Emit the globals, metadata, etc. associated with static variables even when

they're unreachable.  This matters because (if they're POD, or if this is C)
the scope containing the variable might be reachable even if the variable
isn't.  Fixes PR7044.



git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@103052 91177308-0d34-0410-b5e6-96231b3b80d8

3 files changed, 15 insertions, 5 deletions

diff --git a/lib/CodeGen/CGDecl.cpp b/lib/CodeGen/CGDecl.cpp
index ba3a2b47ed..48198ff576 100644
--- a/lib/CodeGen/CGDecl.cpp
+++ b/lib/CodeGen/CGDecl.cpp
@@ -231,9 +231,6 @@ CodeGenFunction::AddInitializerToGlobalBlockVarDecl(const VarDecl &D,
 
 void CodeGenFunction::EmitStaticBlockVarDecl(const VarDecl &D,
                                       llvm::GlobalValue::LinkageTypes Linkage) {
-  // Bail out early if the block is unreachable.
-  if (!Builder.GetInsertBlock()) return;
-
   llvm::Value *&DMEntry = LocalDeclMap[&D];
   assert(DMEntry == 0 && "Decl already exists in localdeclmap!");
 
@@ -245,9 +242,9 @@ void CodeGenFunction::EmitStaticBlockVarDecl(const VarDecl &D,
   if (getContext().getLangOptions().CPlusPlus)
     CGM.setStaticLocalDeclAddress(&D, GV);
 
+  // We can't have a VLA here, but we can have a pointer to a VLA,
+  // even though that doesn't really make any sense.
   // Make sure to evaluate VLA bounds now so that we have them for later.
-  //
-  // FIXME: Can this happen?
   if (D.getType()->isVariablyModifiedType())
     EmitVLASize(D.getType());
 
diff --git a/lib/CodeGen/CGDeclCXX.cpp b/lib/CodeGen/CGDeclCXX.cpp
index f6c805fdca..6afa53868e 100644
--- a/lib/CodeGen/CGDeclCXX.cpp
+++ b/lib/CodeGen/CGDeclCXX.cpp
@@ -279,6 +279,9 @@ static llvm::Constant *getGuardAbortFn(CodeGenFunction &CGF) {
 void
 CodeGenFunction::EmitStaticCXXBlockVarDeclInit(const VarDecl &D,
                                                llvm::GlobalVariable *GV) {
+  // Bail out early if this initializer isn't reachable.
+  if (!Builder.GetInsertBlock()) return;
+
   bool ThreadsafeStatics = getContext().getLangOptions().ThreadsafeStatics;
   
   llvm::SmallString<256> GuardVName;
diff --git a/test/CodeGen/staticinit.c b/test/CodeGen/staticinit.c
index cd1f059e57..8c5cdd0564 100644
--- a/test/CodeGen/staticinit.c
+++ b/test/CodeGen/staticinit.c
@@ -29,3 +29,13 @@ void foo(void) {
 // RUN: grep "f1.l0 = internal global i32 ptrtoint (i32 ()\* @f1 to i32)" %t
 int f1(void) { static int l0 = (unsigned) f1; }
 
+// PR7044
+char *f2(char key) {
+  switch (key) {
+    static char _msg[40];
+  case '\014':
+    return _msg;
+  }
+
+  return 0;
+}