thunks.cpp 13.9 KB
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130 131 132 133 134 135 136 137 138 139 140 141 142 143 144 145 146 147 148 149 150 151 152 153 154 155 156 157 158 159 160 161 162 163 164 165 166 167 168 169 170 171 172 173 174 175 176 177 178 179 180 181 182 183 184 185 186 187 188 189 190 191 192 193 194 195 196 197 198 199 200 201 202 203 204 205 206 207 208 209 210 211 212 213 214 215 216 217 218 219 220 221 222 223 224 225 226 227 228 229 230 231 232 233 234 235 236 237 238 239 240 241 242 243 244 245 246 247 248 249 250 251 252 253 254 255 256 257 258 259 260 261 262 263 264 265 266 267 268 269 270 271 272 273 274 275 276 277 278 279 280 281 282 283 284 285 286 287 288 289 290 291 292 293 294 295 296 297 298 299 300 301 302 303 304 305 306 307 308 309 310 311 312 313 314 315 316 317 318 319 320 321 322 323 324 325 326 327 328 329 330 331 332 333 334 335 336 337 338 339 340 341 342 343 344 345 346 347 348 349 350 351 352 353 354 355 356 357 358 359 360 361 362 363 364 365 366 367 368 369 370 371 372 373 374 375 376 377 378 379 380 381 382 383 384 385 386 387 388 389 390 391 392 393 394 395 396 397 398 399 400 401 402 403 404 405 406 407 408 409 410 411 412 413 414 415 416 417 418 419 420 421 422 423 424 425 426 427 428 429 430 431 432 433 434 435 436 437 438 439 440 441 442 443 444 445 446 447 448 449 450 451 452 453 454 455 456 457 458 459 460 461 462 463 464 465 466 467 468 469 470 471 472 473 474 475 476 477 478 479 480 481 482 483 484 485 486 487 488 489 490 491 492 493 494 495 496 497 498 499 500 501 502 503 504 505 506 507 508 509 510 511 512 513 514 515 516 517 518 519 520 521 522 523 524 525 526 527 528 529 530 531 532 533 534 535 536 537 538 539 540 541 542 543 544 545 546
// Sparc64 doesn't support musttail (yet), so it uses method cloning for
// variadic thunks. Use it for testing.
// RUN: %clang_cc1 %s -triple=sparc64-pc-linux-gnu -munwind-tables -emit-llvm -o - \
// RUN:     | FileCheck --check-prefixes=CHECK,CHECK-CLONE,CHECK-NONOPT %s
// RUN: %clang_cc1 %s -triple=sparc64-pc-linux-gnu -debug-info-kind=standalone -dwarf-version=5 -munwind-tables -emit-llvm -o - \
// RUN:     | FileCheck --check-prefixes=CHECK,CHECK-CLONE,CHECK-NONOPT,CHECK-DBG %s
// RUN: %clang_cc1 %s -triple=sparc64-pc-linux-gnu -munwind-tables -emit-llvm -o - -O1 -disable-llvm-passes \
// RUN:     | FileCheck --check-prefixes=CHECK,CHECK-CLONE,CHECK-OPT %s

// Test x86_64, which uses musttail for variadic thunks.
// RUN: %clang_cc1 %s -triple=x86_64-pc-linux-gnu -munwind-tables -emit-llvm -o - -O1 -disable-llvm-passes \
// RUN:     | FileCheck --check-prefixes=CHECK,CHECK-TAIL,CHECK-OPT %s

// Finally, reuse these tests for the MS ABI.
// RUN: %clang_cc1 %s -triple=x86_64-windows-msvc -munwind-tables -emit-llvm -o - -O1 -disable-llvm-passes \
// RUN:     | FileCheck --check-prefixes=WIN64 %s


namespace Test1 {

// Check that we emit a non-virtual thunk for C::f.

struct A {
  virtual void f();
};

struct B {
  virtual void f();
};

struct C : A, B {
  virtual void c();
  
  virtual void f();
};

// CHECK-LABEL: define void @_ZThn8_N5Test11C1fEv(
// CHECK-DBG-NOT: dbg.declare
// CHECK: ret void
//
// WIN64-LABEL: define dso_local void @"?f@C@Test1@@UEAAXXZ"(
// WIN64-LABEL: define linkonce_odr dso_local void @"?f@C@Test1@@W7EAAXXZ"(
// WIN64: getelementptr i8, i8* {{.*}}, i32 -8
// WIN64: ret void
void C::f() { }

