diff --git a/clang/include/clang/Tooling/DependencyScanning/DependencyScanningTool.h b/clang/include/clang/Tooling/DependencyScanning/DependencyScanningTool.h
--- a/clang/include/clang/Tooling/DependencyScanning/DependencyScanningTool.h
+++ b/clang/include/clang/Tooling/DependencyScanning/DependencyScanningTool.h
@@ -42,8 +42,10 @@
   /// determined that the differences are benign for this compilation.
   std::vector<ModuleID> ClangModuleDeps;
 
-  /// Get additional arguments suitable for appending to the original Clang
-  /// command line.
+  /// The original command line of the TU (excluding the compiler executable).
+  std::vector<std::string> OriginalCommandLine;
+
+  /// Get the full command line.
   ///
   /// \param LookupPCMPath This function is called to fill in "-fmodule-file="
   ///                      arguments and the "-o" argument. It needs to return
@@ -52,10 +54,13 @@
   /// \param LookupModuleDeps This function is called to collect the full
   ///                         transitive set of dependencies for this
   ///                         compilation.
-  std::vector<std::string> getAdditionalArgs(
+  std::vector<std::string> getCommandLine(
       std::function<StringRef(ModuleID)> LookupPCMPath,
       std::function<const ModuleDeps &(ModuleID)> LookupModuleDeps) const;
 
+  /// Get the full command line, excluding -fmodule-file=" arguments.
+  std::vector<std::string> getCommandLineWithoutModulePaths() const;
+
   /// Get additional arguments suitable for appending to the original Clang
   /// command line, excluding "-fmodule-file=" arguments.
   std::vector<std::string> getAdditionalArgsWithoutModulePaths() const;
diff --git a/clang/lib/Tooling/DependencyScanning/DependencyScanningTool.cpp b/clang/lib/Tooling/DependencyScanning/DependencyScanningTool.cpp
--- a/clang/lib/Tooling/DependencyScanning/DependencyScanningTool.cpp
+++ b/clang/lib/Tooling/DependencyScanning/DependencyScanningTool.cpp
@@ -13,10 +13,10 @@
 namespace tooling {
 namespace dependencies {
 
-std::vector<std::string> FullDependencies::getAdditionalArgs(
+std::vector<std::string> FullDependencies::getCommandLine(
     std::function<StringRef(ModuleID)> LookupPCMPath,
     std::function<const ModuleDeps &(ModuleID)> LookupModuleDeps) const {
-  std::vector<std::string> Ret = getAdditionalArgsWithoutModulePaths();
+  std::vector<std::string> Ret = getCommandLineWithoutModulePaths();
 
   std::vector<std::string> PCMPaths;
   std::vector<std::string> ModMapPaths;
@@ -28,6 +28,19 @@
   return Ret;
 }
 
+std::vector<std::string>
+FullDependencies::getCommandLineWithoutModulePaths() const {
+  std::vector<std::string> Args = OriginalCommandLine;
+
+  std::vector<std::string> AdditionalArgs =
+      getAdditionalArgsWithoutModulePaths();
+  Args.insert(Args.end(), AdditionalArgs.begin(), AdditionalArgs.end());
+
+  // TODO: Filter out implicit modules leftovers (e.g. "-fmodules-cache-path=").
+
+  return Args;
+}
+
 std::vector<std::string>
 FullDependencies::getAdditionalArgsWithoutModulePaths() const {
   std::vector<std::string> Args{
@@ -138,9 +151,13 @@
       ContextHash = std::move(Hash);
     }
 
-    FullDependenciesResult getFullDependencies() const {
+    FullDependenciesResult getFullDependencies(
+        const std::vector<std::string> &OriginalCommandLine) const {
       FullDependencies FD;
 
+      FD.OriginalCommandLine =
+          ArrayRef<std::string>(OriginalCommandLine).slice(1);
+
       FD.ID.ContextHash = std::move(ContextHash);
 
