[clang] Make __builtin_expf constexpr. #140841
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…C_ERRNO_MODE=LIBC_ERRNO_MODE_SYSTEM to be header-only.
…ath folder and add libc/shared/math.h
…ntation from LLVM libc.
|
@llvm/pr-subscribers-libc Author: None (lntue) ChangesA draft PR to make Patch is 244.33 KiB, truncated to 20.00 KiB below, full version: https://github.com/llvm/llvm-project/pull/140841.diff 429 Files Affected:
diff --git a/clang/include/clang/Basic/Builtins.td b/clang/include/clang/Basic/Builtins.td
index 187d3b5ed24a7..bbb443e249fae 100644
--- a/clang/include/clang/Basic/Builtins.td
+++ b/clang/include/clang/Basic/Builtins.td
@@ -161,7 +161,22 @@ def ErfcF128 : Builtin {
let Prototype = "__float128(__float128)";
}
-def ExpF16F128 : Builtin, F16F128MathTemplate {
+def BIExpF : Builtin {
+ let Spellings = ["__builtin_expf"];
+#ifdef LLVM_INTEGRATE_LIBC
+ let Attributes = [FunctionWithBuiltinPrefix, NoThrow, Const, Constexpr];
+#else
+ let Attributes = [FunctionWithBuiltinPrefix, NoThrow,
+ ConstIgnoringErrnoAndExceptions];
+#endif // LLVM_INTEGRATE_LIBC
+ let Prototype = "float(float)";
+}
+
+def BIExp
+ : Builtin,
+ Template<["double", "long double", "_Float16", "__float128"], ["", "l",
+ "f16",
+ "f128"]> {
let Spellings = ["__builtin_exp"];
let Attributes = [FunctionWithBuiltinPrefix, NoThrow, ConstIgnoringErrnoAndExceptions];
let Prototype = "T(T)";
@@ -3742,7 +3757,6 @@ def Exp : FPMathTemplate, LibBuiltin<"math.h"> {
let Spellings = ["exp"];
let Attributes = [NoThrow, ConstIgnoringErrnoAndExceptions];
let Prototype = "T(T)";
- let AddBuiltinPrefixedAlias = 1;
}
def Exp2 : FPMathTemplate, LibBuiltin<"math.h"> {
diff --git a/clang/lib/AST/ByteCode/InterpBuiltin.cpp b/clang/lib/AST/ByteCode/InterpBuiltin.cpp
index 8edc6248dcbfd..be64d93fb1345 100644
--- a/clang/lib/AST/ByteCode/InterpBuiltin.cpp
+++ b/clang/lib/AST/ByteCode/InterpBuiltin.cpp
@@ -18,6 +18,7 @@
#include "clang/Basic/TargetBuiltins.h"
#include "clang/Basic/TargetInfo.h"
#include "llvm/ADT/StringExtras.h"
+#include "llvm/Config/llvm-config.h"
#include "llvm/Support/SipHash.h"
namespace clang {
@@ -419,6 +420,13 @@ static bool interp__builtin_copysign(InterpState &S, CodePtr OpPC,
return true;
}
+static bool interp__builtin_exp(InterpState &S, CodePtr OpPC,
+ const InterpFrame *Frame) {
+ APFloat Result = exp(S.Stk.peek<Floating>().getAPFloat());
+ S.Stk.push<Floating>(Floating(Result));
+ return true;
+}
+
static bool interp__builtin_fmin(InterpState &S, CodePtr OpPC,
const InterpFrame *Frame, bool IsNumBuiltin) {
const Floating &LHS = S.Stk.peek<Floating>(align(primSize(PT_Float)) * 2);
@@ -2315,6 +2323,20 @@ bool InterpretBuiltin(InterpState &S, CodePtr OpPC, const CallExpr *Call,
return false;
break;
+ case Builtin::BI__builtin_exp:
+ case Builtin::BI__builtin_expl:
+ case Builtin::BI__builtin_expf16:
+ case Builtin::BI__builtin_expf128:
+ return false;
+ case Builtin::BI__builtin_expf:
+#ifdef LLVM_INTEGRATE_LIBC
+ if (!interp__builtin_exp(S, OpPC, Frame))
+ return false;
+ break;
+#else
+ return false;
+#endif // LLVM_INTEGRATE_LIBC
+
case Builtin::BI__builtin_fmin:
case Builtin::BI__builtin_fminf:
case Builtin::BI__builtin_fminl:
diff --git a/clang/lib/AST/ExprConstant.cpp b/clang/lib/AST/ExprConstant.cpp
index e9a269337404a..f37e916f67560 100644
--- a/clang/lib/AST/ExprConstant.cpp
+++ b/clang/lib/AST/ExprConstant.cpp
@@ -57,6 +57,7 @@
#include "llvm/ADT/Sequence.h"
#include "llvm/ADT/SmallBitVector.h"
#include "llvm/ADT/StringExtras.h"
+#include "llvm/Config/llvm-config.h"
#include "llvm/Support/Casting.h"
#include "llvm/Support/Debug.h"
#include "llvm/Support/SaveAndRestore.h"
@@ -15711,6 +15712,24 @@ bool FloatExprEvaluator::VisitCallExpr(const CallExpr *E) {
return true;
}
+ // FIXME: allow other __builtin_exp* to be constexpr.
