From 27ca64f3d3887ee500c0cab672f6aa9fc87f9ff7 Mon Sep 17 00:00:00 2001
From: Filipe Cabecinhas <me@filcab.net>
Date: Tue, 19 May 2015 18:18:10 +0000
Subject: [PATCH] Change a reachable unreachable to a fatal error.

Summary:
Also tagged a FIXME comment, and added information about why it breaks.

Bug found using AFL fuzz.

Reviewers: rafael, craig.topper

Subscribers: llvm-commits

Differential Revision: http://reviews.llvm.org/D9729

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@237709 91177308-0d34-0410-b5e6-96231b3b80d8
---
 include/llvm/Support/StreamingMemoryObject.h      |  11 ++++++-----
 .../Inputs/invalid-fixme-streaming-blob.bc        | Bin 0 -> 371 bytes
 test/Bitcode/invalid.test                         |   5 +++++
 3 files changed, 11 insertions(+), 5 deletions(-)
 create mode 100644 test/Bitcode/Inputs/invalid-fixme-streaming-blob.bc

diff --git a/include/llvm/Support/StreamingMemoryObject.h b/include/llvm/Support/StreamingMemoryObject.h
index fb63da7dbcc..9d1d607005f 100644
--- a/include/llvm/Support/StreamingMemoryObject.h
+++ b/include/llvm/Support/StreamingMemoryObject.h
@@ -29,11 +29,12 @@ public:
   uint64_t readBytes(uint8_t *Buf, uint64_t Size,
                      uint64_t Address) const override;
   const uint8_t *getPointer(uint64_t address, uint64_t size) const override {
-    // This could be fixed by ensuring the bytes are fetched and making a copy,
-    // requiring that the bitcode size be known, or otherwise ensuring that
-    // the memory doesn't go away/get reallocated, but it's
-    // not currently necessary. Users that need the pointer don't stream.
-    llvm_unreachable("getPointer in streaming memory objects not allowed");
+    // FIXME: This could be fixed by ensuring the bytes are fetched and
+    // making a copy, requiring that the bitcode size be known, or
+    // otherwise ensuring that the memory doesn't go away/get reallocated,
+    // but it's not currently necessary. Users that need the pointer (any
+    // that need Blobs) don't stream.
+    report_fatal_error("getPointer in streaming memory objects not allowed");
     return nullptr;
   }
   bool isValidAddress(uint64_t address) const override;
diff --git a/test/Bitcode/Inputs/invalid-fixme-streaming-blob.bc b/test/Bitcode/Inputs/invalid-fixme-streaming-blob.bc
new file mode 100644
index 0000000000000000000000000000000000000000..7e32f8b0774f9004171ebd4e9d435a2821399ee0
GIT binary patch
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literal 0
HcmV?d00001

diff --git a/test/Bitcode/invalid.test b/test/Bitcode/invalid.test
index 7a2dbdcc1b3..f609d043df4 100644
--- a/test/Bitcode/invalid.test
+++ b/test/Bitcode/invalid.test
@@ -157,3 +157,8 @@ RUN: not llvm-dis -disable-output %p/Inputs/invalid-function-argument-type.bc 2>
 RUN:   FileCheck --check-prefix=INVALID-ARGUMENT-TYPE %s
 
 INVALID-ARGUMENT-TYPE: Invalid function argument type
+
+RUN: not llvm-dis -disable-output %p/Inputs/invalid-fixme-streaming-blob.bc 2>&1 | \
+RUN:   FileCheck --check-prefix=STREAMING-BLOB %s
+
+STREAMING-BLOB: getPointer in streaming memory objects not allowed