       FD.FileDeps.assign(Dependencies.begin(), Dependencies.end());
@@ -181,7 +198,7 @@
       Worker.computeDependencies(CWD, CommandLine, Consumer, ModuleName);
   if (Result)
     return std::move(Result);
-  return Consumer.getFullDependencies();
+  return Consumer.getFullDependencies(CommandLine);
 }
 
 } // end namespace dependencies
diff --git a/clang/test/ClangScanDeps/diagnostics.c b/clang/test/ClangScanDeps/diagnostics.c
--- a/clang/test/ClangScanDeps/diagnostics.c
+++ b/clang/test/ClangScanDeps/diagnostics.c
@@ -38,7 +38,7 @@
 // CHECK-NEXT:         }
 // CHECK-NEXT:       ],
 // CHECK-NEXT:       "command-line": [
-// CHECK-NEXT:         "-fno-implicit-modules"
+// CHECK:              "-fno-implicit-modules"
 // CHECK-NEXT:         "-fno-implicit-module-maps"
 // CHECK-NEXT:       ],
 // CHECK-NEXT:       "file-deps": [
diff --git a/clang/test/ClangScanDeps/modules-context-hash.c b/clang/test/ClangScanDeps/modules-context-hash.c
--- a/clang/test/ClangScanDeps/modules-context-hash.c
+++ b/clang/test/ClangScanDeps/modules-context-hash.c
@@ -50,7 +50,7 @@
 // CHECK-NEXT:         }
 // CHECK-NEXT:       ],
 // CHECK-NEXT:       "command-line": [
-// CHECK-NEXT:         "-fno-implicit-modules",
+// CHECK:              "-fno-implicit-modules",
 // CHECK-NEXT:         "-fno-implicit-module-maps"
 // CHECK-NEXT:       ],
 // CHECK-NEXT:       "file-deps": [
@@ -91,7 +91,7 @@
 // CHECK-NEXT:         }
 // CHECK-NEXT:       ],
 // CHECK-NEXT:       "command-line": [
-// CHECK-NEXT:         "-fno-implicit-modules",
+// CHECK:              "-fno-implicit-modules",
 // CHECK-NEXT:         "-fno-implicit-module-maps"
 // CHECK-NEXT:       ],
 // CHECK-NEXT:       "file-deps": [
diff --git a/clang/test/ClangScanDeps/modules-fmodule-name-no-module-built.m b/clang/test/ClangScanDeps/modules-fmodule-name-no-module-built.m
--- a/clang/test/ClangScanDeps/modules-fmodule-name-no-module-built.m
+++ b/clang/test/ClangScanDeps/modules-fmodule-name-no-module-built.m
@@ -43,7 +43,7 @@
 // CHECK-NEXT:         }
 // CHECK-NEXT:       ],
 // CHECK-NEXT:       "command-line": [
-// CHECK-NEXT:         "-fno-implicit-modules"
+// CHECK:              "-fno-implicit-modules"
 // CHECK-NEXT:         "-fno-implicit-module-maps"
 // CHECK-NEXT:         "-fmodule-file=[[PREFIX]]/module-cache{{(_clangcl)?}}/[[HASH_H2]]/header2-{{[A-Z0-9]+}}.pcm"
 // CHECK-NEXT:       ],
diff --git a/clang/test/ClangScanDeps/modules-full.cpp b/clang/test/ClangScanDeps/modules-full.cpp
--- a/clang/test/ClangScanDeps/modules-full.cpp
+++ b/clang/test/ClangScanDeps/modules-full.cpp
@@ -103,7 +103,7 @@
 // CHECK-NEXT:         }
 // CHECK-NEXT:       ],
 // CHECK-NEXT:       "command-line": [
-// CHECK-NEXT:         "-fno-implicit-modules"
+// CHECK:              "-fno-implicit-modules"
 // CHECK-NEXT:         "-fno-implicit-module-maps"
 // CHECK-NO-ABS-NOT:   "-fmodule-file={{.*}}"
 // CHECK-ABS-NEXT:     "-fmodule-file=[[PREFIX]]/module-cache{{(_clangcl)?}}/[[HASH_H1]]/header1-{{[A-Z0-9]+}}.pcm"
@@ -123,7 +123,7 @@
 // CHECK-NEXT:         }
 // CHECK-NEXT:       ],
 // CHECK-NEXT:       "command-line": [
-// CHECK-NEXT:         "-fno-implicit-modules"
+// CHECK:              "-fno-implicit-modules"
 // CHECK-NEXT:         "-fno-implicit-module-maps"
 // CHECK-NO-ABS-NOT:   "-fmodule-file={{.*}},
 // CHECK-ABS-NEXT:     "-fmodule-file=[[PREFIX]]/module-cache{{(_clangcl)?}}/[[HASH_H1]]/header1-{{[A-Z0-9]+}}.pcm"
@@ -143,7 +143,7 @@
 // CHECK-NEXT:         }
 // CHECK-NEXT:       ],
 // CHECK-NEXT:       "command-line": [
-// CHECK-NEXT:         "-fno-implicit-modules"
+// CHECK:              "-fno-implicit-modules"
 // CHECK-NEXT:         "-fno-implicit-module-maps"
 // CHECK-NO-ABS-NOT:   "-fmodule-file={{.*}}"
 // CHECK-ABS-NEXT:     "-fmodule-file=[[PREFIX]]/module-cache{{(_clangcl)?}}/[[HASH_H1]]/header1-{{[A-Z0-9]+}}.pcm"
@@ -163,7 +163,7 @@
 // CHECK-NEXT:         }
 // CHECK-NEXT:       ],
 // CHECK-NEXT:       "command-line": [
-// CHECK-NEXT:         "-fno-implicit-modules"
+// CHECK:              "-fno-implicit-modules"
 // CHECK-NEXT:         "-fno-implicit-module-maps"
 // CHECK-NO-ABS-NOT:   "-fmodule-file={{.*}}"
 // CHECK-ABS-NEXT:     "-fmodule-file=[[PREFIX]]/module-cache{{(_clangcl)?}}/[[HASH_H2_DINCLUDE]]/header2-{{[A-Z0-9]+}}.pcm"
diff --git a/clang/test/ClangScanDeps/modules-inferred-explicit-build.m b/clang/test/ClangScanDeps/modules-inferred-explicit-build.m
--- a/clang/test/ClangScanDeps/modules-inferred-explicit-build.m
+++ b/clang/test/ClangScanDeps/modules-inferred-explicit-build.m
@@ -12,9 +12,7 @@
 // RUN: %python %S/../../utils/module-deps-to-rsp.py %t.db --tu-index=0 > %t.tu.rsp
 // RUN: %clang @%t.inferred.cc1.rsp -pedantic -Werror
 // RUN: %clang @%t.system.cc1.rsp -pedantic -Werror
-// RUN: %clang -x objective-c -fsyntax-only %t.dir/modules_cdb_input.cpp \
-// RUN:   -F%S/Inputs/frameworks -fmodules -fimplicit-module-maps \
-// RUN:   -pedantic -Werror @%t.tu.rsp
+// RUN: %clang @%t.tu.rsp -pedantic -Werror -Wno-unused-command-line-argument
 
