[Driver] Correctly handle -Wa,--crel -Wa,--no-crel

Follow-up to #97378

Author: MaskRay

clang/lib/Driver/ToolChains/CommonArgs.cpp

@@ -1143,8 +1143,8 @@ void tools::addLTOOptions(const ToolChain &ToolChain, const ArgList &Args,
   addMachineOutlinerArgs(D, Args, CmdArgs, ToolChain.getEffectiveTriple(),
                          /*IsLTO=*/true, PluginOptPrefix);
 
+  bool Crel = false;
   for (const Arg *A : Args.filtered(options::OPT_Wa_COMMA)) {
-    bool Crel = false;
     for (StringRef V : A->getValues()) {
       if (V == "--crel")
         Crel = true;
@@ -1154,13 +1154,13 @@ void tools::addLTOOptions(const ToolChain &ToolChain, const ArgList &Args,
         continue;
       A->claim();
     }
-    if (Crel) {
-      if (Triple.isOSBinFormatELF() && !Triple.isMIPS()) {
-        CmdArgs.push_back(Args.MakeArgString(Twine(PluginOptPrefix) + "-crel"));
-      } else {
-        D.Diag(diag::err_drv_unsupported_opt_for_target)
-            << "-Wa,--crel" << D.getTargetTriple();
-      }
+  }
+  if (Crel) {
+    if (Triple.isOSBinFormatELF() && !Triple.isMIPS()) {
+      CmdArgs.push_back(Args.MakeArgString(Twine(PluginOptPrefix) + "-crel"));
+    } else {
+      D.Diag(diag::err_drv_unsupported_opt_for_target)
+          << "-Wa,--crel" << D.getTargetTriple();
     }
   }
 }

clang/test/Driver/crel.c

@@ -24,8 +24,10 @@
 
 /// The --allow-experimental-crel error check doesn't apply to LTO.
 // RUN: %clang -### --target=x86_64-linux -Werror -flto -Wa,--crel %s 2>&1 | FileCheck %s --check-prefix=LTO
+// RUN: %clang -### --target=x86_64-linux -Werror -flto -Wa,--crel -Wa,--no-crel %s 2>&1 | FileCheck %s --check-prefix=LTO-NO
 
 // LTO: "-plugin-opt=-crel"
+// LTO-NO-NOT: "-plugin-opt=-crel"
 
 // RUN: touch %t.o
 // RUN: not %clang -### --target=mips64-linux-gnu -flto -Wa,--crel %t.o 2>&1 | FileCheck %s --check-prefix=ERR