Enhance the IR type lowering code to be much smarter about recursively lowering

types.  Fore xample, we used to lower:

struct bar { int a; };
struct foo {
 void (*FP)(struct bar);
} G;

to:

%struct.foo = type { {}* }

since the function pointer would cause recursive translation of bar and
we didn't know if that would get us into trouble.  We are now smart enough
to know that it is fine, so we get this type instead:

%struct.foo = type { void (i32)* }

Codegen still needs to be prepared for uncooperative types at any place,
which is why I let the maximally uncooperative code sit around for awhile to
help shake out the bugs.

llvm-svn: 135244

1 files changed, 13 insertions, 0 deletions

diff --git a/clang/lib/CodeGen/CGCall.cpp b/clang/lib/CodeGen/CGCall.cpp
index 39a143feeca..e7700990589 100644
--- a/clang/lib/CodeGen/CGCall.cpp
+++ b/clang/lib/CodeGen/CGCall.cpp
@@ -265,9 +265,15 @@ const CGFunctionInfo &CodeGenTypes::getFunctionInfo(CanQualType ResTy,
                           ArgTys.data(), ArgTys.size());
   FunctionInfos.InsertNode(FI, InsertPos);
 
+  bool Inserted = FunctionsBeingProcessed.insert(FI); (void)Inserted;
+  assert(Inserted && "Recursively being processed?");
+  
   // Compute ABI information.
   getABIInfo().computeInfo(*FI);
 
+  bool Erased = FunctionsBeingProcessed.erase(FI); (void)Erased;
+  assert(Erased && "Not in set?");
+
   // Loop over all of the computed argument and return value info.  If any of
   // them are direct or extend without a specified coerce type, specify the
   // default now.
@@ -604,6 +610,10 @@ llvm::FunctionType *CodeGenTypes::GetFunctionType(GlobalDecl GD) {
 
 llvm::FunctionType *
 CodeGenTypes::GetFunctionType(const CGFunctionInfo &FI, bool isVariadic) {
+  
+  bool Inserted = FunctionsBeingProcessed.insert(&FI); (void)Inserted;
+  assert(Inserted && "Recursively being processed?");
+  
   llvm::SmallVector<llvm::Type*, 8> argTypes;
   const llvm::Type *resultType = 0;
 
@@ -669,6 +679,9 @@ CodeGenTypes::GetFunctionType(const CGFunctionInfo &FI, bool isVariadic) {
     }
   }
 
+  bool Erased = FunctionsBeingProcessed.erase(&FI); (void)Erased;
+  assert(Erased && "Not in set?");
+  
   return llvm::FunctionType::get(resultType, argTypes, isVariadic);
 }