 #include <Inferred/Inferred.h>
 #include <System/System.h>
diff --git a/clang/test/ClangScanDeps/modules-inferred.m b/clang/test/ClangScanDeps/modules-inferred.m
--- a/clang/test/ClangScanDeps/modules-inferred.m
+++ b/clang/test/ClangScanDeps/modules-inferred.m
@@ -47,7 +47,7 @@
 // CHECK-NEXT:         }
 // CHECK-NEXT:       ],
 // CHECK-NEXT:       "command-line": [
-// CHECK-NEXT:         "-fno-implicit-modules",
+// CHECK:              "-fno-implicit-modules",
 // CHECK-NEXT:         "-fno-implicit-module-maps",
 // CHECK-NEXT:         "-fmodule-file=[[PREFIX]]/module-cache/[[HASH_INFERRED]]/Inferred-{{[A-Z0-9]+}}.pcm"
 // CHECK-NEXT:       ],
diff --git a/clang/test/ClangScanDeps/modules-pch-common-submodule.c b/clang/test/ClangScanDeps/modules-pch-common-submodule.c
--- a/clang/test/ClangScanDeps/modules-pch-common-submodule.c
+++ b/clang/test/ClangScanDeps/modules-pch-common-submodule.c
@@ -51,7 +51,7 @@
 // CHECK-PCH-NEXT:         }
 // CHECK-PCH-NEXT:       ],
 // CHECK-PCH-NEXT:       "command-line": [
-// CHECK-PCH-NEXT:         "-fno-implicit-modules"
+// CHECK-PCH:              "-fno-implicit-modules"
 // CHECK-PCH-NEXT:         "-fno-implicit-module-maps"
 // CHECK-PCH-NEXT:         "-fmodule-file=[[PREFIX]]/build/[[HASH_MOD_COMMON]]/ModCommon-{{.*}}.pcm"
 // CHECK-PCH-NEXT:       ],
@@ -72,8 +72,7 @@
 // RUN:   --tu-index=0 > %t/pch.rsp
 //
 // RUN: %clang @%t/mod_common.cc1.rsp
-// RUN: %clang -x c-header %t/pch.h -fmodules -gmodules -fimplicit-module-maps \
-// RUN:   -fmodules-cache-path=%t/cache -o %t/pch.h.gch @%t/pch.rsp
+// RUN: %clang @%t/pch.rsp
 
