Revert "✨ [Sema, Lex, Parse] Preprocessor embed in C and C++ (and Obj-C and Obj-C++ by-proxy)" (#95299)

Reverts #68620

Introduce or expose a memory leak and UB, see #68620

Author: vitalybuka

clang-tools-extra/test/pp-trace/pp-trace-macro.cpp

@@ -31,15 +31,6 @@ X
 // CHECK:        MacroNameTok: __STDC_UTF_32__
 // CHECK-NEXT:   MacroDirective: MD_Define
 // CHECK:      - Callback: MacroDefined
-// CHECK-NEXT:   MacroNameTok: __STDC_EMBED_NOT_FOUND__
-// CHECK-NEXT:   MacroDirective: MD_Define
-// CHECK:      - Callback: MacroDefined
-// CHECK-NEXT:   MacroNameTok: __STDC_EMBED_FOUND__
-// CHECK-NEXT:   MacroDirective: MD_Define
-// CHECK:      - Callback: MacroDefined
-// CHECK-NEXT:   MacroNameTok: __STDC_EMBED_EMPTY__
-// CHECK-NEXT:   MacroDirective: MD_Define
-// CHECK:      - Callback: MacroDefined
 // CHECK:      - Callback: MacroDefined
 // CHECK-NEXT:   MacroNameTok: MACRO
 // CHECK-NEXT:   MacroDirective: MD_Define

clang/docs/LanguageExtensions.rst

@@ -1502,7 +1502,6 @@ Attributes on Structured Bindings            __cpp_structured_bindings        C+
 Designated initializers (N494)                                                C99           C89
 Array & element qualification (N2607)                                         C23           C89
 Attributes (N2335)                                                            C23           C89
-``#embed`` (N3017)                                                            C23           C89, C++
 ============================================ ================================ ============= =============
 
 Type Trait Primitives
@@ -5665,26 +5664,3 @@ Compiling different TUs depending on these flags (including use of
 ``std::hardware_destructive_interference``)  with different compilers, macro
 definitions, or architecture flags will lead to ODR violations and should be
 avoided.
-
-``#embed`` Parameters
-=====================
-
-``clang::offset``
------------------
-The ``clang::offset`` embed parameter may appear zero or one time in the
-embed parameter sequence. Its preprocessor argument clause shall be present and
-have the form:
-
-..code-block: text
-
-  ( constant-expression )
-
-and shall be an integer constant expression. The integer constant expression
-shall not evaluate to a value less than 0. The token ``defined`` shall not
-appear within the constant expression.
-
-The offset will be used when reading the contents of the embedded resource to
-specify the starting offset to begin embedding from. The resources is treated
-as being empty if the specified offset is larger than the number of bytes in
-the resource. The offset will be applied *before* any ``limit`` parameters are
-applied.

clang/include/clang/AST/Expr.h

@@ -4799,166 +4799,6 @@ class SourceLocExpr final : public Expr {
   friend class ASTStmtReader;
 };
 
