[clang] Add the flag -ffile-reproducible

[ayzhao]

Summary

When Clang generates the path prefix (i.e. the path of the directory
where the file is) when generating FILE, __builtin_FILE(), and
std::source_location, Clang uses the platform-specific path separator
character of the build environment where Clang _itself_ is built. This
leads to inconsistencies in Chrome builds where Clang running on
non-Windows environments uses the forward slash (/) path separator
while Clang running on Windows builds uses the backslash (\) path
separator. To fix this, we add a flag -ffile-reproducible (and its
inverse, -fno-file-reproducible) to have Clang use the target's
platform-specific file separator character.

Additionally, the existing flags -fmacro-prefix-map and
-ffile-prefix-map now both imply -ffile-reproducible. This can be
overriden by setting -fno-file-reproducible.

[0]: https://crbug.com/1310767

[ayzhao]

Duplicate of D122766

clang/include/clang/Basic/LangOptions.h

public:
   bool IsHeaderFile = false;
 
   /// The default stream kind used for HIP kernel launching.
   GPUDefaultStreamKind GPUDefaultStream;
 
   /// The seed used by the randomize structure layout feature.
   std::string RandstructSeed;
 
+  /// Indicates whether the __FILE__ macro should use the target's
+  /// platform-specific file separator or whether it should use the build
+  /// environment's platform-specific file separator.
+  ///
+  /// The plaform-specific path separator is the backslash(\) for Windows and
+  /// forward slash (/) elsewhere.
+  bool UseTargetPathSeparator = false;
+
   LangOptions();
 
   /// Set language defaults for the given input language and
   /// language standard in the given LangOptions object.
   ///
   /// \param Opts - The LangOptions object to set up.
   /// \param Lang - The input language.
   /// \param T - The target triple.
#include "clang/Basic/LangOptions.def"
 
   bool hasWasmExceptions() const {
     return getExceptionHandling() == ExceptionHandlingKind::Wasm;
   }
 
   bool isSYCL() const { return SYCLIsDevice || SYCLIsHost; }
 
   /// Remap path prefix according to -fmacro-prefix-path option.
-  void remapPathPrefix(SmallString<256> &Path) const;
+  void remapPathPrefix(SmallVectorImpl<char> &Path) const;
 };
 
 /// Floating point control options
 class FPOptionsOverride;
 class FPOptions {
 public:
   // We start by defining the layout.
   using storage_type = uint16_t;

