to268 updated this revision to Diff 541538.
to268 marked 17 inline comments as done.
to268 added a comment.
Added recommendations from @aaron.ballman.
Adjusting diagnostic messages still need to be done.
Repository:
rG LLVM Github Monorepo
CHANGES SINCE LAST ACTION
https://reviews.llvm.org/D133289/new/
https://reviews.llvm.org/D133289
Files:
clang/include/clang/Basic/DiagnosticSemaKinds.td
clang/lib/Parse/ParseDecl.cpp
clang/lib/Sema/DeclSpec.cpp
clang/lib/Sema/SemaDecl.cpp
clang/lib/Sema/SemaTemplateDeduction.cpp
clang/test/C/C2x/n3007.c
clang/test/CodeGen/auto.c
clang/test/Parser/c2x-auto.c
clang/test/Sema/c2x-auto.c
clang/www/c_status.html
Index: clang/www/c_status.html
===================================================================
--- clang/www/c_status.html
+++ clang/www/c_status.html
@@ -1190,12 +1190,12 @@
<tr>
<td>Underspecified object definitions</td>
<td><a href="https://www.open-std.org/jtc1/sc22/wg14/www/docs/n3006.htm";>N3006</a></td>
- <td class="unknown" align="center">Unknown</td>
+ <td class="none" align="center">No</td>
</tr>
<tr>
<td>Type inference for object declarations</td>
<td><a href="https://www.open-std.org/jtc1/sc22/wg14/www/docs/n3007.htm";>N3007</a></td>
- <td class="none" align="center">No</td>
+ <td class="unreleased" align="center">Clang 17</td>
</tr>
<tr>
<td>constexpr for object definitions</td>
Index: clang/test/Sema/c2x-auto.c
===================================================================
--- /dev/null
+++ clang/test/Sema/c2x-auto.c
@@ -0,0 +1,136 @@
+// RUN: %clang_cc1 -std=c2x -verify -pedantic -Wno-comments %s
+
+void test_basic_types(void) {
+ auto undefined; // expected-error {{declaration of variable 'undefined' with deduced type 'auto' requires an initializer}}
+ auto auto_int = 4;
+ auto auto_long = 4UL;
+ signed auto a = 1L; // expected-error {{'auto' cannot be signed or unsigned}}
+
+ _Static_assert(_Generic(auto_int, int : 1));
+ _Static_assert(_Generic(auto_long, unsigned long : 1));
+}
+
+void test_complex_types(void) {
+ _Complex auto i = 12.0; // expected-error {{'_Complex auto' is invalid}}
+}
+
+void test_gnu_extensions(void) {
+ auto t = ({ // expected-warning {{use of GNU statement expression extension}}
+ auto b = 12;
+ b;
+ });
+ _Static_assert(_Generic(t, int : 1));
+}
+
+void test_sizeof_typeof(void) {
+ auto auto_size = sizeof(auto); // expected-error {{expected expression}}
+ typeof(auto) tpof = 4; // expected-error {{expected expression}}
+}
+
+void test_casts(void) {
+ auto int_cast = (int)(4 + 3);
+ auto double_cast = (double)(1 / 3);
+ auto long_cast = (long)(4UL + 3UL);
+ auto auto_cast = (auto)(4 + 3); // expected-error {{expected expression}}
+
+ _Static_assert(_Generic(int_cast, int : 1));
+ _Static_assert(_Generic(double_cast, double : 1));
+ _Static_assert(_Generic(long_cast, long : 1));
+}
+
+void test_compound_literral(void) {
+ auto int_cl = (int){13};
+ auto double_cl = (double){2.5};
+ auto array[] = { 1, 2, 3 }; // expected-error {{cannot use 'auto' with initializer list in C}}
+
+ auto auto_cl = (auto){13}; // expected-error {{expected expression}}
+
+ _Static_assert(_Generic(int_cl, int : 1));
+ _Static_assert(_Generic(double_cl, double : 1));
+}
+
+void test_array_pointers(void) {
+ double array[3] = { 0 };
+ auto a = array;
+ auto b = &array;
+
+ _Static_assert(_Generic(array, double * : 1));
+ _Static_assert(_Generic(a, double * : 1));
+ _Static_assert(_Generic(b, double (*)[3] : 1));
