From 83494d2f8cc6bb743d408031188c20d6e64c2eff Mon Sep 17 00:00:00 2001
From: Chih-Hung Hsieh <chh@google.com>
Date: Wed, 22 Aug 2018 17:13:40 +0000
Subject: [Tooling] Allow -flto flags and filter out -Wa, flags

This change fixes the problem in https://bugs.llvm.org/show_bug.cgi?id=38332
by allowing driver::Action::BackendJobClass to run with the analyzer.
Otherwise, such jobs will look up the non-existing compilation database
and then run without flags.
Also filter out the -Wa,* flags that could be passed to and ignored
by the clang compiler.  Clang-tidy gives warnings about unused -Wa,* flags.

Differential Revision: http://reviews.llvm.org/D51002

llvm-svn: 340421
---
 clang/lib/Tooling/CompilationDatabase.cpp | 20 ++++++++++++++------
 1 file changed, 14 insertions(+), 6 deletions(-)

(limited to 'clang/lib/Tooling/CompilationDatabase.cpp')

diff --git a/clang/lib/Tooling/CompilationDatabase.cpp b/clang/lib/Tooling/CompilationDatabase.cpp
index 31a769f..246d3c0 100644
--- a/clang/lib/Tooling/CompilationDatabase.cpp
+++ b/clang/lib/Tooling/CompilationDatabase.cpp
@@ -218,6 +218,15 @@ private:
   ArrayRef<std::string> Arr;
 };
 
+// Filter of tools unused flags such as -no-integrated-as and -Wa,*.
+// They are not used for syntax checking, and could confuse targets
+// which don't support these options.
+struct FilterUnusedFlags {
+  bool operator() (StringRef S) {
+    return (S == "-no-integrated-as") || S.startswith("-Wa,");
+  }
+};
+
 } // namespace
 
 /// Strips any positional args and possible argv[0] from a command-line
@@ -275,10 +284,7 @@ static bool stripPositionalArgs(std::vector<const char *> Args,
   // up with no jobs but then this is the user's fault.
   Args.push_back("placeholder.cpp");
 
-  // Remove -no-integrated-as; it's not used for syntax checking,
-  // and it confuses targets which don't support this option.
-  Args.erase(std::remove_if(Args.begin(), Args.end(),
-                            MatchesAny(std::string("-no-integrated-as"))),
+  Args.erase(std::remove_if(Args.begin(), Args.end(), FilterUnusedFlags()),
              Args.end());
 
   const std::unique_ptr<driver::Compilation> Compilation(
@@ -291,9 +297,11 @@ static bool stripPositionalArgs(std::vector<const char *> Args,
   CompileJobAnalyzer CompileAnalyzer;
 
   for (const auto &Cmd : Jobs) {
-    // Collect only for Assemble and Compile jobs. If we do all jobs we get
-    // duplicates since Link jobs point to Assemble jobs as inputs.
+    // Collect only for Assemble, Backend, and Compile jobs. If we do all jobs
+    // we get duplicates since Link jobs point to Assemble jobs as inputs.
+    // -flto* flags make the BackendJobClass, which still needs analyzer.
     if (Cmd.getSource().getKind() == driver::Action::AssembleJobClass ||
+        Cmd.getSource().getKind() == driver::Action::BackendJobClass ||
         Cmd.getSource().getKind() == driver::Action::CompileJobClass) {
       CompileAnalyzer.run(&Cmd.getSource());
     }
-- 
cgit v1.1