Initial commit of the 'landingpad' instruction.

This implements the 'landingpad' instruction. It's used to indicate that a basic
block is a landing pad. There are several restrictions on its use (see
LangRef.html for more detail). These restrictions allow the exception handling
code to gather the information it needs in a much more sane way.

This patch has the definition, implementation, C interface, parsing, and bitcode
support in it.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@137501 91177308-0d34-0410-b5e6-96231b3b80d8

2 files changed, 55 insertions, 0 deletions

diff --git a/lib/Bitcode/Reader/BitcodeReader.cpp b/lib/Bitcode/Reader/BitcodeReader.cpp
index 8f4e8c3e46..a33705d2dd 100644
--- a/lib/Bitcode/Reader/BitcodeReader.cpp
+++ b/lib/Bitcode/Reader/BitcodeReader.cpp
@@ -2543,6 +2543,44 @@ bool BitcodeReader::ParseFunctionBody(Function *F) {
       break;
     }
 
+    case bitc::FUNC_CODE_INST_LANDINGPAD: {
+      // LANDINGPAD: [ty, val, val, num, (id0,val0 ...)?]
+      unsigned Idx = 0;
+      if (Record.size() < 4)
+        return Error("Invalid LANDINGPAD record");
+      Type *Ty = getTypeByID(Record[Idx++]);
+      if (!Ty) return Error("Invalid LANDINGPAD record");
+      Value *PersFn = 0;
+      if (getValueTypePair(Record, Idx, NextValueNo, PersFn))
+        return Error("Invalid LANDINGPAD record");
+
+      bool IsCleanup = !!Record[Idx++];
+      unsigned NumClauses = Record[Idx++];
+      LandingPadInst *LP = LandingPadInst::Create(Ty, PersFn, NumClauses);
+      LP->setCleanup(IsCleanup);
+      for (unsigned J = 0; J != NumClauses; ++J) {
+        LandingPadInst::ClauseType CT =
+          LandingPadInst::ClauseType(Record[Idx++]); (void)CT;
+        Value *Val;
+
+        if (getValueTypePair(Record, Idx, NextValueNo, Val)) {
+          delete LP;
+          return Error("Invalid LANDINGPAD record");
+        }
+
+        assert((CT != LandingPadInst::Catch ||
+                !isa<ArrayType>(Val->getType())) &&
+               "Catch clause has a invalid type!");
+        assert((CT != LandingPadInst::Filter ||
+                isa<ArrayType>(Val->getType())) &&
+               "Filter clause has invalid type!");
+        LP->addClause(Val);
+      }
+
+      I = LP;
+      break;
+    }
+
     case bitc::FUNC_CODE_INST_ALLOCA: { // ALLOCA: [instty, opty, op, align]
       if (Record.size() != 4)
         return Error("Invalid ALLOCA record");
diff --git a/lib/Bitcode/Writer/BitcodeWriter.cpp b/lib/Bitcode/Writer/BitcodeWriter.cpp
index 12f0715f1a..5b3d96953a 100644
--- a/lib/Bitcode/Writer/BitcodeWriter.cpp
+++ b/lib/Bitcode/Writer/BitcodeWriter.cpp
@@ -1165,6 +1165,23 @@ static void WriteInstruction(const Instruction &I, unsigned InstID,
     break;
   }
 
+  case Instruction::LandingPad: {
+    const LandingPadInst &LP = cast<LandingPadInst>(I);
+    Code = bitc::FUNC_CODE_INST_LANDINGPAD;
+    Vals.push_back(VE.getTypeID(LP.getType()));
+    PushValueAndType(LP.getPersonalityFn(), InstID, Vals, VE);
+    Vals.push_back(LP.isCleanup());
+    Vals.push_back(LP.getNumClauses());
+    for (unsigned I = 0, E = LP.getNumClauses(); I != E; ++I) {
+      if (LP.isCatch(I))
+        Vals.push_back(LandingPadInst::Catch);
+      else
+        Vals.push_back(LandingPadInst::Filter);
+      PushValueAndType(LP.getClause(I), InstID, Vals, VE);
+    }
+    break;
+  }
+
   case Instruction::Alloca:
     Code = bitc::FUNC_CODE_INST_ALLOCA;
     Vals.push_back(VE.getTypeID(I.getType()));