+}
+
+void test_typeof() {
+ int typeof_target();
+ auto result = (typeof(typeof_target())){12};
+
+ _Static_assert(_Generic(result, int : 1));
+}
+
+void test_qualifiers(const int y) {
+ const auto a = 12;
+ auto b = y;
+ static auto c = 1UL;
+ int* pa = &a; // expected-warning {{initializing 'int *' with an expression of type 'const int *' discards qualifiers}}
+ const int* pb = &b;
+ int* pc = &c; // expected-warning {{incompatible pointer types initializing 'int *' with an expression of type 'unsigned long *'}}
+
+ _Static_assert(_Generic(a, int : 1));
+ _Static_assert(_Generic(b, int : 1));
+ _Static_assert(_Generic(c, unsigned long : 1));
+ _Static_assert(_Generic(pa, int * : 1));
+ _Static_assert(_Generic(pb, const int * : 1));
+ _Static_assert(_Generic(pc, int * : 1));
+}
+
+void test_strings(void) {
+ auto str = "this is a string";
+ auto str2[] = "this is a string";
+ auto (str3) = "this is a string";
+ auto (((str4))) = "this is a string";
+
+ _Static_assert(_Generic(str, char * : 1));
+ _Static_assert(_Generic(str2, char * : 1));
+ _Static_assert(_Generic(str3, char * : 1));
+ _Static_assert(_Generic(str4, char * : 1));
+}
+
+void test_pointers(void) {
+ auto a = 12;
+ auto *ptr = &a; // expected-warning {{type inference of a declaration other than a plain identifier with optional trailing attributes is a Clang extension}}
+ auto *str = "this is a string"; // expected-warning {{type inference of a declaration other than a plain identifier with optional trailing attributes is a Clang extension}}
+ const auto *str2 = "this is a string"; // expected-warning {{type inference of a declaration other than a plain identifier with optional trailing attributes is a Clang extension}}
+ auto *b = &a; // expected-warning {{type inference of a declaration other than a plain identifier with optional trailing attributes is a Clang extension}}
+ *b = &a; // expected-error {{incompatible pointer to integer conversion assigning to 'int' from 'int *'; remove &}}
+ auto nptr = nullptr;
+
+ _Static_assert(_Generic(a, int : 1));
+ _Static_assert(_Generic(ptr, int * : 1));
+ _Static_assert(_Generic(str, char * : 1));
+ _Static_assert(_Generic(str2, const char * : 1));
+ _Static_assert(_Generic(b, int * : 1));
+}
+
+void test_prototypes(void) {
+ extern void foo(int a, int array[({ auto x = 12; x;})]); // expected-warning {{use of GNU statement expression extension}}
+}
+
+void test_scopes(void) {
+ double a = 7;
+ double b = 9;
+ {
+ auto a = a * a; // expected-error {{variable 'a' declared with deduced type 'auto' cannot appear in its own initializer}} \
+ expected-error {{variable 'a' declared with deduced type 'auto' cannot appear in its own initializer}}
+ }
+ {
+ auto b = a * a;
+ auto a = b;
+
+ _Static_assert(_Generic(b, double : 1));
+ _Static_assert(_Generic(a, double : 1));
+ }
+}
+
+[[clang::overloadable]] auto test(auto x) { // expected-error {{'auto' not allowed in function prototype}} \
+ expected-error {{'auto' not allowed in function return type}}
+ return x;
+}
Index: clang/test/Parser/c2x-auto.c
===================================================================
--- /dev/null
+++ clang/test/Parser/c2x-auto.c
@@ -0,0 +1,133 @@
+// RUN: %clang_cc1 -fsyntax-only -verify=expected,c2x -std=c2x %s
+// RUN: %clang_cc1 -fsyntax-only -verify=expected,c17 -std=c17 %s
+
+#define AUTO_MACRO(_NAME, ARG, ARG2, ARG3) \
+auto _NAME = ARG + (ARG2 / ARG3);