-/// Stores data related to a single #embed directive.
-struct EmbedDataStorage {
-  StringLiteral *Filename;
-  StringLiteral *BinaryData;
-  size_t getDataElementCount() const { return BinaryData->getByteLength(); }
-};
-
-/// Represents a reference to #emded data. By default, this references the whole
-/// range. Otherwise it represents a subrange of data imported by #embed
-/// directive. Needed to handle nested initializer lists with #embed directives.
-/// Example:
-///  struct S {
-///    int x, y;
-///  };
-///
-///  struct T {
-///    int x[2];
-///    struct S s
-///  };
-///
-///  struct T t[] = {
-///  #embed "data" // data contains 10 elements;
-///  };
-///
-/// The resulting semantic form of initializer list will contain (EE stands
-/// for EmbedExpr):
-///  { {EE(first two data elements), {EE(3rd element), EE(4th element) }},
-///  { {EE(5th and 6th element), {EE(7th element), EE(8th element) }},
-///  { {EE(9th and 10th element), { zeroinitializer }}}
-///
-/// EmbedExpr inside of a semantic initializer list and referencing more than
-/// one element can only appear for arrays of scalars.
-class EmbedExpr final : public Expr {
-  SourceLocation EmbedKeywordLoc;
-  IntegerLiteral *FakeChildNode = nullptr;
-  const ASTContext *Ctx = nullptr;
-  EmbedDataStorage *Data;
-  unsigned Begin = 0;
-  unsigned NumOfElements;
-
-public:
-  EmbedExpr(const ASTContext &Ctx, SourceLocation Loc, EmbedDataStorage *Data,
-            unsigned Begin, unsigned NumOfElements);
-  explicit EmbedExpr(EmptyShell Empty) : Expr(SourceLocExprClass, Empty) {}
-
-  SourceLocation getLocation() const { return EmbedKeywordLoc; }
-  SourceLocation getBeginLoc() const { return EmbedKeywordLoc; }
-  SourceLocation getEndLoc() const { return EmbedKeywordLoc; }
-
-  StringLiteral *getFilenameStringLiteral() const { return Data->Filename; }
-  StringLiteral *getDataStringLiteral() const { return Data->BinaryData; }
-  EmbedDataStorage *getData() const { return Data; }
-
-  unsigned getStartingElementPos() const { return Begin; }
-  size_t getDataElementCount() const { return NumOfElements; }
-
-  // Allows accessing every byte of EmbedExpr data and iterating over it.
-  // An Iterator knows the EmbedExpr that it refers to, and an offset value
-  // within the data.
-  // Dereferencing an Iterator results in construction of IntegerLiteral AST
-  // node filled with byte of data of the corresponding EmbedExpr within offset
-  // that the Iterator currently has.
-  template <bool Const>
-  class ChildElementIter
-      : public llvm::iterator_facade_base<
-            ChildElementIter<Const>, std::random_access_iterator_tag,
-            std::conditional_t<Const, const IntegerLiteral *,
-                               IntegerLiteral *>> {
-    friend class EmbedExpr;
-
-    EmbedExpr *EExpr = nullptr;
-    unsigned long long CurOffset = ULLONG_MAX;
-    using BaseTy = typename ChildElementIter::iterator_facade_base;
-
-    ChildElementIter(EmbedExpr *E) : EExpr(E) {
-      if (E)
-        CurOffset = E->getStartingElementPos();
-    }
-
-  public:
-    ChildElementIter() : CurOffset(ULLONG_MAX) {}
-    typename BaseTy::reference operator*() const {
-      assert(EExpr && CurOffset != ULLONG_MAX &&
-             "trying to dereference an invalid iterator");
-      IntegerLiteral *N = EExpr->FakeChildNode;
-      StringRef DataRef = EExpr->Data->BinaryData->getBytes();
-      N->setValue(*EExpr->Ctx,
-                  llvm::APInt(N->getValue().getBitWidth(), DataRef[CurOffset],
-                              N->getType()->isSignedIntegerType()));
-      // We want to return a reference to the fake child node in the
-      // EmbedExpr, not the local variable N.
-      return const_cast<typename BaseTy::reference>(EExpr->FakeChildNode);
-    }
-    typename BaseTy::pointer operator->() const { return **this; }
-    using BaseTy::operator++;
-    ChildElementIter &operator++() {
-      assert(EExpr && "trying to increment an invalid iterator");
-      assert(CurOffset != ULLONG_MAX &&
-             "Already at the end of what we can iterate over");
-      if (++CurOffset >=
-          EExpr->getDataElementCount() + EExpr->getStartingElementPos()) {
-        CurOffset = ULLONG_MAX;
-        EExpr = nullptr;
-      }
-      return *this;
-    }
-    bool operator==(ChildElementIter Other) const {
-      return (EExpr == Other.EExpr && CurOffset == Other.CurOffset);
-    }
-  }; // class ChildElementIter
-
-public:
-  using fake_child_range = llvm::iterator_range<ChildElementIter<false>>;
-  using const_fake_child_range = llvm::iterator_range<ChildElementIter<true>>;
-
-  fake_child_range underlying_data_elements() {
-    return fake_child_range(ChildElementIter<false>(this),
-                            ChildElementIter<false>());
-  }
-
-  const_fake_child_range underlying_data_elements() const {
-    return const_fake_child_range(
-        ChildElementIter<true>(const_cast<EmbedExpr *>(this)),
-        ChildElementIter<true>());
-  }
-
-  child_range children() {
-    return child_range(child_iterator(), child_iterator());
-  }
-
-  const_child_range children() const {
-    return const_child_range(const_child_iterator(), const_child_iterator());
-  }
-
-  static bool classof(const Stmt *T) {
-    return T->getStmtClass() == EmbedExprClass;
-  }
-
-  ChildElementIter<false> begin() { return ChildElementIter<false>(this); }
-
-  ChildElementIter<true> begin() const {
-    return ChildElementIter<true>(const_cast<EmbedExpr *>(this));
-  }
-
-  template <typename Call, typename... Targs>
-  bool doForEachDataElement(Call &&C, unsigned &StartingIndexInArray,
-                            Targs &&...Fargs) const {
-    for (auto It : underlying_data_elements()) {
-      if (!std::invoke(std::forward<Call>(C), const_cast<IntegerLiteral *>(It),
-                       StartingIndexInArray, std::forward<Targs>(Fargs)...))
-        return false;
-      StartingIndexInArray++;
-    }
-    return true;
-  }
-
-private:
-  friend class ASTStmtReader;
-};
-
 /// Describes an C or C++ initializer list.
 ///
 /// InitListExpr describes an initializer list, which can be used to