 // Scan dependencies of the TU:
 //
@@ -115,7 +114,7 @@
 // CHECK-TU-NEXT:         }
 // CHECK-TU-NEXT:       ],
 // CHECK-TU-NEXT:       "command-line": [
-// CHECK-TU-NEXT:         "-fno-implicit-modules",
+// CHECK-TU:              "-fno-implicit-modules",
 // CHECK-TU-NEXT:         "-fno-implicit-module-maps",
 // CHECK-TU-NEXT:         "-fmodule-file=[[PREFIX]]/build/[[HASH_MOD_TU:.*]]/ModTU-{{.*}}.pcm"
 // CHECK-TU-NEXT:       ],
@@ -137,5 +136,4 @@
 // RUN:   --tu-index=0 > %t/tu.rsp
 //
 // RUN: %clang @%t/mod_tu.cc1.rsp
-// RUN: %clang -fsyntax-only %t/tu.c -fmodules -gmodules -fimplicit-module-maps \
-// RUN:   -fmodules-cache-path=%t/cache -include %t/pch.h -o %t/tu.o @%t/tu.rsp
+// RUN: %clang @%t/tu.rsp
diff --git a/clang/test/ClangScanDeps/modules-pch-common-via-submodule.c b/clang/test/ClangScanDeps/modules-pch-common-via-submodule.c
--- a/clang/test/ClangScanDeps/modules-pch-common-via-submodule.c
+++ b/clang/test/ClangScanDeps/modules-pch-common-via-submodule.c
@@ -48,7 +48,7 @@
 // CHECK-PCH-NEXT:         }
 // CHECK-PCH-NEXT:       ],
 // CHECK-PCH-NEXT:       "command-line": [
-// CHECK-PCH-NEXT:         "-fno-implicit-modules"
+// CHECK-PCH:              "-fno-implicit-modules"
 // CHECK-PCH-NEXT:         "-fno-implicit-module-maps"
 // CHECK-PCH-NEXT:         "-fmodule-file=[[PREFIX]]/build/[[HASH_MOD_COMMON]]/ModCommon-{{.*}}.pcm"
 // CHECK-PCH-NEXT:       ],
@@ -69,8 +69,7 @@
 // RUN:   --tu-index=0 > %t/pch.rsp
 //
 // RUN: %clang @%t/mod_common.cc1.rsp
-// RUN: %clang -x c-header %t/pch.h -fmodules -gmodules -fimplicit-module-maps \
-// RUN:   -fmodules-cache-path=%t/cache -o %t/pch.h.gch @%t/pch.rsp
+// RUN: %clang @%t/pch.rsp
 