+ case Builtin::BI__builtin_exp:
+ case Builtin::BI__builtin_expl:
+ case Builtin::BI__builtin_expf16:
+ case Builtin::BI__builtin_expf128:
+ return false;
+ case Builtin::BI__builtin_expf: {
+#ifdef LLVM_INTEGRATE_LIBC
+ APFloat Input(0.);
+ if (!EvaluateFloat(E->getArg(0), Input, Info))
+ return false;
+ Result = exp(Input);
+ return true;
+#else
+ return false;
+#endif // LLVM_INTEGRATE_LIBC
+ }
+
case Builtin::BI__builtin_fmax:
case Builtin::BI__builtin_fmaxf:
case Builtin::BI__builtin_fmaxl:
diff --git a/clang/test/CMakeLists.txt b/clang/test/CMakeLists.txt
index 35a8042ac0e0a..5960601a90e8d 100644
--- a/clang/test/CMakeLists.txt
+++ b/clang/test/CMakeLists.txt
@@ -27,6 +27,7 @@ llvm_canonicalize_cmake_booleans(
LLVM_TOOL_LLVM_DRIVER_BUILD
LLVM_INCLUDE_SPIRV_TOOLS_TESTS
LLVM_EXPERIMENTAL_KEY_INSTRUCTIONS
+ LLVM_INTEGRATE_LIBC
)
configure_lit_site_cfg(
diff --git a/clang/test/Preprocessor/feature_tests.cpp b/clang/test/Preprocessor/feature_tests.cpp
index 029f446113af4..7fec4fef9835b 100644
--- a/clang/test/Preprocessor/feature_tests.cpp
+++ b/clang/test/Preprocessor/feature_tests.cpp
@@ -64,6 +64,16 @@
#error Clang should have these constexpr builtins
#endif
+#ifdef LLVM_INTEGRATE_LIBC
+#if !__has_constexpr_builtin(__builtin_expf)
+#error Clang should have these constexpr builtins
+#endif
+#else
+#if __has_constexpr_builtin(__builtin_expf)
+#error This builtin should not be constexpr in Clang
+#endif
+#endif // LLVM_INTEGRATE_LIBC
+
#if !__has_constexpr_builtin(__builtin_convertvector)
#error Clang should have these constexpr builtins
#endif
diff --git a/clang/test/Sema/constant-builtins-exp.cpp b/clang/test/Sema/constant-builtins-exp.cpp
new file mode 100644
index 0000000000000..6e9a2a070c192
--- /dev/null
+++ b/clang/test/Sema/constant-builtins-exp.cpp
@@ -0,0 +1,12 @@
+// RUN: %clang_cc1 -std=c++17 -fsyntax-only -verify %s
+// RUN: %clang_cc1 -std=c++17 -fsyntax-only -verify -fexperimental-new-constant-interpreter %s
+// REQUIRES: llvm_integrate_libc
+// expected-no-diagnostics
+
+constexpr float Inf = __builtin_inff();
+constexpr float NegInf = -__builtin_inff();
+
+static_assert(Inf == __builtin_expf(Inf));
+static_assert(0.0f == __builtin_expf(NegInf));
+static_assert(1.0f == __builtin_expf(0.0f));
+static_assert(0x1.5bf0a8p1f == __builtin_expf(1.0f));
diff --git a/clang/test/lit.cfg.py b/clang/test/lit.cfg.py
index 2b35bb5dcbdaf..a57e33ae70802 100644
--- a/clang/test/lit.cfg.py
+++ b/clang/test/lit.cfg.py
@@ -385,3 +385,6 @@ def calculate_arch_features(arch_string):
