[AST] Update the comments of the various Expr::Ignore* + Related cleanups
The description of what the various Expr::Ignore* do has drifted from the
actual implementation.
Inspection reveals that IgnoreParenImpCasts() is not equivalent to doing
IgnoreParens() + IgnoreImpCasts() until reaching a fixed point, but
IgnoreParenCasts() is equivalent to doing IgnoreParens() + IgnoreCasts()
until reaching a fixed point. There is also a fair amount of duplication
in the various Expr::Ignore* functions which increase the chance of further
future inconsistencies. In preparation for the next patch which will factor
out the implementation of the various Expr::Ignore*, do the following cleanups:
Remove Stmt::IgnoreImplicit, in favor of Expr::IgnoreImplicit. IgnoreImplicit
is the only function among all of the Expr::Ignore* which is available in Stmt.
There are only a few users of Stmt::IgnoreImplicit. They can just use instead
Expr::IgnoreImplicit like they have to do for the other Ignore*.
Move Expr::IgnoreImpCasts() from Expr.h to Expr.cpp. This made no difference
in the run-time with my usual benchmark (-fsyntax-only on all of Boost).
While we are at it, make IgnoreParenNoopCasts take a const reference to the
ASTContext for const correctness.
Update the comments to match what the Expr::Ignore* are actually doing.
I am not sure that listing exactly what each Expr::Ignore* do is optimal,
but it certainly looks better than the current state which is in my opinion
between misleading and just plain wrong.
The whole patch is NFC (if you count removing Stmt::IgnoreImplicit as NFC).
Differential Revision: https://reviews.llvm.org/D57266
Reviewed By: aaron.ballman
llvm-svn: 353006
diff --git a/clang/lib/AST/Expr.cpp b/clang/lib/AST/Expr.cpp
index 2948acd..6d3ad37 100644
--- a/clang/lib/AST/Expr.cpp
+++ b/clang/lib/AST/Expr.cpp
@@ -2556,32 +2556,66 @@
return QualType();
}
-Expr* Expr::IgnoreParens() {
- Expr* E = this;
+Expr *Expr::IgnoreImpCasts() {
+ Expr *E = this;
while (true) {
- if (ParenExpr* P = dyn_cast<ParenExpr>(E)) {
- E = P->getSubExpr();
+ if (auto *ICE = dyn_cast<ImplicitCastExpr>(E))
+ E = ICE->getSubExpr();
+ else if (auto *FE = dyn_cast<FullExpr>(E))
+ E = FE->getSubExpr();
+ else
+ break;
+ }
+ return E;
+}
+
+Expr *Expr::IgnoreImplicit() {
+ Expr *E = this;
+ Expr *LastE = nullptr;
+ while (E != LastE) {
+ LastE = E;
+
+ if (auto *ICE = dyn_cast<ImplicitCastExpr>(E))
+ E = ICE->getSubExpr();
+
+ if (auto *FE = dyn_cast<FullExpr>(E))
+ E = FE->getSubExpr();
+
+ if (auto *MTE = dyn_cast<MaterializeTemporaryExpr>(E))
+ E = MTE->GetTemporaryExpr();
+
+ if (auto *BTE = dyn_cast<CXXBindTemporaryExpr>(E))
+ E = BTE->getSubExpr();
+ }
+ return E;
+}
+
+Expr *Expr::IgnoreParens() {
+ Expr *E = this;
+ while (true) {
+ if (auto *PE = dyn_cast<ParenExpr>(E)) {