+
+struct S {
+ int a;
+ auto b; // c2x-error {{'auto' not allowed in struct member}} \
+ c17-error {{type name does not allow storage class to be specified}} \
+ c17-error {{type specifier missing, defaults to 'int'; ISO C99 and later do not support implicit int}}
+ union {
+ char c;
+ auto smth; // c2x-error {{'auto' not allowed in union member}} \
+ c17-error {{type name does not allow storage class to be specified}} \
+ c17-error {{type specifier missing, defaults to 'int'; ISO C99 and later do not support implicit int}}
+ } u;
+};
+
+enum E : auto { // c2x-error {{'auto' not allowed here}} \
+ c17-error {{expected a type}} \
+ c17-error {{type name does not allow storage class to be specified}}
+ One,
+ Two,
+ Tree,
+};
+
+auto basic_usage(auto auto) { // c2x-error {{'auto' not allowed in function prototype}} \
+ c2x-error {{'auto' not allowed in function return type}} \
+ c2x-error {{cannot combine with previous 'auto' declaration specifier}} \
+ c17-error {{invalid storage class specifier in function declarator}} \
+ c17-error {{illegal storage class on function}} \
+ c17-warning {{duplicate 'auto' declaration specifier}} \
+ c17-warning {{omitting the parameter name in a function definition is a C2x extension}} \
+ c17-error {{type specifier missing, defaults to 'int'; ISO C99 and later do not support implicit int}} \
+ c17-error {{type specifier missing, defaults to 'int'; ISO C99 and later do not support implicit int}}
+
+ auto = 4; // expected-error {{expected identifier or '('}}
+
+ auto a = 4; // c17-error {{type specifier missing, defaults to 'int'; ISO C99 and later do not support implicit int}}
+
+ auto auto aa = 12; // c2x-error {{cannot combine with previous 'auto' declaration specifier}} \
+ c17-warning {{duplicate 'auto' declaration specifier}} \
+ c17-error {{type specifier missing, defaults to 'int'; ISO C99 and later do not support implicit int}}
+
+ auto b[4]; // c2x-error {{'auto' not allowed in array declaration}} \
+ c17-error {{type specifier missing, defaults to 'int'; ISO C99 and later do not support implicit int}}
+
+ auto array[auto]; // expected-error {{expected expression}} \
+ c2x-error {{declaration of variable 'array' with deduced type 'auto' requires an initializer}} \
+ c17-error {{type specifier missing, defaults to 'int'; ISO C99 and later do not support implicit int}}
+
+ AUTO_MACRO(auto, 1, 2, 3); // c2x-error {{cannot combine with previous 'auto' declaration specifier}} \
+ expected-error {{expected identifier or '('}} \
+ c17-warning {{duplicate 'auto' declaration specifier}}
+
+ auto c = (auto)a; // expected-error {{expected expression}} \
+ c17-error {{type specifier missing, defaults to 'int'; ISO C99 and later do not support implicit int}}
+
+ auto ci = (auto){12}; // expected-error {{expected expression}} \
+ c17-error {{type specifier missing, defaults to 'int'; ISO C99 and later do not support implicit int}}
+
+ int auto_cxx_decl = auto(0); // expected-error {{expected expression}}
+
+ return c;
+}
+
+void structs(void) {
+ struct s_auto { auto a; }; // c2x-error {{'auto' not allowed in struct member}} \
+ c17-error {{type name does not allow storage class to be specified}} \
+ c17-error {{type specifier missing, defaults to 'int'; ISO C99 and later do not support implicit int}}
+
+ // FIXME: this should end up being rejected when we implement underspecified
+ // declarations in N3006.
+ auto s_int = (struct { int a; } *)0; // c17-error {{incompatible pointer to integer conversion initializing 'int' with an expression of type}} \
+ c17-error {{type specifier missing, defaults to 'int'; ISO C99 and later do not support implicit int}}
+
+ typedef auto auto_type; // c2x-error {{'auto' not allowed in typedef}} \
+ c17-error {{cannot combine with previous 'typedef' declaration specifier}} \
+ c17-error {{type specifier missing, defaults to 'int'; ISO C99 and later do not support implicit int}}
+}
+
+void sizeof_alignas(void) {
+ auto auto_size = sizeof(auto); // expected-error {{expected expression}} \
+ c17-error {{type specifier missing, defaults to 'int'; ISO C99 and later do not support implicit int}}
+}
+
+void generic_alignof_alignas(void) {
+ int g;
+ _Generic(g, auto : 0); // c2x-error {{'auto' not allowed here}} \
+ c17-error {{expected a type}} \
+ c17-error {{type name does not allow storage class to be specified}}
+
+ _Alignof(auto); // expected-error {{expected expression}} \
+ expected-warning {{'_Alignof' applied to an expression is a GNU extension}}
+
+ _Alignas(auto); // expected-error {{expected expression}} \
+ expected-warning {{declaration does not declare anything}}
+}
+
+void function_designators(void) {
+ extern auto auto_ret_func(void); // c2x-error {{'auto' not allowed in function return type}} \
+ c17-error {{cannot combine with previous 'extern' declaration specifier}} \
+ c17-error {{type specifier missing, defaults to 'int'; ISO C99 and later do not support implicit int}}
+
+ extern void auto_param_func(auto); // c2x-error {{'auto' not allowed in function prototype}} \
+ c17-error {{invalid storage class specifier in function declarator}} \
+ c17-error {{type specifier missing, defaults to 'int'; ISO C99 and later do not support implicit int}}
+
+ auto (auto_ret_func)(void); // c2x-error {{'auto' not allowed in function return type}} \
+ c17-error {{illegal storage class on function}} \
+ c17-error {{type specifier missing, defaults to 'int'; ISO C99 and later do not support implicit int}}
+
+ void (auto_param_func)(auto); // c2x-error {{'auto' not allowed in function prototype}} \
+ c17-error {{invalid storage class specifier in function declarator}} \
+ c17-error {{type specifier missing, defaults to 'int'; ISO C99 and later do not support implicit int}}
+}
+
+void atomic(void) {
+ _Atomic(auto) atom1 = 12; // c2x-error {{'auto' not allowed here}} \
+ c2x-error {{a type specifier is required for all declarations}} \
+ c17-error {{expected a type}} \
+ c17-error {{type name does not allow storage class to be specified}} \
+ c17-error {{type specifier missing, defaults to 'int'; ISO C99 and later do not support implicit int}}
+
+ _Atomic auto atom2 = 12; // c2x-error {{_Atomic cannot be applied to type 'auto' which is not trivially copyable}} \
+ c17-error {{type specifier missing, defaults to 'int'; ISO C99 and later do not support implicit int}}
+}
+
+void attributes(void) {
+ auto ident [[clang::annotate("this works")]] = 12; // c17-error {{expected expression}} \
+ c17-error {{type specifier missing, defaults to 'int'; ISO C99 and later do not support implicit int}}
+}
Index: clang/test/CodeGen/auto.c
===================================================================
--- /dev/null
+++ clang/test/CodeGen/auto.c
@@ -0,0 +1,41 @@
+// RUN: %clang_cc1 -std=c2x -emit-llvm %s -o - | FileCheck %s
+
+void basic_types(void) {
+ auto nb = 4; // CHECK: %nb = alloca i32, align 4
+ auto dbl = 4.3; // CHECK: %dbl = alloca double, align 8
+ auto lng = 4UL; // CHECK: %lng = alloca i{{32|64}}, align {{4|8}}
+ auto bl = true; // CHECK: %bl = alloca i8, align 1
+ auto chr = 'A'; // CHECK: %chr = alloca i32, align 4
+ auto str = "Test"; // CHECK: %str = alloca ptr, align 8
+ auto str2[] = "Test"; // CHECK: %str2 = alloca [5 x i8], align 1
+ auto nptr = nullptr; // CHECK: %nptr = alloca ptr, align 8
+}
+
+void misc_declarations(void) {
+ // FIXME: this should end up being rejected when we implement underspecified
+ // declarations in N3006.
+ auto strct_ptr = (struct { int a; } *)0; // CHECK: %strct_ptr = alloca ptr, align 8
+ auto int_cl = (int){13}; // CHECK: %int_cl = alloca i32, align 4
+ auto double_cl = (double){2.5}; // CHECK: %double_cl = alloca double, align 8
+
+ auto se = ({ // CHECK: %se = alloca i32, align 4
+ auto snb = 12; // CHECK: %snb = alloca i32, align 4
+ snb;
+ });
+}
+
+void loop(void) {
+ auto j = 4; // CHECK: %j = alloca i32, align 4
+ for (auto i = j; i < 2 * j; i++); // CHECK: %i = alloca i32, align 4
+}
+
+#define AUTO_MACRO(_NAME, ARG, ARG2, ARG3) auto _NAME = ARG + (ARG2 / ARG3);
+
+#define AUTO_INT_MACRO(_NAME, ARG, ARG2, ARG3) auto _NAME = (ARG ^ ARG2) & ARG3;
+
+int macros(int in_int) {
+ auto a = in_int + 1; // CHECK: %a = alloca i32, align 4
+ AUTO_MACRO(b, 1.3, 2.5f, 3); // CHECK: %b = alloca double, align 8
+ AUTO_INT_MACRO(c, 64, 23, 0xff); // CHECK: %c = alloca i32, align 4
+ return (a + (int)b) - c; // CHECK: ret i32 %sub
+}
Index: clang/test/C/C2x/n3007.c
===================================================================
--- /dev/null
+++ clang/test/C/C2x/n3007.c
@@ -0,0 +1,186 @@
+// RUN: %clang_cc1 -std=c2x -verify -pedantic -Wno-comments %s
+
+/* WG14 N3007: Yes
+ * Type Inference for object definitions
+ */
+void test_qualifiers(int x, const int y, int * restrict z) {
+ const auto a = x;
+ auto b = y;
+ static auto c = 1UL;
+ int* pa = &a; // expected-warning {{initializing 'int *' with an expression of type 'const int *' discards qualifiers}}
+ const int* pb = &b;
+ int* pc = &c; // expected-warning {{incompatible pointer types initializing 'int *' with an expression of type 'unsigned long *'}}
+
+ const int ci = 12;
+ auto yup = ci;
+ yup = 12;
+
+ auto r_test = z;
+
+ _Static_assert(_Generic(a, int : 1));
+ _Static_assert(_Generic(c, unsigned long : 1));
+ _Static_assert(_Generic(pa, int * : 1));
+ _Static_assert(_Generic(pb, const int * : 1));
+ _Static_assert(_Generic(r_test, int * : 1));
+}
+
+void test_atomic(void) {
+ _Atomic auto i = 12; // expected-error {{_Atomic cannot be applied to type 'auto' which is not trivially copyable}}
+ _Atomic(auto) j = 12; // expected-error {{'auto' not allowed here}} \
+ expected-error {{a type specifier is required for all declarations}}
+
+ _Atomic(int) foo(void);
+ auto k = foo();
+
+ _Static_assert(_Generic(&i, _Atomic auto *: 1)); // expected-error {{_Atomic cannot be applied to type 'auto' which is not trivially copyable}} \
+ expected-error {{'auto' not allowed here}}
+ _Static_assert(_Generic(k, int: 1));
+}
+
+void test_double(void) {
+ double A[3] = { 0 };
+ auto pA = A;
+ auto qA = &A;
+ auto pi = 3.14;
+
+ _Static_assert(_Generic(A, double * : 1));
+ _Static_assert(_Generic(pA, double * : 1));
+ _Static_assert(_Generic(qA, double (*)[3] : 1));
+ _Static_assert(_Generic(pi, double : 1));
+}
+
+int test_auto_param(auto a) { // expected-error {{'auto' not allowed in function prototype}}
+ return (int)(a * 2);
+}
+
+auto test_auto_return(float a, int b) { // expected-error {{'auto' not allowed in function return type}}
+ return ((a * b) * (a / b));
