win x86: Grab bag of restructuring to get tests working on x86-on-x86

snapshot/win/exception_snapshot_win.cc

Index: snapshot/win/exception_snapshot_win.cc
diff --git a/snapshot/win/exception_snapshot_win.cc b/snapshot/win/exception_snapshot_win.cc
index a32c929487a51548521d9b505b8f32ff27bd7671..000c3e240d3d1efa9abdf4aa86c758cb32502a7d 100644
--- a/snapshot/win/exception_snapshot_win.cc
+++ b/snapshot/win/exception_snapshot_win.cc
@@ -69,6 +69,7 @@ bool ExceptionSnapshotWin::Initialize(ProcessReaderWin* process_reader,
     return false;
   }
 
+#if defined(ARCH_CPU_64_BITS)
   if (process_reader->Is64Bit()) {
     EXCEPTION_RECORD64 first_record;
     if (!process_reader->ReadMemory(
@@ -105,6 +106,39 @@ bool ExceptionSnapshotWin::Initialize(ProcessReaderWin* process_reader,
     CHECK(false) << "TODO(scottmg) x86";
     return false;
   }
+#else
+  EXCEPTION_RECORD32 first_record;

[Mark Mentovai, 2015/09/16 02:57:19]

This is so similar to what’s above that it’s kind of unfortunate to have so much
duplication. The TODO for the WoW64 case above will probably be a third
nearly-identical branch. Is there a decent way to share? Templatized helper
function with traits?

[scottmg, 2015/09/16 18:05:06]

Done.

+  if (!process_reader->ReadMemory(
+          reinterpret_cast<WinVMAddress>(exception_pointers.ExceptionRecord),
+          sizeof(first_record),
+          &first_record)) {
+    LOG(ERROR) << "ExceptionRecord";
+    return false;
+  }
+  exception_code_ = first_record.ExceptionCode;
+  exception_flags_ = first_record.ExceptionFlags;
+  exception_address_ = first_record.ExceptionAddress;
+  for (DWORD i = 0; i < first_record.NumberParameters; ++i)
+    codes_.push_back(first_record.ExceptionInformation[i]);
+  if (first_record.ExceptionRecord) {
+    // https://code.google.com/p/crashpad/issues/detail?id=43
+    LOG(WARNING) << "dropping chained ExceptionRecord";
+  }
+
+  context_.architecture = kCPUArchitectureX86;
+  context_.x86 = &context_union_.x86;
+  // We assume 64-on-64 here in that we're relying on the CONTEXT definition

[Mark Mentovai, 2015/09/16 02:57:19]

Well, the comment shouldn’t have been copied and pasted as-is.

[scottmg, 2015/09/16 18:05:06]

Oops, I noticed that too, but forgot to upload the last snapshot. Anyway,
templated now.

+  // to be the x64 one.
+  CONTEXT context_record;
+  if (!process_reader->ReadMemory(
+          reinterpret_cast<WinVMAddress>(exception_pointers.ContextRecord),
+          sizeof(context_record),
+          &context_record)) {
+    LOG(ERROR) << "ContextRecord";
+    return false;
+  }
+  InitializeX86Context(context_record, context_.x86);
+#endif  // ARCH_CPU_64_BITS
 
   INITIALIZATION_STATE_SET_VALID(initialized_);
   return true;