[clang-cl] Handle -O correctly
We had multiple bugs here:
- We didn't support multiple optimization options in one argument.
e.g. -O2y-
- We didn't correctly expand -O[12dx] to their respective options.
- We treated -O1 as clang -O1 instead of clang -Os.
- We treated -Ox as clang -O3 instead of clang -O2. In fact, cl's -Ox
option is *less* powerful than cl's -O2 option despite -Ox described
as "Full Optimization".
This fixes PR24003.
llvm-svn: 243261
diff --git a/clang/lib/Driver/MSVCToolChain.cpp b/clang/lib/Driver/MSVCToolChain.cpp
index c816b29..b890375 100644
--- a/clang/lib/Driver/MSVCToolChain.cpp
+++ b/clang/lib/Driver/MSVCToolChain.cpp
@@ -528,3 +528,101 @@
Res |= SanitizerKind::Address;
return Res;
}
+
+llvm::opt::DerivedArgList *
+MSVCToolChain::TranslateArgs(const llvm::opt::DerivedArgList &Args,
+ const char *BoundArch) const {
+ DerivedArgList *DAL = new DerivedArgList(Args.getBaseArgs());
+ const OptTable &Opts = getDriver().getOpts();
+
+ // The -O[12xd] flag actually expands to several flags. We must desugar the
+ // flags so that options embedded can be negated. For example, the '-O2' flag
+ // enables '-Oy'. Expanding '-O2' into its constituent flags allows us to
+ // correctly handle '-O2 -Oy-' where the trailing '-Oy-' disables a single
+ // aspect of '-O2'.
+ //
+ // Note that this expansion logic only applies to the *last* of '[12xd]'.
+
+ // First step is to search for the character we'd like to expand.
+ const char *ExpandChar = nullptr;
+ for (Arg *A : Args) {
+ if (!A->getOption().matches(options::OPT__SLASH_O))
+ continue;
+ StringRef OptStr = A->getValue();
+ for (size_t I = 0, E = OptStr.size(); I != E; ++I) {
+ const char &OptChar = *(OptStr.data() + I);
+ if (OptChar == '1' || OptChar == '2' || OptChar == 'x' || OptChar == 'd')
+ ExpandChar = OptStr.data() + I;
+ }
+ }
+
+ // The -O flag actually takes an amalgam of other options. For example,
+ // '/Ogyb2' is equivalent to '/Og' '/Oy' '/Ob2'.
+ for (Arg *A : Args) {
+ if (!A->getOption().matches(options::OPT__SLASH_O)) {
+ DAL->append(A);
+ continue;
+ }
+
+ StringRef OptStr = A->getValue();
+ for (size_t I = 0, E = OptStr.size(); I != E; ++I) {
+ const char &OptChar = *(OptStr.data() + I);
+ switch (OptChar) {
+ default:
+ break;
+ case '1':
+ case '2':
+ case 'x':
+ case 'd':
+ if (&OptChar == ExpandChar) {
+ if (OptChar == 'd') {
+ DAL->AddFlagArg(A, Opts.getOption(options::OPT_O0));
+ } else {
+ if (OptChar == '1') {
+ DAL->AddJoinedArg(A, Opts.getOption(options::OPT_O), "s");
+ } else if (OptChar == '2' || OptChar == 'x') {
+ DAL->AddFlagArg(A, Opts.getOption(options::OPT_fbuiltin));
+ DAL->AddJoinedArg(A, Opts.getOption(options::OPT_O), "2");
+ }
+ DAL->AddFlagArg(A,
+ Opts.getOption(options::OPT_fomit_frame_pointer));
+ if (OptChar == '1' || OptChar == '2')
+ DAL->AddFlagArg(A,
+ Opts.getOption(options::OPT_ffunction_sections));
+ }
+ }
+ break;
+ case 'b':
+ if (isdigit(OptStr[I + 1]))
+ ++I;
+ break;
+ case 'g':
+ break;
+ case 'i':
+ if (OptStr[I + 1] == '-') {
+ ++I;
+ DAL->AddFlagArg(A, Opts.getOption(options::OPT_fno_builtin));
+ } else {
+ DAL->AddFlagArg(A, Opts.getOption(options::OPT_fbuiltin));
+ }
+ break;
+ case 's':
+ DAL->AddJoinedArg(A, Opts.getOption(options::OPT_O), "s");
+ break;
+ case 't':
+ DAL->AddJoinedArg(A, Opts.getOption(options::OPT_O), "2");
+ break;
+ case 'y':
+ if (OptStr[I + 1] == '-') {
+ ++I;
+ DAL->AddFlagArg(A,
+ Opts.getOption(options::OPT_fno_omit_frame_pointer));
+ } else {
+ DAL->AddFlagArg(A, Opts.getOption(options::OPT_fomit_frame_pointer));
+ }
+ break;
+ }
+ }
+ }
+ return DAL;
+}