[clang][deps] Reset non-modular language and preprocessor options

[jansvoboda11]

Summary

There are a number of language and preprocessor options that are reset in the CompilerInvocation that describes the build of an implicit module. This patch uses the logic for explicit modules as well.

[dexonsmith]

clang/test/ClangScanDeps/Inputs/removed-args/cdb.json.template

5

It looks to me like that this test would have passed before the code change, since there was already logic for dropping -include. Can you also add some other argument(s) that wouldn't have been dropped before, but will be now?

clang/test/ClangScanDeps/removed-args.c

4

Please add a comment here explaining what args are expected to be dropped and why, to help future readers to understand the testcase.

[jansvoboda11]

Re-requesting review, since the test does cover the changes to ModuleDepCollector.cpp.

clang/test/ClangScanDeps/Inputs/removed-args/cdb.json.template

5

Only the -include-pch argument was being dropped (PreprocessorOptions::ImplicitPCHInclude). The -include arguments (PreprocessorOptions::Includes) were being preserved. This test would not pass without the changes to ModuleDepCollector.cpp.

I can add checks for other arguments that are being dropped now that weren't before, but assuming resetNonModularOptions are already being tested elsewhere, I don't think there's much value in that.

clang/test/ClangScanDeps/removed-args.c

4

Will do.

[jansvoboda11]

clang/test/ClangScanDeps/Inputs/removed-args/cdb.json.template

5

Note that the driver will expand -include <header> into -include-pch <header>.gch only if the PCH <header>.gch file exists. Since we're not precompiling the header in this particular test, that won't be the case. This argument therefore doesn't map onto PreprocessorOptions::ImplicitPCHInclude. It maps onto PreprocessorOptions::Includes.

[dexonsmith]

LGTM with after adding a comment to the testcase. Thanks for explaining!

clang/lib/Tooling/DependencyScanning/ModuleDepCollector.cpp

 using namespace tooling;
 using namespace dependencies;
 
 CompilerInvocation ModuleDepCollector::makeInvocationForModuleBuildWithoutPaths(
     const ModuleDeps &Deps) const {
   // Make a deep copy of the original Clang invocation.
   CompilerInvocation CI(OriginalInvocation);
 
+  CI.getLangOpts()->resetNonModularOptions();
+  CI.getPreprocessorOpts().resetNonModularOptions();
+
   // Remove options incompatible with explicit module build.
   CI.getFrontendOpts().Inputs.clear();
   CI.getFrontendOpts().OutputFile.clear();
 
   CI.getFrontendOpts().ProgramAction = frontend::GenerateModule;
   CI.getLangOpts()->ModuleName = Deps.ID.ModuleName;
   CI.getFrontendOpts().IsSystemModule = Deps.IsSystem;
 
   CI.getLangOpts()->ImplicitModules = false;
 
   // Report the prebuilt modules this module uses.
   for (const auto &PrebuiltModule : Deps.PrebuiltModuleDeps) {
     CI.getFrontendOpts().ModuleFiles.push_back(PrebuiltModule.PCMFile);
     CI.getFrontendOpts().ModuleMapFiles.push_back(PrebuiltModule.ModuleMapFile);
   }
 
-  CI.getPreprocessorOpts().ImplicitPCHInclude.clear();
-
   return CI;
 }
 
 static std::vector<std::string>
 serializeCompilerInvocation(const CompilerInvocation &CI) {
   // Set up string allocator.
   llvm::BumpPtrAllocator Alloc;
   llvm::StringSaver Strings(Alloc);

clang/test/ClangScanDeps/Inputs/removed-args/cdb.json.template

+[
+  {
+    "directory": "DIR",
+    "command": "clang -fsyntax-only DIR/tu.c -fmodules -fimplicit-module-maps -fmodules-cache-path=DIR/cache -include DIR/header.h -o DIR/tu.o",
+    "file": "DIR/tu.c"
+  }
+]

clang/test/ClangScanDeps/Inputs/removed-args/header.h

+#include "mod_header.h"

clang/test/ClangScanDeps/Inputs/removed-args/module.modulemap

+module ModHeader { header "mod_header.h" }
+module ModTU     { header "mod_tu.h"     }

clang/test/ClangScanDeps/Inputs/removed-args/tu.c

+#include "mod_tu.h"

clang/test/ClangScanDeps/removed-args.c

+// Some command-line arguments used for compiling translation units are not
+// compatible with the semantics of modules and should be removed. In this test
+// case, the command-lines for modules should drop the '-include' argument.
+
+// RUN: rm -rf %t && mkdir %t
+// RUN: cp %S/Inputs/removed-args/* %t
+
+// RUN: sed "s|DIR|%/t|g" %S/Inputs/removed-args/cdb.json.template > %t/cdb.json
+// RUN: echo -%t > %t/result.json
+// RUN: clang-scan-deps -compilation-database %t/cdb.json -format experimental-full >> %t/result.json
+// RUN: cat %t/result.json | sed 's:\\\\\?:/:g' | FileCheck %s
+//
+// CHECK:      -[[PREFIX:.*]]
+// CHECK-NEXT: {
+// CHECK-NEXT:   "modules": [
+// CHECK-NEXT:     {
+// CHECK-NEXT:       "clang-module-deps": [],
+// CHECK-NEXT:       "clang-modulemap-file": "[[PREFIX]]/module.modulemap",
+// CHECK-NEXT:       "command-line": [
+// CHECK-NEXT:         "-cc1"
+// CHECK-NOT:          "-include"
+// CHECK:            ],
+// CHECK-NEXT:       "context-hash": "[[HASH_MOD_HEADER:.*]]",
+// CHECK-NEXT:       "file-deps": [
+// CHECK-NEXT:         "[[PREFIX]]/mod_header.h",
+// CHECK-NEXT:         "[[PREFIX]]/module.modulemap"
+// CHECK-NEXT:       ],
+// CHECK-NEXT:       "name": "ModHeader"
+// CHECK-NEXT:     },
+// CHECK-NEXT:     {
+// CHECK-NEXT:       "clang-module-deps": [],
+// CHECK-NEXT:       "clang-modulemap-file": "[[PREFIX]]/module.modulemap",
+// CHECK-NEXT:       "command-line": [
+// CHECK-NEXT:         "-cc1"
+// CHECK-NOT:          "-include"
+// CHECK:            ],
+// CHECK-NEXT:       "context-hash": "[[HASH_MOD_TU:.*]]",
+// CHECK-NEXT:       "file-deps": [
+// CHECK-NEXT:         "[[PREFIX]]/mod_tu.h",
+// CHECK-NEXT:         "[[PREFIX]]/module.modulemap"
+// CHECK-NEXT:       ],
+// CHECK-NEXT:       "name": "ModTU"
+// CHECK-NEXT:     }
+// CHECK-NEXT:   ],
+// CHECK-NEXT:   "translation-units": [
+// CHECK-NEXT:     {
+// CHECK-NEXT:       "clang-context-hash": "[[HASH_TU:.*]]",
+// CHECK-NEXT:       "clang-module-deps": [
+// CHECK-NEXT:         {
+// CHECK-NEXT:           "context-hash": "[[HASH_MOD_HEADER]]",
+// CHECK-NEXT:           "module-name": "ModHeader"
+// CHECK-NEXT:         },
+// CHECK-NEXT:         {
+// CHECK-NEXT:           "context-hash": "[[HASH_MOD_TU]]",
+// CHECK-NEXT:           "module-name": "ModTU"
+// CHECK-NEXT:         }
+// CHECK-NEXT:       ]
+// CHECK:          }
+// CHECK-NEXT:   ]
+// CHECK-NEXT: }