clang/test/CodeGenCXX/inalloca-stmtexpr.cpp

   1 // RUN: %clang_cc1 %s -emit-llvm -triple i686-windows-msvc -o - | FileCheck %s
   2
   3 // Statement allow the user to exit the evaluation scope of a CallExpr without
   4 // executing the call. Check that clang generates reasonable IR for that case.
   5
   6 // Not trivially copyable, subject to inalloca.
   7 struct Foo {
   8   int x;
   9   Foo();
  10   ~Foo();
  11 };
  12
  13 void inalloca(Foo x, Foo y);
  14
  15 // PR25102: In this case, clang attempts to clean up unreachable blocks *during*
  16 // IR generation. inalloca defers some RAUW operations to the end of codegen,
  17 // and those references would become stale when the unreachable call to
  18 // 'inalloca' got deleted.
  19 extern "C" void pr25102() {
  20   inalloca(Foo(), ({
  21              goto out;
  22              Foo();
  23            }));
  24 out:;
  25 }
  26
  27 // CHECK-LABEL: define dso_local void @pr25102()
  28 // CHECK: br label %out
  29 // CHECK: out:
  30 // CHECK: ret void
  31
  32 bool cond();
  33 extern "C" void seqAbort() {
  34   inalloca(Foo(), ({
  35              if (cond())
  36                goto out;
  37              Foo();
  38            }));
  39 out:;
  40 }
  41
  42 // FIXME: This can cause a stack leak. We should really have a "normal" cleanup
  43 // that goto branches through.
  44 // CHECK-LABEL: define dso_local void @seqAbort()
  45 // CHECK: alloca inalloca <{ %struct.Foo, %struct.Foo }>
  46 // CHECK: call noundef zeroext i1 @"?cond@@YA_NXZ"()
  47 // CHECK: br i1
  48 // CHECK: br label %out
  49 // CHECK: call void @"?inalloca@@YAXUFoo@@0@Z"(ptr inalloca(<{ %struct.Foo, %struct.Foo }>) %{{.*}})
  50 // CHECK: call void @llvm.stackrestore.p0(ptr %inalloca.save)
  51 // CHECK: out: