[clang] 0318ce8 - [C99] Claim conformance for _Complex support (#88161)
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cfe-commits at lists.llvm.org
Fri Apr 12 11:15:25 PDT 2024
Author: Aaron Ballman
Date: 2024-04-12T14:15:22-04:00
New Revision: 0318ce8552896df7b180ee5481463eada65c755e
URL: https://github.com/llvm/llvm-project/commit/0318ce8552896df7b180ee5481463eada65c755e
DIFF: https://github.com/llvm/llvm-project/commit/0318ce8552896df7b180ee5481463eada65c755e.diff
LOG: [C99] Claim conformance for _Complex support (#88161)
There's so much overlap between the cited papers so this condenses the
status page into a single entry rather than trying to test conformance
against multiple papers doing conflicting things.
Added:
clang/test/C/C99/n809.c
clang/test/C/C99/n809_2.c
clang/test/C/C99/n809_3.c
Modified:
clang/www/c_status.html
Removed:
################################################################################
diff --git a/clang/test/C/C99/n809.c b/clang/test/C/C99/n809.c
new file mode 100644
index 00000000000000..7297443a777ccf
--- /dev/null
+++ b/clang/test/C/C99/n809.c
@@ -0,0 +1,122 @@
+// RUN: %clang_cc1 -verify -std=c99 %s
+
+/* WG14 N620, N638, N657, N694, N809: Partial
+ * Complex and imaginary support in <complex.h>
+ *
+ * NB: Clang supports _Complex but not _Imaginary. In C99, _Complex support is
+ * required outside of freestanding, but _Imaginary support is fully optional.
+ * In C11, both are made fully optional.
+ *
+ * NB: _Complex support requires an underlying support library such as
+ * compiler-rt to provide functions like __divsc3. Compiler-rt is not supported
+ * on Windows.
+ *
+ * Because the functionality is so intertwined between the various papers,
+ * we're testing all of the functionality in one file.
+ */
+
+// Demonstrate that we support spelling complex floating-point objects.
+float _Complex f1;
+_Complex float f2;
+
+double _Complex d1;
+_Complex double d2;
+
+long double _Complex ld1;
+_Complex long double ld2;
+
+// Show that we don't support spelling imaginary types.
+float _Imaginary fi1; // expected-error {{imaginary types are not supported}}
+_Imaginary float fi2; // expected-error {{imaginary types are not supported}}
+
+double _Imaginary di1; // expected-error {{imaginary types are not supported}}
+_Imaginary double di2; // expected-error {{imaginary types are not supported}}
+
+long double _Imaginary ldi1; // expected-error {{imaginary types are not supported}}
+_Imaginary long double ldi2; // expected-error {{imaginary types are not supported}}
+
+// Each complex type has the same representation and alignment as an array
+// containing two elements of the corresponding real type. Note, it is not
+// mandatory that the alignment of a structure containing an array of two
+// elements has the same alignment as an array of two elements outside of a
+// structure, but this is a property Clang supports.
+_Static_assert(sizeof(float _Complex) == sizeof(struct { float mem[2]; }), "");
+_Static_assert(_Alignof(float _Complex) == _Alignof(struct { float mem[2]; }), "");
+
+_Static_assert(sizeof(double _Complex) == sizeof(struct { double mem[2]; }), "");
+_Static_assert(_Alignof(double _Complex) == _Alignof(struct { double mem[2]; }), "");
+
+_Static_assert(sizeof(long double _Complex) == sizeof(struct { long double mem[2]; }), "");
+_Static_assert(_Alignof(long double _Complex) == _Alignof(struct { long double mem[2]; }), "");
+
+// The first element corresponds to the real part and the second element
+// corresponds to the imaginary part.
+_Static_assert(__real((float _Complex){ 1.0f, 2.0f }) == 1.0f, "");
+_Static_assert(__imag((float _Complex){ 1.0f, 2.0f }) == 2.0f, "");
+
+_Static_assert(__real((double _Complex){ 1.0, 2.0 }) == 1.0, "");
+_Static_assert(__imag((double _Complex){ 1.0, 2.0 }) == 2.0, "");
+
+_Static_assert(__real((long double _Complex){ 1.0L, 2.0L }) == 1.0L, "");
+_Static_assert(__imag((long double _Complex){ 1.0L, 2.0L }) == 2.0L, "");
+
+// When a real value is converted to a complex value, the real part follows the
+// usual conversion rules and the imaginary part should be zero.
+_Static_assert(__real((float _Complex)1.0f) == 1.0f, "");
+_Static_assert(__imag((float _Complex)1.0f) == 0.0f, "");
+
+_Static_assert(__real((double _Complex)1.0f) == 1.0, "");
+_Static_assert(__imag((double _Complex)1.0f) == 0.0, "");
+
+_Static_assert(__real((long double _Complex)1.0f) == 1.0L, "");
+_Static_assert(__imag((long double _Complex)1.0f) == 0.0L, "");
+
+// When a complex value is converted to a real value, the real part follows the
+// usual conversion rules and the imaginary part is discarded.
+_Static_assert((float)(float _Complex){ 1.0f, 2.0f } == 1.0f, "");
+_Static_assert((double)(float _Complex){ 1.0f, 2.0f } == 1.0, "");
+_Static_assert((long double)(float _Complex){ 1.0f, 2.0f } == 1.0L, "");
+
+// Complex values are only equal if both the real and imaginary parts are equal.
+_Static_assert((float _Complex){ 1.0f, 2.0f } == (float _Complex){ 1.0f, 2.0f }, "");
+_Static_assert((double _Complex){ 1.0, 2.0 } == (double _Complex){ 1.0, 2.0 }, "");
+_Static_assert((long double _Complex){ 1.0L, 2.0L } == (long double _Complex){ 1.0L, 2.0L }, "");
+
+_Static_assert((float _Complex){ 1.0f, 2.0f } != (float _Complex){ 2.0f, 0.0f }, "");
+_Static_assert((double _Complex){ 1.0, 2.0 } != (double _Complex){ 2.0, 0.0 }, "");
+_Static_assert((long double _Complex){ 1.0L, 2.0L } != (long double _Complex){ 2.0L, 0.0L }, "");
+
+// You cannot use relational operator on complex values.
+int i1 = (float _Complex){ 1.0f, 2.0f } < 10; // expected-error {{invalid operands to binary expression}}
+int i2 = (double _Complex){ 1.0f, 2.0f } > 10; // expected-error {{invalid operands to binary expression}}
+int i3 = (long double _Complex){ 1.0f, 2.0f } <= 10; // expected-error {{invalid operands to binary expression}}
+int i4 = (float _Complex){ 1.0f, 2.0f } >= 10; // expected-error {{invalid operands to binary expression}}
+
+// As a type specifier, _Complex cannot appear alone; however, we support it as
+// an extension by assuming _Complex double.
+_Complex c = 1.0f; // expected-warning {{plain '_Complex' requires a type specifier; assuming '_Complex double'}}
+// Because we don't support imaginary types, we don't extend the extension to
+// that type specifier.
+// FIXME: the warning diagnostic here is incorrect and should not be emitted.
+_Imaginary i = 1.0f; // expected-warning {{plain '_Complex' requires a type specifier; assuming '_Complex double'}} \
+ expected-error {{imaginary types are not supported}}
+
+void func(void) {
+#pragma clang diagnostic push
+#pragma clang diagnostic warning "-Wpedantic"
+ // Increment and decrement operators have a constraint that their operand be
+ // a real type; Clang supports this as an extension on complex types as well.
