diff --git a/clang-tools-extra/clangd/IncludeFixer.cpp b/clang-tools-extra/clangd/IncludeFixer.cpp
index 69ec27a024e1fa..7fcb01e6e957a8 100644
--- a/clang-tools-extra/clangd/IncludeFixer.cpp
+++ b/clang-tools-extra/clangd/IncludeFixer.cpp
@@ -198,7 +198,6 @@ std::vector<Fix> IncludeFixer::fix(DiagnosticsEngine::Level DiagLevel,
   case diag::err_no_member_template_suggest:
   case diag::warn_implicit_function_decl:
   case diag::ext_implicit_function_decl_c99:
-  case diag::err_opencl_implicit_function_decl:
     dlog("Unresolved name at {0}, last typo was {1}",
          Info.getLocation().printToString(Info.getSourceManager()),
          LastUnresolvedName
diff --git a/clang/include/clang/Basic/DiagnosticSemaKinds.td b/clang/include/clang/Basic/DiagnosticSemaKinds.td
index 69093a6e51dc38..084d67af570e20 100644
--- a/clang/include/clang/Basic/DiagnosticSemaKinds.td
+++ b/clang/include/clang/Basic/DiagnosticSemaKinds.td
@@ -10198,8 +10198,6 @@ def err_opencl_scalar_type_rank_greater_than_vector_type : Error<
     "element. (%0 and %1)">;
 def err_bad_kernel_param_type : Error<
   "%0 cannot be used as the type of a kernel parameter">;
-def err_opencl_implicit_function_decl : Error<
-  "implicit declaration of function %0 is invalid in OpenCL">;
 def err_record_with_pointers_kernel_param : Error<
   "%select{struct|union}0 kernel parameters may not contain pointers">;
 def note_within_field_of_type : Note<
diff --git a/clang/include/clang/Basic/LangOptions.h b/clang/include/clang/Basic/LangOptions.h
index 9d852d72e593f2..eb4c7c4c7d93e1 100644
--- a/clang/include/clang/Basic/LangOptions.h
+++ b/clang/include/clang/Basic/LangOptions.h
@@ -527,6 +527,12 @@ class LangOptions : public LangOptionsBase {
     return CPlusPlus || C2x || DisableKNRFunctions;
   }
 
+  /// Returns true if implicit function declarations are allowed in the current
+  /// language mode.
+  bool implicitFunctionsAllowed() const {
+    return !requiresStrictPrototypes() && !OpenCL;
+  }
+
   /// Check if return address signing is enabled.
   bool hasSignReturnAddress() const {
     return getSignReturnAddressScope() != SignReturnAddressScopeKind::None;
diff --git a/clang/lib/Sema/SemaDecl.cpp b/clang/lib/Sema/SemaDecl.cpp
index da6d35ca98a44d..5890bbc7d574bb 100644
--- a/clang/lib/Sema/SemaDecl.cpp
+++ b/clang/lib/Sema/SemaDecl.cpp
@@ -934,8 +934,9 @@ Sema::NameClassification Sema::ClassifyName(Scope *S, CXXScopeSpec &SS,
       //   appeared.
       //
       // We also allow this in C99 as an extension. However, this is not
-      // allowed in C2x as there are no functions without prototypes there.
-      if (!getLangOpts().C2x) {
+      // allowed in all language modes as functions without prototypes may not
+      // be supported.
+      if (getLangOpts().implicitFunctionsAllowed()) {
         if (NamedDecl *D = ImplicitlyDefineFunction(NameLoc, *Name, S))
           return NameClassification::NonType(D);
       }
@@ -15273,7 +15274,8 @@ void Sema::ActOnFinishDelayedAttribute(Scope *S, Decl *D,
 NamedDecl *Sema::ImplicitlyDefineFunction(SourceLocation Loc,
                                           IdentifierInfo &II, Scope *S) {
   // It is not valid to implicitly define a function in C2x.
-  assert(!LangOpts.C2x && "Cannot implicitly define a function in C2x");
+  assert(LangOpts.implicitFunctionsAllowed() &&
+         "Implicit function declarations aren't allowed in this language mode");
 
