[clang] Fix warning message when using negative complex range options. (PR #84567)

[via cfe-commits]

llvmbot wrote:


<!--LLVM PR SUMMARY COMMENT-->

@llvm/pr-subscribers-clang

Author: Zahira Ammarguellat (zahiraam)

<details>
<summary>Changes</summary>

When `-fcx-no-limited-range` or` -fno-cx-fortran-rules` follows another complex range option on the command line, it will trigger a warning with empty message.
`warning: overriding '-fcx-fortran-rules' option with '' [-Woverriding-option]`
or
`warning: overriding '-fcx-limited-range' option with '' [-Woverriding-option]`
This patch fixes that.

---
Full diff: https://github.com/llvm/llvm-project/pull/84567.diff


2 Files Affected:

- (modified) clang/lib/Driver/ToolChains/Clang.cpp (+26-9) 
- (modified) clang/test/Driver/range.c (+18-5) 


``````````diff
diff --git a/clang/lib/Driver/ToolChains/Clang.cpp b/clang/lib/Driver/ToolChains/Clang.cpp
index 858d20fbfac015..46faf467dec0de 100644
--- a/clang/lib/Driver/ToolChains/Clang.cpp
+++ b/clang/lib/Driver/ToolChains/Clang.cpp
@@ -2687,8 +2687,8 @@ static void CollectArgsForIntegratedAssembler(Compilation &C,
   }
 }
 
-static StringRef EnumComplexRangeToStr(LangOptions::ComplexRangeKind Range) {
-  StringRef RangeStr = "";
+static StringRef EnumComplexRangeToStr(LangOptions::ComplexRangeKind Range,
+                                       StringRef Option) {
   switch (Range) {
   case LangOptions::ComplexRangeKind::CX_Limited:
     return "-fcx-limited-range";
@@ -2697,17 +2697,32 @@ static StringRef EnumComplexRangeToStr(LangOptions::ComplexRangeKind Range) {
     return "-fcx-fortran-rules";
     break;
   default:
-    return RangeStr;
+    return Option;
     break;
   }
 }
 
 static void EmitComplexRangeDiag(const Driver &D,
                                  LangOptions::ComplexRangeKind Range1,
-                                 LangOptions::ComplexRangeKind Range2) {
-  if (Range1 != Range2 && Range1 != LangOptions::ComplexRangeKind::CX_None)
-    D.Diag(clang::diag::warn_drv_overriding_option)
-        << EnumComplexRangeToStr(Range1) << EnumComplexRangeToStr(Range2);
+                                 LangOptions::ComplexRangeKind Range2,
+                                 StringRef Option = StringRef()) {
+  if (Range1 != Range2 && Range1 != LangOptions::ComplexRangeKind::CX_None) {
+    bool NegateFortranOption = false;
+    bool NegateLimitedOption = false;
+    if (!Option.empty()) {
+      NegateFortranOption =
+          Range1 == LangOptions::ComplexRangeKind::CX_Fortran &&
+          Option == "fno-cx-fortran-rules";
+      NegateLimitedOption =
+          Range1 == LangOptions::ComplexRangeKind::CX_Limited &&
+          Option == "fno-cx-limited-range";
+    }
+    if (Option.empty() ||
+        !Option.empty() && !NegateFortranOption && !NegateLimitedOption)
+      D.Diag(clang::diag::warn_drv_overriding_option)
+          << EnumComplexRangeToStr(Range1, Option)
+          << EnumComplexRangeToStr(Range2, Option);
+  }
 }
 
 static std::string
@@ -2815,7 +2830,8 @@ static void RenderFloatingPointOptions(const ToolChain &TC, const Driver &D,
       break;
     }
     case options::OPT_fno_cx_limited_range:
-      EmitComplexRangeDiag(D, Range, LangOptions::ComplexRangeKind::CX_Full);
+      EmitComplexRangeDiag(D, Range, LangOptions::ComplexRangeKind::CX_Full,
+                           "fno-cx-limited-range");
       Range = LangOptions::ComplexRangeKind::CX_Full;
       break;
     case options::OPT_fcx_fortran_rules: {
@@ -2824,7 +2840,8 @@ static void RenderFloatingPointOptions(const ToolChain &TC, const Driver &D,
       break;
     }
     case options::OPT_fno_cx_fortran_rules:
-      EmitComplexRangeDiag(D, Range, LangOptions::ComplexRangeKind::CX_Full);
+      EmitComplexRangeDiag(D, Range, LangOptions::ComplexRangeKind::CX_Full,
+                           "fno-cx-fortran-rules");
       Range = LangOptions::ComplexRangeKind::CX_Full;
       break;
     case options::OPT_ffp_model_EQ: {
diff --git a/clang/test/Driver/range.c b/clang/test/Driver/range.c
index 49116df2f4480e..fd6f5585104e18 100644
--- a/clang/test/Driver/range.c
+++ b/clang/test/Driver/range.c
@@ -12,12 +12,23 @@
 // RUN: %clang -### -target x86_64 -fcx-fortran-rules -c %s 2>&1 \
 // RUN:   | FileCheck --check-prefix=FRTRN %s
 
+// RUN: %clang -### -target x86_64 -fcx-fortran-rules -c %s 2>&1 \
+// RUN:   -fno-cx-fortran-rules | FileCheck --check-prefix=FULL %s
+
+// RUN: %clang -### -target x86_64 -fcx-fortran-rules -fno-cx-limited-range \
+// RUN: -c %s 2>&1 | FileCheck --check-prefix=WARN3 %s
+
 // RUN: %clang -### -target x86_64 -fno-cx-fortran-rules -c %s 2>&1 \
 // RUN:   | FileCheck  %s
 
-// RUN: %clang -### -target x86_64 -fcx-limited-range \
-// RUN: -fcx-fortran-rules -c %s 2>&1 \
-// RUN:   | FileCheck --check-prefix=WARN1 %s
+// RUN: %clang -### -target x86_64 -fcx-limited-range -fcx-fortran-rules \
+// RUN: -c %s 2>&1 | FileCheck --check-prefix=WARN1 %s
+
+// RUN: %clang -### -target x86_64 -fcx-limited-range -fno-cx-fortran-rules \
+// RUN: -c %s 2>&1 | FileCheck --check-prefix=WARN4 %s
+
+// RUN: %clang -### -target x86_64 -fcx-limited-range -fno-cx-limited-range \
+// RUN: -c %s 2>&1 | FileCheck --check-prefix=FULL %s
 
 // RUN: %clang -### -target x86_64 -fcx-fortran-rules \
 // RUN: -fcx-limited-range  -c %s 2>&1 \
@@ -32,8 +43,8 @@
 // RUN: %clang -### -target x86_64 -fcx-limited-range -ffast-math -c %s 2>&1 \
 // RUN:   | FileCheck --check-prefix=LMTD %s
 
-// RUN: %clang -### -target x86_64 -ffast-math -fno-cx-limited-range -c %s 2>&1 \
-// RUN:   | FileCheck --check-prefix=FULL %s
+// RUN: %clang -### -target x86_64 -ffast-math -fno-cx-limited-range \
+// RUN: -c %s 2>&1 | FileCheck --check-prefix=FULL %s
 
 // RUN: %clang -### -Werror -target x86_64 -fcx-limited-range -c %s 2>&1 \
 // RUN:   | FileCheck --check-prefix=LMTD %s
@@ -50,3 +61,5 @@
 // CHECK-NOT: -complex-range=fortran
 // WARN1: warning: overriding '-fcx-limited-range' option with '-fcx-fortran-rules' [-Woverriding-option]
 // WARN2: warning: overriding '-fcx-fortran-rules' option with '-fcx-limited-range' [-Woverriding-option]
+// WARN3: warning: overriding '-fcx-fortran-rules' option with 'fno-cx-limited-range' [-Woverriding-option]
+// WARN4: warning: overriding '-fcx-limited-range' option with 'fno-cx-fortran-rules' [-Woverriding-option]

``````````

</details>


https://github.com/llvm/llvm-project/pull/84567