Downgrade implicit int and implicit function declaration to warning only

The changes in Clang 15.0.0 which enabled these diagnostics as a
warning which defaulted to an error caused disruption for people
working on distributions such as Gentoo. There was an explicit request
to downgrade these to be warning-only in Clang 15.0.1 with the
expectation that Clang 16 will default the diagnostics to an error.

See
https://discourse.llvm.org/t/configure-script-breakage-with-the-new-werror-implicit-function-declaration/65213
for more details on the discussion.

See https://reviews.llvm.org/D133800 for the public review of these
changes.

clang/docs/ReleaseNotes.rst

@@ -37,6 +37,22 @@ here. Generic improvements to Clang as a whole or to its underlying
 infrastructure are described first, followed by language-specific
 sections with improvements to Clang's support for those languages.
 
+Potentially Breaking Changes
+============================
+These changes are ones which we think may surprise users when upgrading to
+Clang |release| because of the opportunity they pose for disruption to existing
+code bases.
+
+- The ``-Wimplicit-function-declaration`` and ``-Wimplicit-int`` warning
+  diagnostics are now enabled by default in C99, C11, and C17. As of C2x,
+  support for implicit function declarations and implicit int has been removed,
+  and the warning options will have no effect. Specifying ``-Wimplicit-int`` in
+  C89 mode will now issue warnings instead of being a noop.
+  *NOTE* these warnings are expected to default to an error in Clang 16. We
+  recommend that projects using configure scripts verify the results do not
+  change before/after setting ``-Werror=implicit-function-declarations`` or
+  ``-Wimplicit-int`` to avoid incompatibility with Clang 16.
+
 Major New Features
 ------------------
 
@@ -245,18 +261,6 @@ Improvements to Clang's diagnostics
   without a prototype and with no arguments is an invalid redeclaration of a
   function with a prototype. e.g., ``void f(int); void f() {}`` is now properly
   diagnosed.
-- The ``-Wimplicit-function-declaration`` warning diagnostic now defaults to
-  an error in C99 and later. Prior to C2x, it may be downgraded to a warning
-  with ``-Wno-error=implicit-function-declaration``, or disabled entirely with
-  ``-Wno-implicit-function-declaration``. As of C2x, support for implicit
-  function declarations has been removed, and the warning options will have no
-  effect.
-- The ``-Wimplicit-int`` warning diagnostic now defaults to an error in C99 and
-  later. Prior to C2x, it may be downgraded to a warning with
-  ``-Wno-error=implicit-int``, or disabled entirely with ``-Wno-implicit-int``.
-  As of C2x, support for implicit int has been removed, and the warning options
-  will have no effect. Specifying ``-Wimplicit-int`` in C89 mode will now issue
-  warnings instead of being a noop.
 - No longer issue a "declaration specifiers missing, defaulting to int"
   diagnostic in C89 mode because it is not an extension in C89, it was valid
   code. The diagnostic has been removed entirely as it did not have a

clang/include/clang/Basic/DiagnosticSemaKinds.td

@@ -419,7 +419,7 @@ def warn_implicit_function_decl : Warning<
   InGroup<ImplicitFunctionDeclare>, DefaultIgnore;
 def ext_implicit_function_decl_c99 : ExtWarn<
   "call to undeclared function %0; ISO C99 and later do not support implicit "
-  "function declarations">, InGroup<ImplicitFunctionDeclare>, DefaultError;
+  "function declarations">, InGroup<ImplicitFunctionDeclare>;
 def note_function_suggestion : Note<"did you mean %0?">;
 
