[llvm] r305819 - [PDB] Don't write uninitialized bytes to a PDB file.

[Zachary Turner via llvm-commits]

Author: zturner
Date: Tue Jun 20 13:50:55 2017
New Revision: 305819

URL: http://llvm.org/viewvc/llvm-project?rev=305819&view=rev
Log:
[PDB] Don't write uninitialized bytes to a PDB file.

There were certain fields that we didn't know how to write, as
well as various padding bytes that we would ignore.  This leads
to garbage data in the PDB.  While not strictly necessary, we
should initialize these bytes to something meaningful, as it
makes for easier binary comparison between PDBs.

Modified:
    llvm/trunk/lib/DebugInfo/PDB/Native/DbiModuleDescriptorBuilder.cpp
    llvm/trunk/lib/DebugInfo/PDB/Native/DbiStreamBuilder.cpp

Modified: llvm/trunk/lib/DebugInfo/PDB/Native/DbiModuleDescriptorBuilder.cpp
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/DebugInfo/PDB/Native/DbiModuleDescriptorBuilder.cpp?rev=305819&r1=305818&r2=305819&view=diff
==============================================================================
--- llvm/trunk/lib/DebugInfo/PDB/Native/DbiModuleDescriptorBuilder.cpp (original)
+++ llvm/trunk/lib/DebugInfo/PDB/Native/DbiModuleDescriptorBuilder.cpp Tue Jun 20 13:50:55 2017
@@ -51,6 +51,7 @@ DbiModuleDescriptorBuilder::DbiModuleDes
                                                        uint32_t ModIndex,
                                                        msf::MSFBuilder &Msf)
     : MSF(Msf), ModuleName(ModuleName) {
+  ::memset(&Layout, 0, sizeof(Layout));
   Layout.Mod = ModIndex;
 }
 
@@ -102,6 +103,7 @@ template <typename T> struct Foo {
 template <typename T> Foo<T> makeFoo(T &&t) { return Foo<T>(std::move(t)); }
 
 void DbiModuleDescriptorBuilder::finalize() {
+  Layout.SC.ModuleIndex = Layout.Mod;
   Layout.FileNameOffs = 0; // TODO: Fix this
   Layout.Flags = 0;        // TODO: Fix this
   Layout.C11Bytes = 0;

Modified: llvm/trunk/lib/DebugInfo/PDB/Native/DbiStreamBuilder.cpp
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/DebugInfo/PDB/Native/DbiStreamBuilder.cpp?rev=305819&r1=305818&r2=305819&view=diff
==============================================================================
--- llvm/trunk/lib/DebugInfo/PDB/Native/DbiStreamBuilder.cpp (original)
+++ llvm/trunk/lib/DebugInfo/PDB/Native/DbiStreamBuilder.cpp Tue Jun 20 13:50:55 2017
@@ -237,6 +237,7 @@ Error DbiStreamBuilder::finalize() {
     return EC;
 
   DbiStreamHeader *H = Allocator.Allocate<DbiStreamHeader>();
+  ::memset(H, 0, sizeof(DbiStreamHeader));
   H->VersionHeader = *VerHeader;
   H->VersionSignature = -1;
   H->Age = Age;