+}
+
+[[clang::overloadable]] auto test(auto x) { // expected-error {{'auto' not allowed in function prototype}} \
+ expected-error {{'auto' not allowed in function return type}}
+ return x;
+}
+
+void test_sizeof_alignas(void) {
+ (void)sizeof(auto); // expected-error {{expected expression}}
+ _Alignas(auto) int a[4]; // expected-error {{expected expression}}
+}
+
+void test_arrary(void) {
+ auto a[4]; // expected-error {{'auto' not allowed in array declaration}}
+ auto b[] = {1, 2}; // expected-error {{cannot use 'auto' with initializer list in C}}
+}
+
+void test_initializer_list(void) {
+ auto a = {}; // expected-error {{cannot use 'auto' with initializer list in C}}
+ auto b = { 0 }; // expected-error {{cannot use 'auto' with initializer list in C}}
+ auto c = { 1, }; // expected-error {{cannot use 'auto' with initializer list in C}}
+ auto d = { 1 , 2 }; // expected-error {{cannot use 'auto' with initializer list in C}}
+ auto e = (int [3]){ 1, 2, 3 };
+}
+
+void test_structs(void) {
+ // FIXME: Both of these should be diagnosed as invalid underspecified
+ // declarations as described in N3006.
+ auto p1 = (struct { int a; } *)0;
+ struct s;
+ auto p2 = (struct s { int a; } *)0;
+
+ struct B { auto b; }; // expected-error {{'auto' not allowed in struct member}}
+}
+
+void test_typedefs(void) {
+ typedef auto auto_type; // expected-error {{'auto' not allowed in typedef}}
+
+ typedef auto (*fp)(void); // expected-error {{'auto' not allowed in typedef}}
+ typedef void (*fp)(auto); // expected-error {{'auto' not allowed in function prototype}}
+
+ _Generic(0, auto : 1); // expected-error {{'auto' not allowed here}}
+}
+
+void test_misc(void) {
+ auto something; // expected-error {{declaration of variable 'something' with deduced type 'auto' requires an initializer}}
+ auto test_char = 'A';
+ auto test_char_ptr = "test";
+ auto test_char_ptr2[] = "another test";
+ auto auto_size = sizeof(auto); // expected-error {{expected expression}}
+
+ _Static_assert(_Generic(test_char, int : 1));
+ _Static_assert(_Generic(test_char_ptr, char * : 1));
+ _Static_assert(_Generic(test_char_ptr2, char * : 1));
+}
+
+void test_no_integer_promotions(void) {
+ short s;
+ auto a = s;
+ _Generic(a, int : 1); // expected-error {{controlling expression type 'short' not compatible with any generic association type}}
+}
+
+void test_compound_literals(void) {
+ auto a = (int){};
+ auto b = (int){ 0 };
+ auto c = (int){ 0, };
+ auto d = (int){ 0, 1 }; // expected-warning {{excess elements in scalar initializer}}
+
+ auto auto_cl = (auto){13}; // expected-error {{expected expression}}
+
+ _Static_assert(_Generic(a, int : 1));
+ _Static_assert(_Generic(b, int : 1));
+ _Static_assert(_Generic(c, int : 1));
+}
+
+void test_pointers(void) {
+ int a;
+ auto *ptr = &a; // expected-warning {{type inference of a declaration other than a plain identifier with optional trailing attributes is a Clang extension}}
+ auto *ptr2 = a; // expected-error {{variable 'ptr2' with type 'auto *' has incompatible initializer of type 'int'}} \