 // Scan dependencies of the TU:
 //
@@ -113,7 +112,7 @@
 // CHECK-TU-NEXT:         }
 // CHECK-TU-NEXT:       ],
 // CHECK-TU-NEXT:       "command-line": [
-// CHECK-TU-NEXT:         "-fno-implicit-modules",
+// CHECK-TU:              "-fno-implicit-modules",
 // CHECK-TU-NEXT:         "-fno-implicit-module-maps",
 // CHECK-TU-NEXT:         "-fmodule-file=[[PREFIX]]/build/[[HASH_MOD_TU:.*]]/ModTU-{{.*}}.pcm"
 // CHECK-TU-NEXT:       ],
@@ -135,5 +134,4 @@
 // RUN:   --tu-index=0 > %t/tu.rsp
 //
 // RUN: %clang @%t/mod_tu.cc1.rsp
-// RUN: %clang -fsyntax-only %t/tu.c -fmodules -gmodules -fimplicit-module-maps \
-// RUN:   -fmodules-cache-path=%t/cache -include %t/pch.h -o %t/tu.o @%t/tu.rsp
+// RUN: %clang @%t/tu.rsp
diff --git a/clang/test/ClangScanDeps/modules-pch.c b/clang/test/ClangScanDeps/modules-pch.c
--- a/clang/test/ClangScanDeps/modules-pch.c
+++ b/clang/test/ClangScanDeps/modules-pch.c
@@ -91,7 +91,7 @@
 // CHECK-PCH-NEXT:         }
 // CHECK-PCH-NEXT:       ],
 // CHECK-PCH-NEXT:       "command-line": [
-// CHECK-PCH-NEXT:         "-fno-implicit-modules",
+// CHECK-PCH:              "-fno-implicit-modules",
 // CHECK-PCH-NEXT:         "-fno-implicit-module-maps",
 // CHECK-PCH-NEXT:         "-fmodule-file=[[PREFIX]]/build/[[HASH_MOD_COMMON_1]]/ModCommon1-{{.*}}.pcm",
 // CHECK-PCH-NEXT:         "-fmodule-file=[[PREFIX]]/build/[[HASH_MOD_COMMON_2]]/ModCommon2-{{.*}}.pcm",
@@ -120,8 +120,7 @@
 // RUN: %clang @%t/mod_common_1.cc1.rsp
 // RUN: %clang @%t/mod_common_2.cc1.rsp
 // RUN: %clang @%t/mod_pch.cc1.rsp
-// RUN: %clang -x c-header %t/pch.h -fmodules -gmodules -fimplicit-module-maps \
-// RUN:   -fmodules-cache-path=%t/cache -o %t/pch.h.gch @%t/pch.rsp
+// RUN: %clang @%t/pch.rsp
 
 // Scan dependencies of the TU:
 //
@@ -161,7 +160,7 @@
 // CHECK-TU-NEXT:         }
 // CHECK-TU-NEXT:       ],
 // CHECK-TU-NEXT:       "command-line": [
-// CHECK-TU-NEXT:         "-fno-implicit-modules",
+// CHECK-TU:              "-fno-implicit-modules",
 // CHECK-TU-NEXT:         "-fno-implicit-module-maps",
 // CHECK-TU-NEXT:         "-fmodule-file=[[PREFIX]]/build/[[HASH_MOD_TU]]/ModTU-{{.*}}.pcm"
 // CHECK-TU-NEXT:       ],
@@ -183,8 +182,7 @@
 // RUN:   --tu-index=0 > %t/tu.rsp
 //
 // RUN: %clang @%t/mod_tu.cc1.rsp
-// RUN: %clang -fsyntax-only %t/tu.c -fmodules -gmodules -fimplicit-module-maps \
-// RUN:   -fmodules-cache-path=%t/cache -include %t/pch.h -o %t/tu.o @%t/tu.rsp
+// RUN: %clang @%t/tu.rsp
 