+ _Complex float cf = 0.0f;
+
+ cf++; // expected-warning {{'++' on an object of complex type is a Clang extension}}
+ ++cf; // expected-warning {{'++' on an object of complex type is a Clang extension}}
+
+ cf--; // expected-warning {{'--' on an object of complex type is a Clang extension}}
+ --cf; // expected-warning {{'--' on an object of complex type is a Clang extension}}
+
+ // However, unary + and - are fine, as is += 1.
+ (void)-cf;
+ (void)+cf;
+ cf += 1;
+#pragma clang diagnostic pop
+}
diff --git a/clang/test/C/C99/n809_2.c b/clang/test/C/C99/n809_2.c
new file mode 100644
index 00000000000000..3bf163126521a6
--- /dev/null
+++ b/clang/test/C/C99/n809_2.c
@@ -0,0 +1,64 @@
+// RUN: %clang_cc1 -ast-dump -std=c99 %s | FileCheck %s
+
+void variadic(int i, ...);
+
+void func(void) {
+ // CHECK: FunctionDecl {{.*}} func 'void (void)'
+
+ // Show that we correctly convert between two complex domains.
+ _Complex float cf = 1.0f;
+ _Complex double cd;
+
+ cd = cf;
+ // CHECK: BinaryOperator {{.*}} '_Complex double' '='
+ // CHECK-NEXT: DeclRefExpr {{.*}} 'cd'
+ // CHECK-NEXT: ImplicitCastExpr {{.*}} '_Complex double' <FloatingComplexCast>
+ // CHECK-NEXT: ImplicitCastExpr {{.*}} '_Complex float' <LValueToRValue>
+ // CHECK-NEXT: DeclRefExpr {{.*}} 'cf'
+
+ cf = cd;
+ // CHECK: BinaryOperator {{.*}} '_Complex float' '='
+ // CHECK-NEXT: DeclRefExpr {{.*}} 'cf'
+ // CHECK-NEXT: ImplicitCastExpr {{.*}} '_Complex float' <FloatingComplexCast>
+ // CHECK-NEXT: ImplicitCastExpr {{.*}} '_Complex double' <LValueToRValue>
+ // CHECK-NEXT: DeclRefExpr {{.*}} 'cd'
+
+ // Show that we correctly convert to the common type of a complex and real.
+ // This should convert the _Complex float to a _Complex double ("without
+ // change of domain" c.f. C99 6.3.1.8p1).
+ (void)(cf + 1.0);
+ // CHECK: BinaryOperator {{.*}} '_Complex double' '+'
+ // CHECK-NEXT: ImplicitCastExpr {{.*}} '_Complex double' <FloatingComplexCast>
+ // CHECK-NEXT: ImplicitCastExpr {{.*}} '_Complex float' <LValueToRValue>
+ // CHECK-NEXT: DeclRefExpr {{.*}} 'cf'
+ // CHECK-NEXT: FloatingLiteral {{.*}} 'double' 1.0
+
+ // This should convert the float constant to double, then produce a
+ // _Complex double.
+ (void)(cd + 1.0f);
+ // CHECK: BinaryOperator {{.*}} '_Complex double' '+'
+ // CHECK-NEXT: ImplicitCastExpr {{.*}} '_Complex double' <LValueToRValue>
+ // CHECK-NEXT: DeclRefExpr {{.*}} 'cd'
+ // CHECK-NEXT: ImplicitCastExpr {{.*}} 'double' <FloatingCast>
+ // CHECK-NEXT: FloatingLiteral {{.*}} 'float' 1.0
+
+ // This should convert the int constant to float, then produce a
+ // _Complex float.
+ (void)(cf + 1);
+ // CHECK: BinaryOperator {{.*}} '_Complex float' '+'
+ // CHECK-NEXT: ImplicitCastExpr {{.*}} '_Complex float' <LValueToRValue>
+ // CHECK-NEXT: DeclRefExpr {{.*}} 'cf'
+ // CHECK-NEXT: ImplicitCastExpr {{.*}} 'float' <IntegralToFloating>
+ // CHECK-NEXT: IntegerLiteral {{.*}} 'int' 1
+
+ // Show that we do not promote a _Complex float to _Complex double as part of
+ // the default argument promotions when passing to a variadic function.
