llvm_i32_ty],  [llvm_ptr_ty]>;
   def int_eh_sjlj_longjmp : Intrinsic<[llvm_void_ty], [llvm_ptr_ty]>;
   def int_eh_sjlj_lsda    : Intrinsic<[llvm_ptr_ty]>;
+  def int_eh_sjlj_callsite: Intrinsic<[llvm_void_ty], [llvm_i32_ty]>;
 }
 
 //===---------------- Generic Variable Attribute Intrinsics----------------===//

lib/CodeGen/AsmPrinter/DwarfException.cpp

@@ -579,7 +579,16 @@ ComputeCallSiteTable(SmallVectorImpl<CallSiteEntry> &CallSites,
         }
 
         // Otherwise, create a new call-site.
-        CallSites.push_back(Site);
+        if (MAI->getExceptionHandlingType() == ExceptionHandling::Dwarf)
+          CallSites.push_back(Site);
+        else {
+          // SjLj EH must maintain the call sites in the order assigned
+          // to them by the SjLjPrepare pass.
+          unsigned SiteNo = MMI->getCallSiteBeginLabel(BeginLabel);
+          if (CallSites.size() < SiteNo)
+            CallSites.resize(SiteNo);
+          CallSites[SiteNo - 1] = Site;
+        }
         PreviousIsInvoke = true;
       } else {
         // Create a gap.

lib/CodeGen/MachineModuleInfo.cpp

@@ -71,6 +71,7 @@ void MachineModuleInfo::EndFunction() {
 
   // Clean up exception info.
   LandingPads.clear();
+  CallSiteMap.clear();
   TypeInfos.clear();
   FilterIds.clear();
   FilterEnds.clear();

lib/CodeGen/SelectionDAG/SelectionDAGBuilder.cpp

@@ -4327,6 +4327,16 @@ SelectionDAGBuilder::visitIntrinsicCall(CallInst &I, unsigned Intrinsic) {
     DAG.AssignOrdering(Res.getNode(), SDNodeOrder);
     return 0;
   }
+  case Intrinsic::eh_sjlj_callsite: {
+    MachineModuleInfo *MMI = DAG.getMachineModuleInfo();
+    ConstantInt *CI = dyn_cast<ConstantInt>(I.getOperand(1));
+    assert(CI && "Non-constant call site value in eh.sjlj.callsite!");
+    assert(MMI->getCurrentCallSite() == 0 && "Overlapping call sites!");
+
+    MMI->setCurrentCallSite(CI->getZExtValue());
+    return 0;
+  }
+
   case Intrinsic::convertff:
   case Intrinsic::convertfsi:
   case Intrinsic::convertfui:
@@ -4784,6 +4794,15 @@ void SelectionDAGBuilder::LowerCallTo(CallSite CS, SDValue Callee,
     // used to detect deletion of the invoke via the MachineModuleInfo.
     BeginLabel = MMI->NextLabelID();
 
+    // For SjLj, keep track of which landing pads go with which invokes
+    // so as to maintain the ordering of pads in the LSDA.
+    unsigned CallSiteIndex = MMI->getCurrentCallSite();
+    if (CallSiteIndex) {
+      MMI->setCallSiteBeginLabel(BeginLabel, CallSiteIndex);
+      // Now that the call site is handled, stop tracking it.
+      MMI->setCurrentCallSite(0);
+    }
+
     // Both PendingLoads and PendingExports must be flushed here;
     // this call might not return.
     (void)getRoot();

lib/CodeGen/SjLjEHPrepare.cpp

@@ -51,6 +51,7 @@ namespace {
     Value *PersonalityFn;
     Constant *SelectorFn;
     Constant *ExceptionFn;
+    Constant *CallSiteFn;
 
     Value *CallSite;
   public:
@@ -116,6 +117,7 @@ bool SjLjEHPass::doInitialization(Module &M) {
   LSDAAddrFn = Intrinsic::getDeclaration(&M, Intrinsic::eh_sjlj_lsda);
   SelectorFn = Intrinsic::getDeclaration(&M, Intrinsic::eh_selector);
   ExceptionFn = Intrinsic::getDeclaration(&M, Intrinsic::eh_exception);
+  CallSiteFn = Intrinsic::getDeclaration(&M, Intrinsic::eh_sjlj_callsite);
   PersonalityFn = 0;
 
   return true;
@@ -143,15 +145,14 @@ void SjLjEHPass::markInvokeCallSite(InvokeInst *II, unsigned InvokeNo,
     }
   }
 
-  // Insert a store of the invoke num before the invoke and store zero into the
-  // location afterward.
+  // Insert a store of the invoke num before the invoke
   new StoreInst(CallSiteNoC, CallSite, true, II);  // volatile
+  CallInst::Create(CallSiteFn, CallSiteNoC, "", II);
 
   // Add a switch case to our unwind block.
   CatchSwitch->addCase(SwitchValC, II->getUnwindDest());
-  // We still want this to look like an invoke so we emit the LSDA properly
-  // FIXME: ??? Or will this cause strangeness with mis-matched IDs like
-  //  when it was in the front end?
+  // We still want this to look like an invoke so we emit the LSDA properly,
+  // so we don't transform the invoke into a call here.
 }
 
 /// MarkBlocksLiveIn - Insert BB and all of its predescessors into LiveBBs until