# possibly be present in system and user configuration files, so disable
# default configs for the test runs.
config.environment["CLANG_NO_DEFAULT_CONFIG"] = "1"
+
+if config.llvm_integrate_libc:
+ config.available_features.add("llvm_integrate_libc")
diff --git a/clang/test/lit.site.cfg.py.in b/clang/test/lit.site.cfg.py.in
index 77c5f27f47c92..294d1b077ddf2 100644
--- a/clang/test/lit.site.cfg.py.in
+++ b/clang/test/lit.site.cfg.py.in
@@ -49,6 +49,7 @@ config.have_llvm_driver = @LLVM_TOOL_LLVM_DRIVER_BUILD@
config.spirv_tools_tests = @LLVM_INCLUDE_SPIRV_TOOLS_TESTS@
config.substitutions.append(("%llvm-version-major", "@LLVM_VERSION_MAJOR@"))
config.has_key_instructions = @LLVM_EXPERIMENTAL_KEY_INSTRUCTIONS@
+config.llvm_integrate_libc = @LLVM_INTEGRATE_LIBC@
import lit.llvm
lit.llvm.initialize(lit_config, config)
diff --git a/libc/cmake/modules/LLVMLibCCompileOptionRules.cmake b/libc/cmake/modules/LLVMLibCCompileOptionRules.cmake
index 0facb0b9be0c1..a98e7276bef80 100644
--- a/libc/cmake/modules/LLVMLibCCompileOptionRules.cmake
+++ b/libc/cmake/modules/LLVMLibCCompileOptionRules.cmake
@@ -106,6 +106,10 @@ function(_get_compile_options_from_config output_var)
list(APPEND config_options "-DLIBC_MATH=${LIBC_CONF_MATH_OPTIMIZATIONS}")
endif()
+ if(LIBC_CONF_ERRNO_MODE)
+ set(APPEND config_options "-DLIBC_ERRNO_MODE=${LIBC_CONF_ERRNO_MODE}")
+ endif()
+
set(${output_var} ${config_options} PARENT_SCOPE)
endfunction(_get_compile_options_from_config)
diff --git a/libc/cmake/modules/LLVMLibCTestRules.cmake b/libc/cmake/modules/LLVMLibCTestRules.cmake
index 3f804694b5bae..0bef0763ec999 100644
--- a/libc/cmake/modules/LLVMLibCTestRules.cmake
+++ b/libc/cmake/modules/LLVMLibCTestRules.cmake
@@ -1,5 +1,6 @@
function(_get_common_test_compile_options output_var c_test flags)
_get_compile_options_from_flags(compile_flags ${flags})
+ _get_compile_options_from_config(config_flags)
# Remove -fno-math-errno if it was added.
if(LIBC_ADD_FNO_MATH_ERRNO)
@@ -9,7 +10,8 @@ function(_get_common_test_compile_options output_var c_test flags)
set(compile_options
${LIBC_COMPILE_OPTIONS_DEFAULT}
${LIBC_TEST_COMPILE_OPTIONS_DEFAULT}
- ${compile_flags})
+ ${compile_flags}
+ ${config_flags})
if(LLVM_LIBC_COMPILER_IS_GCC_COMPATIBLE)
list(APPEND compile_options "-fpie")
diff --git a/libc/docs/configure.rst b/libc/docs/configure.rst
index 8d53390ae19bf..dee9a63101eb9 100644
--- a/libc/docs/configure.rst
+++ b/libc/docs/configure.rst
@@ -33,7 +33,7 @@ to learn about the defaults for your platform and target.
* **"general" options**
- ``LIBC_ADD_NULL_CHECKS``: Add nullptr checks in the library's implementations to some functions for which passing nullptr is undefined behavior.
* **"math" options**
- - ``LIBC_CONF_FREXP_INF_NAN_EXPONENT``: The value written back to the second parameter when calling frexp/frexpf/frexpl` with `+/-Inf`/`NaN` is unspecified. Configure an explicit exp value for Inf/NaN inputs.
+ - ``LIBC_CONF_FREXP_INF_NAN_EXPONENT``: The value written back to the second parameter when calling frexp/frexpf/frexpl` with `+/-Inf`/`NaN` is unspecified. Configue an explicit exp value for Inf/NaN inputs.
- ``LIBC_CONF_MATH_OPTIMIZATIONS``: Configures optimizations for math functions. Values accepted are LIBC_MATH_SKIP_ACCURATE_PASS, LIBC_MATH_SMALL_TABLES, LIBC_MATH_NO_ERRNO, LIBC_MATH_NO_EXCEPT, and LIBC_MATH_FAST.