   // Find the scope in which the identifier is injected and the corresponding
   // DeclContext.
@@ -15318,8 +15320,6 @@ NamedDecl *Sema::ImplicitlyDefineFunction(SourceLocation Loc,
   if (II.getName().startswith("__builtin_"))
     diag_id = diag::warn_builtin_unknown;
   // OpenCL v2.0 s6.9.u - Implicit function declaration is not supported.
-  else if (getLangOpts().OpenCL)
-    diag_id = diag::err_opencl_implicit_function_decl;
   else if (getLangOpts().C99)
     diag_id = diag::ext_implicit_function_decl_c99;
   else
diff --git a/clang/lib/Sema/SemaExpr.cpp b/clang/lib/Sema/SemaExpr.cpp
index 90f96a3660dea3..67012527888d3a 100644
--- a/clang/lib/Sema/SemaExpr.cpp
+++ b/clang/lib/Sema/SemaExpr.cpp
@@ -2553,10 +2553,10 @@ Sema::ActOnIdExpression(Scope *S, CXXScopeSpec &SS,
   if (R.isAmbiguous())
     return ExprError();
 
-  // This could be an implicitly declared function reference (legal in C90,
-  // extension in C99, forbidden in C++ and C2x).
-  if (R.empty() && HasTrailingLParen && II && !getLangOpts().CPlusPlus &&
-      !getLangOpts().C2x) {
+  // This could be an implicitly declared function reference if the language
+  // mode allows it as a feature.
+  if (R.empty() && HasTrailingLParen && II &&
+      getLangOpts().implicitFunctionsAllowed()) {
     NamedDecl *D = ImplicitlyDefineFunction(NameLoc, *II, S);
     if (D) R.addDecl(D);
   }
diff --git a/clang/test/Driver/default-includes.cl b/clang/test/Driver/default-includes.cl
index 2596ccca96382a..5b96052a54cf1d 100644
--- a/clang/test/Driver/default-includes.cl
+++ b/clang/test/Driver/default-includes.cl
@@ -8,6 +8,6 @@
 void test() {
 int i = get_global_id(0);
 #ifdef NOINC
-//expected-error@-2{{implicit declaration of function 'get_global_id' is invalid in OpenCL}}
+//expected-error@-2{{use of undeclared identifier 'get_global_id'}}
 #endif
 }
diff --git a/clang/test/Preprocessor/macro_variadic.cl b/clang/test/Preprocessor/macro_variadic.cl
index 04e96e3c214650..ee710e7b06dec0 100644
--- a/clang/test/Preprocessor/macro_variadic.cl
+++ b/clang/test/Preprocessor/macro_variadic.cl
@@ -17,11 +17,6 @@ int printf(__constant const char *st, ...);
 
 void foo(void) {
   NO_VAR_FUNC(1, 2, 3);
-  VAR_FUNC(1, 2, 3);
-#if !__OPENCL_CPP_VERSION__
-// expected-error@-2{{implicit declaration of function 'func' is invalid in OpenCL}}
-#else
-// expected-error@-4{{use of undeclared identifier 'func'}}
-#endif
+  VAR_FUNC(1, 2, 3); // expected-error {{use of undeclared identifier 'func'}}
   VAR_PRINTF("%i", 1);
 }
diff --git a/clang/test/SemaOpenCL/arm-integer-dot-product.cl b/clang/test/SemaOpenCL/arm-integer-dot-product.cl
index d61c6a1c506a44..bff3ab4aa42f83 100644
--- a/clang/test/SemaOpenCL/arm-integer-dot-product.cl
+++ b/clang/test/SemaOpenCL/arm-integer-dot-product.cl
@@ -7,13 +7,13 @@ void test_negative() {
     short2 sa16, sb16;
     uint ur;
     int sr;
-    ur = arm_dot(ua8, ub8); // expected-error{{implicit declaration of function 'arm_dot' is invalid in OpenCL}}
-    sr = arm_dot(sa8, sb8);
-    ur = arm_dot_acc(ua8, ub8, ur); // expected-error{{implicit declaration of function 'arm_dot_acc' is invalid in OpenCL}}
-    sr = arm_dot_acc(sa8, sb8, sr);
-    ur = arm_dot_acc(ua16, ub16, ur);
-    sr = arm_dot_acc(sa16, sb16, sr);
-    ur = arm_dot_acc_sat(ua8, ub8, ur); // expected-error{{implicit declaration of function 'arm_dot_acc_sat' is invalid in OpenCL}}
-    sr = arm_dot_acc_sat(sa8, sb8, sr);
+    ur = arm_dot(ua8, ub8); // expected-error{{use of undeclared identifier 'arm_dot'}}
+    sr = arm_dot(sa8, sb8); // expected-error{{use of undeclared identifier 'arm_dot'}}
+    ur = arm_dot_acc(ua8, ub8, ur); // expected-error{{use of undeclared identifier 'arm_dot_acc'}}
+    sr = arm_dot_acc(sa8, sb8, sr); // expected-error{{use of undeclared identifier 'arm_dot_acc'}}
+    ur = arm_dot_acc(ua16, ub16, ur); // expected-error{{use of undeclared identifier 'arm_dot_acc'}}
+    sr = arm_dot_acc(sa16, sb16, sr); // expected-error{{use of undeclared identifier 'arm_dot_acc'}}
+    ur = arm_dot_acc_sat(ua8, ub8, ur); // expected-error{{use of undeclared identifier 'arm_dot_acc_sat'}}
+    sr = arm_dot_acc_sat(sa8, sb8, sr); // expected-error{{use of undeclared identifier 'arm_dot_acc_sat'}}
 }
 
