[llvm-commits] [llvm] r129307 - in /llvm/trunk/lib: CodeGen/ELFWriter.cpp ExecutionEngine/ExecutionEngine.cpp Transforms/IPO/GlobalOpt.cpp

[Nick Lewycky]

Author: nicholas
Date: Mon Apr 11 17:11:20 2011
New Revision: 129307

URL: http://llvm.org/viewvc/llvm-project?rev=129307&view=rev
Log:
Just because a GlobalVariable's initializer is [N x { i32, void ()* }] doesn't
mean that it has to be ConstantArray of ConstantStruct. We might have
ConstantAggregateZero, at either level, so don't crash on that.

Also, semi-deprecate the sentinal value. The linker isn't aware of sentinals so
we end up with the two lists appended, each with their "sentinals" on them.
Different parts of LLVM treated sentinals differently, so make them all just
ignore the single entry and continue on with the rest of the list.

Modified:
    llvm/trunk/lib/CodeGen/ELFWriter.cpp
    llvm/trunk/lib/ExecutionEngine/ExecutionEngine.cpp
    llvm/trunk/lib/Transforms/IPO/GlobalOpt.cpp

Modified: llvm/trunk/lib/CodeGen/ELFWriter.cpp
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/CodeGen/ELFWriter.cpp?rev=129307&r1=129306&r2=129307&view=diff
==============================================================================
--- llvm/trunk/lib/CodeGen/ELFWriter.cpp (original)
+++ llvm/trunk/lib/CodeGen/ELFWriter.cpp Mon Apr 11 17:11:20 2011
@@ -662,12 +662,16 @@
 void ELFWriter::EmitXXStructorList(Constant *List, ELFSection &Xtor) {
   // Should be an array of '{ i32, void ()* }' structs.  The first value is the
   // init priority, which we ignore.
+  if (List->isNullValue()) return;
   ConstantArray *InitList = cast<ConstantArray>(List);
   for (unsigned i = 0, e = InitList->getNumOperands(); i != e; ++i) {
+    if (InitList->getOperand(i)->isNullValue())
+      continue;
     ConstantStruct *CS = cast<ConstantStruct>(InitList->getOperand(i));
 
     if (CS->getOperand(1)->isNullValue())
-      return;  // Found a null terminator, exit printing.
+      continue;
+
     // Emit the function pointer.
     EmitGlobalConstant(CS->getOperand(1), Xtor);
   }

Modified: llvm/trunk/lib/ExecutionEngine/ExecutionEngine.cpp
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/ExecutionEngine/ExecutionEngine.cpp?rev=129307&r1=129306&r2=129307&view=diff
==============================================================================
--- llvm/trunk/lib/ExecutionEngine/ExecutionEngine.cpp (original)
+++ llvm/trunk/lib/ExecutionEngine/ExecutionEngine.cpp Mon Apr 11 17:11:20 2011
@@ -313,13 +313,17 @@
 
   // Should be an array of '{ i32, void ()* }' structs.  The first value is
   // the init priority, which we ignore.
+  if (isa<ConstantAggregateZero>(GV->getInitializer()))
+    return;
   ConstantArray *InitList = cast<ConstantArray>(GV->getInitializer());
   for (unsigned i = 0, e = InitList->getNumOperands(); i != e; ++i) {
+    if (isa<ConstantAggregateZero>(InitList->getOperand(i)))
+      continue;
     ConstantStruct *CS = cast<ConstantStruct>(InitList->getOperand(i));
 
     Constant *FP = CS->getOperand(1);
     if (FP->isNullValue())
-      break;  // Found a null terminator, exit.
+      continue;  // Found a sentinal value, ignore.
 
     // Strip off constant expression casts.
     if (ConstantExpr *CE = dyn_cast<ConstantExpr>(FP))

Modified: llvm/trunk/lib/Transforms/IPO/GlobalOpt.cpp
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/Transforms/IPO/GlobalOpt.cpp?rev=129307&r1=129306&r2=129307&view=diff
==============================================================================
--- llvm/trunk/lib/Transforms/IPO/GlobalOpt.cpp (original)
+++ llvm/trunk/lib/Transforms/IPO/GlobalOpt.cpp Mon Apr 11 17:11:20 2011
@@ -1954,14 +1954,15 @@
   // Verify that the initializer is simple enough for us to handle. We are
   // only allowed to optimize the initializer if it is unique.
   if (!GV->hasUniqueInitializer()) return 0;
-  
-  ConstantArray *CA = dyn_cast<ConstantArray>(GV->getInitializer());
-  if (!CA) return 0;
 
-  for (User::op_iterator i = CA->op_begin(), e = CA->op_end(); i != e; ++i) {
-    ConstantStruct *CS = dyn_cast<ConstantStruct>(*i);
-    if (!CS) return 0;
+  if (isa<ConstantAggregateZero>(GV->getInitializer()))
+    return GV;
+  ConstantArray *CA = cast<ConstantArray>(GV->getInitializer());
 
+  for (User::op_iterator i = CA->op_begin(), e = CA->op_end(); i != e; ++i) {
+    if (isa<ConstantAggregateZero>(*i))
+      continue;
+    ConstantStruct *CS = cast<ConstantStruct>(*i);
     if (isa<ConstantPointerNull>(CS->getOperand(1)))
       continue;
 
@@ -1981,6 +1982,8 @@
 /// ParseGlobalCtors - Given a llvm.global_ctors list that we can understand,
 /// return a list of the functions and null terminator as a vector.
 static std::vector<Function*> ParseGlobalCtors(GlobalVariable *GV) {
+  if (GV->getInitializer()->isNullValue())
+    return std::vector<Function*>();
   ConstantArray *CA = cast<ConstantArray>(GV->getInitializer());
   std::vector<Function*> Result;
   Result.reserve(CA->getNumOperands());
@@ -2011,7 +2014,7 @@
       const PointerType *PFTy = PointerType::getUnqual(FTy);
       CSVals[1] = Constant::getNullValue(PFTy);
       CSVals[0] = ConstantInt::get(Type::getInt32Ty(GCL->getContext()),
-                                   2147483647);
+                                   0x7fffffff);
     }
     CAList.push_back(ConstantStruct::get(GCL->getContext(), CSVals, false));
   }