* **"printf" options**
- ``LIBC_CONF_PRINTF_DISABLE_FIXED_POINT``: Disable printing fixed point values in printf and friends.
diff --git a/libc/docs/dev/code_style.rst b/libc/docs/dev/code_style.rst
index 0bd3a69ae3ffe..86247966552f9 100644
--- a/libc/docs/dev/code_style.rst
+++ b/libc/docs/dev/code_style.rst
@@ -101,7 +101,7 @@ test infrastructure itself can be affected. To avoid perturbing the unit test
infrastructure around the setting of ``errno``, the following rules are to be
followed:
-#. A special macro named ``libc_errno`` defined in ``src/errno/libc_errno.h``
+#. A special macro named ``libc_errno`` defined in ``src/__support/libc_errno.h``
should be used when setting ``errno`` from libc runtime code. For example,
code to set ``errno`` to ``EINVAL`` should be:
@@ -117,7 +117,7 @@ followed:
`ErrorOr <https://github.com/llvm/llvm-project/blob/main/libc/src/__support/error_or.h>`_
to return error values.
-#. The header file ``src/errno/libc_errno.h`` is shipped as part of the target
+#. The header file ``src/__support/libc_errno.h`` is shipped as part of the target
corresponding to the ``errno`` entrypoint ``libc.src.errno.errno``. We do
not in general allow dependencies between entrypoints. However, the ``errno``
entrypoint is the only exceptional entrypoint on which other entrypoints
diff --git a/libc/shared/math.h b/libc/shared/math.h
new file mode 100644
index 0000000000000..19c49bb23bc39
--- /dev/null
+++ b/libc/shared/math.h
@@ -0,0 +1,22 @@
+//===-- Floating point math functions ---------------------------*- C++ -*-===//
+//
+// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
+// See https://llvm.org/LICENSE.txt for license information.
+// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
+//
+//===----------------------------------------------------------------------===//
+
+#ifndef LLVM_LIBC_SHARED_MATH_H
+#define LLVM_LIBC_SHARED_MATH_H
+
+#include "src/__support/math/expf.h"
+
+namespace LIBC_NAMESPACE_DECL {
+namespace shared {
+
+using math::expf;
+
+} // namespace shared
+} // namespace LIBC_NAMESPACE_DECL
+
+#endif // LLVM_LIBC_SHARED_FP_BITS_H
diff --git a/libc/src/__support/CMakeLists.txt b/libc/src/__support/CMakeLists.txt
index f92499fdbf451..e4a3a7983e4de 100644
--- a/libc/src/__support/CMakeLists.txt
+++ b/libc/src/__support/CMakeLists.txt
@@ -381,3 +381,5 @@ add_subdirectory(HashTable)
add_subdirectory(fixed_point)
add_subdirectory(time)
+
+add_subdirectory(math)
diff --git a/libc/src/__support/FPUtil/FEnvImpl.h b/libc/src/__support/FPUtil/FEnvImpl.h
index 4c8f34a435bdf..50a101f833c55 100644
--- a/libc/src/__support/FPUtil/FEnvImpl.h
+++ b/libc/src/__support/FPUtil/FEnvImpl.h
@@ -12,10 +12,10 @@
#include "hdr/fenv_macros.h"
#include "hdr/math_macros.h"
#include "hdr/types/fenv_t.h"
+#include "src/__support/libc_errno.h"
#include "src/__support/macros/attributes.h" // LIBC_INLINE
#include "src/__support/macros/config.h"
#include "src/__support/macros/properties/architectures.h"
-#include "src/errno/libc_errno.h"
#if defined(LIBC_TARGET_ARCH_IS_AARCH64) && defined(__ARM_FP)
#if defined(__APPLE__)
diff --git a/libc/src/__support/File/dir.cpp b/libc/src/__support/File/dir.cpp
index 21b0106f70106..aea8862c15f7f 100644
--- a/libc/src/__support/File/dir.cpp
+++ b/libc/src/__support/File/dir.cpp
@@ -11,8 +11,8 @@
#include "src/__support/CPP/mutex.h" // lock_guard
#include "src/__support/CPP/new.h"
#include "src/__support/error_or.h"
+#include "src/__support/libc_errno.h" // For error macros
#include "src/__support/macros/config.h"
-#include "src/errno/libc_errno.h" // For error macros
namespace LIBC_NAMESPACE_DECL {
diff --git a/libc/src/__support/File/file.cpp b/libc/src/__support/File/file.cpp
index 528542cccf324..303852dbbb717 100644
--- a/libc/src/__support/File/file.cpp
+++ b/libc/src/__support/File/file.cpp
@@ -13,8 +13,8 @@
#include "hdr/types/off_t.h"
#include "src/__support/CPP/new.h"
#include "src/__support/CPP/span.h"
+#include "src/__support/libc_errno.h" // For error macros
#include "src/__support/macros/config.h"
-#include "src/errno/libc_errno.h" // For error macros
namespace LIBC_NAMESPACE_DECL {
diff --git a/libc/src/__support/File/linux/file.cpp b/libc/src/__support/File/linux/file.cpp
index 824c1f200e8c5..761e352f74ead 100644
--- a/libc/src/__support/File/linux/file.cpp
+++ b/libc/src/__support/File/linux/file.cpp
@@ -15,8 +15,8 @@
#include "src/__support/File/linux/lseekImpl.h"
#include "src/__support/OSUtil/fcntl.h"
#include "src/__support/OSUtil/syscall.h" // For internal syscall function.
