MachObjectWriter: Fix calculation of segmentFileSize

filipnavara · filipnavara · commit c48520c4d772 · 2026-02-27T21:10:57.000+01:00
diff --git a/src/coreclr/tools/Common/Compiler/ObjectWriter/MachObjectWriter.cs b/src/coreclr/tools/Common/Compiler/ObjectWriter/MachObjectWriter.cs
@@ -137,6 +137,7 @@ private void LayoutSections(bool recordFinalLayout, ref uint fileOffset, out uin
         {
             ulong virtualAddress = 0;
             byte sectionIndex = 1;
+            uint initialFileOffset = uint.MaxValue;
 
             segmentFileSize = 0;
             segmentSize = 0;
@@ -149,9 +150,10 @@ private void LayoutSections(bool recordFinalLayout, ref uint fileOffset, out uin
 
                 if (section.IsInFile)
                 {
+                    initialFileOffset = Math.Min(initialFileOffset, fileOffset);
                     section.FileOffset = fileOffset;
                     fileOffset += (uint)section.Size;
-                    segmentFileSize = Math.Max(segmentFileSize, fileOffset);
+                    segmentFileSize = Math.Max(segmentFileSize, fileOffset - initialFileOffset);
                 }
                 else
                 {

Original file line number	Diff line number	Diff line change
`@@ -137,6 +137,7 @@ private void LayoutSections(bool recordFinalLayout, ref uint fileOffset, out uin`
`137`	`137`	`{`
`138`	`138`	`ulong virtualAddress = 0;`
`139`	`139`	`byte sectionIndex = 1;`
	`140`	`+ uint initialFileOffset = uint.MaxValue;`
`140`	`141`
`141`	`142`	`segmentFileSize = 0;`
`142`	`143`	`segmentSize = 0;`
`@@ -149,9 +150,10 @@ private void LayoutSections(bool recordFinalLayout, ref uint fileOffset, out uin`
`149`	`150`
`150`	`151`	`if (section.IsInFile)`
`151`	`152`	`{`
	`153`	`+ initialFileOffset = Math.Min(initialFileOffset, fileOffset);`
`152`	`154`	`section.FileOffset = fileOffset;`
`153`	`155`	`fileOffset += (uint)section.Size;`
`154`		`- segmentFileSize = Math.Max(segmentFileSize, fileOffset);`
	`156`	`+ segmentFileSize = Math.Max(segmentFileSize, fileOffset - initialFileOffset);`
`155`	`157`	`}`
`156`	`158`	`else`
`157`	`159`	`{`