diff --git a/clang/test/SemaOpenCL/clang-builtin-version.cl b/clang/test/SemaOpenCL/clang-builtin-version.cl
index 71c6da56f862d1..ec6eecee3106ca 100644
--- a/clang/test/SemaOpenCL/clang-builtin-version.cl
+++ b/clang/test/SemaOpenCL/clang-builtin-version.cl
@@ -6,50 +6,60 @@
 
 kernel void dse_builtins(void) {
   int tmp;
-  enqueue_kernel(tmp, tmp, tmp, ^(void) { // expected-error{{implicit declaration of function 'enqueue_kernel' is invalid in OpenCL}}
+  enqueue_kernel(tmp, tmp, tmp, ^(void) { // expected-error{{use of undeclared identifier 'enqueue_kernel'}}
     return;
   });
-  unsigned size = get_kernel_work_group_size(^(void) { // expected-error{{implicit declaration of function 'get_kernel_work_group_size' is invalid in OpenCL}}
+  unsigned size = get_kernel_work_group_size(^(void) { // expected-error{{use of undeclared identifier 'get_kernel_work_group_size'}}
     return;
   });
-  size = get_kernel_preferred_work_group_size_multiple(^(void) { // expected-error{{implicit declaration of function 'get_kernel_preferred_work_group_size_multiple' is invalid in OpenCL}}
+  size = get_kernel_preferred_work_group_size_multiple(^(void) { // expected-error{{use of undeclared identifier 'get_kernel_preferred_work_group_size_multiple'}}
     return;
   });
 #if (__OPENCL_C_VERSION__ >= CL_VERSION_3_0) && !defined(__opencl_c_device_enqueue)
 // expected-error@-10{{support disabled - compile with -fblocks or for OpenCL C 2.0 or OpenCL C 3.0 with __opencl_c_device_enqueue feature}}
-// expected-error@-8{{support disabled - compile with -fblocks or for OpenCL C 2.0 or OpenCL C 3.0 with __opencl_c_device_enqueue feature}}
-// expected-error@-6{{support disabled - compile with -fblocks or for OpenCL C 2.0 or OpenCL C 3.0 with __opencl_c_device_enqueue feature}}
+// FIXME: the typo correction for the undeclared identifiers finds alternative
+// suggestions, but instantiating the typo correction causes us to
+// re-instantiate the argument to the call, which triggers the support
+// diagnostic a second time.
+// expected-error@-12 2{{support disabled - compile with -fblocks or for OpenCL C 2.0 or OpenCL C 3.0 with __opencl_c_device_enqueue feature}}
+// expected-error@-10 2{{support disabled - compile with -fblocks or for OpenCL C 2.0 or OpenCL C 3.0 with __opencl_c_device_enqueue feature}}
 #endif
 }
 
 void pipe_builtins(void) {
   int tmp;
 
-  foo(void); // expected-error{{implicit declaration of function 'foo' is invalid in OpenCL}}
-  // expected-error@-1{{expected expression}}
-  boo(); // expected-error{{implicit declaration of function 'boo' is invalid in OpenCL}}
+  // FIXME: the typo correction for this case goes off the rails and tries to
+  // convert this mistake into a for loop instead of a local function
+  // declaration.
+  foo(void); // expected-error{{use of undeclared identifier 'foo'; did you mean 'for'?}}
+             // expected-error@-1{{expected identifier or '('}}
+             // expected-note@-2{{to match this '('}}
+  boo(); // expected-error{{use of undeclared identifier 'boo'}}
+         // expected-error@-1{{expected ';' in 'for' statement specifier}}
 
