[clang] ee6ad7a - [clang-cl][MSVC] Map /external:Wn n=1-4 to -Wsystem-headers

[Stephen Long via cfe-commits]

Author: Stephen Long
Date: 2022-06-13T11:26:07-07:00
New Revision: ee6ad7af45a0be36191e0d55f005d9a0dd8005be

URL: https://github.com/llvm/llvm-project/commit/ee6ad7af45a0be36191e0d55f005d9a0dd8005be
DIFF: https://github.com/llvm/llvm-project/commit/ee6ad7af45a0be36191e0d55f005d9a0dd8005be.diff

LOG: [clang-cl][MSVC] Map /external:Wn n=1-4 to -Wsystem-headers

https://docs.microsoft.com/en-us/cpp/build/reference/external-external-headers-diagnostics?view=msvc-170

Reviewed By: hans

Differential Revision: https://reviews.llvm.org/D127452

Added: 
    

Modified: 
    clang/include/clang/Driver/Options.td
    clang/test/Driver/cl-options.c

Removed: 
    


################################################################################
diff  --git a/clang/include/clang/Driver/Options.td b/clang/include/clang/Driver/Options.td
index a5a46bfb3cf0..563ad4611c17 100644
--- a/clang/include/clang/Driver/Options.td
+++ b/clang/include/clang/Driver/Options.td
@@ -775,6 +775,8 @@ def Wa_COMMA : CommaJoined<["-"], "Wa,">,
   MetaVarName<"<arg>">;
 def Wall : Flag<["-"], "Wall">, Group<W_Group>, Flags<[CC1Option, HelpHidden]>;
 def WCL4 : Flag<["-"], "WCL4">, Group<W_Group>, Flags<[CC1Option, HelpHidden]>;
+def Wsystem_headers : Flag<["-"], "Wsystem-headers">, Group<W_Group>, Flags<[CC1Option, HelpHidden]>;
+def Wno_system_headers : Flag<["-"], "Wno-system-headers">, Group<W_Group>, Flags<[CC1Option, HelpHidden]>;
 def Wdeprecated : Flag<["-"], "Wdeprecated">, Group<W_Group>, Flags<[CC1Option]>,
   HelpText<"Enable warnings for deprecated constructs and define __DEPRECATED">;
 def Wno_deprecated : Flag<["-"], "Wno-deprecated">, Group<W_Group>, Flags<[CC1Option]>;
@@ -6475,6 +6477,11 @@ def _SLASH_validate_charset : CLFlag<"validate-charset">,
   Alias<W_Joined>, AliasArgs<["invalid-source-encoding"]>;
 def _SLASH_validate_charset_ : CLFlag<"validate-charset-">,
   Alias<W_Joined>, AliasArgs<["no-invalid-source-encoding"]>;
+def _SLASH_external_W0 : CLFlag<"external:W0">, HelpText<"Ignore warnings from system headers (default)">, Alias<Wno_system_headers>;
+def _SLASH_external_W1 : CLFlag<"external:W1">, HelpText<"Enable -Wsystem-headers">, Alias<Wsystem_headers>;
+def _SLASH_external_W2 : CLFlag<"external:W2">, HelpText<"Enable -Wsystem-headers">, Alias<Wsystem_headers>;
+def _SLASH_external_W3 : CLFlag<"external:W3">, HelpText<"Enable -Wsystem-headers">, Alias<Wsystem_headers>;
+def _SLASH_external_W4 : CLFlag<"external:W4">, HelpText<"Enable -Wsystem-headers">, Alias<Wsystem_headers>;
 def _SLASH_W0 : CLFlag<"W0">, HelpText<"Disable all warnings">, Alias<w>;
 def _SLASH_W1 : CLFlag<"W1">, HelpText<"Enable -Wall">, Alias<Wall>;
 def _SLASH_W2 : CLFlag<"W2">, HelpText<"Enable -Wall">, Alias<Wall>;

diff  --git a/clang/test/Driver/cl-options.c b/clang/test/Driver/cl-options.c
index 1e518e0035ae..89a5a90dfa57 100644
--- a/clang/test/Driver/cl-options.c
+++ b/clang/test/Driver/cl-options.c
@@ -752,4 +752,12 @@
 // RUN: %clang_cl /JMC /Z7 /c -### -- %s 2>&1 | FileCheck %s --check-prefix JMC
 // JMC: -fjmc
 
+// RUN: %clang_cl /external:W0 /c -### -- %s 2>&1 | FileCheck -check-prefix=EXTERNAL_W0 %s
+// RUN: %clang_cl /external:W1 /c -### -- %s 2>&1 | FileCheck -check-prefix=EXTERNAL_Wn %s
+// RUN: %clang_cl /external:W2 /c -### -- %s 2>&1 | FileCheck -check-prefix=EXTERNAL_Wn %s
+// RUN: %clang_cl /external:W3 /c -### -- %s 2>&1 | FileCheck -check-prefix=EXTERNAL_Wn %s
+// RUN: %clang_cl /external:W4 /c -### -- %s 2>&1 | FileCheck -check-prefix=EXTERNAL_Wn %s
+// EXTERNAL_W0: "-Wno-system-headers"
+// EXTERNAL_Wn: "-Wsystem-headers"
+
 void f(void) { }