+ variadic(1, cf);
+ // CHECK: CallExpr
+ // CHECK-NEXT: ImplicitCastExpr {{.*}} <FunctionToPointerDecay>
+ // CHECK-NEXT: DeclRefExpr {{.*}} 'variadic'
+ // CHECK-NEXT: IntegerLiteral {{.*}} 'int' 1
+ // CHECK-NEXT: ImplicitCastExpr {{.*}} '_Complex float' <LValueToRValue>
+ // CHECK-NEXT: DeclRefExpr {{.*}} 'cf'
+}
+
diff --git a/clang/test/C/C99/n809_3.c b/clang/test/C/C99/n809_3.c
new file mode 100644
index 00000000000000..f1283f5fe1632c
--- /dev/null
+++ b/clang/test/C/C99/n809_3.c
@@ -0,0 +1,12 @@
+// RUN: %clang_cc1 -emit-llvm -std=c99 %s -o - | FileCheck %s
+
+// Demonstrate that statics are properly zero initialized.
+static _Complex float f_global;
+void func(void) {
+ static _Complex double d_local;
+ d_local = f_global;
+}
+
+// CHECK-DAG: @func.d_local = internal global { double, double } zeroinitializer
+// CHECK-DAG: @f_global = internal global { float, float } zeroinitializer
+
diff --git a/clang/www/c_status.html b/clang/www/c_status.html
index 411f55447be778..9893170ae84739 100644
--- a/clang/www/c_status.html
+++ b/clang/www/c_status.html
@@ -132,29 +132,22 @@ <h2 id="c99">C99 implementation status</h2>
<td>Unknown</td>
<td class="full" align="center">Yes</td>
</tr>
- <tr id="complex">
- <td rowspan="6">complex and imaginary support in <complex.h></td>
+ <tr>
+ <td>complex and imaginary support in <complex.h></td>
+ <td><a href="https://www.open-std.org/jtc1/sc22/wg14/www/docs/n693.ps">N693</a></td>
+ <td class="partial" align="center">
+ <details><summary>Partial</summary>
+ Clang supports <code>_Complex</code> type specifiers but does not
+ support <code>_Imaginary</code> type specifiers. Support for
+ <code>_Imaginary</code> is optional in C99 and Clang does not claim
+ conformance to Annex G.<br />
+ <br />
+ <code>_Complex</code> support requires an underlying support library
+ such as compiler-rt to provide functions like <code>__divsc3</code>,
+ but compiler-rt is not supported on Windows.
+ </details>
+ </td>
</tr>
- <tr>
- <td><a href="https://www.open-std.org/jtc1/sc22/wg14/www/docs/n620.ps">N620</a></td>
- <td class="unknown" align="center">Unknown</td>
- </tr>
- <tr>
- <td><a href="https://www.open-std.org/jtc1/sc22/wg14/www/docs/n638.ps">N638</a></td>
- <td class="unknown" align="center">Unknown</td>
- </tr>
- <tr>
- <td><a href="https://www.open-std.org/jtc1/sc22/wg14/www/docs/n657.ps">N657</a></td>
- <td class="unknown" align="center">Unknown</td>
- </tr>
- <tr>
- <td><a href="https://www.open-std.org/jtc1/sc22/wg14/www/docs/n694.ps">N694</a></td>
- <td class="unknown" align="center">Unknown</td>
- </tr>
- <tr>
- <td><a href="https://www.open-std.org/jtc1/sc22/wg14/www/docs/n809.ps">N809</a></td>
- <td class="unknown" align="center">Unknown</td>
- </tr>
<tr>
<td>type-generic math macros in <tgmath.h></td>
<td><a href="https://www.open-std.org/jtc1/sc22/wg14/www/docs/n693.ps">N693</a></td>
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