[clang] [clang-tools-extra] [llvm] [clang] Introduce diagnostics suppression mappings (PR #112517)

[Boaz Brickner via cfe-commits]

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@@ -4493,6 +4493,13 @@ static void RenderDiagnosticsOptions(const Driver &D, const ArgList &Args,
 
   Args.addOptOutFlag(CmdArgs, options::OPT_fspell_checking,
                      options::OPT_fno_spell_checking);
+
+  if (const Arg *A =
+          Args.getLastArg(options::OPT_warning_suppression_mappings_EQ)) {
+    if (!D.getVFS().exists(A->getValue()))
+      D.Diag(clang::diag::err_drv_no_such_file) << A->getValue();
+    CmdArgs.push_back(Args.MakeArgString(A->getSpelling() + A->getValue()));
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bricknerb wrote:

Consider putting A->getValue() in a variable to avoid duplication.

https://github.com/llvm/llvm-project/pull/112517