From: Rafael Espindola <rafael.espindola@gmail.com>
Date: Tue, 15 Nov 2011 19:08:46 +0000 (+0000)
Subject: We currently use a callback to handle an IL pass deleting a BB that still
X-Git-Url: http://demsky.eecs.uci.edu/git/?a=commitdiff_plain;h=6c5b2dcd8385e2465f1b9f628d4368fa7c5a3c77;p=oota-llvm.git

We currently use a callback to handle an IL pass deleting a BB that still
has a reference to it. Unfortunately, that doesn't work for codegen passes
since we don't get notified of MBB's being deleted (the original BB stays).

Use that fact to our advantage and after printing a function, check if
any of the IL BBs corresponds to a symbol that was not printed. This fixes
pr11202.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@144674 91177308-0d34-0410-b5e6-96231b3b80d8
---

diff --git a/lib/CodeGen/AsmPrinter/AsmPrinter.cpp b/lib/CodeGen/AsmPrinter/AsmPrinter.cpp
index ec4d30c511b..18670fe1087 100644
--- a/lib/CodeGen/AsmPrinter/AsmPrinter.cpp
+++ b/lib/CodeGen/AsmPrinter/AsmPrinter.cpp
@@ -736,6 +736,18 @@ void AsmPrinter::EmitFunctionBody() {
       OutStreamer.EmitRawText(StringRef("\tnop\n"));
   }
 
+  const Function *F = MF->getFunction();
+  for (Function::const_iterator i = F->begin(), e = F->end(); i != e; ++i) {
+    const BasicBlock *BB = i;
+    if (!BB->hasAddressTaken())
+      continue;
+    MCSymbol *Sym = GetBlockAddressSymbol(BB);
+    if (Sym->isDefined())
+      continue;
+    OutStreamer.AddComment("Address of block that was removed by CodeGen");
+    OutStreamer.EmitLabel(Sym);
+  }
+
   // Emit target-specific gunk after the function body.
   EmitFunctionBodyEnd();
 
diff --git a/test/CodeGen/X86/pr11202.ll b/test/CodeGen/X86/pr11202.ll
new file mode 100644
index 00000000000..2b26a69caad
--- /dev/null
+++ b/test/CodeGen/X86/pr11202.ll
@@ -0,0 +1,19 @@
+; RUN: llc < %s -mtriple=x86_64-pc-linux | FileCheck %s
+
+@bb = constant [1 x i8*] [i8* blockaddress(@main, %l2)]
+
+define void @main() {
+entry:
+  br label %l1
+
+l1:                                               ; preds = %l2, %entry
+  %a = zext i1 false to i32
+  br label %l2
+
+l2:                                               ; preds = %l1
+  %b = zext i1 false to i32
+  br label %l1
+}
+
+; CHECK: .Ltmp1:                                 # Address of block that was removed by CodeGen
+; CHECK: .quad	.Ltmp1