From bc113d557c307e3211e6b6f1d01ab89e42f9f934 Mon Sep 17 00:00:00 2001
From: David Nguyen <87228593+davidnguyen-tech@users.noreply.github.com>
Date: Fri, 2 Jan 2026 16:26:12 +0100
Subject: [PATCH 1/2] Skip empty sections when calculating the PE file layout

---
 .../Compiler/ObjectWriter/PEObjectWriter.cs       | 15 +++++++++++++++
 1 file changed, 15 insertions(+)

diff --git a/src/coreclr/tools/Common/Compiler/ObjectWriter/PEObjectWriter.cs b/src/coreclr/tools/Common/Compiler/ObjectWriter/PEObjectWriter.cs
index 5243d2e214c685..f1eb932f7458c1 100644
--- a/src/coreclr/tools/Common/Compiler/ObjectWriter/PEObjectWriter.cs
+++ b/src/coreclr/tools/Common/Compiler/ObjectWriter/PEObjectWriter.cs
@@ -445,6 +445,21 @@ private void LayoutSections(bool recordFinalLayout, out ushort numberOfSections,
             foreach (SectionDefinition s in _sections)
             {
                 CoffSectionHeader h = s.Header;
+
+                // Skip calculating the layout for empty sections.
+                // Empty sections remain in _sections for index stability but are assigned zero VA/size
+                // to avoid wasting virtual address space and inflating the final PE file size.
+                if (s.Stream.Length == 0 && !h.SectionCharacteristics.HasFlag(SectionCharacteristics.ContainsUninitializedData))
+                {
+                    if (recordFinalLayout)
+                    {
+                        // Ensure that we match the section indexes in _sections, even though we omit them in EmitObjectFile.
+                        _outputSectionLayout.Add(new OutputSection(h.Name, 0, 0, 0));
+                    }
+
+                    continue;
+                }
+
                 h.SizeOfRawData = (uint)s.Stream.Length;
                 uint requestedAlignment = GetSectionAlignment(h);
                 uint rawAligned = h.SectionCharacteristics.HasFlag(SectionCharacteristics.ContainsUninitializedData)

From d694f86cab9e66ee79abb9b6f9d26de2d770172c Mon Sep 17 00:00:00 2001
From: David Nguyen <87228593+davidnguyen-tech@users.noreply.github.com>
Date: Fri, 2 Jan 2026 16:50:24 +0100
Subject: [PATCH 2/2] Update comment

---
 .../tools/Common/Compiler/ObjectWriter/PEObjectWriter.cs   | 7 ++-----
 1 file changed, 2 insertions(+), 5 deletions(-)

diff --git a/src/coreclr/tools/Common/Compiler/ObjectWriter/PEObjectWriter.cs b/src/coreclr/tools/Common/Compiler/ObjectWriter/PEObjectWriter.cs
index f1eb932f7458c1..ca9fb97c0e93b1 100644
--- a/src/coreclr/tools/Common/Compiler/ObjectWriter/PEObjectWriter.cs
+++ b/src/coreclr/tools/Common/Compiler/ObjectWriter/PEObjectWriter.cs
@@ -447,13 +447,12 @@ private void LayoutSections(bool recordFinalLayout, out ushort numberOfSections,
                 CoffSectionHeader h = s.Header;
 
                 // Skip calculating the layout for empty sections.
-                // Empty sections remain in _sections for index stability but are assigned zero VA/size
-                // to avoid wasting virtual address space and inflating the final PE file size.
                 if (s.Stream.Length == 0 && !h.SectionCharacteristics.HasFlag(SectionCharacteristics.ContainsUninitializedData))
                 {
                     if (recordFinalLayout)
                     {
-                        // Ensure that we match the section indexes in _sections, even though we omit them in EmitObjectFile.
+                        // Although we omit the empty sections in EmitObjectFile, we add them to _sections in order to match indexes.
+                        // We assign zero VA/size to avoid wasting virtual address space and inflating the final PE file size.
                         _outputSectionLayout.Add(new OutputSection(h.Name, 0, 0, 0));
                     }
 
@@ -516,8 +515,6 @@ private void LayoutSections(bool recordFinalLayout, out ushort numberOfSections,
                 if (recordFinalLayout)
                 {
                     // Use the stream length so we don't include any space that's appended just for alignment purposes.
-                    // To ensure that we match the section indexes in _sections, we don't skip empty sections here
-                    // even though we omit them in EmitObjectFile.
                     _outputSectionLayout.Add(new OutputSection(h.Name, h.VirtualAddress, h.PointerToRawData, (uint)s.Stream.Length));
                 }
                 firstSection = false;