[llvm] r274373 - [codeview] Assert that our CV type records are valid

[Reid Kleckner via llvm-commits]

Author: rnk
Date: Fri Jul  1 13:05:56 2016
New Revision: 274373

URL: http://llvm.org/viewvc/llvm-project?rev=274373&view=rev
Log:
[codeview] Assert that our CV type records are valid

We were asserting that our type records were valid when emitting
assembly, but not when emitting an object file.

I've been seeing lots of LNK1285 errors (corrupt PDB) during incremental
debug self-host builds with the MSVC linker, and hopefully this will
catch some of them earlier.

Modified:
    llvm/trunk/lib/CodeGen/AsmPrinter/CodeViewDebug.cpp

Modified: llvm/trunk/lib/CodeGen/AsmPrinter/CodeViewDebug.cpp
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/CodeGen/AsmPrinter/CodeViewDebug.cpp?rev=274373&r1=274372&r2=274373&view=diff
==============================================================================
--- llvm/trunk/lib/CodeGen/AsmPrinter/CodeViewDebug.cpp (original)
+++ llvm/trunk/lib/CodeGen/AsmPrinter/CodeViewDebug.cpp Fri Jul  1 13:05:56 2016
@@ -13,6 +13,8 @@
 
 #include "CodeViewDebug.h"
 #include "llvm/ADT/TinyPtrVector.h"
+#include "llvm/DebugInfo/CodeView/ByteStream.h"
+#include "llvm/DebugInfo/CodeView/CVTypeVisitor.h"
 #include "llvm/DebugInfo/CodeView/CodeView.h"
 #include "llvm/DebugInfo/CodeView/FieldListRecordBuilder.h"
 #include "llvm/DebugInfo/CodeView/Line.h"
@@ -20,6 +22,7 @@
 #include "llvm/DebugInfo/CodeView/TypeDumper.h"
 #include "llvm/DebugInfo/CodeView/TypeIndex.h"
 #include "llvm/DebugInfo/CodeView/TypeRecord.h"
+#include "llvm/DebugInfo/CodeView/TypeVisitorCallbacks.h"
 #include "llvm/IR/Constants.h"
 #include "llvm/MC/MCExpr.h"
 #include "llvm/MC/MCSectionCOFF.h"
@@ -433,14 +436,35 @@ void CodeViewDebug::emitTypeInformation(
           ScopedPrinter SP(CommentOS);
           SP.setPrefix(CommentPrefix);
           CVTD.setPrinter(&SP);
-          Error EC = CVTD.dump({Record.bytes_begin(), Record.bytes_end()});
-          assert(!EC && "produced malformed type record");
-          consumeError(std::move(EC));
+          Error E = CVTD.dump({Record.bytes_begin(), Record.bytes_end()});
+          if (E) {
+            logAllUnhandledErrors(std::move(E), errs(), "error: ");
+            llvm_unreachable("produced malformed type record");
+          }
           // emitRawComment will insert its own tab and comment string before
           // the first line, so strip off our first one. It also prints its own
           // newline.
           OS.emitRawComment(
               CommentOS.str().drop_front(CommentPrefix.size() - 1).rtrim());
+        } else {
+#ifndef NDEBUG
+          // Assert that the type data is valid even if we aren't dumping
+          // comments. The MSVC linker doesn't do much type record validation,
+          // so the first link of an invalid type record can succeed while
+          // subsequent links will fail with LNK1285.
+          ByteStream<> Stream({Record.bytes_begin(), Record.bytes_end()});
+          CVTypeArray Types;
+          StreamReader Reader(Stream);
+          Error E = Reader.readArray(Types, Reader.getLength());
+          if (!E) {
+            TypeVisitorCallbacks C;
+            E = CVTypeVisitor(C).visitTypeStream(Types);
+          }
+          if (E) {
+            logAllUnhandledErrors(std::move(E), errs(), "error: ");
+            llvm_unreachable("produced malformed type record");
+          }
+#endif
         }
         OS.EmitBinaryData(Record);
       });