[llvm-rc] Allow -1 for control IDs in old style dialogs with 16 bit fields

-1 is commonly used as ID for controls that one don't want to
refer to later. For DIALOG resources, the IDs are 16 bit numbers,
and -1 gets interpreted as UINT32_MAX earlier, which then later is
too large to write into a uint16_t.

Differential Revision: https://reviews.llvm.org/D46506

llvm-svn: 331901

1 files changed, 5 insertions, 2 deletions

diff --git a/llvm/tools/llvm-rc/ResourceFileWriter.cpp b/llvm/tools/llvm-rc/ResourceFileWriter.cpp
index b2cc2cc42f7..f468fa67f52 100644
--- a/llvm/tools/llvm-rc/ResourceFileWriter.cpp
+++ b/llvm/tools/llvm-rc/ResourceFileWriter.cpp
@@ -1008,8 +1008,11 @@ Error ResourceFileWriter::writeSingleDialogControl(const Control &Ctl,
 
   // ID; it's 16-bit in DIALOG and 32-bit in DIALOGEX.
   if (!IsExtended) {
-    RETURN_IF_ERROR(checkNumberFits<uint16_t>(
-        Ctl.ID, "Control ID in simple DIALOG resource"));
+    // It's common to use -1, i.e. UINT32_MAX, for controls one doesn't
+    // want to refer to later.
+    if (Ctl.ID != static_cast<uint32_t>(-1))
+      RETURN_IF_ERROR(checkNumberFits<uint16_t>(
+          Ctl.ID, "Control ID in simple DIALOG resource"));
     writeInt<uint16_t>(Ctl.ID);
   } else {
     writeInt<uint32_t>(Ctl.ID);