[clang][deps] Return the whole TU command line

[jansvoboda11]

Summary

The dependency scanner already generates canonical -cc1 command lines that can be used to compile discovered modular dependencies.

For translation unit command lines, the scanner only generates additional driver arguments the build system is expected to append to the original command line.

While this works most of the time, there are situations where that's not the case. For example with -Wunused-command-line-argument, Clang will complain about the -fmodules-cache-path= argument that's not being used in explicit modular builds. Combine that with -Werror and the build outright fails.

To prevent such failures, this patch changes the dependency scanner to return the full driver command line to compile the original translation unit. This gives us more opportunities to massage the arguments into something reasonable.

[jansvoboda11]

Undo one test change.

[jansvoboda11]

clang/test/ClangScanDeps/modules-inferred-explicit-build.m

15

This patch will make it possible to strip out -fmodules-cache-path=, allowing us to remove -Wno-unused-command-line-argument in this test. Note that previously, we needed to strip the argument ourselves manually to get the same effect.

[Bigcheese]

This does require build systems to be able to totally replace a command line rather than just add to it, but it seems like that's a requirement unless we add a way to modify the command line to Clang. lgtm.

clang/include/clang/Tooling/DependencyScanning/DependencyScanningTool.h

struct FullDependencies {
 
   /// A list of modules this translation unit directly depends on, not including
   /// transitive dependencies.
   ///
   /// This may include modules with a different context hash when it can be
   /// 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
   ///                      a path for where the PCM for the given module is to
   ///                      be located.
   /// \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;
 };
 
 struct FullDependenciesResult {
   FullDependencies FullDeps;
   std::vector<ModuleDeps> DiscoveredModules;

clang/lib/Tooling/DependencyScanning/DependencyScanningTool.cpp

 //===- DependencyScanningTool.cpp - clang-scan-deps service ---------------===//
 //
 // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
 // See https://llvm.org/LICENSE.txt for license information.
 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
 //
 //===----------------------------------------------------------------------===//
 
 #include "clang/Tooling/DependencyScanning/DependencyScanningTool.h"
 #include "clang/Frontend/Utils.h"
 
 namespace clang {
 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;
   dependencies::detail::collectPCMAndModuleMapPaths(
       ClangModuleDeps, LookupPCMPath, LookupModuleDeps, PCMPaths, ModMapPaths);
   for (const std::string &PCMPath : PCMPaths)
     Ret.push_back("-fmodule-file=" + PCMPath);
 
   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{
       "-fno-implicit-modules",
       "-fno-implicit-module-maps",
   };
 
   for (const PrebuiltModuleDep &PMD : PrebuiltModuleDeps)
     Args.push_back("-fmodule-file=" + PMD.PCMFile);
public:
     void handleModuleDependency(ModuleDeps MD) override {
       ClangModuleDeps[MD.ID.ContextHash + MD.ID.ModuleName] = std::move(MD);
     }
 
     void handleContextHash(std::string Hash) override {
       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());
 
       for (auto &&M : ClangModuleDeps) {
         auto &MD = M.second;
         if (MD.ImportedByMainFile)
           FD.ClangModuleDeps.push_back(MD.ID);
private:
     const llvm::StringSet<> &AlreadySeen;
   };
 
   FullDependencyPrinterConsumer Consumer(AlreadySeen);
   llvm::Error Result =
       Worker.computeDependencies(CWD, CommandLine, Consumer, ModuleName);
   if (Result)
     return std::move(Result);
-  return Consumer.getFullDependencies();
+  return Consumer.getFullDependencies(CommandLine);
 }
 
