1 files changed, 48 insertions, 0 deletions
diff --git a/clang/lib/Driver/ToolChains/CommonArgs.cpp b/clang/lib/Driver/ToolChains/CommonArgs.cpp
index cce4f64..49ee53f 100644
--- a/clang/lib/Driver/ToolChains/CommonArgs.cpp
+++ b/clang/lib/Driver/ToolChains/CommonArgs.cpp
@@ -3557,3 +3557,51 @@ tools::renderComplexRangeOption(LangOptionsBase::ComplexRangeKind Range) {
     return "-complex-range=" + ComplexRangeStr;
   return ComplexRangeStr;
 }
+
+static void emitComplexRangeDiag(const Driver &D, StringRef LastOpt,
+                                 LangOptions::ComplexRangeKind Range,
+                                 StringRef NewOpt,
+                                 LangOptions::ComplexRangeKind NewRange) {
+  //  Do not emit a warning if NewOpt overrides LastOpt in the following cases.
+  //
+  // | LastOpt               | NewOpt                |
+  // |-----------------------|-----------------------|
+  // | -fcx-limited-range    | -fno-cx-limited-range |
+  // | -fno-cx-limited-range | -fcx-limited-range    |
+  // | -fcx-fortran-rules    | -fno-cx-fortran-rules |
+  // | -fno-cx-fortran-rules | -fcx-fortran-rules    |
+  // | -ffast-math           | -fno-fast-math        |
+  // | -ffp-model=           | -ffast-math           |
+  // | -ffp-model=           | -fno-fast-math        |
+  // | -ffp-model=           | -ffp-model=           |
+  // | -fcomplex-arithmetic= | -fcomplex-arithmetic= |
+  if (LastOpt == NewOpt || NewOpt.empty() || LastOpt.empty() ||
+      (LastOpt == "-fcx-limited-range" && NewOpt == "-fno-cx-limited-range") ||
+      (LastOpt == "-fno-cx-limited-range" && NewOpt == "-fcx-limited-range") ||
+      (LastOpt == "-fcx-fortran-rules" && NewOpt == "-fno-cx-fortran-rules") ||
+      (LastOpt == "-fno-cx-fortran-rules" && NewOpt == "-fcx-fortran-rules") ||
+      (LastOpt == "-ffast-math" && NewOpt == "-fno-fast-math") ||
+      (LastOpt.starts_with("-ffp-model=") && NewOpt == "-ffast-math") ||
+      (LastOpt.starts_with("-ffp-model=") && NewOpt == "-fno-fast-math") ||
+      (LastOpt.starts_with("-ffp-model=") &&
+       NewOpt.starts_with("-ffp-model=")) ||
+      (LastOpt.starts_with("-fcomplex-arithmetic=") &&
+       NewOpt.starts_with("-fcomplex-arithmetic=")))
+    return;
+
+  D.Diag(clang::diag::warn_drv_overriding_complex_range)
+      << LastOpt << NewOpt << complexRangeKindToStr(Range)
+      << complexRangeKindToStr(NewRange);
+}
+
+void tools::setComplexRange(const Driver &D, StringRef NewOpt,
+                            LangOptions::ComplexRangeKind NewRange,
+                            StringRef &LastOpt,
+                            LangOptions::ComplexRangeKind &Range) {
+  // Warn if user overrides the previously set complex number
+  // multiplication/division option.
+  if (Range != LangOptions::ComplexRangeKind::CX_None && Range != NewRange)
+    emitComplexRangeDiag(D, LastOpt, Range, NewOpt, NewRange);
+  LastOpt = NewOpt;
+  Range = NewRange;
+}