+#include "src/__support/libc_errno.h" // For error macros
#include "src/__support/macros/config.h"
-#include "src/errno/libc_errno.h" // For error macros
#include "hdr/fcntl_macros.h" // For mode_t and other flags to the open syscall
#include <sys/stat.h> // For S_IS*, S_IF*, and S_IR* flags.
diff --git a/libc/src/__support/File/linux/lseekImpl.h b/libc/src/__support/File/linux/lseekImpl.h
index a034913d9f6ec..300e5c5dd55bf 100644
--- a/libc/src/__support/File/linux/lseekImpl.h
+++ b/libc/src/__support/File/linux/lseekImpl.h
@@ -13,8 +13,8 @@
#include "src/__support/OSUtil/syscall.h" // For internal syscall function.
#include "src/__support/common.h"
#include "src/__support/error_or.h"
+#include "src/__support/libc_errno.h"
#include "src/__support/macros/config.h"
-#include "src/errno/libc_errno.h"
#include <stdint.h> // For uint64_t.
#include <sys/syscall.h> // For syscall numbers.
diff --git a/libc/src/__support/HashTable/randomness.h b/libc/src/__support/HashTable/randomness.h
index 244dd41be3eec..6b58a4125f785 100644
--- a/libc/src/__support/HashTable/randomness.h
+++ b/libc/src/__support/HashTable/randomness.h
@@ -14,7 +14,7 @@
#include "src/__support/macros/attributes.h"
#include "src/__support/macros/config.h"
#if defined(LIBC_HASHTABLE_USE_GETRANDOM)
-#include "src/errno/libc_errno.h"
+#include "src/__support/libc_errno.h"
#include "src/sys/random/getrandom.h"
#endif
diff --git a/libc/src/__support/OSUtil/linux/fcntl.cpp b/libc/src/__support/OSUtil/linux/fcntl.cpp
index 4742b2a00220b..99e16ad58c918 100644
--- a/libc/src/__support/OSUtil/linux/fcntl.cpp
+++ b/libc/src/__support/OSUtil/linux/fcntl.cpp
@@ -15,8 +15,8 @@
#include "hdr/types/struct_flock64.h"
#include "src/__support/OSUtil/syscall.h" // For internal syscall function.
#include "src/__support/common.h"
+#include "src/__support/libc_errno.h"
#include "src/__support/macros/config.h"
-#include "src/errno/libc_errno.h"
#include <stdarg.h>
#include <sys/syscall.h> // For syscall numbers.
diff --git a/libc/src/__support/OSUtil/linux/vdso.cpp b/libc/src/__support/OSUtil/linux/vdso.cpp
index 8c9bd3e1bcc72..e4e53c3c2a0f2 100644
--- a/libc/src/__support/OSUtil/linux/vdso.cpp
+++ b/libc/src/__support/OSUtil/linux/vdso.cpp
@@ -11,9 +11,9 @@
#include "src/__support/CPP/array.h"
#include "src/__support/CPP/optional.h"
#include "src/__support/CPP/string_view.h"
+#include "src/__support/libc_errno.h"
#include "src/__support/threads/callonce.h"
#include "src/__support/threads/linux/futex_word.h"
-#include "src/errno/libc_errno.h"
#include "src/sys/auxv/getauxval.h"
#include <linux/auxvec.h>
diff --git a/libc/src/__support/StringUtil/tables/linux_extension_errors.h b/libc/src/__support/StringUtil/tables/linux_extension_errors.h
index 425590f6e91c9..de637d60bea97 100644
--- a/libc/src/__support/StringUtil/tables/linux_extension_errors.h
+++ b/libc/src/__support/StringUtil/tables/linux_extension_errors.h
@@ -10,8 +10,8 @@
#define LLVM_LIBC_SRC___SUPPORT_STRINGUTIL_TABLES_LINUX_EXTENSION_ERRORS_H
#include "src/__support/StringUtil/message_mapper.h"
+#include "src/__support/libc_errno.h"
#include "src/__support/macros/config.h"
-#include "src/errno/libc_errno.h"
namespace LIBC_NAMESPACE_DECL {
diff --git a/libc/src/__support/libc_errno.h b/libc/src/__support/libc_errno.h
new file mode 100644
index 0000000000000..cf971d0bd1ae3
--- /dev/null
+++ b/libc/src/__support/libc_errno.h
@@ -0,0 +1,93 @@
+//===-- Implementation header for libc_errno --------------------*- C++ -*-===//
+//
+// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
+// See https://llvm.org/LICENSE.txt for license information.
+// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
+//
+//===----------------------------------------------------------------------===//
+
+#ifndef LLVM_LIBC_SRC___SUPPORT_LIBC_ERRNO_H
+#define LLVM_LIBC_SRC___SUPPORT_LIBC_ERRNO_H
+
+#include "src/__support/macros/attributes.h"
+#include "src/__support/macros/config.h"
+#include "src/__support/macros/properties/architectures.h"
+
+#include "hdr/errno_macros.h"
+
+// This header is to be consumed by internal implementations, in which all of
+// them should refer to `libc_errno` instead of using `errno` directly from
+// <errno.h> header.
+
+// Unit and hermetic tests should:
+// - #include "src/__support/libc_errno.h"
+// - NOT #include <errno.h>
+// - Only use `libc_errno` in the code
+// - Depend on libc.src.errno.errno
+
+// Integration tests should:
+// - NOT #include "src/__support/libc_errno.h"
+// - #include <errno.h>
+// - Use regular `errno` in the code
+// - Still depend on libc.src.errno.errno
+
+// libc uses a fallback default value, either system or thread local.
+#define LIBC_ERRNO_MODE_DEFAULT 0
+// libc never stores a value; `errno` macro uses get link-time failure.
+#define LIBC_ERRNO_MODE_UNDEFINED 1
+// libc maintains per-thread state (requires C++ `thread_local` support).
+#define LIBC_ERRNO_MODE_THREAD_LOCAL 2
+// libc maintains shared state used by all threads, contrary to standard C
+// semantics unless always single-threaded; nothing prevents data races.
+#define LIBC_ERRNO_MODE_SHARED 3
+// libc doesn't maintain any internal state, instead the embedder must define
+// `int *__llvm_libc_errno(void);` C function.
+#define LIBC_ERRNO_MODE_EXTERNAL 4
+// libc uses system `<errno.h>` `errno` macro directly in the overlay mode; in
+// fullbuild mode, effectively the same as `LIBC_ERRNO_MODE_EXTERNAL`.
+#define LIBC_ERRNO_MODE_SYSTEM 5
+
+#if !defined(LIBC_ERRNO_MODE) || LIBC_ERRNO_MODE == LIBC_ERRNO_MODE_DEFAULT
+#undef LIBC_ERRNO_MODE
+#if defined(LIBC_FULL_BUILD) || !defined(LIBC_COPT_PUBLIC_PACKAGING)
+#define LIBC_ERRNO_MODE LIBC_ERRNO_MODE_THREAD_LOCAL
+#else
+#define LIBC_ERRNO_MODE LIBC_ERRNO_MODE_SYSTEM
+#endif
+#endif // LIBC_ERRNO_MODE
+
+#if LIBC_ERRNO_MODE != LIBC_ERRNO_MODE_DEFAULT && \
+ LIBC_ERRNO_MODE != LIBC_ERRNO_MODE_UNDEFINED && \
+ LIBC_ERRNO_MODE != LIBC_ERRNO_MODE_THREAD_LOCAL && \
+ LIBC...
