From 559a83330416affb0e341a2c53800cbf924a5178 Mon Sep 17 00:00:00 2001
From: Anders Carlsson <andersca@mac.com>
Date: Sun, 22 Feb 2009 01:38:57 +0000
Subject: [PATCH] Correctly encode incomplete and variable length arrays. Fixes
 PR3639.

git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@65255 91177308-0d34-0410-b5e6-96231b3b80d8
---
 lib/AST/ASTContext.cpp           | 27 +++++++++++++++++++--------
 test/CodeGenObjC/encode-test-3.m | 11 +++++++++++
 2 files changed, 30 insertions(+), 8 deletions(-)
 create mode 100644 test/CodeGenObjC/encode-test-3.m

diff --git a/lib/AST/ASTContext.cpp b/lib/AST/ASTContext.cpp
index 605f46b44b..181ea90691 100644
--- a/lib/AST/ASTContext.cpp
+++ b/lib/AST/ASTContext.cpp
@@ -2214,16 +2214,27 @@ void ASTContext::getObjCEncodingForTypeImpl(QualType T, std::string& S,
   } else if (const ArrayType *AT =
                // Ignore type qualifiers etc.
                dyn_cast<ArrayType>(T->getCanonicalTypeInternal())) {
-    S += '[';
+    if (isa<IncompleteArrayType>(AT)) {
+      // Incomplete arrays are encoded as a pointer to the array element.
+      S += '^';
+
+      getObjCEncodingForTypeImpl(AT->getElementType(), S, 
+                                 false, ExpandStructures, FD);
+    } else {
+      S += '[';
     
-    if (const ConstantArrayType *CAT = dyn_cast<ConstantArrayType>(AT))
-      S += llvm::utostr(CAT->getSize().getZExtValue());
-    else
-      assert(0 && "Unhandled array type!");
+      if (const ConstantArrayType *CAT = dyn_cast<ConstantArrayType>(AT))
+        S += llvm::utostr(CAT->getSize().getZExtValue());
+      else {
+        //Variable length arrays are encoded as a regular array with 0 elements.
+        assert(isa<VariableArrayType>(AT) && "Unknown array type!");
+        S += '0';
+      }
     
-    getObjCEncodingForTypeImpl(AT->getElementType(), S, 
-                               false, ExpandStructures, FD);
-    S += ']';
+      getObjCEncodingForTypeImpl(AT->getElementType(), S, 
+                                 false, ExpandStructures, FD);
+      S += ']';
+    }
   } else if (T->getAsFunctionType()) {
     S += '?';
   } else if (const RecordType *RTy = T->getAsRecordType()) {
diff --git a/test/CodeGenObjC/encode-test-3.m b/test/CodeGenObjC/encode-test-3.m
new file mode 100644
index 0000000000..8bd4421d6c
--- /dev/null
+++ b/test/CodeGenObjC/encode-test-3.m
@@ -0,0 +1,11 @@
+// RUN: clang -triple=i686-apple-darwin9 -fnext-runtime -emit-llvm -o %t %s &&
+// RUN: grep -e "\^i" %t | count 1 &&
+// RUN: grep -e "\[0i\]" %t | count 1
+
+int main()
+{
+  int n;
+  
+  const char * inc = @encode(int[]);
+  const char * vla = @encode(int[n]);
+}
-- 
2.40.0