1 files changed, 18 insertions, 8 deletions
diff --git a/llvm/lib/DebugInfo/MSF/MSFBuilder.cpp b/llvm/lib/DebugInfo/MSF/MSFBuilder.cpp
index 1a92e2cb7754..f9a763d724a8 100644
--- a/llvm/lib/DebugInfo/MSF/MSFBuilder.cpp
+++ b/llvm/lib/DebugInfo/MSF/MSFBuilder.cpp
@@ -343,15 +343,25 @@ Expected<FileBufferByteStream> MSFBuilder::commit(StringRef Path,
   Layout = std::move(*L);
 
   uint64_t FileSize = uint64_t(Layout.SB->BlockSize) * Layout.SB->NumBlocks;
-  if (FileSize > UINT32_MAX) {
-    // FIXME: Changing the BinaryStream classes to use 64-bit numbers lets
-    // us create PDBs larger than 4 GiB successfully. The file format is
-    // block-based and as long as each stream is small enough, PDBs larger than
-    // 4 GiB might work. Check if tools can handle these large PDBs, and if so
-    // add support for writing them.
+  // Ensure that the file size is under the limit for the specified block size.
+  if (FileSize > getMaxFileSizeFromBlockSize(Layout.SB->BlockSize)) {
+    msf_error_code error_code = [](uint32_t BlockSize) {
+      switch (BlockSize) {
+      case 8192:
+        return msf_error_code::size_overflow_8192;
+      case 16384:
+        return msf_error_code::size_overflow_16384;
+      case 32768:
+        return msf_error_code::size_overflow_32768;
+      default:
+        return msf_error_code::size_overflow_4096;
+      }
+    }(Layout.SB->BlockSize);
+
     return make_error<MSFError>(
-        msf_error_code::size_overflow,
-        formatv("File size would have been {0,1:N}", FileSize));
+        error_code,
+        formatv("File size {0,1:N} too large for current PDB page size {1}",
+                FileSize, Layout.SB->BlockSize));
   }
 
   auto OutFileOrError = FileOutputBuffer::create(Path, FileSize);