-  read_pipe(tmp, tmp);  // expected-error{{implicit declaration of function 'read_pipe' is invalid in OpenCL}}
-  write_pipe(tmp, tmp); // expected-error{{implicit declaration of function 'write_pipe' is invalid in OpenCL}}
+  read_pipe(tmp, tmp);  // expected-error{{use of undeclared identifier 'read_pipe'}}
+                        // expected-error@-1{{expected ')'}}
+  write_pipe(tmp, tmp); // expected-error{{use of undeclared identifier 'write_pipe'}}
 
-  reserve_read_pipe(tmp, tmp);  // expected-error{{implicit declaration of function 'reserve_read_pipe' is invalid in OpenCL}}
-  reserve_write_pipe(tmp, tmp); // expected-error{{implicit declaration of function 'reserve_write_pipe' is invalid in OpenCL}}
+  reserve_read_pipe(tmp, tmp);  // expected-error{{use of undeclared identifier 'reserve_read_pipe'}}
+  reserve_write_pipe(tmp, tmp); // expected-error{{use of undeclared identifier 'reserve_write_pipe'}}
 
-  work_group_reserve_read_pipe(tmp, tmp);  // expected-error{{implicit declaration of function 'work_group_reserve_read_pipe' is invalid in OpenCL}}
-  work_group_reserve_write_pipe(tmp, tmp); // expected-error{{implicit declaration of function 'work_group_reserve_write_pipe' is invalid in OpenCL}}
+  work_group_reserve_read_pipe(tmp, tmp);  // expected-error{{use of undeclared identifier 'work_group_reserve_read_pipe'}}
+  work_group_reserve_write_pipe(tmp, tmp); // expected-error{{use of undeclared identifier 'work_group_reserve_write_pipe'}}
 
-  sub_group_reserve_write_pipe(tmp, tmp); // expected-error{{implicit declaration of function 'sub_group_reserve_write_pipe' is invalid in OpenCL}}
-  sub_group_reserve_read_pipe(tmp, tmp);  // expected-error{{implicit declaration of function 'sub_group_reserve_read_pipe' is invalid in OpenCL}}
+  sub_group_reserve_write_pipe(tmp, tmp); // expected-error{{use of undeclared identifier 'sub_group_reserve_write_pipe'}}
+  sub_group_reserve_read_pipe(tmp, tmp);  // expected-error{{use of undeclared identifier 'sub_group_reserve_read_pipe'}}
 
-  commit_read_pipe(tmp, tmp);  // expected-error{{implicit declaration of function 'commit_read_pipe' is invalid in OpenCL}}
-  commit_write_pipe(tmp, tmp); // expected-error{{implicit declaration of function 'commit_write_pipe' is invalid in OpenCL}}
+  commit_read_pipe(tmp, tmp);  // expected-error{{use of undeclared identifier 'commit_read_pipe'}}
+  commit_write_pipe(tmp, tmp); // expected-error{{use of undeclared identifier 'commit_write_pipe'}}
 
-  work_group_commit_read_pipe(tmp, tmp);  // expected-error{{implicit declaration of function 'work_group_commit_read_pipe' is invalid in OpenCL}}
-  work_group_commit_write_pipe(tmp, tmp); // expected-error{{implicit declaration of function 'work_group_commit_write_pipe' is invalid in OpenCL}}
+  work_group_commit_read_pipe(tmp, tmp);  // expected-error{{use of undeclared identifier 'work_group_commit_read_pipe'}}
+  work_group_commit_write_pipe(tmp, tmp); // expected-error{{use of undeclared identifier 'work_group_commit_write_pipe'}}
 
-  sub_group_commit_write_pipe(tmp, tmp); // expected-error{{implicit declaration of function 'sub_group_commit_write_pipe' is invalid in OpenCL}}
-  sub_group_commit_read_pipe(tmp, tmp);  // expected-error{{implicit declaration of function 'sub_group_commit_read_pipe' is invalid in OpenCL}}
+  sub_group_commit_write_pipe(tmp, tmp); // expected-error{{use of undeclared identifier 'sub_group_commit_write_pipe'}}
+  sub_group_commit_read_pipe(tmp, tmp);  // expected-error{{use of undeclared identifier 'sub_group_commit_read_pipe'}}
 
