[PATCH] D33704: [DIBuilder] Add a more fine-grained finalization method

[Keno Fischer via Phabricator via llvm-commits]

loladiro created this revision.

Clang wants to clone a function before it is done building the entire
compilation unit. As of now, there is no good way to do that, because
CloneFunction doesn't like dealing with temporary metadata. However,
as long as clang doesn't want to add any variables to this SP, it
should be fine to just prematurely finalize it. Add an API to allow this.

This is done in preparation of a clang commit to fix the assertion that
necessitated the revert of https://reviews.llvm.org/D33655.


https://reviews.llvm.org/D33704

Files:
  include/llvm/IR/DIBuilder.h
  lib/IR/DIBuilder.cpp


Index: lib/IR/DIBuilder.cpp
===================================================================
--- lib/IR/DIBuilder.cpp
+++ lib/IR/DIBuilder.cpp
@@ -39,6 +39,21 @@
   UnresolvedNodes.emplace_back(N);
 }
 
+void DIBuilder::finalizeSP(DISubprogram *SP) {
+  MDTuple *Temp = SP->getVariables().get();
+  if (!Temp || !Temp->isTemporary())
+    return;
+
+  SmallVector<Metadata *, 4> Variables;
+
+  auto PV = PreservedVariables.find(SP);
+  if (PV != PreservedVariables.end())
+    Variables.append(PV->second.begin(), PV->second.end());
+
+  DINodeArray AV = getOrCreateArray(Variables);
+  TempMDTuple(Temp)->replaceAllUsesWith(AV.get());
+}
+
 void DIBuilder::finalize() {
   if (!CUNode) {
     assert(!AllowUnresolvedNodes &&
@@ -62,25 +77,11 @@
     CUNode->replaceRetainedTypes(MDTuple::get(VMContext, RetainValues));
 
   DISubprogramArray SPs = MDTuple::get(VMContext, AllSubprograms);
-  auto resolveVariables = [&](DISubprogram *SP) {
-    MDTuple *Temp = SP->getVariables().get();
-    if (!Temp)
-      return;
-
-    SmallVector<Metadata *, 4> Variables;
-
-    auto PV = PreservedVariables.find(SP);
-    if (PV != PreservedVariables.end())
-      Variables.append(PV->second.begin(), PV->second.end());
-
-    DINodeArray AV = getOrCreateArray(Variables);
-    TempMDTuple(Temp)->replaceAllUsesWith(AV.get());
-  };
   for (auto *SP : SPs)
-    resolveVariables(SP);
+    finalizeSP(SP);
   for (auto *N : RetainValues)
     if (auto *SP = dyn_cast<DISubprogram>(N))
-      resolveVariables(SP);
+      finalizeSP(SP);
 
   if (!AllGVs.empty())
     CUNode->replaceGlobalVariables(MDTuple::get(VMContext, AllGVs));
Index: include/llvm/IR/DIBuilder.h
===================================================================
--- include/llvm/IR/DIBuilder.h
+++ include/llvm/IR/DIBuilder.h
@@ -86,6 +86,10 @@
     /// Construct any deferred debug info descriptors.
     void finalize();
 
+    /// Finalize a specific subprogram - no new variables may be added to this
+    /// subprogram afterwards.
+    void finalizeSP(DISubprogram *SP);
+
     /// A CompileUnit provides an anchor for all debugging
     /// information generated during this instance of compilation.
     /// \param Lang          Source programming language, eg. dwarf::DW_LANG_C99


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