Beginning of the Great Exception Handling Rewrite.

* Add a "landing pad" attribute to the BasicBlock.
* Modify the bitcode reader and writer to handle said attribute.

Later: The verifier will ensure that the landing pad attribute is used in the
appropriate manner. I.e., not applied to the entry block, and applied only to
basic blocks that are branched to via a `dispatch' instruction.

(This is a work-in-progress.)


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@129235 91177308-0d34-0410-b5e6-96231b3b80d8

3 files changed, 10 insertions, 0 deletions

diff --git a/lib/AsmParser/LLLexer.cpp b/lib/AsmParser/LLLexer.cpp
index 857fa1ef62..da26cb8210 100644
--- a/lib/AsmParser/LLLexer.cpp
+++ b/lib/AsmParser/LLLexer.cpp
@@ -587,6 +587,8 @@ lltok::Kind LLLexer::LexIdentifier() {
 
   KEYWORD(x);
   KEYWORD(blockaddress);
+
+  KEYWORD(landingpad);
 #undef KEYWORD
 
   // Keywords for types.
diff --git a/lib/AsmParser/LLParser.cpp b/lib/AsmParser/LLParser.cpp
index 0c3237a679..afd10a0826 100644
--- a/lib/AsmParser/LLParser.cpp
+++ b/lib/AsmParser/LLParser.cpp
@@ -2918,6 +2918,11 @@ bool LLParser::ParseBasicBlock(PerFunctionState &PFS) {
   BasicBlock *BB = PFS.DefineBB(Name, NameLoc);
   if (BB == 0) return true;
 
+  if (Lex.getKind() == lltok::kw_landingpad) {
+    BB->setIsLandingPad();
+    Lex.Lex();
+  }
+
   std::string NameStr;
 
   // Parse the instructions in this block until we get a terminator.
diff --git a/lib/AsmParser/LLToken.h b/lib/AsmParser/LLToken.h
index 576da191ae..53cf8d87f3 100644
--- a/lib/AsmParser/LLToken.h
+++ b/lib/AsmParser/LLToken.h
@@ -125,6 +125,9 @@ namespace lltok {
     kw_extractelement, kw_insertelement, kw_shufflevector, kw_getresult,
     kw_extractvalue, kw_insertvalue, kw_blockaddress,
 
+    // Basic block attribute.
+    kw_landingpad,
+
     // Unsigned Valued tokens (UIntVal).
     GlobalID,          // @42
     LocalVarID,        // %42