[clang] Teach -fembed-bitcode option not to embed W_value Group

[steven_wu]

Summary

-fembed-bitcode options doesn't embed warning options since they are
useless to code generation. Make sure it handles the W_value group and
not embed those options in the output.

[zixuw]

Would llvm::Option::matches be more appropriate than getID and checking for equality here? Option::matches tracks subgroups correctly, without having to explicitly check for W_value_Group.

[steven_wu]

Use Option::matches instead.

[zixuw]

LGTM

clang/lib/Frontend/CompilerInvocation.cpp

static bool ParseCodeGenArgs(CodeGenOptions &Opts, ArgList &Args, InputKind IK,
   // separate data section and use them when building the bitcode.
   if (Opts.getEmbedBitcode() == CodeGenOptions::Embed_All) {
     for (const auto &A : Args) {
       // Do not encode output and input.
       if (A->getOption().getID() == options::OPT_o ||
           A->getOption().getID() == options::OPT_INPUT ||
           A->getOption().getID() == options::OPT_x ||
           A->getOption().getID() == options::OPT_fembed_bitcode ||
-          (A->getOption().getGroup().isValid() &&
-           A->getOption().getGroup().getID() == options::OPT_W_Group))
+          A->getOption().matches(options::OPT_W_Group))
         continue;
       ArgStringList ASL;
       A->render(Args, ASL);
       for (const auto &arg : ASL) {
         StringRef ArgStr(arg);
         Opts.CmdArgs.insert(Opts.CmdArgs.end(), ArgStr.begin(), ArgStr.end());
         // using \00 to separate each commandline options.
         Opts.CmdArgs.push_back('\0');

clang/test/Frontend/embed-bitcode.ll

 
 ; check the magic number of bitcode at the beginning of the string
 ; CHECK: @llvm.embedded.module = private constant
 ; CHECK: c"\DE\C0\17\0B
 ; CHECK: section "__LLVM,__bitcode"
 ; CHECK: @llvm.cmdline = private constant
 ; CHECK: section "__LLVM,__cmdline"
 
+; check warning options are not embedded
+; RUN: %clang_cc1 -triple thumbv7-apple-ios8.0.0 -emit-llvm \
+; RUN:    -fembed-bitcode=all -x ir %s -o - -Wall -Wundef-prefix=TEST \
+; RUN:    | FileCheck %s -check-prefix=CHECK-WARNING
+
 ; CHECK-ELF: @llvm.embedded.module
 ; CHECK-ELF: section ".llvmbc"
 ; CHECK-ELF: @llvm.cmdline
 ; CHECK-ELF: section ".llvmcmd"
 
 ; CHECK-ONLY-BITCODE: @llvm.embedded.module = private constant
 ; CHECK-ONLY-BITCODE: c"\DE\C0\17\0B
 ; CHECK-ONLY-BITCODE: section "__LLVM,__bitcode"
 ; CHECK-ONLY-BITCODE-NOT: @llvm.cmdline = private constant
 ; CHECK-ONLY-BITCODE-NOT: section "__LLVM,__cmdline"
 
 ; CHECK-MARKER: @llvm.embedded.module
 ; CHECK-MARKER: constant [0 x i8] zeroinitializer
 ; CHECK-MARKER: section "__LLVM,__bitcode"
 ; CHECK-MARKER: @llvm.cmdline
 ; CHECK-MARKER: section "__LLVM,__cmdline"
 
+; CHECK-WARNING-NOT: Wall
+; CHECK-WARNING-NOT: Wundef-prefix
+
 define i32 @f0() {
   ret i32 0
 }