clang/include/clang/Driver/Options.td

 def : Flag<["-"], "fno-expensive-optimizations">, Group<clang_ignored_gcc_optimization_f_Group>;
 def fextdirs_EQ : Joined<["-"], "fextdirs=">, Group<f_Group>;
 def : Flag<["-"], "fdefer-pop">, Group<clang_ignored_gcc_optimization_f_Group>;
 def : Flag<["-"], "fno-defer-pop">, Group<clang_ignored_gcc_optimization_f_Group>;
 def : Flag<["-"], "fextended-identifiers">, Group<clang_ignored_f_Group>;
 def : Flag<["-"], "fno-extended-identifiers">, Group<f_Group>, Flags<[Unsupported]>;
 def fhosted : Flag<["-"], "fhosted">, Group<f_Group>;
 def fdenormal_fp_math_EQ : Joined<["-"], "fdenormal-fp-math=">, Group<f_Group>, Flags<[CC1Option]>;
+def ffile_reproducible : Flag<["-"], "ffile-reproducible">, Group<f_Group>,
+  Flags<[CoreOption, CC1Option]>,
+  HelpText<"Use the target's platform-specific path separator character when "
+           "expanding the __FILE__ macro">;
+def fno_file_reproducible : Flag<["-"], "fno-file-reproducible">,
+  Group<f_Group>, Flags<[CoreOption, CC1Option]>,
+  HelpText<"Use the build environment's platform-specific path separator "
+           "character when expanding the __FILE__ macro">;
 def ffp_eval_method_EQ : Joined<["-"], "ffp-eval-method=">, Group<f_Group>, Flags<[CC1Option]>,
   HelpText<"Specifies the evaluation method to use for floating-point arithmetic.">,
   Values<"source,double,extended">, NormalizedValuesScope<"LangOptions">,
   NormalizedValues<["FEM_Source", "FEM_Double", "FEM_Extended"]>,
   MarshallingInfoEnum<LangOpts<"FPEvalMethod">, "FEM_UnsetOnCommandLine">;
 def ffp_model_EQ : Joined<["-"], "ffp-model=">, Group<f_Group>, Flags<[NoXarchOption]>,
   HelpText<"Controls the semantics of floating-point calculations.">;
 def ffp_exception_behavior_EQ : Joined<["-"], "ffp-exception-behavior=">, Group<f_Group>, Flags<[CC1Option]>,
: Joined<["-"], "fdebug-prefix-map=">, Group<f_Group>,
     Flags<[CC1Option,CC1AsOption]>,
     HelpText<"remap file source paths in debug info">;
 def fcoverage_prefix_map_EQ
   : Joined<["-"], "fcoverage-prefix-map=">, Group<f_Group>,
     Flags<[CC1Option]>,
     HelpText<"remap file source paths in coverage mapping">;
 def ffile_prefix_map_EQ
   : Joined<["-"], "ffile-prefix-map=">, Group<f_Group>,
-    HelpText<"remap file source paths in debug info, predefined preprocessor macros and __builtin_FILE()">;
+    HelpText<"remap file source paths in debug info, predefined preprocessor macros and __builtin_FILE(). Implies -ffile-reproducible.">;
 def fmacro_prefix_map_EQ
   : Joined<["-"], "fmacro-prefix-map=">, Group<f_Group>, Flags<[CC1Option]>,
-    HelpText<"remap file source paths in predefined preprocessor macros and __builtin_FILE()">;
+    HelpText<"remap file source paths in predefined preprocessor macros and __builtin_FILE(). Implies -ffile-reproducible.">;
 defm force_dwarf_frame : BoolFOption<"force-dwarf-frame",
   CodeGenOpts<"ForceDwarfFrameSection">, DefaultFalse,
   PosFlag<SetTrue, [CC1Option], "Always emit a debug frame section">, NegFlag<SetFalse>>;
 def g_Flag : Flag<["-"], "g">, Group<g_Group>,
   HelpText<"Generate source-level debug information">;
 def gline_tables_only : Flag<["-"], "gline-tables-only">, Group<gN_Group>,
   Flags<[CoreOption]>, HelpText<"Emit debug line number tables only">;
 def gline_directives_only : Flag<["-"], "gline-directives-only">, Group<gN_Group>,

clang/include/clang/Lex/Preprocessor.h

void emitMacroExpansionWarnings(const Token &Identifier) const {
     if (Identifier.getIdentifierInfo()->isDeprecatedMacro())
       emitMacroDeprecationWarning(Identifier);
 
     if (Identifier.getIdentifierInfo()->isRestrictExpansion() &&
         !SourceMgr.isInMainFile(Identifier.getLocation()))
       emitRestrictExpansionWarning(Identifier);
   }
 
+  static void processPathForFileMacro(SmallVectorImpl<char> &Path,
+                                      const LangOptions &LangOpts,
+                                      const TargetInfo &TI);
+
 private:
   void emitMacroDeprecationWarning(const Token &Identifier) const;
   void emitRestrictExpansionWarning(const Token &Identifier) const;
   void emitFinalMacroWarning(const Token &Identifier, bool IsUndef) const;
 
   Optional<unsigned>
   getSkippedRangeForExcludedConditionalBlock(SourceLocation HashLoc);
 

clang/lib/AST/Expr.cpp

 #include "clang/AST/RecordLayout.h"
 #include "clang/AST/StmtVisitor.h"
 #include "clang/Basic/Builtins.h"
 #include "clang/Basic/CharInfo.h"
 #include "clang/Basic/SourceManager.h"
 #include "clang/Basic/TargetInfo.h"
 #include "clang/Lex/Lexer.h"
 #include "clang/Lex/LiteralSupport.h"
+#include "clang/Lex/Preprocessor.h"
 #include "llvm/Support/ErrorHandling.h"
 #include "llvm/Support/Format.h"
 #include "llvm/Support/raw_ostream.h"
 #include <algorithm>
 #include <cstring>
 using namespace clang;
 