 } // end namespace dependencies
 } // end namespace tooling
 } // end namespace clang

clang/test/ClangScanDeps/diagnostics.c

 // CHECK-NEXT:       "clang-context-hash": "[[HASH_TU:.*]],
 // CHECK-NEXT:       "clang-module-deps": [
 // CHECK-NEXT:         {
 // CHECK-NEXT:           "context-hash": "[[HASH_MOD]]",
 // CHECK-NEXT:           "module-name": "mod"
 // 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": [
 // CHECK-NEXT:         "[[PREFIX]]/tu.c"
 // CHECK-NEXT:       ],
 // CHECK-NEXT:       "input-file": "[[PREFIX]]/tu.c"
 // CHECK-NEXT:     }
 // CHECK-NEXT:   ]
 // CHECK-NEXT: }

clang/test/ClangScanDeps/modules-context-hash.c

 // CHECK-NEXT:       "clang-context-hash": "{{.*}}",
 // CHECK-NEXT:       "clang-module-deps": [
 // CHECK-NEXT:         {
 // CHECK-NEXT:           "context-hash": "[[HASH_MOD_A]]",
 // CHECK-NEXT:           "module-name": "mod"
 // 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": [
 // CHECK-NEXT:         "[[PREFIX]]/tu.c"
 // CHECK-NEXT:       ],
 // CHECK-NEXT:       "input-file": "[[PREFIX]]/tu.c"
 // CHECK-NEXT:     }
 // CHECK-NEXT:   ]

 // CHECK-NEXT:       "clang-context-hash": "{{.*}}",
 // CHECK-NEXT:       "clang-module-deps": [
 // CHECK-NEXT:         {
 // CHECK-NOT:            "context-hash": "[[HASH_MOD_A]]",
 // CHECK:                "module-name": "mod"
 // 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": [
 // CHECK-NEXT:         "[[PREFIX]]/tu.c"
 // CHECK-NEXT:       ],
 // CHECK-NEXT:       "input-file": "[[PREFIX]]/tu.c"
 // CHECK-NEXT:     }
 // CHECK-NEXT:   ]
 // CHECK-NEXT: }

clang/test/ClangScanDeps/modules-fmodule-name-no-module-built.m

 // CHECK-NEXT:       "clang-context-hash": "[[HASH_TU:[A-Z0-9]+]]",
 // CHECK-NEXT:       "clang-module-deps": [
 // CHECK-NEXT:         {
 // CHECK-NEXT:           "context-hash": "[[HASH_H2]]",
 // CHECK-NEXT:           "module-name": "header2"
 // 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:       ],
 // CHECK-NEXT:       "file-deps": [
 // CHECK-NEXT:         "[[PREFIX]]/modules-fmodule-name-no-module-built.m"
 // CHECK-NEXT:         "[[PREFIX]]/Inputs/header3.h"
 // CHECK-NEXT:         "[[PREFIX]]/Inputs/header.h"
 // CHECK-NEXT:       ],
 // CHECK-NEXT:       "input-file": "[[PREFIX]]/modules-fmodule-name-no-module-built.m"
 // CHECK-NEXT:     }
 // CHECK-NEXT:   ]
 // CHECK-NEXT: }

