[llvm] r218126 - Change DwarfCompileUnit::createGlobalVariable to getOrCreateGlobalVariable.

[Frederic Riss]

Author: friss
Date: Fri Sep 19 10:12:03 2014
New Revision: 218126

URL: http://llvm.org/viewvc/llvm-project?rev=218126&view=rev
Log:
Change DwarfCompileUnit::createGlobalVariable to getOrCreateGlobalVariable.

Summary:
This will allow to request the creation of a forward delacred variable
at is point of use (for imported declarations, this will be
DwarfDebug::constructImportedEntityDIE) rather than having to put the
forward decl in a retention list.

Note that getOrCreateGlobalVariable returns the actual definition DIE when the
routine creates a declaration and a definition DIE. If you agree this is the
right behavior, then I'll have a followup patch that registers the definition
in the DIE map instead of the declaration as it is today (this 'breaks' only
one test, where we test that the imported entity is the declaration). I'm
not sure what's best here, but it's easy enough for a consumer to follow the
DW_AT_specification link to get to the declaration, whereas it takes more
work to find the actual definition from a declaration DIE.

Reviewers: echristo, dblaikie, aprantl

Subscribers: llvm-commits

Differential Revision: http://reviews.llvm.org/D5381

Modified:
    llvm/trunk/lib/CodeGen/AsmPrinter/DwarfDebug.cpp
    llvm/trunk/lib/CodeGen/AsmPrinter/DwarfUnit.cpp
    llvm/trunk/lib/CodeGen/AsmPrinter/DwarfUnit.h

Modified: llvm/trunk/lib/CodeGen/AsmPrinter/DwarfDebug.cpp
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/CodeGen/AsmPrinter/DwarfDebug.cpp?rev=218126&r1=218125&r2=218126&view=diff
==============================================================================
--- llvm/trunk/lib/CodeGen/AsmPrinter/DwarfDebug.cpp (original)
+++ llvm/trunk/lib/CodeGen/AsmPrinter/DwarfDebug.cpp Fri Sep 19 10:12:03 2014
@@ -783,7 +783,7 @@ void DwarfDebug::beginModule() {
               ScopesWithImportedEntities.end(), less_first());
     DIArray GVs = CUNode.getGlobalVariables();
     for (unsigned i = 0, e = GVs.getNumElements(); i != e; ++i)
-      CU.createGlobalVariableDIE(DIGlobalVariable(GVs.getElement(i)));
+      CU.getOrCreateGlobalVariableDIE(DIGlobalVariable(GVs.getElement(i)));
     DIArray SPs = CUNode.getSubprograms();
     for (unsigned i = 0, e = SPs.getNumElements(); i != e; ++i)
       SPMap.insert(std::make_pair(SPs.getElement(i), &CU));

Modified: llvm/trunk/lib/CodeGen/AsmPrinter/DwarfUnit.cpp
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/CodeGen/AsmPrinter/DwarfUnit.cpp?rev=218126&r1=218125&r2=218126&view=diff
==============================================================================
--- llvm/trunk/lib/CodeGen/AsmPrinter/DwarfUnit.cpp (original)
+++ llvm/trunk/lib/CodeGen/AsmPrinter/DwarfUnit.cpp Fri Sep 19 10:12:03 2014
@@ -1596,11 +1596,11 @@ static const ConstantExpr *getMergedGlob
   return CE;
 }
 
-/// createGlobalVariableDIE - create global variable DIE.
-void DwarfCompileUnit::createGlobalVariableDIE(DIGlobalVariable GV) {
+/// getOrCreateGlobalVariableDIE - get or create global variable DIE.
+DIE *DwarfCompileUnit::getOrCreateGlobalVariableDIE(DIGlobalVariable GV) {
   // Check for pre-existence.
-  if (getDIE(GV))
-    return;
+  if (DIE *Die = getDIE(GV))
+    return Die;
 
   assert(GV.isGlobalVariable());
 
@@ -1725,18 +1725,19 @@ void DwarfCompileUnit::createGlobalVaria
     addBlock(*VariableDIE, dwarf::DW_AT_location, Loc);
   }
 
+  DIE *ResultDIE = VariableSpecDIE ? VariableSpecDIE : VariableDIE;
+
   if (addToAccelTable) {
-    DIE &AddrDIE = VariableSpecDIE ? *VariableSpecDIE : *VariableDIE;
-    DD->addAccelName(GV.getName(), AddrDIE);
+    DD->addAccelName(GV.getName(), *ResultDIE);
 
     // If the linkage name is different than the name, go ahead and output
     // that as well into the name table.
     if (GV.getLinkageName() != "" && GV.getName() != GV.getLinkageName())
-      DD->addAccelName(GV.getLinkageName(), AddrDIE);
+      DD->addAccelName(GV.getLinkageName(), *ResultDIE);
   }
 
-  addGlobalName(GV.getName(), VariableSpecDIE ? *VariableSpecDIE : *VariableDIE,
-                GV.getContext());
+  addGlobalName(GV.getName(), *ResultDIE, GV.getContext());
+  return ResultDIE;
 }
 
 /// constructSubrangeDIE - Construct subrange DIE from DISubrange.

Modified: llvm/trunk/lib/CodeGen/AsmPrinter/DwarfUnit.h
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/CodeGen/AsmPrinter/DwarfUnit.h?rev=218126&r1=218125&r2=218126&view=diff
==============================================================================
--- llvm/trunk/lib/CodeGen/AsmPrinter/DwarfUnit.h (original)
+++ llvm/trunk/lib/CodeGen/AsmPrinter/DwarfUnit.h Fri Sep 19 10:12:03 2014
@@ -536,8 +536,8 @@ public:
   /// Apply the DW_AT_stmt_list from this compile unit to the specified DIE.
   void applyStmtList(DIE &D);
 
-  /// createGlobalVariableDIE - create global variable DIE.
-  void createGlobalVariableDIE(DIGlobalVariable GV);
+  /// getOrCreateGlobalVariableDIE - get or create global variable DIE.
+  DIE *getOrCreateGlobalVariableDIE(DIGlobalVariable GV);
 
   /// addLabelAddress - Add a dwarf label attribute data and value using
   /// either DW_FORM_addr or DW_FORM_GNU_addr_index.