[clang] 5537b22 - Make CompoundStmtBitfields::NumStmts not a bit-field

[Serge Pavlov via cfe-commits]

Author: Serge Pavlov
Date: 2022-05-20T14:20:09+07:00
New Revision: 5537b22ccbdc562929949844f9f816cf720e5205

URL: https://github.com/llvm/llvm-project/commit/5537b22ccbdc562929949844f9f816cf720e5205
DIFF: https://github.com/llvm/llvm-project/commit/5537b22ccbdc562929949844f9f816cf720e5205.diff

LOG: Make CompoundStmtBitfields::NumStmts not a bit-field

Number of statements in CompoundStmt is kept in a bit-field of the common
part of Stmt. The field has 24 bits for the number. To allocate a new
bit field (as attempted in https://reviews.llvm.org/D123952), this
number must be reduced, maximal number of statements in a compound
statement becomes smaller. It can result in compilation errors of some
programs.

With this change the number of statements is kept in a field of type
'unsigned int' rather than in bit-field. To make room in CompoundStmtBitfields
LBraceLoc is moved to fields of CompoundStmt.

Differential Revision: https://reviews.llvm.org/D125635

Added: 
    

Modified: 
    clang/include/clang/AST/Stmt.h
    clang/lib/AST/Stmt.cpp
    clang/lib/Serialization/ASTReaderStmt.cpp

Removed: 
    


################################################################################
diff  --git a/clang/include/clang/AST/Stmt.h b/clang/include/clang/AST/Stmt.h
index 1135981319c1a..653ce4b4b90c5 100644
--- a/clang/include/clang/AST/Stmt.h
+++ b/clang/include/clang/AST/Stmt.h
@@ -128,10 +128,7 @@ class alignas(void *) Stmt {
 
     unsigned : NumStmtBits;
 
-    unsigned NumStmts : 32 - NumStmtBits;
-
-    /// The location of the opening "{".
-    SourceLocation LBraceLoc;
+    unsigned NumStmts;
   };
 
   class LabelStmtBitfields {
@@ -1406,7 +1403,10 @@ class CompoundStmt final : public Stmt,
   friend class ASTStmtReader;
   friend TrailingObjects;
 
-  /// The location of the closing "}". LBraceLoc is stored in CompoundStmtBits.
+  /// The location of the opening "{".
+  SourceLocation LBraceLoc;
+
+  /// The location of the closing "}".
   SourceLocation RBraceLoc;
 
   CompoundStmt(ArrayRef<Stmt *> Stmts, SourceLocation LB, SourceLocation RB);
@@ -1420,9 +1420,8 @@ class CompoundStmt final : public Stmt,
 
   // Build an empty compound statement with a location.
   explicit CompoundStmt(SourceLocation Loc)
-      : Stmt(CompoundStmtClass), RBraceLoc(Loc) {
+      : Stmt(CompoundStmtClass), LBraceLoc(Loc), RBraceLoc(Loc) {
     CompoundStmtBits.NumStmts = 0;
-    CompoundStmtBits.LBraceLoc = Loc;
   }
 
   // Build an empty compound statement.
@@ -1505,10 +1504,10 @@ class CompoundStmt final : public Stmt,
     return const_cast<CompoundStmt *>(this)->getStmtExprResult();
   }
 
-  SourceLocation getBeginLoc() const { return CompoundStmtBits.LBraceLoc; }
+  SourceLocation getBeginLoc() const { return LBraceLoc; }
   SourceLocation getEndLoc() const { return RBraceLoc; }
 
-  SourceLocation getLBracLoc() const { return CompoundStmtBits.LBraceLoc; }
+  SourceLocation getLBracLoc() const { return LBraceLoc; }
   SourceLocation getRBracLoc() const { return RBraceLoc; }
 
   static bool classof(const Stmt *T) {

diff  --git a/clang/lib/AST/Stmt.cpp b/clang/lib/AST/Stmt.cpp
index be19d3b2cce2c..d562717bf6b22 100644
--- a/clang/lib/AST/Stmt.cpp
+++ b/clang/lib/AST/Stmt.cpp
@@ -363,10 +363,9 @@ int64_t Stmt::getID(const ASTContext &Context) const {
 
 CompoundStmt::CompoundStmt(ArrayRef<Stmt *> Stmts, SourceLocation LB,
                            SourceLocation RB)
-    : Stmt(CompoundStmtClass), RBraceLoc(RB) {
+    : Stmt(CompoundStmtClass), LBraceLoc(LB), RBraceLoc(RB) {
   CompoundStmtBits.NumStmts = Stmts.size();
   setStmts(Stmts);
-  CompoundStmtBits.LBraceLoc = LB;
 }
 
 void CompoundStmt::setStmts(ArrayRef<Stmt *> Stmts) {

diff  --git a/clang/lib/Serialization/ASTReaderStmt.cpp b/clang/lib/Serialization/ASTReaderStmt.cpp
index 77ea1b95d5be5..09342de1eee96 100644
--- a/clang/lib/Serialization/ASTReaderStmt.cpp
+++ b/clang/lib/Serialization/ASTReaderStmt.cpp
@@ -155,7 +155,7 @@ void ASTStmtReader::VisitCompoundStmt(CompoundStmt *S) {
   while (NumStmts--)
     Stmts.push_back(Record.readSubStmt());
   S->setStmts(Stmts);
-  S->CompoundStmtBits.LBraceLoc = readSourceLocation();
+  S->LBraceLoc = readSourceLocation();
   S->RBraceLoc = readSourceLocation();
 }