clang/test/ClangScanDeps/modules-full.cpp

 // CHECK-NEXT:       "clang-context-hash": "[[HASH_TU:[A-Z0-9]+]]",
 // CHECK-NEXT:       "clang-module-deps": [
 // CHECK-NEXT:         {
 // CHECK-NEXT:           "context-hash": "[[HASH_H1]]",
 // CHECK-NEXT:           "module-name": "header1"
 // 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"
 // CHECK-CUSTOM-NEXT:  "-fmodule-file=[[PREFIX]]/custom/[[HASH_H1]]/header1-{{[A-Z0-9]+}}.pcm"
 // CHECK-NEXT:       ],
 // CHECK-NEXT:       "file-deps": [
 // CHECK-NEXT:         "[[PREFIX]]/modules_cdb_input.cpp"
 // CHECK-NEXT:       ],
 // CHECK-NEXT:       "input-file": "[[PREFIX]]/modules_cdb_input.cpp"
 // CHECK-NEXT:     },
 // CHECK-NEXT:     {
 // CHECK-NEXT:       "clang-context-hash": "[[HASH_TU:[A-Z0-9]+]]",
 // CHECK-NEXT:       "clang-module-deps": [
 // CHECK-NEXT:         {
 // CHECK-NEXT:           "context-hash": "[[HASH_H1]]",
 // CHECK-NEXT:           "module-name": "header1"
 // 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"
 // CHECK-CUSTOM-NEXT:  "-fmodule-file=[[PREFIX]]/custom/[[HASH_H1]]/header1-{{[A-Z0-9]+}}.pcm"
 // CHECK-NEXT:       ],
 // CHECK-NEXT:       "file-deps": [
 // CHECK-NEXT:         "[[PREFIX]]/modules_cdb_input.cpp"
 // CHECK-NEXT:       ],
 // CHECK-NEXT:       "input-file": "[[PREFIX]]/modules_cdb_input.cpp"
 // CHECK-NEXT:     },
 // CHECK-NEXT:     {
 // CHECK-NEXT:       "clang-context-hash": "[[HASH_TU:[A-Z0-9]+]]",
 // CHECK-NEXT:       "clang-module-deps": [
 // CHECK-NEXT:         {
 // CHECK-NEXT:           "context-hash": "[[HASH_H1]]",
 // CHECK-NEXT:           "module-name": "header1"
 // 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"
 // CHECK-CUSTOM-NEXT:  "-fmodule-file=[[PREFIX]]/custom/[[HASH_H1]]/header1-{{[A-Z0-9]+}}.pcm"
 // CHECK-NEXT:       ],
 // CHECK-NEXT:       "file-deps": [
 // CHECK-NEXT:         "[[PREFIX]]/modules_cdb_input.cpp"
 // CHECK-NEXT:       ],
 // CHECK-NEXT:       "input-file": "[[PREFIX]]/modules_cdb_input.cpp"
 // CHECK-NEXT:     },
 // CHECK-NEXT:     {
 // CHECK-NEXT:       "clang-context-hash": "[[HASH_TU_DINCLUDE:[A-Z0-9]+]]",
 // CHECK-NEXT:       "clang-module-deps": [
 // CHECK-NEXT:         {
 // CHECK-NEXT:           "context-hash": "[[HASH_H1_DINCLUDE]]",
 // CHECK-NEXT:           "module-name": "header1"
 // 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"
 // CHECK-ABS-NEXT:     "-fmodule-file=[[PREFIX]]/module-cache{{(_clangcl)?}}/[[HASH_H1_DINCLUDE]]/header1-{{[A-Z0-9]+}}.pcm"
 // CHECK-CUSTOM-NEXT:  "-fmodule-file=[[PREFIX]]/custom/[[HASH_H2_DINCLUDE]]/header2-{{[A-Z0-9]+}}.pcm"
 // CHECK-CUSTOM-NEXT:  "-fmodule-file=[[PREFIX]]/custom/[[HASH_H1_DINCLUDE]]/header1-{{[A-Z0-9]+}}.pcm"
 // CHECK-NEXT:       ],
 // CHECK-NEXT:       "file-deps": [
 // CHECK-NEXT:         "[[PREFIX]]/modules_cdb_input2.cpp"
 // CHECK-NEXT:       ],
 // CHECK-NEXT:       "input-file": "[[PREFIX]]/modules_cdb_input2.cpp"
 // CHECK-NEXT:     }
 // CHECK-NEXT:   ]
 // CHECK-NEXT: }

clang/test/ClangScanDeps/modules-inferred-explicit-build.m

 // RUN: rm -rf %t.dir
 // RUN: rm -rf %t.cdb
 // RUN: mkdir -p %t.dir
 // RUN: cp %s %t.dir/modules_cdb_input.cpp
 // RUN: sed -e "s|DIR|%/t.dir|g" -e "s|FRAMEWORKS|%/S/Inputs/frameworks|g" -e "s|-E|-x objective-c -E|g" \
 // RUN:   %S/Inputs/modules_inferred_cdb.json > %t.cdb
 //
 // RUN: clang-scan-deps -compilation-database %t.cdb -j 1 -format experimental-full \
 // RUN:   -mode preprocess-minimized-sources -generate-modules-path-args > %t.db
 // RUN: %python %S/../../utils/module-deps-to-rsp.py %t.db --module-name=Inferred > %t.inferred.cc1.rsp
 // RUN: %python %S/../../utils/module-deps-to-rsp.py %t.db --module-name=System > %t.system.cc1.rsp
 // 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>
 