 // Scan dependencies of the TU that has common modules with the PCH:
 //
@@ -225,7 +223,7 @@
 // CHECK-TU-WITH-COMMON-NEXT:         }
 // CHECK-TU-WITH-COMMON-NEXT:       ],
 // CHECK-TU-WITH-COMMON-NEXT:       "command-line": [
-// CHECK-TU-WITH-COMMON-NEXT:         "-fno-implicit-modules",
+// CHECK-TU-WITH-COMMON:              "-fno-implicit-modules",
 // CHECK-TU-WITH-COMMON-NEXT:         "-fno-implicit-module-maps",
 // CHECK-TU-WITH-COMMON-NEXT:         "-fmodule-file=[[PREFIX]]/build/{{.*}}/ModCommon2-{{.*}}.pcm",
 // CHECK-TU-WITH-COMMON-NEXT:         "-fmodule-file=[[PREFIX]]/build/[[HASH_MOD_TU_WITH_COMMON]]/ModTUWithCommon-{{.*}}.pcm"
@@ -248,5 +246,4 @@
 // RUN:   --tu-index=0 > %t/tu_with_common.rsp
 //
 // RUN: %clang @%t/mod_tu_with_common.cc1.rsp
-// RUN: %clang -fsyntax-only %t/tu_with_common.c -fmodules -gmodules -fimplicit-module-maps \
-// RUN:   -fmodules-cache-path=%t/cache -include %t/pch.h -o %t/tu_with_common.o @%t/tu_with_common.rsp
+// RUN: %clang @%t/tu_with_common.rsp
diff --git a/clang/test/ClangScanDeps/modules-symlink.c b/clang/test/ClangScanDeps/modules-symlink.c
--- a/clang/test/ClangScanDeps/modules-symlink.c
+++ b/clang/test/ClangScanDeps/modules-symlink.c
@@ -49,8 +49,7 @@
 // RUN:   --tu-index=0 > %t/pch.rsp
 //
 // RUN: %clang @%t/mod.cc1.rsp
-// RUN: %clang -x c-header %t/pch.h -fmodules -gmodules -fimplicit-module-maps \
-// RUN:   -fmodules-cache-path=%t/cache -o %t/pch.h.gch -I %t @%t/pch.rsp
+// RUN: %clang @%t/pch.rsp
 
 // RUN: sed -e "s|DIR|%/t|g" %t/cdb_tu.json > %t/cdb.json
 // RUN: clang-scan-deps -compilation-database %t/cdb.json -format experimental-full \
diff --git a/clang/tools/clang-scan-deps/ClangScanDeps.cpp b/clang/tools/clang-scan-deps/ClangScanDeps.cpp
--- a/clang/tools/clang-scan-deps/ClangScanDeps.cpp
+++ b/clang/tools/clang-scan-deps/ClangScanDeps.cpp
@@ -296,14 +296,13 @@
       Modules.insert(I, {{MD.ID, InputIndex}, std::move(MD)});
     }
 
-    ID.AdditionalCommandLine =
-        GenerateModulesPathArgs
-            ? FD.getAdditionalArgs(
-                  [&](ModuleID MID) { return lookupPCMPath(MID); },
-                  [&](ModuleID MID) -> const ModuleDeps & {
-                    return lookupModuleDeps(MID);
-                  })
-            : FD.getAdditionalArgsWithoutModulePaths();
+    ID.CommandLine = GenerateModulesPathArgs
+                         ? FD.getCommandLine(
+                               [&](ModuleID MID) { return lookupPCMPath(MID); },
+                               [&](ModuleID MID) -> const ModuleDeps & {
+                                 return lookupModuleDeps(MID);
+                               })
+                         : FD.getCommandLineWithoutModulePaths();
 
     Inputs.push_back(std::move(ID));
   }
@@ -353,7 +352,7 @@
           {"clang-context-hash", I.ContextHash},
           {"file-deps", I.FileDeps},
           {"clang-module-deps", toJSONSorted(I.ModuleDeps)},
-          {"command-line", I.AdditionalCommandLine},
+          {"command-line", I.CommandLine},
       };
       TUs.push_back(std::move(O));
     }
@@ -415,7 +414,7 @@
     std::string ContextHash;
     std::vector<std::string> FileDeps;
     std::vector<ModuleID> ModuleDeps;
-    std::vector<std::string> AdditionalCommandLine;
+    std::vector<std::string> CommandLine;
   };
 
   std::mutex Lock;