 def err_ellipsis_first_param : Error<
@@ -705,7 +705,7 @@ def ext_implicit_lib_function_decl : ExtWarn<
 def ext_implicit_lib_function_decl_c99 : ExtWarn<
   "call to undeclared library function '%0' with type %1; ISO C99 and later "
   "do not support implicit function declarations">,
-  InGroup<ImplicitFunctionDeclare>, DefaultError;
+  InGroup<ImplicitFunctionDeclare>;
 def note_include_header_or_declare : Note<
   "include the header <%0> or explicitly provide a declaration for '%1'">;
 def note_previous_builtin_declaration : Note<"%0 is a builtin with type %1">;
@@ -4359,7 +4359,7 @@ def err_ident_list_in_fn_declaration : Error<
   "a parameter list without types is only allowed in a function definition">;
 def ext_param_not_declared : ExtWarn<
   "parameter %0 was not declared, defaults to 'int'; ISO C99 and later do not "
-  "support implicit int">, InGroup<ImplicitInt>, DefaultError;
+  "support implicit int">, InGroup<ImplicitInt>;
 def err_param_default_argument : Error<
   "C does not support default arguments">;
 def err_param_default_argument_redefinition : Error<
@@ -10029,7 +10029,7 @@ def warn_receiver_forward_class : Warning<
 def note_method_sent_forward_class : Note<"method %0 is used for the forward class">;
 def ext_missing_type_specifier : ExtWarn<
   "type specifier missing, defaults to 'int'; ISO C99 and later do not support "
-  "implicit int">, InGroup<ImplicitInt>, DefaultError;
+  "implicit int">, InGroup<ImplicitInt>;
 def err_missing_type_specifier : Error<
   "a type specifier is required for all declarations">;
 def err_decimal_unsupported : Error<

clang/test/C/drs/dr0xx.c

@@ -110,7 +110,7 @@ struct dr007_b;
  * of treated as declaring a parameter of type 'int (*)(dr009_t);'
  */
 typedef int dr009_t;
-void dr009_f((dr009_t)); /* c99untilc2x-error {{type specifier missing, defaults to 'int'; ISO C99 and later do not support implicit int}}
+void dr009_f((dr009_t)); /* c99untilc2x-warning {{type specifier missing, defaults to 'int'; ISO C99 and later do not support implicit int}}
                             c2xandup-error {{a type specifier is required for all declarations}} */
 
 /* WG14 DR010:

clang/test/C/drs/dr1xx.c

@@ -369,7 +369,7 @@ void dr163(void) {
   int i;
   i = undeclared; /* expected-error {{use of undeclared identifier 'undeclared'}} */
   sdfsdfsf = 1;   /* expected-error {{use of undeclared identifier 'sdfsdfsf'}} */
-  i = also_undeclared(); /* c99untilc2x-error {{call to undeclared function 'also_undeclared'; ISO C99 and later do not support implicit function declarations}}
+  i = also_undeclared(); /* c99untilc2x-warning {{call to undeclared function 'also_undeclared'; ISO C99 and later do not support implicit function declarations}}
                             c2xandup-error {{use of undeclared identifier 'also_undeclared'}}
                           */
 }

clang/test/CodeGen/PowerPC/builtins-ppc-p8vector.c

@@ -143,7 +143,7 @@ void test1() {
   res_vui = vec_mergee(vui, vui);
 // CHECK: @llvm.ppc.altivec.vperm
 // CHECK-LE: @llvm.ppc.altivec.vperm
-// CHECK-PPC: error: call to undeclared function 'vec_mergee'
+// CHECK-PPC: warning: call to undeclared function 'vec_mergee'
 
   res_vbll = vec_mergee(vbll, vbll);
 // CHECK: @llvm.ppc.altivec.vperm
@@ -177,7 +177,7 @@ void test1() {
   res_vui = vec_mergeo(vui, vui);
 // CHECK: @llvm.ppc.altivec.vperm
 // CHECK-LE: @llvm.ppc.altivec.vperm
-// CHECK-PPC: error: call to undeclared function 'vec_mergeo'
+// CHECK-PPC: warning: call to undeclared function 'vec_mergeo'
 
   /* vec_cmpeq */
   res_vbll = vec_cmpeq(vbll, vbll);
@@ -403,7 +403,7 @@ void test1() {
   res_vsc = vec_cntlz(vsc);
 // CHECK: call <16 x i8> @llvm.ctlz.v16i8(<16 x i8> %{{.+}}, i1 false)
 // CHECK-LE: call <16 x i8> @llvm.ctlz.v16i8(<16 x i8> %{{.+}}, i1 false)
-// CHECK-PPC: error: call to undeclared function 'vec_cntlz'
+// CHECK-PPC: warning: call to undeclared function 'vec_cntlz'
 
   res_vuc = vec_cntlz(vuc);
 // CHECK: call <16 x i8> @llvm.ctlz.v16i8(<16 x i8> %{{.+}}, i1 false)
@@ -754,19 +754,19 @@ void test1() {
   res_vsi = vec_vpksdss(vsll, vsll);
 // CHECK: llvm.ppc.altivec.vpksdss
 // CHECK-LE: llvm.ppc.altivec.vpksdss
-// CHECK-PPC: error: call to undeclared function 'vec_vpksdss'
+// CHECK-PPC: warning: call to undeclared function 'vec_vpksdss'
 
