Author: cor3ntin Date: 2025-03-19T15:16:38+01:00 New Revision: baef6fadbf0e4ddac33c6a8a6275208435f52965
URL: https://github.com/llvm/llvm-project/commit/baef6fadbf0e4ddac33c6a8a6275208435f52965 DIFF: https://github.com/llvm/llvm-project/commit/baef6fadbf0e4ddac33c6a8a6275208435f52965.diff LOG: [Clang] Increase the default expression nesting limit (#132021) This iterates on #104717 (which we had to revert) In a bid to increase our chances of success, we try to avoid blowing up the stack by - Using `runWithSufficientStackSpace` in ParseCompoundStatement - Reducing the size of `StmtVector` a bit - Reducing the size of `DeclsInGroup` a bit - Removing a few `ParsedAttributes` from the stacks in places where they are not strictly necessary. `ParsedAttributes` is a _huge_ object On a 64 bits system, the following stack size reductions are observed ``` ParseStatementOrDeclarationAfterAttributes: 344 -> 264 ParseStatementOrDeclaration: 520 -> 376 ParseCompoundStatementBody: 1080 -> 1016 ParseDeclaration: 264 -> 120 ``` Fixes #94728 Added: Modified: clang/docs/ReleaseNotes.rst clang/include/clang/Driver/Options.td clang/include/clang/Parse/Parser.h clang/include/clang/Sema/ParsedAttr.h clang/lib/Parse/ParseDecl.cpp clang/lib/Parse/ParseStmt.cpp clang/lib/Parse/ParseTemplate.cpp clang/lib/Parse/Parser.cpp clang/lib/Sema/ParsedAttr.cpp clang/test/Parser/parser_overflow.c Removed: ################################################################################ diff --git a/clang/docs/ReleaseNotes.rst b/clang/docs/ReleaseNotes.rst index 075bcc64b1c59..666bbf22acc93 100644 --- a/clang/docs/ReleaseNotes.rst +++ b/clang/docs/ReleaseNotes.rst @@ -174,6 +174,8 @@ Modified Compiler Flags the behavior of ``-mtp`` in gcc. This changes the default behavior for ARM targets that provide the ``TPIDRURO`` register as this will be used instead of a call to the ``__aeabi_read_tp``. Programs that use ``__aeabi_read_tp`` but do not use the ``TPIDRURO`` register must use ``-mtp=soft``. Fixes #123864 +- The compiler flag `-fbracket-depth` default value is increased from 256 to 2048. (#GH94728) + Removed Compiler Flags ------------------------- @@ -269,7 +271,7 @@ Improvements to Clang's diagnostics as function arguments or return value respectively. Note that :doc:`ThreadSafetyAnalysis` still does not perform alias analysis. The feature will be default-enabled with ``-Wthread-safety`` in a future release. -- The ``-Wsign-compare`` warning now treats expressions with bitwise not(~) and minus(-) as signed integers +- The ``-Wsign-compare`` warning now treats expressions with bitwise not(~) and minus(-) as signed integers except for the case where the operand is an unsigned integer and throws warning if they are compared with unsigned integers (##18878). - The ``-Wunnecessary-virtual-specifier`` warning has been added to warn about diff --git a/clang/include/clang/Driver/Options.td b/clang/include/clang/Driver/Options.td index 66ae8f1c7f064..d41c7f20feba9 100644 --- a/clang/include/clang/Driver/Options.td +++ b/clang/include/clang/Driver/Options.td @@ -8161,7 +8161,7 @@ def fapply_global_visibility_to_externs : Flag<["-"], "fapply-global-visibility- MarshallingInfoFlag<LangOpts<"SetVisibilityForExternDecls">>; def fbracket_depth : Separate<["-"], "fbracket-depth">, HelpText<"Maximum nesting level for parentheses, brackets, and braces">, - MarshallingInfoInt<LangOpts<"BracketDepth">, "256">; + MarshallingInfoInt<LangOpts<"BracketDepth">, "2048">; defm