Make sure that all globals are internal, except for "start" functions.

src/IceGlobalInits.h

Index: src/IceGlobalInits.h
diff --git a/src/IceGlobalInits.h b/src/IceGlobalInits.h
index 8f51db243f02d229ee057634a1d9b3e6e60a5246..6c82fea3ebc3923db222c2b7abce8d4cacc12532 100644
--- a/src/IceGlobalInits.h
+++ b/src/IceGlobalInits.h
@@ -92,6 +92,19 @@ protected:
                     llvm::GlobalValue::LinkageTypes Linkage)
       : Kind(Kind), Linkage(Linkage) {}
 
+  /// Returns true if linkage is defined correctly for the global declaration,
+  /// based on default rules.
+  bool verifyLinkageDefault(GlobalContext *Ctx) const {

[Jim Stichnoth, 2015/10/06 20:16:21]

Here and below, maybe you can use "const GlobalContext *"?

[Karl, 2015/10/06 21:47:18]

Done.

+    switch (Linkage) {
+      default:
+        return false;
+      case llvm::GlobalValue::InternalLinkage:
+        return true;
+      case llvm::GlobalValue::ExternalLinkage:
+        return Ctx->getFlags().getAllowExternDefinedSymbols();
+    }
+  }
+
   const GlobalDeclarationKind Kind;
   IceString Name;
   llvm::GlobalValue::LinkageTypes Linkage;
@@ -124,6 +137,13 @@ public:
   void dump(GlobalContext *Ctx, Ostream &Stream) const final;
   bool getSuppressMangling() const final { return isExternal() && IsProto; }
 
+  /// Returns true if linkage is correct for the function declaration.
+  bool verifyLinkageCorrect(GlobalContext *Ctx) const {
+    if (isPNaClABIExternalName() || isIntrinsicName(Ctx))
+      return Linkage == llvm::GlobalValue::ExternalLinkage;
+    return verifyLinkageDefault(Ctx);
+  }
+
 private:
   const Ice::FuncSigType Signature;
   llvm::CallingConv::ID CallingConv;
@@ -134,6 +154,18 @@ private:
                       llvm::GlobalValue::LinkageTypes Linkage, bool IsProto)
       : GlobalDeclaration(FunctionDeclarationKind, Linkage),
         Signature(Signature), CallingConv(CallingConv), IsProto(IsProto) {}
+
+  bool isPNaClABIExternalName() const {
+    const char *Name = getName().c_str();
+    return strcmp(Name, "_start") == 0 || strcmp(Name, "__pnacl_pso_root") == 0;
+  }
+
+  bool isIntrinsicName(GlobalContext *Ctx) const {
+    if (!hasName()) return false;

[Jim Stichnoth, 2015/10/06 20:16:21]

make format

[Karl, 2015/10/06 21:47:18]

Done.

+    bool BadIntrinsic;
+    return Ctx->getIntrinsicsInfo().find(getName(), BadIntrinsic)
+        && !BadIntrinsic;
+  }
 };
 
 /// Models a global variable declaration, and its initializers.
@@ -309,6 +341,11 @@ public:
   /// initialization).
   void dump(GlobalContext *Ctx, Ostream &Stream) const final;
 
+  /// Returns true if linkage is correct for the variable declaration.
+  bool verifyLinkageCorrect(GlobalContext *Ctx) const {
+    return verifyLinkageDefault(Ctx);
+  }
+
   static bool classof(const GlobalDeclaration *Addr) {
     return Addr->getKind() == VariableDeclarationKind;
   }