Fix the bug that would cause Python to crash at startup.

When emitting the static variables we need to make sure that the order is preserved. 
Fix this by making StaticDecls a std::list which has O(1) random removal.


git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@61621 91177308-0d34-0410-b5e6-96231b3b80d8

lib/CodeGen/CodeGenModule.cpp

@@ -361,26 +361,27 @@ void CodeGenModule::EmitStatics() {
   bool Changed;
   do {
     Changed = false;
-    for (unsigned i = 0, e = StaticDecls.size(); i != e; ++i) {
-      const ValueDecl *D = StaticDecls[i];
-
+    
+    for (std::list<const ValueDecl*>::iterator i = StaticDecls.begin(),
+         e = StaticDecls.end(); i != e; ) {
+      const ValueDecl *D = *i;
+      
       // Check if we have used a decl with the same name
       // FIXME: The AST should have some sort of aggregate decls or
       // global symbol map.
       // FIXME: This is missing some important cases. For example, we
       // need to check for uses in an alias and in a constructor.
-      if (!GlobalDeclMap.count(D->getIdentifier()))
+      if (!GlobalDeclMap.count(D->getIdentifier())) {
+        i++;
         continue;
-
+      }
+      
       // Emit the definition.
       EmitGlobalDefinition(D);
 
       // Erase the used decl from the list.
-      StaticDecls[i] = StaticDecls.back();
-      StaticDecls.pop_back();
-      --i;
-      --e;
-      
+      i = StaticDecls.erase(i);
+
       // Remember that we made a change.
       Changed = true;
     }

lib/CodeGen/CodeGenModule.h

@@ -21,6 +21,8 @@
 
 #include "CGCall.h"
 
+#include <list>
+
 namespace llvm {
   class Module;
   class Constant;
@@ -97,7 +99,7 @@ class CodeGenModule {
   /// will lazily emit definitions for only the decls that were
   /// actually used.  This should contain only Function and Var decls,
   /// and only those which actually define something.
-  std::vector<const ValueDecl*> StaticDecls;
+  std::list<const ValueDecl*> StaticDecls;
   
   /// GlobalCtors - Store the list of global constructors and their
   /// respective priorities to be emitted when the translation unit is

test/CodeGen/static-order.c

@@ -0,0 +1,19 @@
+// RUN: clang -emit-llvm -o - %s | not grep "zeroinitializer"
+
+struct s {
+    int a;
+};
+
+static void *v;
+
+static struct s a;
+
+static struct s a = {
+    10
+};
+
+void *f()
+{
+  if (a.a)
+    return v;
+}