[clang] [clang] Stop parsing warning suppression mappings in driver (PR #125722)

[kadir çetinkaya via cfe-commits]

https://github.com/kadircet created https://github.com/llvm/llvm-project/pull/125722

This gets rid of some extra IO from driver startup, and possiblity of
emitting warnings twice.


>From 7dce959f33d828e4a06ba386715a3d92b7be34bf Mon Sep 17 00:00:00 2001
From: Kadir Cetinkaya <kadircet at google.com>
Date: Tue, 4 Feb 2025 17:45:55 +0100
Subject: [PATCH] [clang] Stop parsing warning suppression mappings in driver

This gets rid of some extra IO from driver startup, and possiblity of
emitting warnings twice.
---
 clang/tools/driver/driver.cpp | 4 ++++
 1 file changed, 4 insertions(+)

diff --git a/clang/tools/driver/driver.cpp b/clang/tools/driver/driver.cpp
index 74923247b7ee16..00c00cea16f470 100644
--- a/clang/tools/driver/driver.cpp
+++ b/clang/tools/driver/driver.cpp
@@ -318,6 +318,10 @@ int clang_main(int Argc, char **Argv, const llvm::ToolContext &ToolContext) {
 
   IntrusiveRefCntPtr<DiagnosticOptions> DiagOpts =
       CreateAndPopulateDiagOpts(Args);
+  // Driver's diagnostics don't use suppression mappings, so don't bother
+  // parsing them. CC1 still receives full args, so this doesn't impact other
+  // actions.
+  DiagOpts->DiagnosticSuppressionMappingsFile.clear();
 
   TextDiagnosticPrinter *DiagClient
     = new TextDiagnosticPrinter(llvm::errs(), &*DiagOpts);