-  get_pipe_num_packets(tmp); // expected-error{{implicit declaration of function 'get_pipe_num_packets' is invalid in OpenCL}}
-  get_pipe_max_packets(tmp); // expected-error{{implicit declaration of function 'get_pipe_max_packets' is invalid in OpenCL}}
+  get_pipe_num_packets(tmp); // expected-error{{use of undeclared identifier 'get_pipe_num_packets'}}
+  get_pipe_max_packets(tmp); // expected-error{{use of undeclared identifier 'get_pipe_max_packets'}}
 }
diff --git a/clang/test/SemaOpenCL/fdeclare-opencl-builtins.cl b/clang/test/SemaOpenCL/fdeclare-opencl-builtins.cl
index 416f5342ef22e6..737632fdf07b15 100644
--- a/clang/test/SemaOpenCL/fdeclare-opencl-builtins.cl
+++ b/clang/test/SemaOpenCL/fdeclare-opencl-builtins.cl
@@ -194,7 +194,7 @@ void test_atomics_without_scope_device(volatile __generic atomic_int *a_int) {
   int d;
 
   atomic_exchange(a_int, d);
-  // expected-error@-1{{implicit declaration of function 'atomic_exchange' is invalid in OpenCL}}
+  // expected-error@-1{{use of undeclared identifier 'atomic_exchange'}}
 
   atomic_exchange_explicit(a_int, d, memory_order_seq_cst);
   // expected-error@-1{{no matching function for call to 'atomic_exchange_explicit'}}
@@ -225,7 +225,7 @@ kernel void basic_conversion(void) {
 
 #ifdef NO_FP64
   (void)convert_double_rtp(f);
-  // expected-error@-1{{implicit declaration of function 'convert_double_rtp' is invalid in OpenCL}}
+  // expected-error@-1{{use of undeclared identifier 'convert_double_rtp'}}
 #else
   double d;
   f = convert_float(d);
@@ -240,11 +240,10 @@ kernel void basic_conversion_neg(void) {
 
   f = convert_float_sat(i);
 #if !defined(__OPENCL_CPP_VERSION__)
-  // expected-error@-2{{implicit declaration of function 'convert_float_sat' is invalid in OpenCL}}
-  // expected-error@-3{{implicit conversion from 'int' to 'float' may lose precision}}
+  // expected-error@-2{{use of undeclared identifier 'convert_float_sat'}}
 #else
-  // expected-error@-5{{use of undeclared identifier 'convert_float_sat'; did you mean 'convert_float'?}}
-  // expected-note@-6{{'convert_float' declared here}}
+  // expected-error@-4{{use of undeclared identifier 'convert_float_sat'; did you mean 'convert_float'?}}
+  // expected-note@-5{{'convert_float' declared here}}
 #endif
 }
 
@@ -312,8 +311,7 @@ kernel void basic_image_writeonly(write_only image1d_buffer_t image_write_only_i
 kernel void basic_subgroup(global uint *out) {
   out[0] = get_sub_group_size();
 #if __OPENCL_C_VERSION__ <= CL_VERSION_1_2 && !defined(__OPENCL_CPP_VERSION__)
-  // expected-error@-2{{implicit declaration of function 'get_sub_group_size' is invalid in OpenCL}}
-  // expected-error@-3{{implicit conversion changes signedness}}
+  // expected-error@-2{{use of undeclared identifier 'get_sub_group_size'}}
 #endif
 