 const Expr *Expr::getBestDynamicClassTypeExpr() const {
auto MakeStringLiteral = [&](StringRef Tmp) {
     // Decay the string to a pointer to the first character.
     LValuePathEntry Path[1] = {LValuePathEntry::ArrayIndex(0)};
     return APValue(Res, CharUnits::Zero(), Path, /*OnePastTheEnd=*/false);
   };
 
   switch (getIdentKind()) {
   case SourceLocExpr::File: {
     SmallString<256> Path(PLoc.getFilename());
-    Ctx.getLangOpts().remapPathPrefix(Path);
+    clang::Preprocessor::processPathForFileMacro(Path, Ctx.getLangOpts(),
+                                                 Ctx.getTargetInfo());
     return MakeStringLiteral(Path);
   }
   case SourceLocExpr::Function: {
     const auto *CurDecl = dyn_cast<Decl>(Context);
     return MakeStringLiteral(
         CurDecl ? PredefinedExpr::ComputeName(PredefinedExpr::Function, CurDecl)
                 : std::string(""));
   }
case SourceLocExpr::SourceLocStruct: {
     // corresponding to that. Note that we've already verified that the shape of
     // the ImplDecl type is as expected.
 
     APValue Value(APValue::UninitStruct(), 0, 4);
     for (FieldDecl *F : ImplDecl->fields()) {
       StringRef Name = F->getName();
       if (Name == "_M_file_name") {
         SmallString<256> Path(PLoc.getFilename());
-        Ctx.getLangOpts().remapPathPrefix(Path);
+        clang::Preprocessor::processPathForFileMacro(Path, Ctx.getLangOpts(),
+                                                     Ctx.getTargetInfo());
         Value.getStructField(F->getFieldIndex()) = MakeStringLiteral(Path);
       } else if (Name == "_M_function_name") {
         // Note: this emits the PrettyFunction name -- different than what
         // __builtin_FUNCTION() above returns!
         const auto *CurDecl = dyn_cast<Decl>(Context);
         Value.getStructField(F->getFieldIndex()) = MakeStringLiteral(
             CurDecl && !isa<TranslationUnitDecl>(CurDecl)
                 ? StringRef(PredefinedExpr::ComputeName(

clang/lib/Basic/LangOptions.cpp

if (!OpenCLCPlusPlus)
     return OpenCLVersion;
   if (OpenCLCPlusPlusVersion == 100)
     return 200;
   if (OpenCLCPlusPlusVersion == 202100)
     return 300;
   llvm_unreachable("Unknown OpenCL version");
 }
 
-void LangOptions::remapPathPrefix(SmallString<256> &Path) const {
+void LangOptions::remapPathPrefix(SmallVectorImpl<char> &Path) const {
   for (const auto &Entry : MacroPrefixMap)
     if (llvm::sys::path::replace_path_prefix(Path, Entry.first, Entry.second))
       break;
 }
 
 std::string LangOptions::getOpenCLVersionString() const {
   std::string Result;
   {

clang/lib/Driver/ToolChains/Clang.cpp

forAllAssociatedToolChains(C, JA, getToolChain(),
                                });
   else {
     // For IAMCU add special include arguments.
     getToolChain().AddIAMCUIncludeArgs(Args, CmdArgs);
   }
 
   addMacroPrefixMapArg(D, Args, CmdArgs);
   addCoveragePrefixMapArg(D, Args, CmdArgs);
+
+  Args.AddLastArg(CmdArgs, options::OPT_ffile_reproducible);
+  Args.AddLastArg(CmdArgs, options::OPT_fno_file_reproducible);
 }
 
 // FIXME: Move to target hook.
 static bool isSignedCharDefault(const llvm::Triple &Triple) {
   switch (Triple.getArch()) {
   default:
     return true;
 

clang/lib/Frontend/CompilerInvocation.cpp

if (Opts.CXXABI)
     GenerateArg(Args, OPT_fcxx_abi_EQ, TargetCXXABI::getSpelling(*Opts.CXXABI),
                 SA);
 
   if (Opts.RelativeCXXABIVTables)
     GenerateArg(Args, OPT_fexperimental_relative_cxx_abi_vtables, SA);
   else
     GenerateArg(Args, OPT_fno_experimental_relative_cxx_abi_vtables, SA);
 