 inferred a = bigger_than_int;

clang/test/ClangScanDeps/modules-inferred.m

 // CHECK-NEXT:       "clang-context-hash": "[[HASH_TU:[A-Z0-9]+]]",
 // CHECK-NEXT:       "clang-module-deps": [
 // CHECK-NEXT:         {
 // CHECK-NEXT:           "context-hash": "[[HASH_INFERRED]]",
 // CHECK-NEXT:           "module-name": "Inferred"
 // 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:       ],
 // CHECK-NEXT:       "file-deps": [
 // CHECK-NEXT:         "[[PREFIX]]/modules_cdb_input.cpp"
 // CHECK-NEXT:       ],
 // CHECK-NEXT:       "input-file": "[[PREFIX]]/modules_cdb_input.cpp"
 // CHECK-NEXT:     }
 // CHECK-NEXT:   ]
 // CHECK-NEXT: }

clang/test/ClangScanDeps/modules-pch-common-submodule.c

 // CHECK-PCH-NEXT:       "clang-context-hash": "[[HASH_PCH:.*]]",
 // CHECK-PCH-NEXT:       "clang-module-deps": [
 // CHECK-PCH-NEXT:         {
 // CHECK-PCH-NEXT:           "context-hash": "[[HASH_MOD_COMMON]]",
 // CHECK-PCH-NEXT:           "module-name": "ModCommon"
 // 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:       ],
 // CHECK-PCH-NEXT:       "file-deps": [
 // CHECK-PCH-NEXT:         "[[PREFIX]]/pch.h"
 // CHECK-PCH-NEXT:       ],
 // CHECK-PCH-NEXT:       "input-file": "[[PREFIX]]/pch.h"
 // CHECK-PCH-NEXT:     }
 // CHECK-PCH-NEXT:   ]
 // CHECK-PCH-NEXT: }
 
 // Explicitly build the PCH:
 //
 // RUN: tail -n +2 %t/result_pch.json > %t/result_pch_stripped.json
 // RUN: %python %S/../../utils/module-deps-to-rsp.py %t/result_pch_stripped.json \
 // RUN:   --module-name=ModCommon > %t/mod_common.cc1.rsp
 // RUN: %python %S/../../utils/module-deps-to-rsp.py %t/result_pch_stripped.json \
 // 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:
 //
 // RUN: sed "s|DIR|%/t|g" %S/Inputs/modules-pch-common-submodule/cdb_tu.json > %t/cdb.json
 // RUN: echo -%t > %t/result_tu.json
 // RUN: clang-scan-deps -compilation-database %t/cdb.json -format experimental-full \
 // RUN:   -generate-modules-path-args -module-files-dir %t/build >> %t/result_tu.json
 // RUN: cat %t/result_tu.json | sed 's:\\\\\?:/:g' | FileCheck %s -check-prefix=CHECK-TU

 // CHECK-TU-NEXT:       "clang-context-hash": "[[HASH_TU:.*]]",
 // CHECK-TU-NEXT:       "clang-module-deps": [
 // CHECK-TU-NEXT:         {
 // CHECK-TU-NEXT:           "context-hash": "[[HASH_MOD_TU]]"
 // CHECK-TU-NEXT:           "module-name": "ModTU"
 // 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:       ],
 // CHECK-TU-NEXT:       "file-deps": [
 // CHECK-TU-NEXT:         "[[PREFIX]]/tu.c",
 // CHECK-TU-NEXT:         "[[PREFIX]]/pch.h.gch"
 // CHECK-TU-NEXT:       ],
 // CHECK-TU-NEXT:       "input-file": "[[PREFIX]]/tu.c"
 // CHECK-TU-NEXT:     }
 // CHECK-TU-NEXT:   ]
 // CHECK-TU-NEXT: }
 