 // Only test when the base header is included, because we need the enum declarations.
@@ -328,12 +326,10 @@ kernel void extended_subgroup(global uint4 *out, global int *scalar, global char
   scalar[1] = sub_group_clustered_reduce_logical_xor(2, 4);
   *c2 = sub_group_broadcast(*c2, 2);
 #if __OPENCL_C_VERSION__ < CL_VERSION_2_0 && !defined(__OPENCL_CPP_VERSION__)
-  // expected-error@-5{{implicit declaration of function 'get_sub_group_eq_mask' is invalid in OpenCL}}
-  // expected-error@-6{{implicit conversion changes signedness}}
-  // expected-error@-6{{implicit declaration of function 'sub_group_non_uniform_scan_inclusive_or' is invalid in OpenCL}}
-  // expected-error@-6{{implicit declaration of function 'sub_group_clustered_reduce_logical_xor' is invalid in OpenCL}}
-  // expected-error@-6{{implicit declaration of function 'sub_group_broadcast' is invalid in OpenCL}}
-  // expected-error@-7{{implicit conversion loses integer precision}}
+  // expected-error@-5{{use of undeclared identifier 'get_sub_group_eq_mask'}}
+  // expected-error@-5{{use of undeclared identifier 'sub_group_non_uniform_scan_inclusive_or'}}
+  // expected-error@-5{{use of undeclared identifier 'sub_group_clustered_reduce_logical_xor'}}
+  // expected-error@-5{{use of undeclared identifier 'sub_group_broadcast'}}
 #endif
 }
 
@@ -376,7 +372,7 @@ kernel void basic_work_item(void) {
 
   get_enqueued_local_size(ui);
 #if !defined(__OPENCL_CPP_VERSION__) && __OPENCL_C_VERSION__ < CL_VERSION_2_0
-// expected-error@-2{{implicit declaration of function 'get_enqueued_local_size' is invalid in OpenCL}}
+// expected-error@-2{{use of undeclared identifier 'get_enqueued_local_size'}}
 #endif
 }
 
diff --git a/clang/test/SemaOpenCL/invalid-block.cl b/clang/test/SemaOpenCL/invalid-block.cl
index ddc0f80d1da447..6c918d302f8018 100644
--- a/clang/test/SemaOpenCL/invalid-block.cl
+++ b/clang/test/SemaOpenCL/invalid-block.cl
@@ -35,7 +35,7 @@ bl_t f3b(bl_t bl);
 void f3c(void) {
   // Block with a block argument.
   int (^const bl2)(bl_t block_arg) = ^(void) { // expected-error{{declaring function parameter of type '__private bl_t' (aka 'int (__generic ^const __private)(void)') is not allowed}}
-    return block_arg(); // expected-error{{implicit declaration of function 'block_arg' is invalid in OpenCL}}
+    return block_arg(); // expected-error{{use of undeclared identifier 'block_arg'}}
   };
 }
 
diff --git a/clang/test/SemaOpenCL/to_addr_builtin.cl b/clang/test/SemaOpenCL/to_addr_builtin.cl
index 5b1f7839cdbce4..5cd74885aa9df9 100644
--- a/clang/test/SemaOpenCL/to_addr_builtin.cl
+++ b/clang/test/SemaOpenCL/to_addr_builtin.cl
@@ -14,37 +14,36 @@ void test(void) {
 
   glob = to_global(glob, loc);
 #if (__OPENCL_C_VERSION__ < CL_VERSION_2_0) || (__OPENCL_C_VERSION__ >= CL_VERSION_3_0 && !defined(__opencl_c_generic_address_space))
-  // expected-error@-2{{implicit declaration of function 'to_global' is invalid in OpenCL}}
-  // expected-warning@-3{{incompatible integer to pointer conversion assigning to '__global int *__private' from 'int'}}
+  // expected-error@-2{{use of undeclared identifier 'to_global'}}
 #else
-  // expected-error@-5{{too many arguments to function call, expected 1, have 2}}
+  // expected-error@-4{{too many arguments to function call, expected 1, have 2}}
 #endif
 
   int x;
   glob = to_global(x);
 #if (__OPENCL_C_VERSION__ < CL_VERSION_2_0) || (__OPENCL_C_VERSION__ >= CL_VERSION_3_0 && !defined(__opencl_c_generic_address_space))
-  // expected-warning@-2{{incompatible integer to pointer conversion assigning to '__global int *__private' from 'int'}}
+  // expected-error@-2{{use of undeclared identifier 'to_global'}}
 #else
   // expected-error@-4{{invalid argument x to function: 'to_global', expecting a generic pointer argument}}
 #endif
 
   glob = to_global(con);
 #if (__OPENCL_C_VERSION__ < CL_VERSION_2_0) || (__OPENCL_C_VERSION__ >= CL_VERSION_3_0 && !defined(__opencl_c_generic_address_space))
-  // expected-warning@-2{{incompatible integer to pointer conversion assigning to '__global int *__private' from 'int'}}
+  // expected-error@-2{{use of undeclared identifier 'to_global'}}
 #else
   // expected-error@-4{{invalid argument con to function: 'to_global', expecting a generic pointer argument}}
 #endif
 
