Apply -fmacro-prefix-map to __builtin_FILE()

This matches the behavior of GCC.
Patch does not change remapping logic itself, so adding one simple smoke test should be enough.

Reviewed By: MaskRay

Differential Revision: https://reviews.llvm.org/D107393

clang/include/clang/Basic/LangOptions.h

@@ -367,6 +367,9 @@ public:
   /// A list of all -fno-builtin-* function names (e.g., memset).
   std::vector<std::string> NoBuiltinFuncs;
 
+  /// A prefix map for __FILE__, __BASE_FILE__ and __builtin_FILE().
+  std::map<std::string, std::string, std::greater<std::string>> MacroPrefixMap;
+
   /// Triples of the OpenMP targets that the host code codegen should
   /// take into account in order to generate accurate offloading descriptors.
   std::vector<llvm::Triple> OMPTargetTriples;
@@ -473,6 +476,9 @@ public:
   }
 
   bool isSYCL() const { return SYCLIsDevice || SYCLIsHost; }
+
+  /// Remap path prefix according to -fmacro-prefix-path option.
+  void remapPathPrefix(SmallString<256> &Path) const;
 };
 
 /// Floating point control options

clang/include/clang/Driver/Options.td

@@ -2840,10 +2840,10 @@ def fcoverage_prefix_map_EQ
     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 and predefined preprocessor macros">;
+    HelpText<"remap file source paths in debug info, predefined preprocessor macros and __builtin_FILE()">;
 def fmacro_prefix_map_EQ
-  : Joined<["-"], "fmacro-prefix-map=">, Group<Preprocessor_Group>, Flags<[CC1Option]>,
+  : Joined<["-"], "fmacro-prefix-map=">, Group<f_Group>, Flags<[CC1Option]>,
-    HelpText<"remap file source paths in predefined preprocessor macros">;
+    HelpText<"remap file source paths in predefined preprocessor macros and __builtin_FILE()">;
 defm force_dwarf_frame : BoolFOption<"force-dwarf-frame",
   CodeGenOpts<"ForceDwarfFrameSection">, DefaultFalse,
   PosFlag<SetTrue, [CC1Option], "Always emit a debug frame section">, NegFlag<SetFalse>>;

clang/include/clang/Lex/PreprocessorOptions.h

@@ -202,9 +202,6 @@ public:
   /// build it again.
   std::shared_ptr<FailedModulesSet> FailedModules;
 
-  /// A prefix map for __FILE__ and __BASE_FILE__.
-  std::map<std::string, std::string, std::greater<std::string>> MacroPrefixMap;
-
   /// Contains the currently active skipped range mappings for skipping excluded
   /// conditional directives.
   ///

clang/lib/AST/Expr.cpp

@@ -2233,8 +2233,11 @@ APValue SourceLocExpr::EvaluateInContext(const ASTContext &Ctx,
   };
 
   switch (getIdentKind()) {
-  case SourceLocExpr::File:
+  case SourceLocExpr::File: {
-    return MakeStringLiteral(PLoc.getFilename());
+    SmallString<256> Path(PLoc.getFilename());
+    Ctx.getLangOpts().remapPathPrefix(Path);
+    return MakeStringLiteral(Path);
+  }
   case SourceLocExpr::Function: {
     const Decl *CurDecl = dyn_cast_or_null<Decl>(Context);
     return MakeStringLiteral(

clang/lib/Basic/LangOptions.cpp

@@ -11,6 +11,8 @@
 //===----------------------------------------------------------------------===//
 
 #include "clang/Basic/LangOptions.h"
+#include "llvm/ADT/SmallString.h"
+#include "llvm/Support/Path.h"
 
 using namespace clang;
 
@@ -48,6 +50,12 @@ VersionTuple LangOptions::getOpenCLVersionTuple() const {
   return VersionTuple(Ver / 100, (Ver % 100) / 10);
 }
 