   /* vec_vpksdus */
   res_vui = vec_vpksdus(vsll, vsll);
 // CHECK: llvm.ppc.altivec.vpksdus
 // CHECK-LE: llvm.ppc.altivec.vpksdus
-// CHECK-PPC: error: call to undeclared function 'vec_vpksdus'
+// CHECK-PPC: warning: call to undeclared function 'vec_vpksdus'
 
   /* vec_vpkudum */
   res_vsi = vec_vpkudum(vsll, vsll);
 // CHECK: vperm
 // CHECK-LE: vperm
-// CHECK-PPC: error: call to undeclared function 'vec_vpkudum'
+// CHECK-PPC: warning: call to undeclared function 'vec_vpkudum'
 
   res_vui = vec_vpkudum(vull, vull);
 // CHECK: vperm
@@ -775,13 +775,13 @@ void test1() {
   res_vui = vec_vpkudus(vull, vull);
 // CHECK: llvm.ppc.altivec.vpkudus
 // CHECK-LE: llvm.ppc.altivec.vpkudus
-// CHECK-PPC: error: call to undeclared function 'vec_vpkudus'
+// CHECK-PPC: warning: call to undeclared function 'vec_vpkudus'
 
   /* vec_vupkhsw */
   res_vsll = vec_vupkhsw(vsi);
 // CHECK: llvm.ppc.altivec.vupkhsw
 // CHECK-LE: llvm.ppc.altivec.vupklsw
-// CHECK-PPC: error: call to undeclared function 'vec_vupkhsw'
+// CHECK-PPC: warning: call to undeclared function 'vec_vupkhsw'
 
   res_vbll = vec_vupkhsw(vbi);
 // CHECK: llvm.ppc.altivec.vupkhsw
@@ -791,7 +791,7 @@ void test1() {
   res_vsll = vec_vupklsw(vsi);
 // CHECK: llvm.ppc.altivec.vupklsw
 // CHECK-LE: llvm.ppc.altivec.vupkhsw
-// CHECK-PPC: error: call to undeclared function 'vec_vupklsw'
+// CHECK-PPC: warning: call to undeclared function 'vec_vupklsw'
 
   res_vbll = vec_vupklsw(vbi);
 // CHECK: llvm.ppc.altivec.vupklsw
@@ -845,7 +845,7 @@ void test1() {
 // CHECK: xor <16 x i8> [[T1]], <i8 -1, i8 -1, i8 -1, i8 -1, i8 -1, i8 -1, i8 -1, i8 -1, i8 -1, i8 -1, i8 -1, i8 -1, i8 -1, i8 -1, i8 -1, i8 -1>
 // CHECK-LE: [[T1:%.+]] = and <16 x i8>
 // CHECK-LE: xor <16 x i8> [[T1]], <i8 -1, i8 -1, i8 -1, i8 -1, i8 -1, i8 -1, i8 -1, i8 -1, i8 -1, i8 -1, i8 -1, i8 -1, i8 -1, i8 -1, i8 -1, i8 -1>
-// CHECK-PPC: error: call to undeclared function 'vec_nand'
+// CHECK-PPC: warning: call to undeclared function 'vec_nand'
 
   res_vbc = vec_nand(vbc, vbc);
 // CHECK: [[T1:%.+]] = and <16 x i8>
@@ -937,7 +937,7 @@ void test1() {
 // CHECK: or <16 x i8> {{%.+}}, [[T1]]
 // CHECK-LE: [[T1:%.+]] = xor <16 x i8> {{%.+}}, <i8 -1, i8 -1, i8 -1, i8 -1, i8 -1, i8 -1, i8 -1, i8 -1, i8 -1, i8 -1, i8 -1, i8 -1, i8 -1, i8 -1, i8 -1, i8 -1>
 // CHECK-LE: or <16 x i8> {{%.+}}, [[T1]]
-// CHECK-PPC: error: call to undeclared function 'vec_orc'
+// CHECK-PPC: warning: call to undeclared function 'vec_orc'
 