clang/include/clang/AST/RecursiveASTVisitor.h

@@ -2864,11 +2864,6 @@ DEF_TRAVERSE_STMT(ShuffleVectorExpr, {})
 DEF_TRAVERSE_STMT(ConvertVectorExpr, {})
 DEF_TRAVERSE_STMT(StmtExpr, {})
 DEF_TRAVERSE_STMT(SourceLocExpr, {})
-DEF_TRAVERSE_STMT(EmbedExpr, {
-  for (IntegerLiteral *IL : S->underlying_data_elements()) {
-    TRY_TO_TRAVERSE_OR_ENQUEUE_STMT(IL);
-  }
-})
 
 DEF_TRAVERSE_STMT(UnresolvedLookupExpr, {
   TRY_TO(TraverseNestedNameSpecifierLoc(S->getQualifierLoc()));

clang/include/clang/AST/TextNodeDumper.h

@@ -409,7 +409,6 @@ class TextNodeDumper
   void VisitHLSLBufferDecl(const HLSLBufferDecl *D);
   void VisitOpenACCConstructStmt(const OpenACCConstructStmt *S);
   void VisitOpenACCLoopConstruct(const OpenACCLoopConstruct *S);
-  void VisitEmbedExpr(const EmbedExpr *S);
 };
 
 } // namespace clang

clang/include/clang/Basic/DiagnosticCommonKinds.td

@@ -275,9 +275,6 @@ def err_too_large_for_fixed_point : Error<
 def err_unimplemented_conversion_with_fixed_point_type : Error<
   "conversion between fixed point and %0 is not yet supported">;
 