+  if (Opts.UseTargetPathSeparator)
+    GenerateArg(Args, OPT_ffile_reproducible, SA);
+  else
+    GenerateArg(Args, OPT_fno_file_reproducible, SA);
+
   for (const auto &MP : Opts.MacroPrefixMap)
     GenerateArg(Args, OPT_fmacro_prefix_map_EQ, MP.first + "=" + MP.second, SA);
 
   if (!Opts.RandstructSeed.empty())
     GenerateArg(Args, OPT_frandomize_layout_seed_EQ, Opts.RandstructSeed, SA);
 }
 
 bool CompilerInvocation::ParseLangArgs(LangOptions &Opts, ArgList &Args,
Opts.RelativeCXXABIVTables =
                    TargetCXXABI::usesRelativeVTables(T));
 
   for (const auto &A : Args.getAllArgValues(OPT_fmacro_prefix_map_EQ)) {
     auto Split = StringRef(A).split('=');
     Opts.MacroPrefixMap.insert(
         {std::string(Split.first), std::string(Split.second)});
   }
 
+  Opts.UseTargetPathSeparator =
+      !Args.getLastArg(options::OPT_fno_file_reproducible) &&
+      (Args.getLastArg(options::OPT_ffile_compilation_dir_EQ) ||
+       Args.getLastArg(options::OPT_fmacro_prefix_map_EQ) ||
+       Args.getLastArg(options::OPT_ffile_reproducible));
+
   // Error if -mvscale-min is unbounded.
   if (Arg *A = Args.getLastArg(options::OPT_mvscale_min_EQ)) {
     unsigned VScaleMin;
     if (StringRef(A->getValue()).getAsInteger(10, VScaleMin) || VScaleMin == 0)
       Diags.Report(diag::err_cc1_unbounded_vscale_min);
   }
 
   if (const Arg *A = Args.getLastArg(OPT_frandomize_layout_seed_file_EQ)) {

clang/lib/Lex/PPMacroExpansion.cpp

if (PLoc.isValid()) {
         StringRef PLFileName = llvm::sys::path::filename(PLoc.getFilename());
         if (PLFileName != "")
           FN += PLFileName;
         else
           FN += PLoc.getFilename();
       } else {
         FN += PLoc.getFilename();
       }
-      getLangOpts().remapPathPrefix(FN);
+      processPathForFileMacro(FN, getLangOpts(), getTargetInfo());
       Lexer::Stringify(FN);
       OS << '"' << FN << '"';
     }
     Tok.setKind(tok::string_literal);
   } else if (II == Ident__DATE__) {
     Diag(Tok.getLocation(), diag::warn_pp_date_time);
     if (!DATELoc.isValid())
       ComputeDATE_TIME(DATELoc, TIMELoc, *this);

 
 void Preprocessor::markMacroAsUsed(MacroInfo *MI) {
   // If the 'used' status changed, and the macro requires 'unused' warning,
   // remove its SourceLocation from the warn-for-unused-macro locations.
   if (MI->isWarnIfUnused() && !MI->isUsed())
     WarnUnusedMacroLocs.erase(MI->getDefinitionLoc());
   MI->setIsUsed(true);
 }
+
+void Preprocessor::processPathForFileMacro(SmallVectorImpl<char> &Path,
+                                           const LangOptions &LangOpts,
+                                           const TargetInfo &TI) {
+  LangOpts.remapPathPrefix(Path);
+  if (LangOpts.UseTargetPathSeparator) {
+    if (TI.getTriple().isOSWindows()) {
+      llvm::sys::path::make_preferred(
+          Path, llvm::sys::path::Style::windows_backslash);
+    } else {
+      llvm::sys::path::make_preferred(Path, llvm::sys::path::Style::posix);
+    }
+  }
+}

clang/test/CodeGenCXX/builtin-source-location.cpp

 // RUN: %clang_cc1 -no-opaque-pointers -std=c++2a -fblocks %s -triple x86_64-unknown-unknown -emit-llvm -o %t.ll
 
 // This needs to be performed before #line directives which alter filename
-// RUN: %clang_cc1 -no-opaque-pointers -fmacro-prefix-map=%p=/UNLIKELY/PATH -emit-llvm -o - %s | FileCheck %s --check-prefix=CHECK-PREFIX-MAP
+// RUN: %clang_cc1 -no-opaque-pointers -fno-file-reproducible -fmacro-prefix-map=%p=/UNLIKELY/PATH -emit-llvm -o - %s | FileCheck %s --check-prefix=CHECK-PREFIX-MAP
 //
 // CHECK-PREFIX-MAP: /UNLIKELY/PATH{{/|\\\\}}builtin-source-location.cpp
 void testRemap() {
   const char *file = __builtin_FILE();
 }
 