+ expected-warning {{type inference of a declaration other than a plain identifier with optional trailing attributes is a Clang extension}}
+ auto nptr = nullptr;
+
+ _Static_assert(_Generic(ptr, int * : 1));
+ _Static_assert(_Generic(ptr2, int * : 1));
+}
+
+void test_scopes(void) {
+ double a = 7;
+ double b = 9;
+ {
+ auto a = a * a; // expected-error {{variable 'a' declared with deduced type 'auto' cannot appear in its own initializer}} \
+ expected-error {{variable 'a' declared with deduced type 'auto' cannot appear in its own initializer}}
+ }
+ {
+ auto b = a * a;
+ auto a = b;
+
+ _Static_assert(_Generic(a, double : 1));
+ _Static_assert(_Generic(b, double : 1));
+ }
+}
+
+void test_loop(void) {
+ auto j = 4;
+ for (auto i = j; i < 2 * j; i++);
+
+ _Static_assert(_Generic(j, int : 1));
+}
+
+#define AUTO_MACRO(_NAME, ARG, ARG2, ARG3) \
+auto _NAME = ARG + (ARG2 / ARG3);
+
+// This macro should only work with integers due to the usage of binary operators
+#define AUTO_INT_MACRO(_NAME, ARG, ARG2, ARG3) \
+auto _NAME = (ARG ^ ARG2) & ARG3;
+
+void test_macros(int in_int) {
+ auto a = in_int + 1;
+ AUTO_MACRO(b, 1.3, 2.5f, 3);
+ AUTO_INT_MACRO(c, 64, 23, 0xff);
+ AUTO_INT_MACRO(not_valid, 51.5, 25, 0xff); // expected-error {{invalid operands to binary expression ('double' and 'int')}}
+
+ auto result = (a + (int)b) - c;
+
+ _Static_assert(_Generic(a, int : 1));
+ _Static_assert(_Generic(b, double : 1));
+ _Static_assert(_Generic(c, int : 1));
+ _Static_assert(_Generic(result, int : 1));
+}
Index: clang/lib/Sema/SemaTemplateDeduction.cpp
===================================================================
--- clang/lib/Sema/SemaTemplateDeduction.cpp
+++ clang/lib/Sema/SemaTemplateDeduction.cpp
@@ -4785,9 +4785,24 @@
return TDK_Success;
}
+ // Make sure that we treat 'char[]' equaly as 'char*' in C2x mode.
+ auto *String = dyn_cast<StringLiteral>(Init);
+ if (getLangOpts().C2x && String && Type.getType()->isArrayType()) {
+ TypeLoc TL = TypeLoc(Init->getType(), Type.getOpaqueData());
+ Result = SubstituteDeducedTypeTransform(*this, DependentResult).Apply(TL);
+ assert(!Result.isNull() && "substituting DependentTy can't fail");
+ return TDK_Success;
+ }
+
+ // Emit a warning if 'auto*' is used in pedantic and in C2x mode.
+ if (getLangOpts().C2x && Type.getType()->isPointerType()) {
+ Diag(Type.getBeginLoc(), diag::ext_c2x_auto_non_plain_identifier);
+ }
+
auto *InitList = dyn_cast<InitListExpr>(Init);
if (!getLangOpts().CPlusPlus && InitList) {
- Diag(Init->getBeginLoc(), diag::err_auto_init_list_from_c);
+ Diag(Init->getBeginLoc(), diag::err_auto_init_list_from_c)
+ << (int)AT->getKeyword();
return TDK_AlreadyDiagnosed;
}
Index: clang/lib/Sema/SemaDecl.cpp
===================================================================
--- clang/lib/Sema/SemaDecl.cpp
+++ clang/lib/Sema/SemaDecl.cpp
@@ -12682,6 +12682,15 @@
DeducedType *Deduced = Type->getContainedDeducedType();
assert(Deduced && "deduceVarTypeFromInitializer for non-deduced type");
+ // Diagnose auto array declarations in C2x, unless it's a supported extension.
