[clang] [CIR] Upstream support for emitting ignored statements (PR #130869)

[Erich Keane via cfe-commits]

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@@ -55,10 +55,154 @@ mlir::LogicalResult CIRGenFunction::emitStmt(const Stmt *s,
   if (mlir::succeeded(emitSimpleStmt(s, useCurrentScope)))
     return mlir::success();
 
-  // Only a subset of simple statements are supported at the moment.  When more
-  // kinds of statements are supported, a
-  //     switch (s->getStmtClass()) {
-  // will be added here.
+  switch (s->getStmtClass()) {
+
+#define STMT(Type, Base)
+#define ABSTRACT_STMT(Op)
+#define EXPR(Type, Base) case Stmt::Type##Class:
+#include "clang/AST/StmtNodes.inc"
+    {
+      // Remember the block we came in on.
+      mlir::Block *incoming = builder.getInsertionBlock();
+      assert(incoming && "expression emission must have an insertion point");
+
+      emitIgnoredExpr(cast<Expr>(s));
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erichkeane wrote:

OH, wait, I see it now.  The point is that this is an expression that _IS_ ignored, meaning we're not doing anything with the result.  So this is appropriate for any expression where its return value/result/etc isn't dealt with.

https://github.com/llvm/llvm-project/pull/130869