   res_vsc = vec_orc(vsc, vbc);
 // CHECK: [[T1:%.+]] = xor <16 x i8> {{%.+}}, <i8 -1, i8 -1, i8 -1, i8 -1, i8 -1, i8 -1, i8 -1, i8 -1, i8 -1, i8 -1, i8 -1, i8 -1, i8 -1, i8 -1, i8 -1, i8 -1>
@@ -1166,7 +1166,7 @@ void test1() {
   res_vsll = vec_vbpermq(vuc, vuc);
 // CHECK: llvm.ppc.altivec.vbpermq
 // CHECK-LE: llvm.ppc.altivec.vbpermq
-// CHECK-PPC: error: call to undeclared function 'vec_vbpermq'
+// CHECK-PPC: warning: call to undeclared function 'vec_vbpermq'
 
   /* vec_vgbbd */
   res_vsc = vec_vgbbd(vsc);
@@ -1176,12 +1176,12 @@ void test1() {
   res_vuc = vec_vgbbd(vuc);
 // CHECK: llvm.ppc.altivec.vgbbd
 // CHECK-LE: llvm.ppc.altivec.vgbbd
-// CHECK-PPC: error: call to undeclared function 'vec_vgbbd'
+// CHECK-PPC: warning: call to undeclared function 'vec_vgbbd'
 
   res_vuc = vec_gb(vuc);
 // CHECK: llvm.ppc.altivec.vgbbd
 // CHECK-LE: llvm.ppc.altivec.vgbbd
-// CHECK-PPC: error: call to undeclared function 'vec_gb'
+// CHECK-PPC: warning: call to undeclared function 'vec_gb'
 
   res_vsll = vec_gbb(vsll);
 // CHECK: llvm.ppc.altivec.vgbbd

clang/test/CodeGen/builtins-arm-msvc-compat-only.c

@@ -1,6 +1,6 @@
 // RUN: %clang_cc1 -triple thumbv7-windows -fms-extensions -emit-llvm -o - %s \
 // RUN:     | FileCheck %s -check-prefix CHECK-MSVC
-// RUN: not %clang_cc1 -triple armv7-eabi -emit-llvm %s -o /dev/null 2>&1 \
+// RUN: %clang_cc1 -triple armv7-eabi -emit-llvm %s -o /dev/null 2>&1 \
 // RUN:     | FileCheck %s -check-prefix CHECK-EABI
 // REQUIRES: arm-registered-target
 
@@ -9,7 +9,7 @@ void emit() {
 }
 
 // CHECK-MSVC: call void asm sideeffect ".inst.n 0xDEFE", ""()
-// CHECK-EABI: error: call to undeclared function '__emit'
+// CHECK-EABI: warning: call to undeclared function '__emit'
 
 void emit_truncated() {
   __emit(0x11110000); // movs r0, r0

clang/test/CodeGen/neon-crypto.c

@@ -14,7 +14,7 @@
 
 uint8x16_t test_vaeseq_u8(uint8x16_t data, uint8x16_t key) {
   // CHECK-LABEL: @test_vaeseq_u8
-  // CHECK-NO-CRYPTO: error: call to undeclared function 'vaeseq_u8'
+  // CHECK-NO-CRYPTO: warning: call to undeclared function 'vaeseq_u8'
   return vaeseq_u8(data, key);
   // CHECK: call <16 x i8> @llvm.{{arm.neon|aarch64.crypto}}.aese(<16 x i8> %data, <16 x i8> %key)
 }

clang/test/Driver/cxx_for_opencl.clcpp

@@ -13,6 +13,6 @@ kernel void k(){
   auto a = get_local_id(1);
 #ifndef __OPENCL_CPP_VERSION__
 //expected-error@-2{{OpenCL C version 2.0 does not support the 'auto' storage class specifier}}
-//expected-error@-3{{type specifier missing, defaults to 'int'}}
+//expected-warning@-3{{type specifier missing, defaults to 'int'}}
 #endif
 }

clang/test/FixIt/fixit.c

@@ -29,7 +29,7 @@ int array0[5] = { [3] 3 }; // expected-warning {{GNU 'missing ='}}
 
 // CHECK: int x
 // CHECK: int y
-void f1(x, y) // expected-error 2{{was not declared, defaults to 'int'; ISO C99 and later do not support implicit int}}
+void f1(x, y) // expected-warning 2{{was not declared, defaults to 'int'; ISO C99 and later do not support implicit int}}
 {
 }
 

clang/test/Frontend/fixed_point_errors.c

@@ -228,9 +228,9 @@ void CheckSuffixOnIntegerLiterals(void) {
 
   // Using auto
   auto auto_fract = 0r;  // expected-error{{invalid suffix 'r' on integer constant}}
-                         // expected-error@-1{{type specifier missing, defaults to 'int'}}
+                         // expected-warning@-1{{type specifier missing, defaults to 'int'}}
   auto auto_accum = 0k;  // expected-error{{invalid suffix 'k' on integer constant}}
-                         // expected-error@-1{{type specifier missing, defaults to 'int'}}
+                         // expected-warning@-1{{type specifier missing, defaults to 'int'}}
 }
 
 // Ok conversions

clang/test/Frontend/fixed_point_not_enabled.c

@@ -11,7 +11,7 @@ unsigned long _Accum u_long_accum;    // expected-error{{compile with '-ffixed-p
 // Aliased fixed point types
 short _Accum short_accum;             // expected-error{{compile with '-ffixed-point' to enable fixed point types}}
 _Accum accum;                         // expected-error{{compile with '-ffixed-point' to enable fixed point types}}
-                                      // expected-error@-1{{type specifier missing, defaults to 'int'}}
+                                      // expected-warning@-1{{type specifier missing, defaults to 'int'}}
 long _Accum long_accum;               // expected-error{{compile with '-ffixed-point' to enable fixed point types}}
 
 // Cannot use fixed point suffixes

clang/test/Frontend/system-header-line-directive.c

@@ -3,7 +3,7 @@
 #include <noline.h>
 #include <line-directive-in-system.h>
 
-// expected-error@line-directive.h:* {{type specifier missing, defaults to 'int'}}
+// expected-warning@line-directive.h:* {{type specifier missing, defaults to 'int'}}
 #include "line-directive.h"
 
 // This tests that "#line" directives in system headers preserve system

clang/test/Headers/arm-cmse-header-ns.c

@@ -1,4 +1,4 @@
-// RUN: not %clang_cc1 -triple thumbv8m.base-eabi -fsyntax-only %s 2>&1 | FileCheck --check-prefix=CHECK-c %s
+// RUN: %clang_cc1 -triple thumbv8m.base-eabi -fsyntax-only %s 2>&1 | FileCheck --check-prefix=CHECK-c %s
 // RUN: not %clang_cc1 -triple thumbv8m.base-eabi -fsyntax-only -x c++ %s 2>&1 | FileCheck --check-prefix=CHECK-cpp %s
 
 #include <arm_cmse.h>
@@ -16,10 +16,10 @@ void func(callback_t fptr, void *p)
   cmse_TTAT(p);
   cmse_TTA_fptr(fptr);
   cmse_TTAT_fptr(fptr);
-// CHECK-c: error: call to undeclared function 'cmse_TTA'
-// CHECK-c: error: call to undeclared function 'cmse_TTAT'
-// CHECK-c: error: call to undeclared function 'cmse_TTA_fptr'
-// CHECK-c: error: call to undeclared function 'cmse_TTAT_fptr'
+// CHECK-c: warning: call to undeclared function 'cmse_TTA'
+// CHECK-c: warning: call to undeclared function 'cmse_TTAT'
+// CHECK-c: warning: call to undeclared function 'cmse_TTA_fptr'
+// CHECK-c: warning: call to undeclared function 'cmse_TTAT_fptr'
 // CHECK-cpp: error: use of undeclared identifier 'cmse_TTA'
 // CHECK-cpp: error: use of undeclared identifier 'cmse_TTAT'
 // CHECK-cpp: error: use of undeclared identifier 'cmse_TTA_fptr'

clang/test/Modules/config_macros.m

@@ -5,7 +5,7 @@
 }
 
 char *test_bar(void) {
-  return bar(); // expected-error{{call to undeclared function 'bar'; ISO C99 and later do not support implicit function declarations}} \
+  return bar(); // expected-warning{{call to undeclared function 'bar'; ISO C99 and later do not support implicit function declarations}} \
                 // expected-error{{incompatible integer to pointer conversion}}
 }
 

clang/test/Modules/malformed-overload.m

@@ -1,6 +1,6 @@
 // RUN: rm -rf %t
 // RUN: %clang_cc1 -fsyntax-only -I%S/Inputs/malformed-overload -fmodules -fimplicit-module-maps -fmodules-cache-path=%t -Wno-strict-prototypes -verify %s
-NSLog(@"%@", path); // expected-error {{expected parameter declarator}} expected-error {{expected ')'}} expected-error {{type specifier missing}} expected-warning {{incompatible redeclaration}} expected-note {{to match this '('}} expected-note {{'NSLog' is a builtin with type}}
+NSLog(@"%@", path); // expected-error {{expected parameter declarator}} expected-error {{expected ')'}} expected-warning {{type specifier missing}} expected-warning {{incompatible redeclaration}} expected-note {{to match this '('}} expected-note {{'NSLog' is a builtin with type}}
 #import "X.h"
 
 @class NSString;

clang/test/Modules/modulemap-locations.m

@@ -12,9 +12,7 @@
 
 void test(void) {
   will_be_found1();
-  wont_be_found1(); // expected-error{{call to undeclared function 'wont_be_found1'; ISO C99 and later do not support implicit function declarations}} \
-                       expected-note {{did you mean 'will_be_found1'?}} \
-                       expected-note@Inputs/ModuleMapLocations/Module_ModuleMap/a.h:1 {{'will_be_found1' declared here}}
+  wont_be_found1(); // expected-warning{{call to undeclared function 'wont_be_found1'; ISO C99 and later do not support implicit function declarations}}
   will_be_found2();
-  wont_be_found2(); // expected-error{{call to undeclared function 'wont_be_found2'; ISO C99 and later do not support implicit function declarations}}
+  wont_be_found2(); // expected-warning{{call to undeclared function 'wont_be_found2'; ISO C99 and later do not support implicit function declarations}}
 }

clang/test/OpenMP/declare_mapper_messages.c

@@ -42,9 +42,9 @@ int fun(int arg) {
       {}
 #pragma omp target map(mapper:vv)                                       // expected-error {{expected '(' after 'mapper'}}
       {}
-#pragma omp target map(mapper( :vv)                                     // expected-error {{expected expression}} expected-error {{expected ')'}} expected-error {{call to undeclared function 'mapper'}} expected-note {{to match this '('}}
+#pragma omp target map(mapper( :vv)                                     // expected-error {{expected expression}} expected-error {{expected ')'}} expected-warning {{call to undeclared function 'mapper'}} expected-note {{to match this '('}}
       {}
-#pragma omp target map(mapper(aa :vv)                                   // expected-error {{use of undeclared identifier 'aa'}} expected-error {{expected ')'}} expected-error {{call to undeclared function 'mapper'}} expected-note {{to match this '('}}
+#pragma omp target map(mapper(aa :vv)                                   // expected-error {{use of undeclared identifier 'aa'}} expected-error {{expected ')'}} expected-warning {{call to undeclared function 'mapper'}} expected-note {{to match this '('}}
       {}
 #pragma omp target map(mapper(ab) :vv)                                  // expected-error {{missing map type}} expected-error {{cannot find a valid user-defined mapper for type 'struct vec' with name 'ab'}}
       {}

clang/test/PCH/chain-macro-override.c

@@ -10,7 +10,7 @@ int foo(void) {
   f();
   g();
   h();
-  h2(); // expected-error {{call to undeclared function 'h2'; ISO C99 and later do not support implicit function declarations}}
+  h2(); // expected-warning {{call to undeclared function 'h2'; ISO C99 and later do not support implicit function declarations}}
   h3();
   return x;
 }

clang/test/Parser/altivec.c

@@ -97,8 +97,8 @@ vector unsigned long int v_uli;     // nonaix-warning {{Use of 'long' with '__ve
 // These should have warnings.
 __vector long double  vv_ld;        // expected-error {{cannot use 'long double' with '__vector'}}
 vector long double  v_ld;           // expected-error {{cannot use 'long double' with '__vector'}}
-vector bool v_b;                    // expected-error {{type specifier missing, defaults to 'int'}}
-vector __bool v___b;                // expected-error {{type specifier missing, defaults to 'int'}}
+vector bool v_b;                    // expected-warning {{type specifier missing, defaults to 'int'}}
+vector __bool v___b;                // expected-warning {{type specifier missing, defaults to 'int'}}
 
 // These should have errors.
 #ifndef __VSX__