-def err_requires_positive_value : Error<
-  "%select{invalid value '%0'; must be positive|value '%0' is too large}1">;
-
 // SEH
 def err_seh_expected_handler : Error<
   "expected '__except' or '__finally' block">;

clang/include/clang/Basic/DiagnosticLexKinds.td

@@ -436,14 +436,6 @@ def warn_cxx23_compat_warning_directive : Warning<
 def warn_c23_compat_warning_directive : Warning<
   "#warning is incompatible with C standards before C23">,
   InGroup<CPre23Compat>, DefaultIgnore;
-def ext_pp_embed_directive : ExtWarn<
-  "#embed is a %select{C23|Clang}0 extension">,
-  InGroup<C23>;
-def warn_compat_pp_embed_directive : Warning<
-  "#embed is incompatible with C standards before C23">,
-  InGroup<CPre23Compat>, DefaultIgnore;
-def err_pp_embed_dup_params : Error<
-  "cannot specify parameter '%0' twice in the same '#embed' directive">;
 
 def ext_pp_extra_tokens_at_eol : ExtWarn<
   "extra tokens at end of #%0 directive">, InGroup<ExtraTokens>;
@@ -513,8 +505,6 @@ def err_pp_invalid_directive : Error<
   "invalid preprocessing directive%select{|, did you mean '#%1'?}0">;
 def warn_pp_invalid_directive : Warning<
   err_pp_invalid_directive.Summary>, InGroup<DiagGroup<"unknown-directives">>;
-def err_pp_unknown_parameter : Error<
-  "unknown%select{ | embed}0 preprocessor parameter '%1'">;
 def err_pp_directive_required : Error<
   "%0 must be used within a preprocessing directive">;
 def err_pp_file_not_found : Error<"'%0' file not found">, DefaultFatal;
@@ -729,8 +719,6 @@ def err_pp_module_build_missing_end : Error<
   "no matching '#pragma clang module endbuild' for this '#pragma clang module build'">;
 
 def err_defined_macro_name : Error<"'defined' cannot be used as a macro name">;
-def err_defined_in_pp_embed : Error<
-  "'defined' cannot appear within this context">;
 def err_paste_at_start : Error<
   "'##' cannot appear at start of macro expansion">;
 def err_paste_at_end : Error<"'##' cannot appear at end of macro expansion">;

clang/include/clang/Basic/DiagnosticSemaKinds.td

@@ -1097,6 +1097,8 @@ def note_surrounding_namespace_starts_here : Note<
   "surrounding namespace with visibility attribute starts here">;
 def err_pragma_loop_invalid_argument_type : Error<
   "invalid argument of type %0; expected an integer type">;
+def err_pragma_loop_invalid_argument_value : Error<
+  "%select{invalid value '%0'; must be positive|value '%0' is too large}1">;
 def err_pragma_loop_compatibility : Error<
   "%select{incompatible|duplicate}0 directives '%1' and '%2'">;
 def err_pragma_loop_precedes_nonloop : Error<

clang/include/clang/Basic/FileManager.h

@@ -286,15 +286,12 @@ class FileManager : public RefCountedBase<FileManager> {
   /// MemoryBuffer if successful, otherwise returning null.
   llvm::ErrorOr<std::unique_ptr<llvm::MemoryBuffer>>
   getBufferForFile(FileEntryRef Entry, bool isVolatile = false,
-                   bool RequiresNullTerminator = true,
-                   std::optional<int64_t> MaybeLimit = std::nullopt);
+                   bool RequiresNullTerminator = true);
   llvm::ErrorOr<std::unique_ptr<llvm::MemoryBuffer>>
   getBufferForFile(StringRef Filename, bool isVolatile = false,
-                   bool RequiresNullTerminator = true,
-                   std::optional<int64_t> MaybeLimit = std::nullopt) const {
-    return getBufferForFileImpl(Filename,
-                                /*FileSize=*/(MaybeLimit ? *MaybeLimit : -1),
-                                isVolatile, RequiresNullTerminator);
+                   bool RequiresNullTerminator = true) const {
+    return getBufferForFileImpl(Filename, /*FileSize=*/-1, isVolatile,
+                                RequiresNullTerminator);
   }
 
 private:

clang/include/clang/Basic/StmtNodes.td

@@ -204,7 +204,6 @@ def OpaqueValueExpr : StmtNode<Expr>;
 def TypoExpr : StmtNode<Expr>;
 def RecoveryExpr : StmtNode<Expr>;
 def BuiltinBitCastExpr : StmtNode<ExplicitCastExpr>;
-def EmbedExpr : StmtNode<Expr>;
 