+void LangOptions::remapPathPrefix(SmallString<256> &Path) const {
+  for (const auto &Entry : MacroPrefixMap)
+    if (llvm::sys::path::replace_path_prefix(Path, Entry.first, Entry.second))
+      break;
+}
+
 FPOptions FPOptions::defaultWithoutTrailingStorage(const LangOptions &LO) {
   FPOptions result(LO);
   return result;

clang/lib/CodeGen/CodeGenModule.cpp

@@ -186,7 +186,7 @@ CodeGenModule::CodeGenModule(ASTContext &C, const HeaderSearchOptions &HSO,
       !getModule().getSourceFileName().empty()) {
     std::string Path = getModule().getSourceFileName();
     // Check if a path substitution is needed from the MacroPrefixMap.
-    for (const auto &Entry : PPO.MacroPrefixMap)
+    for (const auto &Entry : LangOpts.MacroPrefixMap)
       if (Path.rfind(Entry.first, 0) != std::string::npos) {
         Path = Entry.second + Path.substr(Entry.first.size());
         break;

clang/lib/Frontend/CompilerInvocation.cpp

@@ -3526,6 +3526,9 @@ void CompilerInvocation::GenerateLangArgs(const LangOptions &Opts,
     GenerateArg(Args, OPT_fexperimental_relative_cxx_abi_vtables, SA);
   else
     GenerateArg(Args, OPT_fno_experimental_relative_cxx_abi_vtables, SA);
+
+  for (const auto &MP : Opts.MacroPrefixMap)
+    GenerateArg(Args, OPT_fmacro_prefix_map_EQ, MP.first + "=" + MP.second, SA);
 }
 
 bool CompilerInvocation::ParseLangArgs(LangOptions &Opts, ArgList &Args,
@@ -4036,6 +4039,12 @@ bool CompilerInvocation::ParseLangArgs(LangOptions &Opts, ArgList &Args,
                    options::OPT_fno_experimental_relative_cxx_abi_vtables,
                    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)});
+  }
+
   return Diags.getNumErrors() == NumErrorsBefore;
 }
 
@@ -4108,9 +4117,6 @@ static void GeneratePreprocessorArgs(PreprocessorOptions &Opts,
   for (const auto &D : Opts.DeserializedPCHDeclsToErrorOn)
     GenerateArg(Args, OPT_error_on_deserialized_pch_decl, D, SA);
 
-  for (const auto &MP : Opts.MacroPrefixMap)
-    GenerateArg(Args, OPT_fmacro_prefix_map_EQ, MP.first + "=" + MP.second, SA);
-
   if (Opts.PrecompiledPreambleBytes != std::make_pair(0u, false))
     GenerateArg(Args, OPT_preamble_bytes_EQ,
                 Twine(Opts.PrecompiledPreambleBytes.first) + "," +
@@ -4179,12 +4185,6 @@ static bool ParsePreprocessorArgs(PreprocessorOptions &Opts, ArgList &Args,
   for (const auto *A : Args.filtered(OPT_error_on_deserialized_pch_decl))
     Opts.DeserializedPCHDeclsToErrorOn.insert(A->getValue());
 
-  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)});
-  }
-
   if (const Arg *A = Args.getLastArg(OPT_preamble_bytes_EQ)) {
     StringRef Value(A->getValue());
     size_t Comma = Value.find(',');

clang/lib/Lex/PPMacroExpansion.cpp

@@ -1460,15 +1460,6 @@ static bool isTargetEnvironment(const TargetInfo &TI,
   return TI.getTriple().getEnvironment() == Env.getEnvironment();
 }
 
-static void remapMacroPath(
-    SmallString<256> &Path,
-    const std::map<std::string, std::string, std::greater<std::string>>
-        &MacroPrefixMap) {
-  for (const auto &Entry : MacroPrefixMap)
-    if (llvm::sys::path::replace_path_prefix(Path, Entry.first, Entry.second))
-      break;
-}
-
 /// ExpandBuiltinMacro - If an identifier token is read that is to be expanded
 /// as a builtin macro, handle it and return the next token as 'Tok'.
 void Preprocessor::ExpandBuiltinMacro(Token &Tok) {
@@ -1550,7 +1541,7 @@ void Preprocessor::ExpandBuiltinMacro(Token &Tok) {
       } else {
         FN += PLoc.getFilename();
       }
-      remapMacroPath(FN, PPOpts->MacroPrefixMap);
+      getLangOpts().remapPathPrefix(FN);
       Lexer::Stringify(FN);
       OS << '"' << FN << '"';
     }

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

@@ -1,5 +1,13 @@
 // RUN: %clang_cc1 -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 -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"
 
 struct source_location {