+ E = PE->getSubExpr();
continue;
}
- if (UnaryOperator* P = dyn_cast<UnaryOperator>(E)) {
- if (P->getOpcode() == UO_Extension) {
- E = P->getSubExpr();
+ if (auto *UO = dyn_cast<UnaryOperator>(E)) {
+ if (UO->getOpcode() == UO_Extension) {
+ E = UO->getSubExpr();
continue;
}
}
- if (GenericSelectionExpr* P = dyn_cast<GenericSelectionExpr>(E)) {
- if (!P->isResultDependent()) {
- E = P->getResultExpr();
+ if (auto *GSE = dyn_cast<GenericSelectionExpr>(E)) {
+ if (!GSE->isResultDependent()) {
+ E = GSE->getResultExpr();
continue;
}
}
- if (ChooseExpr* P = dyn_cast<ChooseExpr>(E)) {
- if (!P->isConditionDependent()) {
- E = P->getChosenSubExpr();
+ if (auto *CE = dyn_cast<ChooseExpr>(E)) {
+ if (!CE->isConditionDependent()) {
+ E = CE->getChosenSubExpr();
continue;
}
}
- if (ConstantExpr *CE = dyn_cast<ConstantExpr>(E)) {
+ if (auto *CE = dyn_cast<ConstantExpr>(E)) {
E = CE->getSubExpr();
continue;
}
@@ -2595,21 +2629,19 @@
Expr *E = this;
while (true) {
E = E->IgnoreParens();
- if (CastExpr *P = dyn_cast<CastExpr>(E)) {
- E = P->getSubExpr();
+ if (auto *CE = dyn_cast<CastExpr>(E)) {
+ E = CE->getSubExpr();
continue;
}
- if (MaterializeTemporaryExpr *Materialize
- = dyn_cast<MaterializeTemporaryExpr>(E)) {
- E = Materialize->GetTemporaryExpr();
+ if (auto *MTE = dyn_cast<MaterializeTemporaryExpr>(E)) {
+ E = MTE->GetTemporaryExpr();
continue;
}
- if (SubstNonTypeTemplateParmExpr *NTTP
- = dyn_cast<SubstNonTypeTemplateParmExpr>(E)) {
+ if (auto *NTTP = dyn_cast<SubstNonTypeTemplateParmExpr>(E)) {
E = NTTP->getReplacement();
continue;
}
- if (FullExpr *FE = dyn_cast<FullExpr>(E)) {
+ if (auto *FE = dyn_cast<FullExpr>(E)) {
E = FE->getSubExpr();
continue;
}
@@ -2620,21 +2652,19 @@
Expr *Expr::IgnoreCasts() {
Expr *E = this;
while (true) {
- if (CastExpr *P = dyn_cast<CastExpr>(E)) {
- E = P->getSubExpr();
+ if (auto *CE = dyn_cast<CastExpr>(E)) {
+ E = CE->getSubExpr();
continue;
}
- if (MaterializeTemporaryExpr *Materialize
- = dyn_cast<MaterializeTemporaryExpr>(E)) {
- E = Materialize->GetTemporaryExpr();
+ if (auto *MTE = dyn_cast<MaterializeTemporaryExpr>(E)) {
+ E = MTE->GetTemporaryExpr();
continue;
}
- if (SubstNonTypeTemplateParmExpr *NTTP
- = dyn_cast<SubstNonTypeTemplateParmExpr>(E)) {
+ if (auto *NTTP = dyn_cast<SubstNonTypeTemplateParmExpr>(E)) {
E = NTTP->getReplacement();
continue;
}
- if (FullExpr *FE = dyn_cast<FullExpr>(E)) {
+ if (auto *FE = dyn_cast<FullExpr>(E)) {
E = FE->getSubExpr();
continue;
}
@@ -2650,20 +2680,18 @@
Expr *E = this;
while (true) {
E = E->IgnoreParens();
- if (CastExpr *P = dyn_cast<CastExpr>(E)) {
- if (P->getCastKind() == CK_LValueToRValue) {
- E = P->getSubExpr();
+ if (auto *CE = dyn_cast<CastExpr>(E)) {
+ if (CE->getCastKind() == CK_LValueToRValue) {
+ E = CE->getSubExpr();
continue;
}
- } else if (MaterializeTemporaryExpr *Materialize