}

namespace Test2 {

// Check that we emit a thunk for B::f since it's overriding a virtual base.

struct A {
  virtual void f();
};

struct B : virtual A {
  virtual void b();
  virtual void f();
};

// CHECK-LABEL: define void @_ZTv0_n24_N5Test21B1fEv(
// CHECK-DBG-NOT: dbg.declare
// CHECK: ret void
void B::f() { }

// No thunk is used for this case in the MS ABI.
// WIN64-LABEL: define dso_local void @"?f@B@Test2@@UEAAXXZ"(
// WIN64-NOT: define {{.*}} void @"?f@B@Test2

}

namespace Test3 {

// Check that we emit a covariant thunk for B::f.

struct V1 { };
struct V2 : virtual V1 { };

struct A {
  virtual V1 *f();
};

struct B : A {
  virtual void b();
  
  virtual V2 *f();
};

// CHECK: define %{{.*}}* @_ZTch0_v0_n24_N5Test31B1fEv(
// WIN64: define weak_odr dso_local %{{.*}} @"?f@B@Test3@@QEAAPEAUV1@2@XZ"(
V2 *B::f() { return 0; }

}

namespace Test4 {

// Check that the thunk for 'C::f' has the same visibility as the function itself.

struct A {
  virtual void f();
};

struct B {
  virtual void f();
};

struct __attribute__((visibility("protected"))) C : A, B {
  virtual void c();
  
  virtual void f();
};

// CHECK-LABEL: define protected void @_ZThn8_N5Test41C1fEv(
// CHECK-DBG-NOT: dbg.declare
// CHECK: ret void
void C::f() { }

// Visibility doesn't matter on COFF, but whatever. We could add an ELF test
// mode later.
// WIN64-LABEL: define protected void @"?f@C@Test4@@UEAAXXZ"(
// WIN64-LABEL: define linkonce_odr protected void @"?f@C@Test4@@W7EAAXXZ"(
}

// Check that the thunk gets internal linkage.
namespace Test4B {
  struct A {
    virtual void f();
  };

  struct B {
    virtual void f();
  };

  namespace {
    struct C : A, B {
      virtual void c();
      virtual void f();
    };
  }
  void C::c() {}
  void C::f() {}

  // Force C::f to be used.
  void f() { 
    C c; 
    c.f();
  }
}
// Not sure why this isn't delayed like in Itanium.
// WIN64-LABEL: define internal void @"?f@C@?A{{.*}}@Test4B@@UEAAXXZ"(

namespace Test5 {

// Check that the thunk for 'B::f' gets the same linkage as the function itself.
struct A {
  virtual void f();
};

struct B : virtual A {
  virtual void f() { }
};

void f(B b) {
  b.f();
}
// No thunk in MS ABI in this case.
}

namespace Test6 {
  struct X {
    X();
    X(const X&);
    X &operator=(const X&);
    ~X();
  };

  struct P {
    P();
    P(const P&);
    ~P();
    X first;
    X second;
  };

  P getP();

  struct Base1 {
    int i;

    virtual X f() { return X(); }
  };

  struct Base2 {
    float real;

    virtual X f() { return X(); }
  };

  struct Thunks : Base1, Base2 {
    long l;

    virtual X f();
  };

  // CHECK-LABEL: define void @_ZThn16_N5Test66Thunks1fEv
	// CHECK-DBG-NOT: dbg.declare
  // CHECK-NOT: memcpy
  // CHECK: {{call void @_ZN5Test66Thunks1fEv.*sret align 1}}
  // CHECK: ret void
  X Thunks::f() { return X(); }