   glob = to_global(con_typedef);
 #if (__OPENCL_C_VERSION__ < CL_VERSION_2_0) || (__OPENCL_C_VERSION__ >= CL_VERSION_3_0 && !defined(__opencl_c_generic_address_space))
-  // expected-warning@-2{{incompatible integer to pointer conversion assigning to '__global int *__private' from 'int'}}
+  // expected-error@-2{{use of undeclared identifier 'to_global'}}
 #else
   // expected-error@-4{{invalid argument con_typedef to function: 'to_global', expecting a generic pointer argument}}
 #endif
 
   loc = to_global(glob);
 #if (__OPENCL_C_VERSION__ < CL_VERSION_2_0) || (__OPENCL_C_VERSION__ >= CL_VERSION_3_0 && !defined(__opencl_c_generic_address_space))
-  // expected-warning@-2{{incompatible integer to pointer conversion assigning to '__local int *__private' from 'int'}}
+  // expected-error@-2{{use of undeclared identifier 'to_global'}}
 #else
   // expected-error@-4{{assigning '__global int *' to '__local int *__private' changes address space of pointer}}
   // expected-warning@-5{{passing non-generic address space pointer to to_global may cause dynamic conversion affecting performance}}
@@ -52,24 +51,22 @@ void test(void) {
 
   loc = to_private(glob);
 #if (__OPENCL_C_VERSION__ < CL_VERSION_2_0) || (__OPENCL_C_VERSION__ >= CL_VERSION_3_0 && !defined(__opencl_c_generic_address_space))
-  // expected-error@-2{{implicit declaration of function 'to_private' is invalid in OpenCL}}
-  // expected-warning@-3{{incompatible integer to pointer conversion assigning to '__local int *__private' from 'int'}}
+  // expected-error@-2{{use of undeclared identifier 'to_private'}}
 #else
-  // expected-error@-5{{assigning '__private int *' to '__local int *__private' changes address space of pointer}}
-  // expected-warning@-6{{passing non-generic address space pointer to to_private may cause dynamic conversion affecting performance}}
+  // expected-error@-4{{assigning '__private int *' to '__local int *__private' changes address space of pointer}}
+  // expected-warning@-5{{passing non-generic address space pointer to to_private may cause dynamic conversion affecting performance}}
 #endif
 
   loc = to_local(glob);
 #if (__OPENCL_C_VERSION__ < CL_VERSION_2_0) || (__OPENCL_C_VERSION__ >= CL_VERSION_3_0 && !defined(__opencl_c_generic_address_space))
-  // expected-error@-2{{implicit declaration of function 'to_local' is invalid in OpenCL}}
-  // expected-warning@-3{{incompatible integer to pointer conversion assigning to '__local int *__private' from 'int'}}
+  // expected-error@-2{{use of undeclared identifier 'to_local'}}
 #else
-  // expected-warning@-5{{passing non-generic address space pointer to to_local may cause dynamic conversion affecting performance}}
+  // expected-warning@-4{{passing non-generic address space pointer to to_local may cause dynamic conversion affecting performance}}
 #endif
 
   priv = to_global(glob);
 #if (__OPENCL_C_VERSION__ < CL_VERSION_2_0) || (__OPENCL_C_VERSION__ >= CL_VERSION_3_0 && !defined(__opencl_c_generic_address_space))
-  // expected-warning@-2{{incompatible integer to pointer conversion assigning to '__private int *__private' from 'int'}}
+  // expected-error@-2{{use of undeclared identifier 'to_global'}}
 #else
   // expected-error@-4{{assigning '__global int *' to '__private int *__private' changes address space of pointer}}
   // expected-warning@-5{{passing non-generic address space pointer to to_global may cause dynamic conversion affecting performance}}
@@ -77,7 +74,7 @@ void test(void) {
 
   priv = to_private(glob);
 #if (__OPENCL_C_VERSION__ < CL_VERSION_2_0) || (__OPENCL_C_VERSION__ >= CL_VERSION_3_0 && !defined(__opencl_c_generic_address_space))
-  // expected-warning@-2{{incompatible integer to pointer conversion assigning to '__private int *__private' from 'int'}}
+  // expected-error@-2{{use of undeclared identifier 'to_private'}}
 #else
   // expected-warning@-4{{passing non-generic address space pointer to to_private may cause dynamic conversion affecting performance}}
 #endif
@@ -85,7 +82,7 @@ void test(void) {
 