[truncated]
|
|
@llvm/pr-subscribers-clang Author: None (lntue) ChangesA draft PR to make Patch is 244.33 KiB, truncated to 20.00 KiB below, full version: https://github.com/llvm/llvm-project/pull/140841.diff 429 Files Affected:
diff --git a/clang/include/clang/Basic/Builtins.td b/clang/include/clang/Basic/Builtins.td
index 187d3b5ed24a7..bbb443e249fae 100644
--- a/clang/include/clang/Basic/Builtins.td
+++ b/clang/include/clang/Basic/Builtins.td
@@ -161,7 +161,22 @@ def ErfcF128 : Builtin {
let Prototype = "__float128(__float128)";
}
-def ExpF16F128 : Builtin, F16F128MathTemplate {
+def BIExpF : Builtin {
+ let Spellings = ["__builtin_expf"];
+#ifdef LLVM_INTEGRATE_LIBC
+ let Attributes = [FunctionWithBuiltinPrefix, NoThrow, Const, Constexpr];
+#else
+ let Attributes = [FunctionWithBuiltinPrefix, NoThrow,
+ ConstIgnoringErrnoAndExceptions];
+#endif // LLVM_INTEGRATE_LIBC
+ let Prototype = "float(float)";
+}
+
+def BIExp
+ : Builtin,
+ Template<["double", "long double", "_Float16", "__float128"], ["", "l",
+ "f16",
+ "f128"]> {
let Spellings = ["__builtin_exp"];
let Attributes = [FunctionWithBuiltinPrefix, NoThrow, ConstIgnoringErrnoAndExceptions];
let Prototype = "T(T)";
@@ -3742,7 +3757,6 @@ def Exp : FPMathTemplate, LibBuiltin<"math.h"> {
let Spellings = ["exp"];
let Attributes = [NoThrow, ConstIgnoringErrnoAndExceptions];
let Prototype = "T(T)";
- let AddBuiltinPrefixedAlias = 1;
}
def Exp2 : FPMathTemplate, LibBuiltin<"math.h"> {
diff --git a/clang/lib/AST/ByteCode/InterpBuiltin.cpp b/clang/lib/AST/ByteCode/InterpBuiltin.cpp
index 8edc6248dcbfd..be64d93fb1345 100644
--- a/clang/lib/AST/ByteCode/InterpBuiltin.cpp
+++ b/clang/lib/AST/ByteCode/InterpBuiltin.cpp
@@ -18,6 +18,7 @@
#include "clang/Basic/TargetBuiltins.h"
#include "clang/Basic/TargetInfo.h"
#include "llvm/ADT/StringExtras.h"
+#include "llvm/Config/llvm-config.h"
#include "llvm/Support/SipHash.h"
namespace clang {
@@ -419,6 +420,13 @@ static bool interp__builtin_copysign(InterpState &S, CodePtr OpPC,
return true;
}
+static bool interp__builtin_exp(InterpState &S, CodePtr OpPC,
+ const InterpFrame *Frame) {
+ APFloat Result = exp(S.Stk.peek<Floating>().getAPFloat());
+ S.Stk.push<Floating>(Floating(Result));
+ return true;
+}
+
static bool interp__builtin_fmin(InterpState &S, CodePtr OpPC,
const InterpFrame *Frame, bool IsNumBuiltin) {
const Floating &LHS = S.Stk.peek<Floating>(align(primSize(PT_Float)) * 2);
@@ -2315,6 +2323,20 @@ bool InterpretBuiltin(InterpState &S, CodePtr OpPC, const CallExpr *Call,
return false;
break;
+ case Builtin::BI__builtin_exp:
+ case Builtin::BI__builtin_expl:
+ case Builtin::BI__builtin_expf16:
+ case Builtin::BI__builtin_expf128:
+ return false;
+ case Builtin::BI__builtin_expf:
+#ifdef LLVM_INTEGRATE_LIBC
+ if (!interp__builtin_exp(S, OpPC, Frame))
+ return false;
+ break;
+#else
+ return false;
+#endif // LLVM_INTEGRATE_LIBC
+
case Builtin::BI__builtin_fmin:
case Builtin::BI__builtin_fminf:
case Builtin::BI__builtin_fminl:
diff --git a/clang/lib/AST/ExprConstant.cpp b/clang/lib/AST/ExprConstant.cpp
index e9a269337404a..f37e916f67560 100644
--- a/clang/lib/AST/ExprConstant.cpp
+++ b/clang/lib/AST/ExprConstant.cpp
@@ -57,6 +57,7 @@
#include "llvm/ADT/Sequence.h"
#include "llvm/ADT/SmallBitVector.h"
#include "llvm/ADT/StringExtras.h"
+#include "llvm/Config/llvm-config.h"
#include "llvm/Support/Casting.h"
#include "llvm/Support/Debug.h"
#include "llvm/Support/SaveAndRestore.h"
@@ -15711,6 +15712,24 @@ bool FloatExprEvaluator::VisitCallExpr(const CallExpr *E) {
return true;
}
+ // FIXME: allow other __builtin_exp* to be constexpr.
