[clang] Add storage for APValue in ConstantExpr
Summary:
When using ConstantExpr we often need the result of the expression to be kept in the AST. Currently this is done on a by the node that needs the result and has been done multiple times for enumerator, for constexpr variables... . This patch adds to ConstantExpr the ability to store the result of evaluating the expression. no functional changes expected.
Changes:
- Add trailling object to ConstantExpr that can hold an APValue or an uint64_t. the uint64_t is here because most ConstantExpr yield integral values so there is an optimized layout for integral values.
- Add basic* serialization support for the trailing result.
- Move conversion functions from an enum to a fltSemantics from clang::FloatingLiteral to llvm::APFloatBase. this change is to make it usable for serializing APValues.
- Add basic* Import support for the trailing result.
- ConstantExpr created in CheckConvertedConstantExpression now stores the result in the ConstantExpr Node.
- Adapt AST dump to print the result when present.
basic* : None, Indeterminate, Int, Float, FixedPoint, ComplexInt, ComplexFloat,
the result is not yet used anywhere but for -ast-dump.
Reviewers: rsmith, martong, shafik
Reviewed By: rsmith
Subscribers: rnkovacs, hiraditya, dexonsmith, cfe-commits, llvm-commits
Tags: #clang, #llvm
Differential Revision: https://reviews.llvm.org/D62399
llvm-svn: 363493
diff --git a/clang/lib/Serialization/ASTWriterStmt.cpp b/clang/lib/Serialization/ASTWriterStmt.cpp
index bd71546..20a6b7d 100644
--- a/clang/lib/Serialization/ASTWriterStmt.cpp
+++ b/clang/lib/Serialization/ASTWriterStmt.cpp
@@ -432,6 +432,16 @@
void ASTStmtWriter::VisitConstantExpr(ConstantExpr *E) {
VisitExpr(E);
+ Record.push_back(static_cast<uint64_t>(E->ConstantExprBits.ResultKind));
+ switch (E->ConstantExprBits.ResultKind) {
+ case ConstantExpr::RSK_Int64:
+ Record.push_back(E->Int64Result());
+ Record.push_back(E->ConstantExprBits.IsUnsigned |
+ E->ConstantExprBits.BitWidth << 1);
+ break;
+ case ConstantExpr::RSK_APValue:
+ Record.AddAPValue(E->APValueResult());
+ }
Record.AddStmt(E->getSubExpr());
Code = serialization::EXPR_CONSTANT;
}