Check that GlobalAliases don't have section or alignment.

An alias is always in the section of its aliasee and has the same alignment
(since it has the same address).

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@201354 91177308-0d34-0410-b5e6-96231b3b80d8

include/llvm/IR/GlobalValue.h

@@ -112,8 +112,12 @@ public:
 
   bool hasSection() const { return !Section.empty(); }
   const std::string &getSection() const { return Section; }
-  void setSection(StringRef S) { Section = S; }
-  
+  void setSection(StringRef S) {
+    assert((getValueID() != Value::GlobalAliasVal || S.empty()) &&
+           "GlobalAlias should not have a section!");
+    Section = S;
+  }
+
   /// If the usage is empty (except transitively dead constants), then this
   /// global value can be safely deleted since the destructor will
   /// delete the dead constants as well.

lib/IR/Globals.cpp

@@ -57,6 +57,8 @@ void GlobalValue::copyAttributesFrom(const GlobalValue *Src) {
 }
 
 void GlobalValue::setAlignment(unsigned Align) {
+  assert((!isa<GlobalAlias>(this) || !Align) &&
+         "GlobalAlias should not have an alignment!");
   assert((Align & (Align-1)) == 0 && "Alignment is not a power of 2!");
   assert(Align <= MaximumAlignment &&
          "Alignment is greater than MaximumAlignment!");

lib/IR/Verifier.cpp

@@ -475,6 +475,8 @@ void Verifier::visitGlobalAlias(const GlobalAlias &GA) {
   Assert1(GA.getType() == GA.getAliasee()->getType(),
           "Alias and aliasee types should match!", &GA);
   Assert1(!GA.hasUnnamedAddr(), "Alias cannot have unnamed_addr!", &GA);
+  Assert1(!GA.hasSection(), "Alias cannot have a section!", &GA);
+  Assert1(!GA.getAlignment(), "Alias connot have an alignment", &GA);
 
   const Constant *Aliasee = GA.getAliasee();