 #line 8 "builtin-source-location.cpp"
 

clang/test/Preprocessor/file_test.c

 // UNSUPPORTED: system-windows
 // RUN: %clang -E -ffile-prefix-map=%p=/UNLIKELY_PATH/empty -c -o - %s | FileCheck %s
 // RUN: %clang -E -fmacro-prefix-map=%p=/UNLIKELY_PATH/empty -c -o - %s | FileCheck %s
 // RUN: %clang -E -fmacro-prefix-map=%p=/UNLIKELY_PATH=empty -c -o - %s | FileCheck %s -check-prefix CHECK-EVIL
 // RUN: %clang -E -fmacro-prefix-map=%p/= -c -o - %s | FileCheck %s --check-prefix CHECK-REMOVE
+// RUN: %clang -E -fno-file-reproducible -fmacro-prefix-map=%p/= -target x86_64-pc-win32 -c -o - %s | FileCheck %s --check-prefix CHECK-REMOVE
+// RUN: %clang -E -fno-file-reproducible -ffile-prefix-map=%p/= -target x86_64-pc-win32 -c -o - %s | FileCheck %s --check-prefix CHECK-REMOVE
+// RUN: %clang -E -fmacro-prefix-map=%p/= -target x86_64-pc-win32 -c -o - %s | FileCheck %s --check-prefix CHECK-WINDOWS
+// RUN: %clang -E -ffile-prefix-map=%p/= -target x86_64-pc-win32 -c -o - %s | FileCheck %s --check-prefix CHECK-WINDOWS
+// RUN: %clang -E -ffile-reproducible -target x86_64-pc-win32 -c -o - %s | FileCheck %s --check-prefix CHECK-WINDOWS-REPRODUCIBLE
 
 filename: __FILE__
 #include "Inputs/include-file-test/file_test.h"
 
 // CHECK: filename: "/UNLIKELY_PATH/empty/file_test.c"
 // CHECK: filename: "/UNLIKELY_PATH/empty/Inputs/include-file-test/file_test.h"
 // CHECK: basefile: "/UNLIKELY_PATH/empty/file_test.c"
 // CHECK-NOT: filename:
 
 // CHECK-EVIL: filename: "/UNLIKELY_PATH=empty/file_test.c"
 // CHECK-EVIL: filename: "/UNLIKELY_PATH=empty/Inputs/include-file-test/file_test.h"
 // CHECK-EVIL: basefile: "/UNLIKELY_PATH=empty/file_test.c"
 // CHECK-EVIL-NOT: filename:
 
 // CHECK-REMOVE: filename: "file_test.c"
 // CHECK-REMOVE: filename: "Inputs/include-file-test/file_test.h"
 // CHECK-REMOVE: basefile: "file_test.c"
 // CHECK-REMOVE-NOT: filename:
+
+// CHECK-WINDOWS: filename: "file_test.c"
+// CHECK-WINDOWS: filename: "Inputs\\include-file-test\\file_test.h"
+// CHECK-WINDOWS: basefile: "file_test.c"
+// CHECK-WINDOWS-NOT: filename:
+
+// CHECK-WINDOWS-REPRODUCIBLE: filename: "{{[^/]*}}file_test.c"
+// CHECK-WINDOWS-REPRODUCIBLE: filename: "{{[^/]*}}Inputs\\include-file-test\\file_test.h"
+// CHECK-WINDOWS-REPRODUCIBLE: basefile: "{{[^/]*}}file_test.c"
+// CHECK-WINDOWS-REPRODUCIBLE-NOT: filename:
 No newline at end of file