const_strings : BoolOption<"f", "const-strings", LangOpts<"ConstStrings">, DefaultFalse, PosFlag<SetTrue, [], [ClangOption, CC1Option], "Use">, diff --git a/clang/include/clang/Parse/Parser.h b/clang/include/clang/Parse/Parser.h index 1c8caf55a546d..fbe2865b1b7c1 100644 --- a/clang/include/clang/Parse/Parser.h +++ b/clang/include/clang/Parse/Parser.h @@ -91,6 +91,8 @@ class Parser : public CodeCompletionHandler { DiagnosticsEngine &Diags; + StackExhaustionHandler StackHandler; + /// ScopeCache - Cache scopes to reduce malloc traffic. enum { ScopeCacheSize = 16 }; unsigned NumCachedScopes; @@ -518,7 +520,7 @@ class Parser : public CodeCompletionHandler { typedef Sema::FullExprArg FullExprArg; /// A SmallVector of statements. - typedef SmallVector<Stmt *, 32> StmtVector; + typedef SmallVector<Stmt *, 24> StmtVector; // Parsing methods. @@ -3842,6 +3844,8 @@ class Parser : public CodeCompletionHandler { DeclGroupPtrTy ParseTemplateDeclarationOrSpecialization( DeclaratorContext Context, SourceLocation &DeclEnd, ParsedAttributes &AccessAttrs, AccessSpecifier AS); + clang::Parser::DeclGroupPtrTy ParseTemplateDeclarationOrSpecialization( + DeclaratorContext Context, SourceLocation &DeclEnd, AccessSpecifier AS); DeclGroupPtrTy ParseDeclarationAfterTemplate( DeclaratorContext Context, ParsedTemplateInfo &TemplateInfo, ParsingDeclRAIIObject &DiagsFromParams, SourceLocation &DeclEnd, diff --git a/clang/include/clang/Sema/ParsedAttr.h b/clang/include/clang/Sema/ParsedAttr.h index e1faab205f647..b88b871dc8821 100644 --- a/clang/include/clang/Sema/ParsedAttr.h +++ b/clang/include/clang/Sema/ParsedAttr.h @@ -970,6 +970,14 @@ class ParsedAttributes : public ParsedAttributesView { pool.takeAllFrom(Other.pool); } + void takeAllAtEndFrom(ParsedAttributes &Other) { + assert(&Other != this && + "ParsedAttributes can't take attributes from itself"); + addAllAtEnd(Other.begin(), Other.end()); + Other.clearListOnly(); + pool.takeAllFrom(Other.pool); + } + void takeOneFrom(ParsedAttributes &Other, ParsedAttr *PA) { assert(&Other != this && "ParsedAttributes can't take attribute from itself"); @@ -1067,10 +1075,11 @@ class ParsedAttributes : public ParsedAttributesView { mutable AttributePool pool; }; -/// Consumes the attributes from `First` and `Second` and concatenates them into -/// `Result`. Sets `Result.Range` to the combined range of `First` and `Second`. -void takeAndConcatenateAttrs(ParsedAttributes &First, ParsedAttributes &Second, - ParsedAttributes &Result); +/// Consumes the attributes from `Second` and concatenates them +/// at the end of `First`. Sets `First.Range` +/// to the combined range of `First` and `Second`. +void takeAndConcatenateAttrs(ParsedAttributes &First, + ParsedAttributes &&Second); /// These constants match the enumerated choices of /// err_attribute_argument_n_type and err_attribute_argument_type. diff --git a/clang/lib/Parse/ParseDecl.cpp b/clang/lib/Parse/ParseDecl.cpp index 82b394d5b4ca6..9ca3e2b5756ca 100644 --- a/clang/lib/Parse/ParseDecl.cpp +++ b/clang/lib/Parse/ParseDecl.cpp @@ -2076,10 +2076,9 @@ Parser::DeclGroupPtrTy Parser::ParseDeclaration(DeclaratorContext Context, ProhibitAttributes(DeclSpecAttrs); return ParseNamespace(Context, DeclEnd); case tok::kw_using: { - ParsedAttributes Attrs(AttrFactory); - takeAndConcatenateAttrs(DeclAttrs, DeclSpecAttrs, Attrs); + takeAndConcatenateAttrs(DeclAttrs, std::move(DeclSpecAttrs)); return