Add option to switch off putting header modules into the dependency file.

[rsmith]

As a driver flag, this should have a -f form as well as the -fno- form.

[klimek]

Add -fmodule-file-deps.

[klimek]

Break line.

[klimek]

In D8378#142065, @rsmith wrote:

As a driver flag, this should have a -f form as well as the -fno- form.

Done.

[djasper]

Looks good.

test/Driver/pch-deps.c

18

nit: I'd either line wrap both of these command lines (slightly preferable) or none of them.

[djasper]

test/Driver/pch-deps.c

18

Ah, sorry, this was just Phabricator confusing me.

[djasper]

This was submitted in r232721.

include/clang/Driver/Options.td

 def fno_module_maps : Flag <["-"], "fno-module-maps">, Group<f_Group>,
   Flags<[DriverOption]>;
 def fno_modules_decluse : Flag <["-"], "fno-modules-decluse">, Group<f_Group>,
   Flags<[DriverOption]>;
 def fno_modules_strict_decluse : Flag <["-"], "fno-strict-modules-decluse">, Group<f_Group>,
   Flags<[DriverOption]>;
 def fimplicit_modules : Flag <["-"], "fimplicit-modules">, Group<f_Group>,
   Flags<[DriverOption]>;
+def fmodule_file_deps : Flag <["-"], "fmodule-file-deps">, Group<f_Group>,
+  Flags<[DriverOption]>;
+def fno_module_file_deps : Flag <["-"], "fno-module-file-deps">, Group<f_Group>,
+  Flags<[DriverOption]>;
 def fno_ms_extensions : Flag<["-"], "fno-ms-extensions">, Group<f_Group>;
 def fno_ms_compatibility : Flag<["-"], "fno-ms-compatibility">, Group<f_Group>;
 def fno_delayed_template_parsing : Flag<["-"], "fno-delayed-template-parsing">, Group<f_Group>;
 def fno_objc_exceptions: Flag<["-"], "fno-objc-exceptions">, Group<f_Group>;
 def fno_objc_legacy_dispatch : Flag<["-"], "fno-objc-legacy-dispatch">, Group<f_Group>;
 def fno_omit_frame_pointer : Flag<["-"], "fno-omit-frame-pointer">, Group<f_Group>;
 def fno_operator_names : Flag<["-"], "fno-operator-names">, Group<f_Group>,
   HelpText<"Do not treat C++ operator name keywords as synonyms for operators">,

lib/Driver/Tools.cpp

if (!Args.hasArg(options::OPT_MT) && !Args.hasArg(options::OPT_MQ)) {
       SmallString<128> Quoted;
       QuoteTarget(DepTarget, Quoted);
       CmdArgs.push_back(Args.MakeArgString(Quoted));
     }
 
     if (A->getOption().matches(options::OPT_M) ||
         A->getOption().matches(options::OPT_MD))
       CmdArgs.push_back("-sys-header-deps");
-
-    if (isa<PrecompileJobAction>(JA))
+    if ((isa<PrecompileJobAction>(JA) &&
+         !Args.hasArg(options::OPT_fno_module_file_deps)) ||
+        Args.hasArg(options::OPT_fmodule_file_deps))
       CmdArgs.push_back("-module-file-deps");
   }
 
   if (Args.hasArg(options::OPT_MG)) {
     if (!A || A->getOption().matches(options::OPT_MD) ||
               A->getOption().matches(options::OPT_MMD))
       D.Diag(diag::err_drv_mg_requires_m_or_mm);
     CmdArgs.push_back("-MG");

test/Driver/pch-deps.c

 // RUN: %clang -x c-header %s -o %t.pch -MMD -MT dependencies -MF %t.d -### 2> %t
 // RUN: FileCheck %s -input-file=%t
 // CHECK: -emit-pch
 // CHECK: -dependency-file
 // CHECK: -module-file-deps
 
 // RUN: %clang -c %s -o %t -MMD -MT dependencies -MF %t.d -### 2> %t
 // RUN: FileCheck %s -check-prefix=CHECK-NOPCH -input-file=%t
 // CHECK-NOPCH: -dependency-file
 // CHECK-NOPCH-NOT: -module-file-deps
+
+// RUN: %clang -x c-header %s -o %t.pch -MMD -MT dependencies -MF %t.d \
+// RUN:     -fno-module-file-deps -### 2> %t
+// RUN: FileCheck %s -check-prefix=CHECK-EXPLICIT -input-file=%t
+// CHECK-EXPLICIT: -dependency-file
+// CHECK-EXPLICIT-NOT: -module-file-deps
+
+// RUN: %clang -x c++ %s -o %t.o -MMD -MT dependencies -MF %t.d -fmodule-file-deps -### 2> %t
+// RUN: FileCheck %s -check-prefix=CHECK-EXPLICIT-NOPCH -input-file=%t
+// CHECK-EXPLICIT-NOPCH: -dependency-file
+// CHECK-EXPLICIT-NOPCH: -module-file-deps