  // WIN64-LABEL: define linkonce_odr dso_local void @"?f@Thunks@Test6@@WBA@EAA?AUX@2@XZ"({{.*}} sret align 1 %{{.*}})
  // WIN64-NOT: memcpy
  // WIN64: tail call void @"?f@Thunks@Test6@@UEAA?AUX@2@XZ"({{.*}} sret align 1 %{{.*}})
}

namespace Test7 {
  // PR7188
  struct X {
    X();
    X(const X&);
    X &operator=(const X&);
    ~X();
  };

  struct Small { short s; };
  struct Large {
    char array[1024];
  };

  class A {
  protected:
    virtual void foo() = 0;
  };

  class B : public A {
  protected:
    virtual void bar() = 0;
  };

  class C : public A  {
  protected:
    virtual void baz(X, X&, _Complex float, Small, Small&, Large) = 0;
  };

  class D : public B,
            public C {

    void foo() {}
    void bar() {}
    void baz(X, X&, _Complex float, Small, Small&, Large);
  };

  void D::baz(X, X&, _Complex float, Small, Small&, Large) { }

  // CHECK-LABEL: define void @_ZThn8_N5Test71D3bazENS_1XERS1_CfNS_5SmallERS4_NS_5LargeE(
  // CHECK-DBG-NOT: dbg.declare
  // CHECK-NOT: memcpy
  // CHECK: ret void
  void testD() { D d; }

  // MS C++ ABI doesn't use a thunk, so this case isn't interesting.
}

namespace Test8 {
  struct NonPOD { ~NonPOD(); int x, y, z; };
  struct A { virtual void foo(); };
  struct B { virtual void bar(NonPOD); };
  struct C : A, B { virtual void bar(NonPOD); static void helper(NonPOD); };

  // CHECK: define void @_ZN5Test81C6helperENS_6NonPODE([[NONPODTYPE:%.*]]*
  void C::helper(NonPOD var) {}

  // CHECK-LABEL: define void @_ZThn8_N5Test81C3barENS_6NonPODE(
  // CHECK-DBG-NOT: dbg.declare
  // CHECK-NOT: load [[NONPODTYPE]], [[NONPODTYPE]]*
  // CHECK-NOT: memcpy
  // CHECK: ret void
  void C::bar(NonPOD var) {}

  // MS C++ ABI doesn't use a thunk, so this case isn't interesting.
}

// PR7241: Emitting thunks for a method shouldn't require the vtable for
// that class to be emitted.
namespace Test9 {
  struct A { virtual ~A() { } };
  struct B : A { virtual void test() const {} };
  struct C : B { C(); ~C(); };
  struct D : C { D() {} };
  void test() {
    D d;
  }
}

namespace Test10 {
  struct A { virtual void foo(); };
  struct B { virtual void foo(); };
  struct C : A, B { void foo() {} };

  // Test later.
  void test() {
    C c;
  }
}

// PR7611
namespace Test11 {
  struct A {             virtual A* f(); };
  struct B : virtual A { virtual A* f(); };
  struct C : B         { virtual C* f(); };
  C* C::f() { return 0; }

  //  C::f itself.
  // CHECK: define {{.*}} @_ZN6Test111C1fEv(

  //  The this-adjustment and return-adjustment thunk required when
  //  C::f appears in a vtable where A is at a nonzero offset from C.
  // CHECK: define {{.*}} @_ZTcv0_n24_v0_n32_N6Test111C1fEv(
  // CHECK-DBG-NOT: dbg.declare
  // CHECK: ret

  //  The return-adjustment thunk required when C::f appears in a vtable
  //  where A is at a zero offset from C.
  // CHECK: define {{.*}} @_ZTch0_v0_n32_N6Test111C1fEv(
  // CHECK-DBG-NOT: dbg.declare
  // CHECK: ret

  // WIN64-LABEL: define dso_local %{{.*}}* @"?f@C@Test11@@UEAAPEAU12@XZ"(i8*

  // WIN64-LABEL: define weak_odr dso_local %{{.*}}* @"?f@C@Test11@@QEAAPEAUA@2@XZ"(i8*
  // WIN64: call %{{.*}}* @"?f@C@Test11@@UEAAPEAU12@XZ"(i8* %{{.*}})
  //
  // Match the vbtable return adjustment.
  // WIN64: load i32*, i32** %{{[^,]*}}, align 8
  // WIN64: getelementptr inbounds i32, i32* %{{[^,]*}}, i32 1
  // WIN64: load i32, i32* %{{[^,]*}}, align 4
}

// Varargs thunk test.
namespace Test12 {
  struct A {
    virtual A* f(int x, ...);
  };
  struct B {
    virtual B* f(int x, ...);
  };
  struct C : A, B {
    virtual void c();
    virtual C* f(int x, ...);
  };
  C* makeC();
  C* C::f(int x, ...) { return makeC(); }