ParseUsingDirectiveOrDeclaration(Context, ParsedTemplateInfo(), - DeclEnd, Attrs); + DeclEnd, DeclAttrs); } case tok::kw_static_assert: case tok::kw__Static_assert: diff --git a/clang/lib/Parse/ParseStmt.cpp b/clang/lib/Parse/ParseStmt.cpp index 623b4c799327c..150b2879fc94f 100644 --- a/clang/lib/Parse/ParseStmt.cpp +++ b/clang/lib/Parse/ParseStmt.cpp @@ -126,18 +126,15 @@ Parser::ParseStatementOrDeclaration(StmtVector &Stmts, Stmts, StmtCtx, TrailingElseLoc, CXX11Attrs, GNUOrMSAttrs); MaybeDestroyTemplateIds(); - // Attributes that are left should all go on the statement, so concatenate the - // two lists. - ParsedAttributes Attrs(AttrFactory); - takeAndConcatenateAttrs(CXX11Attrs, GNUOrMSAttrs, Attrs); + takeAndConcatenateAttrs(CXX11Attrs, std::move(GNUOrMSAttrs)); - assert((Attrs.empty() || Res.isInvalid() || Res.isUsable()) && + assert((CXX11Attrs.empty() || Res.isInvalid() || Res.isUsable()) && "attributes on empty statement"); - if (Attrs.empty() || Res.isInvalid()) + if (CXX11Attrs.empty() || Res.isInvalid()) return Res; - return Actions.ActOnAttributedStmt(Attrs, Res.get()); + return Actions.ActOnAttributedStmt(CXX11Attrs, Res.get()); } namespace { @@ -207,11 +204,10 @@ StmtResult Parser::ParseStatementOrDeclarationAfterAttributes( // Both C++11 and GNU attributes preceding the label appertain to the // label, so put them in a single list to pass on to // ParseLabeledStatement(). - ParsedAttributes Attrs(AttrFactory); - takeAndConcatenateAttrs(CXX11Attrs, GNUAttrs, Attrs); + takeAndConcatenateAttrs(CXX11Attrs, std::move(GNUAttrs)); // identifier ':' statement - return ParseLabeledStatement(Attrs, StmtCtx); + return ParseLabeledStatement(CXX11Attrs, StmtCtx); } // Look up the identifier, and typo-correct it to a keyword if it's not @@ -302,9 +298,7 @@ StmtResult Parser::ParseStatementOrDeclarationAfterAttributes( case tok::kw_template: { SourceLocation DeclEnd; - ParsedAttributes Attrs(AttrFactory); ParseTemplateDeclarationOrSpecialization(DeclaratorContext::Block, DeclEnd, - Attrs, getAccessSpecifierIfPresent()); return StmtError(); } @@ -1057,7 +1051,11 @@ StmtResult Parser::ParseCompoundStatement(bool isStmtExpr, ParseScope CompoundScope(this, ScopeFlags); // Parse the statements in the body. - return ParseCompoundStatementBody(isStmtExpr); + StmtResult R; + StackHandler.runWithSufficientStackSpace(Tok.getLocation(), [&, this]() { + R = ParseCompoundStatementBody(isStmtExpr); + }); + return R; } /// Parse any pragmas at the start of the compound expression. We handle these @@ -1222,7 +1220,7 @@ StmtResult Parser::ParseCompoundStatementBody(bool isStmtExpr) { while (Tok.is(tok::kw___label__)) { SourceLocation LabelLoc = ConsumeToken(); - SmallVector<Decl *, 8> DeclsInGroup; + SmallVector<Decl *, 4> DeclsInGroup; while (true) { if (Tok.isNot(tok::identifier)) { Diag(Tok, diag::err_expected) << tok::identifier; diff --git a/clang/lib/Parse/ParseTemplate.cpp b/clang/lib/Parse/ParseTemplate.cpp index b2cb3d71e09f9..e8b4aee8c2686 100644 --- a/clang/lib/Parse/ParseTemplate.cpp +++ b/clang/lib/Parse/ParseTemplate.cpp @@ -179,6 +179,13 @@ Parser::DeclGroupPtrTy Parser::ParseTemplateDeclarationOrSpecialization( Context, TemplateInfo, ParsingTemplateParams, DeclEnd, AccessAttrs, AS); } +Parser::DeclGroupPtrTy Parser::ParseTemplateDeclarationOrSpecialization( + DeclaratorContext Context, SourceLocation &DeclEnd, AccessSpecifier AS) { + ParsedAttributes AccessAttrs(AttrFactory); + return ParseTemplateDeclarationOrSpecialization(Context, DeclEnd, AccessAttrs, + AS); +} + /// Parse