 // Microsoft Extensions.
 def MSPropertyRefExpr : StmtNode<Expr>;

clang/include/clang/Basic/TokenKinds.def

@@ -126,9 +126,6 @@ PPKEYWORD(error)
 // C99 6.10.6 - Pragma Directive.
 PPKEYWORD(pragma)
 
-// C23 & C++26 #embed
-PPKEYWORD(embed)
-
 // GNU Extensions.
 PPKEYWORD(import)
 PPKEYWORD(include_next)
@@ -1002,9 +999,6 @@ ANNOTATION(header_unit)
 // Annotation for end of input in clang-repl.
 ANNOTATION(repl_input_end)
 
-// Annotation for #embed
-ANNOTATION(embed)
-
 #undef PRAGMA_ANNOTATION
 #undef ANNOTATION
 #undef TESTING_KEYWORD

clang/include/clang/Driver/Options.td

@@ -880,9 +880,6 @@ will be ignored}]>;
 def L : JoinedOrSeparate<["-"], "L">, Flags<[RenderJoined]>, Group<Link_Group>,
     Visibility<[ClangOption, FlangOption]>,
     MetaVarName<"<dir>">, HelpText<"Add directory to library search path">;
-def embed_dir_EQ : Joined<["--"], "embed-dir=">, Group<Preprocessor_Group>,
-    Visibility<[ClangOption, CC1Option]>, MetaVarName<"<dir>">,
-    HelpText<"Add directory to embed search path">;
 def MD : Flag<["-"], "MD">, Group<M_Group>,
     HelpText<"Write a depfile containing user and system headers">;
 def MMD : Flag<["-"], "MMD">, Group<M_Group>,
@@ -1476,9 +1473,6 @@ def dD : Flag<["-"], "dD">, Group<d_Group>, Visibility<[ClangOption, CC1Option]>
 def dI : Flag<["-"], "dI">, Group<d_Group>, Visibility<[ClangOption, CC1Option]>,
   HelpText<"Print include directives in -E mode in addition to normal output">,
   MarshallingInfoFlag<PreprocessorOutputOpts<"ShowIncludeDirectives">>;
-def dE : Flag<["-"], "dE">, Group<d_Group>, Visibility<[CC1Option]>,
-  HelpText<"Print embed directives in -E mode in addition to normal output">,
-  MarshallingInfoFlag<PreprocessorOutputOpts<"ShowEmbedDirectives">>;
 def dM : Flag<["-"], "dM">, Group<d_Group>, Visibility<[ClangOption, CC1Option, FlangOption, FC1Option]>,
   HelpText<"Print macro definitions in -E mode instead of normal output">;
 def dead__strip : Flag<["-"], "dead_strip">;

clang/include/clang/Frontend/PreprocessorOutputOptions.h

@@ -32,8 +32,6 @@ class PreprocessorOutputOptions {
   LLVM_PREFERRED_TYPE(bool)
   unsigned ShowIncludeDirectives : 1;  ///< Print includes, imports etc. within preprocessed output.
   LLVM_PREFERRED_TYPE(bool)
-  unsigned ShowEmbedDirectives : 1; ///< Print embeds, etc. within preprocessed
-  LLVM_PREFERRED_TYPE(bool)
   unsigned RewriteIncludes : 1;    ///< Preprocess include directives only.
   LLVM_PREFERRED_TYPE(bool)
   unsigned RewriteImports  : 1;    ///< Include contents of transitively-imported modules.
@@ -53,7 +51,6 @@ class PreprocessorOutputOptions {
     ShowMacroComments = 0;
     ShowMacros = 0;
     ShowIncludeDirectives = 0;
-    ShowEmbedDirectives = 0;
     RewriteIncludes = 0;
     RewriteImports = 0;
     MinimizeWhitespace = 0;