 // Explicitly build the TU:
 //
 // RUN: tail -n +2 %t/result_tu.json > %t/result_tu_stripped.json
 // RUN: %python %S/../../utils/module-deps-to-rsp.py %t/result_tu_stripped.json \
 // RUN:   --module-name=ModTU > %t/mod_tu.cc1.rsp
 // RUN: %python %S/../../utils/module-deps-to-rsp.py %t/result_tu_stripped.json \
 // 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

clang/test/ClangScanDeps/modules-pch-common-via-submodule.c

 // CHECK-PCH-NEXT:       "clang-context-hash": "[[HASH_PCH:.*]]",
 // CHECK-PCH-NEXT:       "clang-module-deps": [
 // CHECK-PCH-NEXT:         {
 // CHECK-PCH-NEXT:           "context-hash": "[[HASH_MOD_COMMON]]",
 // CHECK-PCH-NEXT:           "module-name": "ModCommon"
 // 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:       ],
 // CHECK-PCH-NEXT:       "file-deps": [
 // CHECK-PCH-NEXT:         "[[PREFIX]]/pch.h"
 // CHECK-PCH-NEXT:       ],
 // CHECK-PCH-NEXT:       "input-file": "[[PREFIX]]/pch.h"
 // CHECK-PCH-NEXT:     }
 // CHECK-PCH-NEXT:   ]
 // CHECK-PCH-NEXT: }
 
 // Explicitly build the PCH:
 //
 // RUN: tail -n +2 %t/result_pch.json > %t/result_pch_stripped.json
 // RUN: %python %S/../../utils/module-deps-to-rsp.py %t/result_pch_stripped.json \
 // RUN:   --module-name=ModCommon > %t/mod_common.cc1.rsp
 // RUN: %python %S/../../utils/module-deps-to-rsp.py %t/result_pch_stripped.json \
 // 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:
 //
 // RUN: sed "s|DIR|%/t|g" %S/Inputs/modules-pch-common-via-submodule/cdb_tu.json > %t/cdb.json
 // RUN: echo -%t > %t/result_tu.json
 // RUN: clang-scan-deps -compilation-database %t/cdb.json -format experimental-full \
 // RUN:   -generate-modules-path-args -module-files-dir %t/build >> %t/result_tu.json
 // RUN: cat %t/result_tu.json | sed 's:\\\\\?:/:g' | FileCheck %s -check-prefix=CHECK-TU

 // CHECK-TU-NEXT:       "clang-context-hash": "[[HASH_TU:.*]]",
 // CHECK-TU-NEXT:       "clang-module-deps": [
 // CHECK-TU-NEXT:         {
 // CHECK-TU-NEXT:           "context-hash": "[[HASH_MOD_TU]]"
 // CHECK-TU-NEXT:           "module-name": "ModTU"
 // 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:       ],
 // CHECK-TU-NEXT:       "file-deps": [
 // CHECK-TU-NEXT:         "[[PREFIX]]/tu.c",
 // CHECK-TU-NEXT:         "[[PREFIX]]/pch.h.gch"
 // CHECK-TU-NEXT:       ],
 // CHECK-TU-NEXT:       "input-file": "[[PREFIX]]/tu.c"
 // CHECK-TU-NEXT:     }
 // CHECK-TU-NEXT:   ]
 // CHECK-TU-NEXT: }
 