clang/test/Preprocessor/file_test_windows.c

 // REQUIRES: system-windows
-// RUN: %clang -E -ffile-prefix-map=%p=A:\UNLIKELY_PATH\empty -c -o - %s | FileCheck %s
-// RUN: %clang -E -fmacro-prefix-map=%p=A:\UNLIKELY_PATH\empty -c -o - %s | FileCheck %s
-// RUN: %clang -E -fmacro-prefix-map=%p=A:\UNLIKELY_PATH=empty -c -o - %s | FileCheck %s -check-prefix CHECK-EVIL
-// RUN: %clang -E -fmacro-prefix-map=%p/iNPUTS\=A:\UNLIKELY_PATH_INC\ -fmacro-prefix-map=%p/=A:\UNLIKELY_PATH_BASE\ -c -o - %s | FileCheck %s -check-prefix CHECK-CASE
-// RUN: %clang -E -fmacro-prefix-map=%p\= -c -o - %s | FileCheck %s --check-prefix CHECK-REMOVE
+// RUN: %clang -E -fno-file-reproducible -ffile-prefix-map=%p=A:\UNLIKELY_PATH\empty -c -o - %s | FileCheck %s
+// RUN: %clang -E -fno-file-reproducible -fmacro-prefix-map=%p=A:\UNLIKELY_PATH\empty -c -o - %s | FileCheck %s
+// RUN: %clang -E -fno-file-reproducible -fmacro-prefix-map=%p=A:\UNLIKELY_PATH=empty -c -o - %s | FileCheck %s -check-prefix CHECK-EVIL
+// RUN: %clang -E -fno-file-reproducible -fmacro-prefix-map=%p/iNPUTS\=A:\UNLIKELY_PATH_INC\ -fmacro-prefix-map=%p/=A:\UNLIKELY_PATH_BASE\ -c -o - %s | FileCheck %s -check-prefix CHECK-CASE
+// RUN: %clang -E -fno-file-reproducible -fmacro-prefix-map=%p\= -c -o - %s | FileCheck %s --check-prefix CHECK-REMOVE
+
+// RUN: %clang -E -ffile-prefix-map=%p=A:\UNLIKELY_PATH\empty -c -o - %s | FileCheck %s --check-prefix CHECK-REPRODUCIBLE
+// RUN: %clang -E -fmacro-prefix-map=%p=A:\UNLIKELY_PATH\empty -c -o - %s | FileCheck %s --check-prefix CHECK-REPRODUCIBLE
+// RUN: %clang -E -fmacro-prefix-map=%p=A:\UNLIKELY_PATH=empty -c -o - %s | FileCheck %s -check-prefix CHECK-EVIL-REPRODUCIBLE
+// RUN: %clang -E -fmacro-prefix-map=%p/iNPUTS\=A:\UNLIKELY_PATH_INC\ -fmacro-prefix-map=%p/=A:\UNLIKELY_PATH_BASE\ -c -o - %s | FileCheck %s -check-prefix CHECK-CASE-REPRODUCIBLE
+// RUN: %clang -E -fmacro-prefix-map=%p\= -c -o - %s | FileCheck %s --check-prefix CHECK-REMOVE-REPRODUCIBLE
+
+// RUN: %clang -E -target x86_64-pc-linux-gnu -fmacro-prefix-map=%p\= -c -o - %s | FileCheck %s --check-prefix CHECK-REMOVE
+// RUN: %clang -E -target x86_64-pc-linux-gnu -ffile-prefix-map=%p\= -c -o - %s | FileCheck %s --check-prefix CHECK-REMOVE
+
+// Clang defaults to forward slashes for the non-prefix portion of the path even if the build environment is Windows.
+// RUN: %clang -E -fno-file-reproducible -target x86_64-pc-linux-gnu -fmacro-prefix-map=%p\= -c -o - %s | FileCheck %s --check-prefix CHECK-REMOVE
+// RUN: %clang -E -fno-file-reproducible -target x86_64-pc-linux-gnu -ffile-prefix-map=%p\= -c -o - %s | FileCheck %s --check-prefix CHECK-REMOVE
+
+// RUN: %clang -E -ffile-reproducible -target x86_64-pc-win32 -c -o - %s | FileCheck %s --check-prefix CHECK-WINDOWS-FULL
+// RUN: %clang -E -ffile-reproducible -target x86_64-pc-linux-gnu -c -o - %s | FileCheck %s --check-prefix CHECK-LINUX-FULL
 
 filename: __FILE__
 #include "Inputs/include-file-test/file_test.h"
 