+ if (getLangOpts().C2x && Type->isArrayType() &&
+ !isa_and_present<StringLiteral, InitListExpr>(Init)) {
+ Diag(Range.getBegin(), diag::err_auto_not_allowed)
+ << (int)Deduced->getContainedAutoType()->getKeyword()
+ << /* 'here' */ 23 << Range;
+ return QualType();
+ }
+
// C++11 [dcl.spec.auto]p3
if (!Init) {
assert(VDecl && "no init for init capture deduction?");
Index: clang/lib/Sema/DeclSpec.cpp
===================================================================
--- clang/lib/Sema/DeclSpec.cpp
+++ clang/lib/Sema/DeclSpec.cpp
@@ -1363,8 +1363,9 @@
StorageClassSpecLoc = SourceLocation();
}
// Diagnose if we've recovered from an ill-formed 'auto' storage class
- // specifier in a pre-C++11 dialect of C++.
- if (!S.getLangOpts().CPlusPlus11 && TypeSpecType == TST_auto)
+ // specifier in a pre-C++11 dialect of C++ or in a C2X dialect of C.
+ if ((!S.getLangOpts().CPlusPlus11 && !S.getLangOpts().C2x) &&
+ TypeSpecType == TST_auto)
S.Diag(TSTLoc, diag::ext_auto_type_specifier);
if (S.getLangOpts().CPlusPlus && !S.getLangOpts().CPlusPlus11 &&
StorageClassSpec == SCS_auto)
Index: clang/lib/Parse/ParseDecl.cpp
===================================================================
--- clang/lib/Parse/ParseDecl.cpp
+++ clang/lib/Parse/ParseDecl.cpp
@@ -3960,7 +3960,7 @@
isStorageClass = true;
break;
case tok::kw_auto:
- if (getLangOpts().CPlusPlus11) {
+ if (getLangOpts().CPlusPlus11 || getLangOpts().C2x) {
if (isKnownToBeTypeSpecifier(GetLookAheadToken(1))) {
isInvalid = DS.SetStorageClassSpec(Actions, DeclSpec::SCS_auto, Loc,
PrevSpec, DiagID, Policy);
Index: clang/include/clang/Basic/DiagnosticSemaKinds.td
===================================================================
--- clang/include/clang/Basic/DiagnosticSemaKinds.td
+++ clang/include/clang/Basic/DiagnosticSemaKinds.td
@@ -237,6 +237,10 @@
"imaginary constants are a GNU extension">, InGroup<GNUImaginaryConstant>;
def ext_integer_complex : Extension<
"complex integer types are a GNU extension">, InGroup<GNUComplexInteger>;
+def ext_c2x_auto_non_plain_identifier : Extension<
+ "type inference of a declaration other than a plain identifier with optional "
+ "trailing attributes is a Clang extension">,
+ InGroup<DiagGroup<"auto-decl-extensions">>;
def err_invalid_saturation_spec : Error<"'_Sat' specifier is only valid on "
"'_Fract' or '_Accum', not '%0'">;
@@ -2334,7 +2338,8 @@
"|in conversion function type|here|in lambda parameter"
"|in type allocated by 'new'|in K&R-style function parameter"
"|in template parameter|in friend declaration|in function prototype that is "
- "not a function declaration|in requires expression parameter}1">;
+ "not a function declaration|in requires expression parameter"
+ "|in array declaration}1">;
def err_dependent_deduced_tst : Error<
"typename specifier refers to "
"%select{class template|function template|variable template|alias template|"
@@ -2407,7 +2412,7 @@
def err_malformed_std_initializer_list : Error<
"std::initializer_list must be a class template with a single type parameter">;
def err_auto_init_list_from_c : Error<
- "cannot use __auto_type with initializer list in C">;
+ "cannot use %select{'auto'|<ERROR>|'__auto_type'}0 with initializer list in C">;
def err_auto_bitfield : Error<
"cannot pass bit-field as __auto_type initializer in C">;
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