a single declaration that declares a template, /// template specialization, or explicit instantiation of a template. /// diff --git a/clang/lib/Parse/Parser.cpp b/clang/lib/Parse/Parser.cpp index 83dd7b17c73b8..6128bc58d69c0 100644 --- a/clang/lib/Parse/Parser.cpp +++ b/clang/lib/Parse/Parser.cpp @@ -17,6 +17,7 @@ #include "clang/AST/DeclTemplate.h" #include "clang/Basic/DiagnosticParse.h" #include "clang/Basic/FileManager.h" +#include "clang/Basic/StackExhaustionHandler.h" #include "clang/Parse/RAIIObjectsForParser.h" #include "clang/Sema/DeclSpec.h" #include "clang/Sema/EnterExpressionEvaluationContext.h" @@ -54,9 +55,10 @@ IdentifierInfo *Parser::getSEHExceptKeyword() { Parser::Parser(Preprocessor &pp, Sema &actions, bool skipFunctionBodies) : PP(pp), PreferredType(pp.isCodeCompletionEnabled()), Actions(actions), - Diags(PP.getDiagnostics()), GreaterThanIsOperator(true), - ColonIsSacred(false), InMessageExpression(false), - TemplateParameterDepth(0), ParsingInObjCContainer(false) { + Diags(PP.getDiagnostics()), StackHandler(Diags), + GreaterThanIsOperator(true), ColonIsSacred(false), + InMessageExpression(false), TemplateParameterDepth(0), + ParsingInObjCContainer(false) { SkipFunctionBodies = pp.isCodeCompletionEnabled() || skipFunctionBodies; Tok.startToken(); Tok.setKind(tok::eof); diff --git a/clang/lib/Sema/ParsedAttr.cpp b/clang/lib/Sema/ParsedAttr.cpp index eadc6ed6e6f58..b19a02b8c1a09 100644 --- a/clang/lib/Sema/ParsedAttr.cpp +++ b/clang/lib/Sema/ParsedAttr.cpp @@ -310,18 +310,13 @@ bool ParsedAttr::checkAtMostNumArgs(Sema &S, unsigned Num) const { } void clang::takeAndConcatenateAttrs(ParsedAttributes &First, - ParsedAttributes &Second, - ParsedAttributes &Result) { - // Note that takeAllFrom() puts the attributes at the beginning of the list, - // so to obtain the correct ordering, we add `Second`, then `First`. - Result.takeAllFrom(Second); - Result.takeAllFrom(First); - if (First.Range.getBegin().isValid()) - Result.Range.setBegin(First.Range.getBegin()); - else - Result.Range.setBegin(Second.Range.getBegin()); + ParsedAttributes &&Second) { + + First.takeAllAtEndFrom(Second); + + if (!First.Range.getBegin().isValid()) + First.Range.setBegin(Second.Range.getBegin()); + if (Second.Range.getEnd().isValid()) - Result.Range.setEnd(Second.Range.getEnd()); - else - Result.Range.setEnd(First.Range.getEnd()); + First.Range.setEnd(Second.Range.getEnd()); } diff --git a/clang/test/Parser/parser_overflow.c b/clang/test/Parser/parser_overflow.c index 9514e808550a4..53c79bc06d993 100644 --- a/clang/test/Parser/parser_overflow.c +++ b/clang/test/Parser/parser_overflow.c @@ -1,5 +1,5 @@ // RUN: not %clang_cc1 %s -fsyntax-only -DHUGE 2>&1 | FileCheck %s -// RUN: not %clang_cc1 %s -fsyntax-only 2>&1 | FileCheck %s +// RUN: %clang_cc1 %s -fsyntax-only // RUN: not %clang_cc1 %s -fsyntax-only -fbracket-depth 299 2>&1 | FileCheck %s // RUN: %clang_cc1 %s -fsyntax-only -fbracket-depth 300 // RUN: not %clang %s -fsyntax-only -fbracket-depth=299 2>&1 | FileCheck %s @@ -15,5 +15,5 @@ void foo(void) { #endif } -// CHECK: fatal error: bracket nesting level exceeded maximum of {{256|299}} +// CHECK: fatal error: bracket nesting level exceeded maximum of {{2048|299}} // CHECK: note: use -fbracket-depth=N to increase maximum nesting level _______________________________________________ cfe-commits mailing list cfe-commits@lists.llvm.org https://lists.llvm.org/cgi-bin/mailman/listinfo/cfe-commits
