[llvm-branch-commits] [clang] [Driver] Add support for crtbegin.o, crtend.o and libgloss lib to BareMetal toolchain object (PR #121830)

[Garvit Gupta via llvm-branch-commits]

================
@@ -540,19 +577,54 @@ void baremetal::Linker::ConstructJob(Compilation &C, const JobAction &JA,
     CmdArgs.push_back(Arch == llvm::Triple::aarch64_be ? "-EB" : "-EL");
   }
 
-  if (!Args.hasArg(options::OPT_nostdlib, options::OPT_nostartfiles,
-                   options::OPT_r)) {
-    CmdArgs.push_back(Args.MakeArgString(TC.GetFilePath("crt0.o")));
+  bool WantCRTs =
+      !Args.hasArg(options::OPT_nostdlib, options::OPT_nostartfiles);
+
+  const char *crtbegin, *crtend;
+  if (WantCRTs) {
+    if (!Args.hasArg(options::OPT_r))
+      CmdArgs.push_back(Args.MakeArgString(TC.GetFilePath("crt0.o")));
+    if (TC.isUsingLD()) {
+      auto RuntimeLib = TC.GetRuntimeLibType(Args);
+      if (RuntimeLib == ToolChain::RLT_Libgcc) {
+        crtbegin = "crtbegin.o";
+        crtend = "crtend.o";
+      } else {
+        assert(RuntimeLib == ToolChain::RLT_CompilerRT);
+        crtbegin =
+            TC.getCompilerRTArgString(Args, "crtbegin", ToolChain::FT_Object);
+        crtend =
+            TC.getCompilerRTArgString(Args, "crtend", ToolChain::FT_Object);
+      }
+      CmdArgs.push_back(Args.MakeArgString(TC.GetFilePath(crtbegin)));
+    }
   }
 
-  Args.addAllArgs(CmdArgs, {options::OPT_L, options::OPT_T_Group,
-                            options::OPT_s, options::OPT_t, options::OPT_r});
+  Args.addAllArgs(CmdArgs,
+                  {options::OPT_L, options::OPT_u, options::OPT_T_Group,
+                   options::OPT_s, options::OPT_t, options::OPT_r});
 
   TC.AddFilePathLibArgs(Args, CmdArgs);
 
   for (const auto &LibPath : TC.getLibraryPaths())
     CmdArgs.push_back(Args.MakeArgString(llvm::Twine("-L", LibPath)));
 
+  if (D.isUsingLTO()) {
+    assert(!Inputs.empty() && "Must have at least one input.");
+    // Find the first filename InputInfo object.
+    auto Input = llvm::find_if(
+        Inputs, [](const InputInfo &II) -> bool { return II.isFilename(); });
+    if (Input == Inputs.end())
+      // For a very rare case, all of the inputs to the linker are
+      // InputArg. If that happens, just use the first InputInfo.
+      Input = Inputs.begin();
+
+    addLTOOptions(TC, Args, CmdArgs, Output, *Input,
+                  D.getLTOMode() == LTOK_Thin);
+  }
----------------
quic-garvgupt wrote:

Done
[Driver] Fix link order of BareMetal toolchain object https://github.com/llvm/llvm-project/pull/132806

https://github.com/llvm/llvm-project/pull/121830