 // Explicitly build the TU:
 //
 // RUN: tail -n +2 %t/result_tu.json > %t/result_tu_stripped.json
 // RUN: %python %S/../../utils/module-deps-to-rsp.py %t/result_tu_stripped.json \
 // RUN:   --module-name=ModTU > %t/mod_tu.cc1.rsp
 // RUN: %python %S/../../utils/module-deps-to-rsp.py %t/result_tu_stripped.json \
 // 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

clang/test/ClangScanDeps/modules-pch.c

 // CHECK-PCH-NEXT:           "module-name": "ModCommon1"
 // CHECK-PCH-NEXT:         },
 // CHECK-PCH-NEXT:         {
 // CHECK-PCH-NEXT:           "context-hash": "[[HASH_MOD_PCH]]",
 // CHECK-PCH-NEXT:           "module-name": "ModPCH"
 // 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",
 // CHECK-PCH-NEXT:         "-fmodule-file=[[PREFIX]]/build/[[HASH_MOD_PCH]]/ModPCH-{{.*}}.pcm"
 // CHECK-PCH-NEXT:       ],
 // CHECK-PCH-NEXT:       "file-deps": [
 // CHECK-PCH-NEXT:         "[[PREFIX]]/pch.h"
 // CHECK-PCH-NEXT:       ],

 // RUN: %python %S/../../utils/module-deps-to-rsp.py %t/result_pch_stripped.json \
 // RUN:   --module-name=ModPCH > %t/mod_pch.cc1.rsp
 // RUN: %python %S/../../utils/module-deps-to-rsp.py %t/result_pch_stripped.json \
 // RUN:   --tu-index=0 > %t/pch.rsp
 //
 // 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:
 //
 // RUN: sed "s|DIR|%/t|g" %S/Inputs/modules-pch/cdb_tu.json > %t/cdb.json
 // RUN: echo -%t > %t/result_tu.json
 // RUN: clang-scan-deps -compilation-database %t/cdb.json -format experimental-full \
 // RUN:   -generate-modules-path-args -module-files-dir %t/build >> %t/result_tu.json
 // RUN: cat %t/result_tu.json | sed 's:\\\\\?:/:g' | FileCheck %s -check-prefix=CHECK-TU

 // CHECK-TU-NEXT:       "clang-context-hash": "[[HASH_TU:.*]]",
 // CHECK-TU-NEXT:       "clang-module-deps": [
 // CHECK-TU-NEXT:         {
 // CHECK-TU-NEXT:           "context-hash": "[[HASH_MOD_TU]]",
 // CHECK-TU-NEXT:           "module-name": "ModTU"
 // 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:       ],
 // CHECK-TU-NEXT:       "file-deps": [
 // CHECK-TU-NEXT:         "[[PREFIX]]/tu.c",
 // CHECK-TU-NEXT:         "[[PREFIX]]/pch.h.gch"
 // CHECK-TU-NEXT:       ],
 // CHECK-TU-NEXT:       "input-file": "[[PREFIX]]/tu.c"
 // CHECK-TU-NEXT:     }
 // CHECK-TU-NEXT:   ]
 // CHECK-TU-NEXT: }
 
 // Explicitly build the TU:
 //
 // RUN: tail -n +2 %t/result_tu.json > %t/result_tu_stripped.json
 // RUN: %python %S/../../utils/module-deps-to-rsp.py %t/result_tu_stripped.json \
 // RUN:   --module-name=ModTU > %t/mod_tu.cc1.rsp
 // RUN: %python %S/../../utils/module-deps-to-rsp.py %t/result_tu_stripped.json \
 // 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:
 //
 // RUN: sed "s|DIR|%/t|g" %S/Inputs/modules-pch/cdb_tu_with_common.json > %t/cdb.json
 // RUN: echo -%t > %t/result_tu_with_common.json
 // RUN: clang-scan-deps -compilation-database %t/cdb.json -format experimental-full \
 // RUN:   -generate-modules-path-args -module-files-dir %t/build >> %t/result_tu_with_common.json
 // RUN: cat %t/result_tu_with_common.json | sed 's:\\\\\?:/:g' | FileCheck %s -check-prefix=CHECK-TU-WITH-COMMON

