[Frontend] Verify that the bitstream is not empty before reading
the serialised diagnostics
Clang should avoid calling report_fatal_error when the file with the serialised
diagnostics is empty. This commit changes Clang's serialised diagnostic reader,
now it reports an appropriate error instead of crashing.
rdar://31939877
Differential Revision: https://reviews.llvm.org/D35069
git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@307384 91177308-0d34-0410-b5e6-96231b3b80d8
(cherry picked from commit a43da8254fec1e97522a57b74b7a8f8bb04d827c)
diff --git a/lib/Frontend/SerializedDiagnosticReader.cpp b/lib/Frontend/SerializedDiagnosticReader.cpp
index c4461d4..81a483a 100644
--- a/lib/Frontend/SerializedDiagnosticReader.cpp
+++ b/lib/Frontend/SerializedDiagnosticReader.cpp
@@ -27,6 +27,9 @@
llvm::BitstreamCursor Stream(**Buffer);
Optional<llvm::BitstreamBlockInfo> BlockInfo;
+ if (Stream.AtEndOfStream())
+ return SDError::InvalidSignature;
+
// Sniff for the signature.
if (Stream.Read(8) != 'D' ||
Stream.Read(8) != 'I' ||
diff --git a/test/Index/Inputs/empty.dia b/test/Index/Inputs/empty.dia
new file mode 100644
index 0000000..e69de29
--- /dev/null
+++ b/test/Index/Inputs/empty.dia
diff --git a/test/Index/read-empty-diags.test b/test/Index/read-empty-diags.test
new file mode 100644
index 0000000..cef751c
--- /dev/null
+++ b/test/Index/read-empty-diags.test
@@ -0,0 +1,2 @@
+// RUN: not c-index-test -read-diagnostics %S/Inputs/empty.dia 2>&1 | FileCheck %s
+// CHECK: Trouble deserializing file (Invalid File): Invalid diagnostics signature