  // C::f
  // CHECK: define {{.*}} @_ZN6Test121C1fEiz

  // Varargs thunk; check that both the this and covariant adjustments
  // are generated.
  // CHECK: define {{.*}} @_ZTchn8_h8_N6Test121C1fEiz
  // CHECK-DBG-NOT: dbg.declare
  // CHECK: getelementptr inbounds i8, i8* {{.*}}, i64 -8
  // CHECK: getelementptr inbounds i8, i8* {{.*}}, i64 8

  // The vtable layout goes:
  // C vtable in A:
  // - f impl, no adjustment
  // C vtable in B:
  // - f thunk 2, covariant, clone
  // - f thunk 2, musttail this adjust to impl
  // FIXME: The weak_odr linkage is probably not necessary and just an artifact
  // of Itanium ABI details.
  // WIN64-LABEL: define dso_local {{.*}} @"?f@C@Test12@@UEAAPEAU12@HZZ"(
  // WIN64: call %{{.*}}* @"?makeC@Test12@@YAPEAUC@1@XZ"()
  //
  // This thunk needs return adjustment, clone.
  // WIN64-LABEL: define weak_odr dso_local {{.*}} @"?f@C@Test12@@W7EAAPEAUB@2@HZZ"(
  // WIN64: call %{{.*}}* @"?makeC@Test12@@YAPEAUC@1@XZ"()
  // WIN64: getelementptr inbounds i8, i8* %{{.*}}, i32 8
  //
  // Musttail call back to the A implementation after this adjustment from B to A.
  // WIN64-LABEL: define linkonce_odr dso_local %{{.*}}* @"?f@C@Test12@@W7EAAPEAU12@HZZ"(
  // WIN64: getelementptr i8, i8* %{{[^,]*}}, i32 -8
  // WIN64: musttail call {{.*}} @"?f@C@Test12@@UEAAPEAU12@HZZ"(
  C c;
}

// PR13832
namespace Test13 {
  struct B1 {
    virtual B1 &foo1();
  };
  struct Pad1 {
    virtual ~Pad1();
  };
  struct Proxy1 : Pad1, B1 {
    virtual ~Proxy1();
  };
  struct D : virtual Proxy1 {
    virtual ~D();
    virtual D &foo1();
  };
  D& D::foo1() {
    return *this;
  }
  // CHECK: define {{.*}} @_ZTcvn8_n32_v8_n24_N6Test131D4foo1Ev
  // CHECK-DBG-NOT: dbg.declare
  // CHECK: getelementptr inbounds i8, i8* {{.*}}, i64 -8
  // CHECK: getelementptr inbounds i8, i8* {{.*}}, i64 -32
  // CHECK: getelementptr inbounds i8, i8* {{.*}}, i64 -24
  // CHECK: getelementptr inbounds i8, i8* {{.*}}, i64 8
  // CHECK: ret %"struct.Test13::D"*

  // WIN64-LABEL: define weak_odr dso_local nonnull align 8 dereferenceable(8) %"struct.Test13::D"* @"?foo1@D@Test13@@$4PPPPPPPE@A@EAAAEAUB1@2@XZ"(
  //    This adjustment.
  // WIN64: getelementptr inbounds i8, i8* {{.*}}, i64 -12
  //    Call implementation.
  // WIN64: call {{.*}} @"?foo1@D@Test13@@UEAAAEAU12@XZ"(i8* {{.*}})
  //    Virtual + nonvirtual return adjustment.
  // WIN64: load i32*, i32** %{{[^,]*}}, align 8
  // WIN64: getelementptr inbounds i32, i32* %{{[^,]*}}, i32 1
  // WIN64: load i32, i32* %{{[^,]*}}, align 4
  // WIN64: getelementptr inbounds i8, i8* %{{[^,]*}}, i32 %{{[^,]*}}
}

namespace Test14 {
  class A {
    virtual void f();
  };
  class B {
    virtual void f();
  };
  class C : public A, public B  {
    virtual void f();
  };
  void C::f() {
  }
  // CHECK: define void @_ZThn8_N6Test141C1fEv({{.*}}) unnamed_addr [[NUW:#[0-9]+]]
  // CHECK-DBG-NOT: dbg.declare
  // CHECK: ret void
}

