llvm.global_[cd]tor is defined to be either external, or appending with an array

of { i32, void ()* }. Teach the verifier to verify that, deleting copies of
checks strewn about.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@129128 91177308-0d34-0410-b5e6-96231b3b80d8

4 files changed, 33 insertions, 37 deletions

diff --git a/lib/CodeGen/ELFWriter.cpp b/lib/CodeGen/ELFWriter.cpp
index 0fd1e8e..25c2e02 100644
--- a/lib/CodeGen/ELFWriter.cpp
+++ b/lib/CodeGen/ELFWriter.cpp
@@ -660,19 +660,17 @@ bool ELFWriter::EmitSpecialLLVMGlobal(const GlobalVariable *GV) {
 /// EmitXXStructorList - Emit the ctor or dtor list.  This just emits out the 
 /// function pointers, ignoring the init priority.
 void ELFWriter::EmitXXStructorList(Constant *List, ELFSection &Xtor) {
-  // Should be an array of '{ int, void ()* }' structs.  The first value is the
+  // Should be an array of '{ i32, void ()* }' structs.  The first value is the
   // init priority, which we ignore.
-  if (!isa<ConstantArray>(List)) return;
   ConstantArray *InitList = cast<ConstantArray>(List);
-  for (unsigned i = 0, e = InitList->getNumOperands(); i != e; ++i)
-    if (ConstantStruct *CS = dyn_cast<ConstantStruct>(InitList->getOperand(i))){
-      if (CS->getNumOperands() != 2) return;  // Not array of 2-element structs.
-
-      if (CS->getOperand(1)->isNullValue())
-        return;  // Found a null terminator, exit printing.
-      // Emit the function pointer.
-      EmitGlobalConstant(CS->getOperand(1), Xtor);
-    }
+  for (unsigned i = 0, e = InitList->getNumOperands(); i != e; ++i) {
+    ConstantStruct *CS = cast<ConstantStruct>(InitList->getOperand(i));
+
+    if (CS->getOperand(1)->isNullValue())
+      return;  // Found a null terminator, exit printing.
+    // Emit the function pointer.
+    EmitGlobalConstant(CS->getOperand(1), Xtor);
+  }
 }
 
 bool ELFWriter::runOnMachineFunction(MachineFunction &MF) {
diff --git a/lib/ExecutionEngine/ExecutionEngine.cpp b/lib/ExecutionEngine/ExecutionEngine.cpp
index 438e119..13e07ac 100644
--- a/lib/ExecutionEngine/ExecutionEngine.cpp
+++ b/lib/ExecutionEngine/ExecutionEngine.cpp
@@ -313,13 +313,9 @@ void ExecutionEngine::runStaticConstructorsDestructors(Module *module,
 
   // Should be an array of '{ i32, void ()* }' structs.  The first value is
   // the init priority, which we ignore.
-  ConstantArray *InitList = dyn_cast<ConstantArray>(GV->getInitializer());
-  if (!InitList) return;
+  ConstantArray *InitList = cast<ConstantArray>(GV->getInitializer());
   for (unsigned i = 0, e = InitList->getNumOperands(); i != e; ++i) {
-    ConstantStruct *CS =
-      dyn_cast<ConstantStruct>(InitList->getOperand(i));
-    if (!CS) continue;
-    if (CS->getNumOperands() != 2) return; // Not array of 2-element structs.
+    ConstantStruct *CS = cast<ConstantStruct>(InitList->getOperand(i));
 
     Constant *FP = CS->getOperand(1);
     if (FP->isNullValue())
diff --git a/lib/Transforms/IPO/GlobalOpt.cpp b/lib/Transforms/IPO/GlobalOpt.cpp
index 1f13c55..5b6ed2c 100644
--- a/lib/Transforms/IPO/GlobalOpt.cpp
+++ b/lib/Transforms/IPO/GlobalOpt.cpp
@@ -1944,35 +1944,20 @@ bool GlobalOpt::OptimizeGlobalVars(Module &M) {
   return Changed;
 }
 
-/// FindGlobalCtors - Find the llvm.globalctors list, verifying that all
+/// FindGlobalCtors - Find the llvm.global_ctors list, verifying that all
 /// initializers have an init priority of 65535.
 GlobalVariable *GlobalOpt::FindGlobalCtors(Module &M) {
   GlobalVariable *GV = M.getGlobalVariable("llvm.global_ctors");
   if (GV == 0) return 0;
   
-  // Found it, verify it's an array of { int, void()* }.
-  const ArrayType *ATy =dyn_cast<ArrayType>(GV->getType()->getElementType());
-  if (!ATy) return 0;
-  const StructType *STy = dyn_cast<StructType>(ATy->getElementType());
-  if (!STy || STy->getNumElements() != 2 ||
-      !STy->getElementType(0)->isIntegerTy(32)) return 0;
-  const PointerType *PFTy = dyn_cast<PointerType>(STy->getElementType(1));
-  if (!PFTy) return 0;
-  const FunctionType *FTy = dyn_cast<FunctionType>(PFTy->getElementType());
-  if (!FTy || !FTy->getReturnType()->isVoidTy() ||
-      FTy->isVarArg() || FTy->getNumParams() != 0)
-    return 0;
-
   // 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;
+  ConstantArray *CA = cast<ConstantArray>(GV->getInitializer());
   
   for (User::op_iterator i = CA->op_begin(), e = CA->op_end(); i != e; ++i) {
-    ConstantStruct *CS = dyn_cast<ConstantStruct>(*i);
-    if (CS == 0) return 0;
+    ConstantStruct *CS = cast<ConstantStruct>(*i);
     
     if (isa<ConstantPointerNull>(CS->getOperand(1)))
       continue;
@@ -1982,8 +1967,8 @@ GlobalVariable *GlobalOpt::FindGlobalCtors(Module &M) {
       return 0;
 
     // Init priority must be standard.
-    ConstantInt *CI = dyn_cast<ConstantInt>(CS->getOperand(0));
-    if (!CI || CI->getZExtValue() != 65535)
+    ConstantInt *CI = cast<ConstantInt>(CS->getOperand(0));
+    if (CI->getZExtValue() != 65535)
       return 0;
   }
 
diff --git a/lib/VMCore/Verifier.cpp b/lib/VMCore/Verifier.cpp
index 1143151..8b89110 100644
--- a/lib/VMCore/Verifier.cpp
+++ b/lib/VMCore/Verifier.cpp
@@ -471,6 +471,23 @@ void Verifier::visitGlobalVariable(GlobalVariable &GV) {
             "invalid linkage type for global declaration", &GV);
   }
 
+  if (GV.hasName() && (GV.getName() == "llvm.global_ctors" ||
+                       GV.getName() == "llvm.global_dtors")) {
+    Assert1(!GV.hasInitializer() || GV.hasAppendingLinkage(),
+            "invalid linkage for intrinsic global variable", &GV);
+    // Don't worry about emitting an error for it not being an array,
+    // visitGlobalValue will complain on appending non-array.
+    if (const ArrayType *ATy = dyn_cast<ArrayType>(GV.getType())) {
+      const StructType *STy = dyn_cast<StructType>(ATy->getElementType());
+      const PointerType *FuncPtrTy =
+          FunctionType::get(Type::getVoidTy(*Context), false)->getPointerTo();
+      Assert1(STy && STy->getNumElements() == 2 &&
+              STy->getTypeAtIndex(0u)->isIntegerTy(32) &&
+              STy->getTypeAtIndex(1) == FuncPtrTy,
+              "wrong type for intrinsic global variable", &GV);
+    }
+  }
+
   visitGlobalValue(GV);
 }