averello/swift-mirror
1
0
Fork 0
mirror of https://github.com/apple/swift.git synced 2025-12-14 20:36:38 +01:00
Code Issues Packages Projects Releases Wiki Activity

[DSL] Allow function builders to opt in to "if" statements.

Browse Source 
If a function builder contains a buildIf function, then "if" statements
will be supported by passing an optional of the "then" branch.
"if" statements with an "else" statement are unsupported at present.
This commit is contained in:
Doug Gregor
2019-04-16 23:34:59 -07:00
committed by John McCall
parent ffd160162f
commit c98f01705c
4 changed files with 66 additions and 5 deletions
Download Patch File Download Diff File Expand all files Collapse all files

46
lib/Sema/ConstraintSystem.cpp
View File

@@ -2871,7 +2871,51 @@ namespace {
CONTROL_FLOW_STMT(Yield)
CONTROL_FLOW_STMT(Defer)
CONTROL_FLOW_STMT(If)
static Expr *getTrivialBooleanCondition(StmtCondition condition) {
if (condition.size() != 1)
return nullptr;
return condition.front().getBooleanOrNull();
}
Expr *visitIfStmt(IfStmt *ifStmt) {
if (!builderSupports(ctx.Id_buildIf) ||
ifStmt->getElseStmt() ||
!getTrivialBooleanCondition(ifStmt->getCond())) {
this->controlFlowStmt = ifStmt;
return nullptr;
}
auto thenArg = visit(ifStmt->getThenStmt());
if (!thenArg)
return nullptr;
if (!wantExpr)
return nullptr;
auto optionalDecl = ctx.getOptionalDecl();
auto optionalType = optionalDecl->getDeclaredType();
auto optionalTypeExpr = TypeExpr::createImplicit(optionalType, ctx);
auto someRef = new (ctx) UnresolvedDotExpr(
optionalTypeExpr, SourceLoc(), ctx.getIdentifier("some"),
DeclNameLoc(), /*implicit=*/true);
auto someCall = CallExpr::createImplicit(ctx, someRef, thenArg, { });
optionalTypeExpr = TypeExpr::createImplicit(optionalType, ctx);
auto noneRef = new (ctx) UnresolvedDotExpr(
optionalTypeExpr, ifStmt->getEndLoc(), ctx.getIdentifier("none"),
DeclNameLoc(ifStmt->getEndLoc()), /*implicit=*/true);
auto ifExpr = new (ctx) IfExpr(
getTrivialBooleanCondition(ifStmt->getCond()),
SourceLoc(), someCall,
SourceLoc(), noneRef);
ifExpr->setImplicit();
return buildCallIfWanted(ctx.Id_buildIf, ifExpr);
}
CONTROL_FLOW_STMT(Guard)
CONTROL_FLOW_STMT(While)
CONTROL_FLOW_STMT(DoCatch)