[lld] [Coverage][WebAssembly] Remove InstrProf sections if object not live (PR #172023)

[via llvm-commits]

https://github.com/Spxg updated https://github.com/llvm/llvm-project/pull/172023

>From cba9c10a4d79ba6abf07523c43691c8871a7cb7d Mon Sep 17 00:00:00 2001
From: Spxg <unsafe at outlook.es>
Date: Sat, 13 Dec 2025 10:39:01 +0800
Subject: [PATCH] [Coverage][WebAssembly] Discard InstrProf sections if object
 not live

---
 lld/wasm/Writer.cpp | 7 +++++++
 1 file changed, 7 insertions(+)

diff --git a/lld/wasm/Writer.cpp b/lld/wasm/Writer.cpp
index 9a5b56fc52e2f..c229917a1ecb5 100644
--- a/lld/wasm/Writer.cpp
+++ b/lld/wasm/Writer.cpp
@@ -26,6 +26,7 @@
 #include "llvm/ADT/SmallVector.h"
 #include "llvm/ADT/StringMap.h"
 #include "llvm/BinaryFormat/Wasm.h"
+#include "llvm/ProfileData/InstrProf.h"
 #include "llvm/Support/FileOutputBuffer.h"
 #include "llvm/Support/FormatVariadic.h"
 #include "llvm/Support/Parallel.h"
@@ -153,6 +154,12 @@ void Writer::calculateCustomSections() {
       // Strip debug section in that option was specified.
       if (stripDebug && name.starts_with(".debug_"))
         continue;
+      // If the object is not live, discard `__llvm_covfun` and `__llvm_covmap`
+      // sections since `__llvm_prf_*` segments have already been discarded.
+      if (!file->isLive() &&
+          (name == getInstrProfSectionName(IPSK_covfun, Triple::Wasm) ||
+           name == getInstrProfSectionName(IPSK_covmap, Triple::Wasm)))
+        continue;
       // Otherwise include custom sections by default and concatenate their
       // contents.
       customSectionMapping[name].push_back(section);