[clang] [clang][WebAssembly] Link crt2-command.o if available (PR #104755)

[YAMAMOTO Takashi via cfe-commits]

https://github.com/yamt created https://github.com/llvm/llvm-project/pull/104755

cf. https://github.com/WebAssembly/wasi-libc/pull/528

>From 9cd6ddd576c70dfd21c35ae4721ee9f2e03d986f Mon Sep 17 00:00:00 2001
From: YAMAMOTO Takashi <yamamoto at midokura.com>
Date: Mon, 19 Aug 2024 19:14:04 +0900
Subject: [PATCH] [clang][WebAssembly] Link crt2-command.o if available

cf. https://github.com/WebAssembly/wasi-libc/pull/528
---
 clang/lib/Driver/ToolChains/WebAssembly.cpp | 11 ++++++++++-
 1 file changed, 10 insertions(+), 1 deletion(-)

diff --git a/clang/lib/Driver/ToolChains/WebAssembly.cpp b/clang/lib/Driver/ToolChains/WebAssembly.cpp
index 9aacda5fd5702f..7b95b95e3eee8d 100644
--- a/clang/lib/Driver/ToolChains/WebAssembly.cpp
+++ b/clang/lib/Driver/ToolChains/WebAssembly.cpp
@@ -103,6 +103,7 @@ void wasm::Linker::ConstructJob(Compilation &C, const JobAction &JA,
 
   bool IsCommand = true;
   const char *Crt1;
+  const char *Crt2 = nullptr;
   const char *Entry = nullptr;
 
   // When -shared is specified, use the reactor exec model unless
@@ -132,13 +133,21 @@ void wasm::Linker::ConstructJob(Compilation &C, const JobAction &JA,
     Crt1 = "crt1.o";
     if (ToolChain.GetFilePath("crt1-command.o") != "crt1-command.o")
       Crt1 = "crt1-command.o";
+    // Link another object as well if it's provided. It's planned to
+    // be used to fix https://github.com/WebAssembly/wasi-libc/issues/485
+    if (ToolChain.GetFilePath("crt2-command.o") != "crt2-command.o") {
+      Crt2 = "crt2-command.o";
+    }
   } else {
     Crt1 = "crt1-reactor.o";
     Entry = "_initialize";
   }
 
-  if (!Args.hasArg(options::OPT_nostdlib, options::OPT_nostartfiles))
+  if (!Args.hasArg(options::OPT_nostdlib, options::OPT_nostartfiles)) {
     CmdArgs.push_back(Args.MakeArgString(ToolChain.GetFilePath(Crt1)));
+    if (Crt2)
+      CmdArgs.push_back(Args.MakeArgString(ToolChain.GetFilePath(Crt2)));
+  }
   if (Entry) {
     CmdArgs.push_back(Args.MakeArgString("--entry"));
     CmdArgs.push_back(Args.MakeArgString(Entry));