// Varargs non-covariant thunk test.
// PR18098
namespace Test15 {
  struct A {
    virtual ~A();
  };
  struct B {
    virtual void f(int x, ...);
  };
  struct C : A, B {
    virtual void c();
    virtual void f(int x, ...);
  };
  void C::c() {}

  // C::c
  // CHECK-CLONE: declare void @_ZN6Test151C1fEiz
  // non-virtual thunk to C::f
  // CHECK-CLONE: declare void @_ZThn8_N6Test151C1fEiz

  // If we have musttail, then we emit the thunk as available_externally.
  // CHECK-TAIL: declare void @_ZN6Test151C1fEiz
  // CHECK-TAIL: define available_externally void @_ZThn8_N6Test151C1fEiz({{.*}})
  // CHECK-TAIL: musttail call void (%"struct.Test15::C"*, i32, ...) @_ZN6Test151C1fEiz({{.*}}, ...)

  // MS C++ ABI doesn't use a thunk, so this case isn't interesting.
}

namespace Test16 {
struct A {
  virtual ~A();
};
struct B {
  virtual void foo();
};
struct C : public A, public B {
  void foo() {}
};
struct D : public C {
  ~D();
};
D::~D() {}
// CHECK: define linkonce_odr void @_ZThn8_N6Test161C3fooEv({{.*}}) {{.*}} comdat
// CHECK-DBG-NOT: dbg.declare
// CHECK: ret void
}

namespace Test17 {
class A {
  virtual void f(const char *, ...);
};
class B {
  virtual void f(const char *, ...);
};
class C : A, B {
  virtual void anchor();
  void f(const char *, ...) override;
};
// Key method and object anchor vtable for Itanium and MSVC.
void C::anchor() {}
C c;

// CHECK-CLONE-LABEL: declare void @_ZThn8_N6Test171C1fEPKcz(

// CHECK-TAIL-LABEL: define available_externally void @_ZThn8_N6Test171C1fEPKcz(
// CHECK-TAIL: getelementptr inbounds i8, i8* %{{.*}}, i64 -8
// CHECK-TAIL: musttail call {{.*}} @_ZN6Test171C1fEPKcz({{.*}}, ...)

// MSVC-LABEL: define linkonce_odr dso_local void @"?f@C@Test17@@G7EAAXPEBDZZ"
// MSVC-SAME: (%"class.Test17::C"* %this, i8* %[[ARG:[^,]+]], ...)
// MSVC: getelementptr i8, i8* %{{.*}}, i32 -8
// MSVC: musttail call void (%"class.Test17::C"*, i8*, ...) @"?f@C@Test17@@EEAAXPEBDZZ"(%"class.Test17::C"* %{{.*}}, i8* %[[ARG]], ...)
}

/**** The following has to go at the end of the file ****/

// checking without opt
// CHECK-NONOPT-LABEL: define internal void @_ZThn8_N6Test4B12_GLOBAL__N_11C1fEv(
// CHECK-NONOPT-NOT: comdat

// This is from Test5:
// CHECK-NONOPT-LABEL: define linkonce_odr void @_ZTv0_n24_N5Test51B1fEv

// This is from Test10:
// CHECK-NONOPT-LABEL: define linkonce_odr void @_ZN6Test101C3fooEv
// CHECK-NONOPT-LABEL: define linkonce_odr void @_ZThn8_N6Test101C3fooEv

// Checking with opt
// CHECK-OPT-LABEL: define internal void @_ZThn8_N6Test4B12_GLOBAL__N_11C1fEv(%"struct.Test4B::(anonymous namespace)::C"* %this) unnamed_addr #0 align 2

// This is from Test5:
// CHECK-OPT-LABEL: define linkonce_odr void @_ZTv0_n24_N5Test51B1fEv

// This is from Test10:
// CHECK-OPT-LABEL: define linkonce_odr void @_ZN6Test101C3fooEv
// CHECK-OPT-LABEL: define linkonce_odr void @_ZThn8_N6Test101C3fooEv

// This is from Test10:
// WIN64-LABEL: define linkonce_odr dso_local void @"?foo@C@Test10@@UEAAXXZ"(
// WIN64-LABEL: define linkonce_odr dso_local void @"?foo@C@Test10@@W7EAAXXZ"(

// CHECK-NONOPT: attributes [[NUW]] = { noinline nounwind optnone uwtable{{.*}} }
// CHECK-OPT: attributes [[NUW]] = { nounwind uwtable{{.*}} }