 // CHECK: filename: "A:\\UNLIKELY_PATH\\empty\\file_test_windows.c"
 // CHECK: filename: "A:\\UNLIKELY_PATH\\empty/Inputs/include-file-test/file_test.h"
 // CHECK: basefile: "A:\\UNLIKELY_PATH\\empty\\file_test_windows.c"
 // CHECK-NOT: filename:
 
 // CHECK-EVIL: filename: "A:\\UNLIKELY_PATH=empty\\file_test_windows.c"
 // CHECK-EVIL: filename: "A:\\UNLIKELY_PATH=empty/Inputs/include-file-test/file_test.h"
 // CHECK-EVIL: basefile: "A:\\UNLIKELY_PATH=empty\\file_test_windows.c"
 // CHECK-EVIL-NOT: filename:
 
 // CHECK-CASE: filename: "A:\\UNLIKELY_PATH_BASE\\file_test_windows.c"
 // CHECK-CASE: filename: "A:\\UNLIKELY_PATH_INC\\include-file-test/file_test.h"
 // CHECK-CASE: basefile: "A:\\UNLIKELY_PATH_BASE\\file_test_windows.c"
 // CHECK-CASE-NOT: filename:
 
 // CHECK-REMOVE: filename: "file_test_windows.c"
 // CHECK-REMOVE: filename: "Inputs/include-file-test/file_test.h"
 // CHECK-REMOVE: basefile: "file_test_windows.c"
 // CHECK-REMOVE-NOT: filename:
+
+// CHECK-REPRODUCIBLE: filename: "A:\\UNLIKELY_PATH\\empty\\file_test_windows.c"
+// CHECK-REPRODUCIBLE: filename: "A:\\UNLIKELY_PATH\\empty\\Inputs\\include-file-test\\file_test.h"
+// CHECK-REPRODUCIBLE: basefile: "A:\\UNLIKELY_PATH\\empty\\file_test_windows.c"
+// CHECK-REPRODUCIBLE-NOT: filename:
+
+// CHECK-EVIL-REPRODUCIBLE: filename: "A:\\UNLIKELY_PATH=empty\\file_test_windows.c"
+// CHECK-EVIL-REPRODUCIBLE: filename: "A:\\UNLIKELY_PATH=empty\\Inputs\\include-file-test\\file_test.h"
+// CHECK-EVIL-REPRODUCIBLE: basefile: "A:\\UNLIKELY_PATH=empty\\file_test_windows.c"
+// CHECK-EVIL-REPRODUCIBLE-NOT: filename:
+
+// CHECK-CASE-REPRODUCIBLE: filename: "A:\\UNLIKELY_PATH_BASE\\file_test_windows.c"
+// CHECK-CASE-REPRODUCIBLE: filename: "A:\\UNLIKELY_PATH_INC\\include-file-test\\file_test.h"
+// CHECK-CASE-REPRODUCIBLE: basefile: "A:\\UNLIKELY_PATH_BASE\\file_test_windows.c"
+// CHECK-CASE-REPRODUCIBLE-NOT: filename:
+
+// CHECK-REMOVE-REPRODUCIBLE: filename: "file_test_windows.c"
+// CHECK-REMOVE-REPRODUCIBLE: filename: "Inputs\\include-file-test\\file_test.h"
+// CHECK-REMOVE-REPRODUCIBLE: basefile: "file_test_windows.c"
+// CHECK-REMOVE-REPRODUCIBLE-NOT: filename:
+
+// CHECK-WINDOWS-FULL: filename: "{{[^/]*}}file_test_windows.c"
+// CHECK-WINDOWS-FULL: filename: "{{[^/]*}}Inputs\\include-file-test\\file_test.h"
+// CHECK-WINDOWS-FULL: basefile: "{{[^/]*}}file_test_windows.c"
+// CHECK-WINDOWS-FULL-NOT: filename:
+
+// Clang does not modify the prefix for POSIX style, so it may have backslashes.
+// CHECK-LINUX-FULL: filename: "{{.*}}file_test_windows.c"
+// CHECK-LINUX-FULL: filename: "{{.*}}Inputs/include-file-test/file_test.h"
+// CHECK-LINUX-FULL: basefile: "{{.*}}file_test_windows.c"
+// CHECK-LINUX-FULL-NOT: filename:
 No newline at end of file