clang/test/CodeGen/attr-function-return.c

   1 // RUN: %clang_cc1 -std=gnu2x -triple x86_64-linux-gnu %s -emit-llvm -o - \
   2 // RUN:   -Werror=ignored-attributes \
   3 // RUN:   | FileCheck %s --check-prefixes=CHECK,CHECK-NOM
   4 // RUN: %clang_cc1 -std=gnu2x -triple x86_64-linux-gnu %s -emit-llvm -o - \
   5 // RUN:   -Werror=ignored-attributes -mfunction-return=keep \
   6 // RUN:   | FileCheck %s --check-prefixes=CHECK,CHECK-KEEP
   7 // RUN: %clang_cc1 -std=gnu2x -triple x86_64-linux-gnu %s -emit-llvm -o - \
   8 // RUN:   -Werror=ignored-attributes -mfunction-return=thunk-extern \
   9 // RUN:   | FileCheck %s --check-prefixes=CHECK,CHECK-EXTERN
  10 // RUN: %clang_cc1 -std=gnu2x -triple x86_64-linux-gnu %s -emit-llvm -o - \
  11 // RUN:  -mfunction-return=thunk-extern -coverage-data-file=/dev/null \
  12 // RUN:   | FileCheck %s --check-prefix=CHECK-GCOV
  13 // RUN: %clang_cc1 -std=gnu2x -triple x86_64-linux-gnu %s -emit-llvm -o - \
  14 // RUN:  -mfunction-return=thunk-extern -fsanitize=address \
  15 // RUN:   | FileCheck %s --check-prefix=CHECK-ASAN
  16 // RUN: %clang_cc1 -std=gnu2x -triple x86_64-linux-gnu %s -emit-llvm -o - \
  17 // RUN:  -mfunction-return=thunk-extern -fsanitize=thread \
  18 // RUN:   | FileCheck %s --check-prefix=CHECK-TSAN
  19
  20 #if !__has_attribute(function_return)
  21 #error "missing attribute support for function_return"
  22 #endif
  23
  24 // CHECK: @keep() [[KEEP:#[0-9]+]]
  25 __attribute__((function_return("keep"))) void keep(void) {}
  26
  27 // CHECK: @keep2() [[KEEP]]
  28 [[gnu::function_return("keep")]] void keep2(void) {}
  29
  30 // CHECK: @thunk_extern() [[EXTERN:#[0-9]+]]
  31 __attribute__((function_return("thunk-extern"))) void thunk_extern(void) {}
  32
  33 // CHECK: @thunk_extern2() [[EXTERN]]
  34 [[gnu::function_return("thunk-extern")]] void thunk_extern2(void) {}
  35
  36 // CHECK: @double_thunk_keep() [[KEEP]]
  37 // clang-format off
  38 __attribute__((function_return("thunk-extern")))
  39 __attribute__((function_return("keep")))
  40 void double_thunk_keep(void) {}
  41
  42 // CHECK: @double_thunk_keep2() [[KEEP]]
  43 [[gnu::function_return("thunk-extern")]][[gnu::function_return("keep")]]
  44 void double_thunk_keep2(void) {}
  45
  46 // CHECK: @double_keep_thunk() [[EXTERN]]
  47 __attribute__((function_return("keep")))
  48 __attribute__((function_return("thunk-extern")))
  49 void double_keep_thunk(void) {}
  50
  51 // CHECK: @double_keep_thunk2() [[EXTERN]]
  52 [[gnu::function_return("keep")]][[gnu::function_return("thunk-extern")]]
  53 void double_keep_thunk2(void) {}
  54
  55 // CHECK: @thunk_keep() [[KEEP]]
  56 __attribute__((function_return("thunk-extern"), function_return("keep")))
  57 void thunk_keep(void) {}
  58
  59 // CHECK: @thunk_keep2() [[KEEP]]
  60 [[gnu::function_return("thunk-extern"), gnu::function_return("keep")]]
  61 void thunk_keep2(void) {}
  62
  63 // CHECK: @keep_thunk() [[EXTERN]]
  64 __attribute__((function_return("keep"), function_return("thunk-extern")))
  65 void keep_thunk(void) {}
  66
  67 // CHECK: @keep_thunk2() [[EXTERN]]
  68 [[gnu::function_return("keep"), gnu::function_return("thunk-extern")]]
  69 void keep_thunk2(void) {}
  70 // clang-format on
  71
  72 void undef(void);
  73 // CHECK: @undef() [[KEEP]]
  74 __attribute__((function_return("keep"))) void undef(void) {}
  75
  76 void undef2(void);
  77 // CHECK: @undef2() [[EXTERN]]
  78 __attribute__((function_return("thunk-extern"))) void undef2(void) {}
  79
  80 __attribute__((function_return("thunk-extern"))) void change_def(void);
  81 // CHECK: @change_def() [[KEEP]]
  82 __attribute__((function_return("keep"))) void change_def(void) {}
  83
  84 __attribute__((function_return("keep"))) void change_def2(void);
  85 // CHECK: @change_def2() [[EXTERN]]
  86 __attribute__((function_return("thunk-extern"))) void change_def2(void) {}
  87
  88 __attribute__((function_return("thunk-extern"))) void change_def3(void);
  89 // CHECK: @change_def3() [[KEEP]]
  90 [[gnu::function_return("keep")]] void change_def3(void) {}
  91
  92 [[gnu::function_return("keep")]] void change_def4(void);
  93 // CHECK: @change_def4() [[EXTERN]]
  94 __attribute__((function_return("thunk-extern"))) void change_def4(void) {}
  95
  96 // When there is no -mfunction-return= flag set (NOM) or it's set to keep,
  97 // we don't emit anything into the IR for unattributed functions.
  98
  99 // CHECK-NOM:    @no_attrs() [[NOATTR:#[0-9]+]]
 100 // CHECK-KEEP:   @no_attrs() [[NOATTR:#[0-9]+]]
 101 // CHECK-EXTERN: @no_attrs() [[EXTERN]]
 102 void no_attrs(void) {}
 103
 104 // Test synthetic functions.
 105 // CHECK-GCOV: @__llvm_gcov_writeout() unnamed_addr [[EXTERNGCOV:#[0-9]+]]
 106 // CHECK-GCOV: @__llvm_gcov_reset() unnamed_addr [[EXTERNGCOV]]
 107 // CHECK-GCOV: @__llvm_gcov_init() unnamed_addr [[EXTERNGCOV]]
 108 // CHECK-ASAN: @asan.module_ctor() [[EXTERNASAN:#[0-9]+]]
 109 // CHECK-TSAN: @tsan.module_ctor() [[EXTERNTSAN:#[0-9]+]]
 110
 111 // CHECK-NOM-NOT:  [[NOATTR]] = {{.*}}fn_ret_thunk_extern
 112 // CHECK-KEEP-NOT: [[NOATTR]] = {{.*}}fn_ret_thunk_extern
 113 // CHECK: [[EXTERN]] = {{.*}}fn_ret_thunk_extern
 114 // CHECK-GCOV: [[EXTERNGCOV]] = {{.*}}fn_ret_thunk_extern
 115 // CHECK-ASAN: [[EXTERNASAN]] = {{.*}}fn_ret_thunk_extern
 116 // CHECK-TSAN: [[EXTERNTSAN]] = {{.*}}fn_ret_thunk_extern