   priv = to_local(glob);
 #if (__OPENCL_C_VERSION__ < CL_VERSION_2_0) || (__OPENCL_C_VERSION__ >= CL_VERSION_3_0 && !defined(__opencl_c_generic_address_space))
-  // expected-warning@-2{{incompatible integer to pointer conversion assigning to '__private int *__private' from 'int'}}
+  // expected-error@-2{{use of undeclared identifier 'to_local'}}
 #else
   // expected-error@-4{{assigning '__local int *' to '__private int *__private' changes address space of pointer}}
   // expected-warning@-5{{passing non-generic address space pointer to to_local may cause dynamic conversion affecting performance}}
@@ -93,14 +90,14 @@ void test(void) {
 
   glob = to_global(glob);
 #if (__OPENCL_C_VERSION__ < CL_VERSION_2_0) || (__OPENCL_C_VERSION__ >= CL_VERSION_3_0 && !defined(__opencl_c_generic_address_space))
-  // expected-warning@-2{{incompatible integer to pointer conversion assigning to '__global int *__private' from 'int'}}
+  // expected-error@-2{{use of undeclared identifier 'to_global'}}
 #else
   // expected-warning@-4{{passing non-generic address space pointer to to_global may cause dynamic conversion affecting performance}}
 #endif
 
   glob = to_private(glob);
 #if (__OPENCL_C_VERSION__ < CL_VERSION_2_0) || (__OPENCL_C_VERSION__ >= CL_VERSION_3_0 && !defined(__opencl_c_generic_address_space))
-  // expected-warning@-2{{incompatible integer to pointer conversion assigning to '__global int *__private' from 'int'}}
+  // expected-error@-2{{use of undeclared identifier 'to_private'}}
 #else
   // expected-error@-4{{assigning '__private int *' to '__global int *__private' changes address space of pointer}}
   // expected-warning@-5{{passing non-generic address space pointer to to_private may cause dynamic conversion affecting performance}}
@@ -108,7 +105,7 @@ void test(void) {
 
   glob = to_local(glob);
 #if (__OPENCL_C_VERSION__ < CL_VERSION_2_0) || (__OPENCL_C_VERSION__ >= CL_VERSION_3_0 && !defined(__opencl_c_generic_address_space))
-  // expected-warning@-2{{incompatible integer to pointer conversion assigning to '__global int *__private' from 'int'}}
+  // expected-error@-2{{use of undeclared identifier 'to_local'}}
 #else
   // expected-error@-4{{assigning '__local int *' to '__global int *__private' changes address space of pointer}}
   // expected-warning@-5{{passing non-generic address space pointer to to_local may cause dynamic conversion affecting performance}}
@@ -116,7 +113,7 @@ void test(void) {
 
   global char *glob_c = to_global(loc);
 #if (__OPENCL_C_VERSION__ < CL_VERSION_2_0) || (__OPENCL_C_VERSION__ >= CL_VERSION_3_0 && !defined(__opencl_c_generic_address_space))
-  // expected-warning@-2{{incompatible integer to pointer conversion initializing '__global char *__private' with an expression of type 'int'}}
+  // expected-error@-2{{use of undeclared identifier 'to_global'}}
 #else
   // expected-warning@-4{{incompatible pointer types initializing '__global char *__private' with an expression of type '__global int *'}}
   // expected-warning@-5{{passing non-generic address space pointer to to_global may cause dynamic conversion affecting performance}}
@@ -124,7 +121,7 @@ void test(void) {
 
   glob_wrong_ty = to_global(glob);
 #if (__OPENCL_C_VERSION__ < CL_VERSION_2_0) || (__OPENCL_C_VERSION__ >= CL_VERSION_3_0 && !defined(__opencl_c_generic_address_space))
-  // expected-warning@-2{{incompatible integer to pointer conversion assigning to '__global float *__private' from 'int'}}
+  // expected-error@-2{{use of undeclared identifier 'to_global'}}
 #else
   // expected-warning@-4{{incompatible pointer types assigning to '__global float *__private' from '__global int *'}}
   // expected-warning@-5{{passing non-generic address space pointer to to_global may cause dynamic conversion affecting performance}}