- = dyn_cast<MaterializeTemporaryExpr>(E)) {
- E = Materialize->GetTemporaryExpr();
+ } else if (auto *MTE = dyn_cast<MaterializeTemporaryExpr>(E)) {
+ E = MTE->GetTemporaryExpr();
continue;
- } else if (SubstNonTypeTemplateParmExpr *NTTP
- = dyn_cast<SubstNonTypeTemplateParmExpr>(E)) {
+ } else if (auto *NTTP = dyn_cast<SubstNonTypeTemplateParmExpr>(E)) {
E = NTTP->getReplacement();
continue;
- } else if (FullExpr *FE = dyn_cast<FullExpr>(E)) {
+ } else if (auto *FE = dyn_cast<FullExpr>(E)) {
E = FE->getSubExpr();
continue;
}
@@ -2676,7 +2704,7 @@
Expr *E = this;
while (true) {
E = E->IgnoreParens();
- if (CastExpr *CE = dyn_cast<CastExpr>(E)) {
+ if (auto *CE = dyn_cast<CastExpr>(E)) {
if (CE->getCastKind() == CK_DerivedToBase ||
CE->getCastKind() == CK_UncheckedDerivedToBase ||
CE->getCastKind() == CK_NoOp) {
@@ -2693,17 +2721,15 @@
Expr *E = this;
while (true) {
E = E->IgnoreParens();
- if (ImplicitCastExpr *P = dyn_cast<ImplicitCastExpr>(E)) {
- E = P->getSubExpr();
+ if (auto *ICE = dyn_cast<ImplicitCastExpr>(E)) {
+ E = ICE->getSubExpr();
continue;
}
- if (MaterializeTemporaryExpr *Materialize
- = dyn_cast<MaterializeTemporaryExpr>(E)) {
- E = Materialize->GetTemporaryExpr();
+ if (auto *MTE = dyn_cast<MaterializeTemporaryExpr>(E)) {
+ E = MTE->GetTemporaryExpr();
continue;
}
- if (SubstNonTypeTemplateParmExpr *NTTP
- = dyn_cast<SubstNonTypeTemplateParmExpr>(E)) {
+ if (auto *NTTP = dyn_cast<SubstNonTypeTemplateParmExpr>(E)) {
E = NTTP->getReplacement();
continue;
}
@@ -2712,7 +2738,7 @@
}
Expr *Expr::IgnoreConversionOperator() {
- if (CXXMemberCallExpr *MCE = dyn_cast<CXXMemberCallExpr>(this)) {
+ if (auto *MCE = dyn_cast<CXXMemberCallExpr>(this)) {
if (MCE->getMethodDecl() && isa<CXXConversionDecl>(MCE->getMethodDecl()))
return MCE->getImplicitObjectArgument();
}
@@ -2722,15 +2748,15 @@
/// IgnoreParenNoopCasts - Ignore parentheses and casts that do not change the
/// value (including ptr->int casts of the same size). Strip off any
/// ParenExpr or CastExprs, returning their operand.
-Expr *Expr::IgnoreParenNoopCasts(ASTContext &Ctx) {
+Expr *Expr::IgnoreParenNoopCasts(const ASTContext &Ctx) {
Expr *E = this;
while (true) {
E = E->IgnoreParens();
- if (CastExpr *P = dyn_cast<CastExpr>(E)) {
+ if (auto *CE = dyn_cast<CastExpr>(E)) {
// We ignore integer <-> casts that are of the same width, ptr<->ptr and
// ptr<->int casts of the same width. We also ignore all identity casts.
- Expr *SE = P->getSubExpr();
+ Expr *SE = CE->getSubExpr();
if (Ctx.hasSameUnqualifiedType(E->getType(), SE->getType())) {
E = SE;
@@ -2747,8 +2773,7 @@
}
}
- if (SubstNonTypeTemplateParmExpr *NTTP
- = dyn_cast<SubstNonTypeTemplateParmExpr>(E)) {
+ if (auto *NTTP = dyn_cast<SubstNonTypeTemplateParmExpr>(E)) {
E = NTTP->getReplacement();
continue;
}