 // CHECK-TU-WITH-COMMON-NEXT:       "clang-context-hash": "[[HASH_TU_WITH_COMMON:.*]]",
 // CHECK-TU-WITH-COMMON-NEXT:       "clang-module-deps": [
 // CHECK-TU-WITH-COMMON-NEXT:         {
 // CHECK-TU-WITH-COMMON-NEXT:           "context-hash": "[[HASH_MOD_TU_WITH_COMMON]]",
 // CHECK-TU-WITH-COMMON-NEXT:           "module-name": "ModTUWithCommon"
 // 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"
 // CHECK-TU-WITH-COMMON-NEXT:       ],
 // CHECK-TU-WITH-COMMON-NEXT:       "file-deps": [
 // CHECK-TU-WITH-COMMON-NEXT:         "[[PREFIX]]/tu_with_common.c",
 // CHECK-TU-WITH-COMMON-NEXT:         "[[PREFIX]]/pch.h.gch"
 // CHECK-TU-WITH-COMMON-NEXT:       ],
 // CHECK-TU-WITH-COMMON-NEXT:       "input-file": "[[PREFIX]]/tu_with_common.c"
 // CHECK-TU-WITH-COMMON-NEXT:     }
 // CHECK-TU-WITH-COMMON-NEXT:   ]
 // CHECK-TU-WITH-COMMON-NEXT: }
 
 // Explicitly build the TU that has common modules with the PCH:
 //
 // RUN: tail -n +2 %t/result_tu_with_common.json > %t/result_tu_with_common_stripped.json
 // RUN: %python %S/../../utils/module-deps-to-rsp.py %t/result_tu_with_common_stripped.json \
 // RUN:   --module-name=ModTUWithCommon > %t/mod_tu_with_common.cc1.rsp
 // RUN: %python %S/../../utils/module-deps-to-rsp.py %t/result_tu_with_common_stripped.json \
 // 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

clang/test/ClangScanDeps/modules-symlink.c

 // RUN:   -generate-modules-path-args -module-files-dir %t/build > %t/result_pch.json
 //
 // RUN: %python %S/../../utils/module-deps-to-rsp.py %t/result_pch.json \
 // RUN:   --module-name=mod > %t/mod.cc1.rsp
 // RUN: %python %S/../../utils/module-deps-to-rsp.py %t/result_pch.json \
 // 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 \
 // RUN:   -generate-modules-path-args -module-files-dir %t/build > %t/result_tu.json

clang/tools/clang-scan-deps/ClangScanDeps.cpp

for (const ModuleDeps &MD : FDR.DiscoveredModules) {
       auto I = Modules.find({MD.ID, 0});
       if (I != Modules.end()) {
         I->first.InputIndex = std::min(I->first.InputIndex, InputIndex);
         continue;
       }
       Modules.insert(I, {{MD.ID, InputIndex}, std::move(MD)});
     }
 
-    ID.AdditionalCommandLine =
-        GenerateModulesPathArgs
-            ? FD.getAdditionalArgs(
+    ID.CommandLine = GenerateModulesPathArgs
+                         ? FD.getCommandLine(
                                [&](ModuleID MID) { return lookupPCMPath(MID); },
                                [&](ModuleID MID) -> const ModuleDeps & {
                                  return lookupModuleDeps(MID);
                                })
-            : FD.getAdditionalArgsWithoutModulePaths();
+                         : FD.getCommandLineWithoutModulePaths();
 
     Inputs.push_back(std::move(ID));
   }
 
   void printFullOutput(raw_ostream &OS) {
     // Sort the modules by name to get a deterministic order.
     std::vector<IndexedModuleID> ModuleIDs;
     for (auto &&M : Modules)
void printFullOutput(raw_ostream &OS) {
 
     Array TUs;
     for (auto &&I : Inputs) {
       Object O{
           {"input-file", I.FileName},
           {"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));
     }
 
     Object Output{
         {"modules", std::move(OutModules)},
         {"translation-units", std::move(TUs)},
     };
struct IndexedModuleIDHasher {
     }
   };
 
   struct InputDeps {
     std::string FileName;
     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;
   std::unordered_map<IndexedModuleID, ModuleDeps, IndexedModuleIDHasher>
       Modules;
   std::unordered_map<ModuleID, std::string, ModuleIDHasher> PCMPaths;
   std::vector<InputDeps> Inputs;
 };