Avoid crashing if a MacroExpansionExpr failed to produce an expression

DougGregor · DougGregor · commit 2ce04930a43b · 2025-03-21T08:30:11.000-07:00
diff --git a/lib/Sema/TypeCheckConcurrency.cpp b/lib/Sema/TypeCheckConcurrency.cpp
@@ -4113,7 +4113,8 @@ namespace {
       }
 
       if (auto *macro = dyn_cast<MacroExpansionExpr>(expr)) {
-        expr = macro->getRewritten();
+        if (auto rewritten = macro->getRewritten())
+          expr = rewritten;
       }
 
       if (auto *isolation = dyn_cast<CurrentContextIsolationExpr>(expr)) {

Original file line number	Diff line number	Diff line change
`@@ -4113,7 +4113,8 @@ namespace {`
`4113`	`4113`	`}`
`4114`	`4114`
`4115`	`4115`	`if (auto *macro = dyn_cast<MacroExpansionExpr>(expr)) {`
`4116`		`- expr = macro->getRewritten();`
	`4116`	`+ if (auto rewritten = macro->getRewritten())`
	`4117`	`+ expr = rewritten;`
`4117`	`4118`	`}`
`4118`	`4119`
`4119`	`4120`	`if (auto *isolation = dyn_cast<CurrentContextIsolationExpr>(expr)) {`