+ case Builtin::BI__builtin_exp:
+ case Builtin::BI__builtin_expl:
+ case Builtin::BI__builtin_expf16:
+ case Builtin::BI__builtin_expf128:
+ return false;
+ case Builtin::BI__builtin_expf: {
+#ifdef LLVM_INTEGRATE_LIBC
+ APFloat Input(0.);
+ if (!EvaluateFloat(E->getArg(0), Input, Info))
+ return false;
+ Result = exp(Input);
+ return true;
+#else
+ return false;
+#endif // LLVM_INTEGRATE_LIBC
+ }
+
case Builtin::BI__builtin_fmax:
case Builtin::BI__builtin_fmaxf:
case Builtin::BI__builtin_fmaxl:
diff --git a/clang/test/CMakeLists.txt b/clang/test/CMakeLists.txt
index 35a8042ac0e0a..5960601a90e8d 100644
--- a/clang/test/CMakeLists.txt
+++ b/clang/test/CMakeLists.txt
@@ -27,6 +27,7 @@ llvm_canonicalize_cmake_booleans(
LLVM_TOOL_LLVM_DRIVER_BUILD
LLVM_INCLUDE_SPIRV_TOOLS_TESTS
LLVM_EXPERIMENTAL_KEY_INSTRUCTIONS
+ LLVM_INTEGRATE_LIBC
)
configure_lit_site_cfg(
diff --git a/clang/test/Preprocessor/feature_tests.cpp b/clang/test/Preprocessor/feature_tests.cpp
index 029f446113af4..7fec4fef9835b 100644
--- a/clang/test/Preprocessor/feature_tests.cpp
+++ b/clang/test/Preprocessor/feature_tests.cpp
@@ -64,6 +64,16 @@
#error Clang should have these constexpr builtins
#endif
+#ifdef LLVM_INTEGRATE_LIBC
+#if !__has_constexpr_builtin(__builtin_expf)
+#error Clang should have these constexpr builtins
+#endif
+#else
+#if __has_constexpr_builtin(__builtin_expf)
+#error This builtin should not be constexpr in Clang
+#endif
+#endif // LLVM_INTEGRATE_LIBC
+
#if !__has_constexpr_builtin(__builtin_convertvector)
#error Clang should have these constexpr builtins
#endif
diff --git a/clang/test/Sema/constant-builtins-exp.cpp b/clang/test/Sema/constant-builtins-exp.cpp
new file mode 100644
index 0000000000000..6e9a2a070c192
--- /dev/null
+++ b/clang/test/Sema/constant-builtins-exp.cpp
@@ -0,0 +1,12 @@
+// RUN: %clang_cc1 -std=c++17 -fsyntax-only -verify %s
+// RUN: %clang_cc1 -std=c++17 -fsyntax-only -verify -fexperimental-new-constant-interpreter %s
+// REQUIRES: llvm_integrate_libc
+// expected-no-diagnostics
+
+constexpr float Inf = __builtin_inff();
+constexpr float NegInf = -__builtin_inff();
+
+static_assert(Inf == __builtin_expf(Inf));
+static_assert(0.0f == __builtin_expf(NegInf));
+static_assert(1.0f == __builtin_expf(0.0f));
+static_assert(0x1.5bf0a8p1f == __builtin_expf(1.0f));
diff --git a/clang/test/lit.cfg.py b/clang/test/lit.cfg.py
index 2b35bb5dcbdaf..a57e33ae70802 100644
--- a/clang/test/lit.cfg.py
+++ b/clang/test/lit.cfg.py
@@ -385,3 +385,6 @@ def calculate_arch_features(arch_string):
# possibly be present in system and user configuration files, so disable
# default configs for the test runs.
config.environment["CLANG_NO_DEFAULT_CONFIG"] = "1"
+
+if config.llvm_integrate_libc:
+ config.available_features.add("llvm_integrate_libc")
diff --git a/clang/test/lit.site.cfg.py.in b/clang/test/lit.site.cfg.py.in
index 77c5f27f47c92..294d1b077ddf2 100644
--- a/clang/test/lit.site.cfg.py.in
+++ b/clang/test/lit.site.cfg.py.in
@@ -49,6 +49,7 @@ config.have_llvm_driver = @LLVM_TOOL_LLVM_DRIVER_BUILD@
config.spirv_tools_tests = @LLVM_INCLUDE_SPIRV_TOOLS_TESTS@
config.substitutions.append(("%llvm-version-major", "@LLVM_VERSION_MAJOR@"))
config.has_key_instructions = @LLVM_EXPERIMENTAL_KEY_INSTRUCTIONS@
+config.llvm_integrate_libc = @LLVM_INTEGRATE_LIBC@
import lit.llvm
lit.llvm.initialize(lit_config, config)
diff --git a/libc/cmake/modules/LLVMLibCCompileOptionRules.cmake b/libc/cmake/modules/LLVMLibCCompileOptionRules.cmake
index 0facb0b9be0c1..a98e7276bef80 100644
--- a/libc/cmake/modules/LLVMLibCCompileOptionRules.cmake
+++ b/libc/cmake/modules/LLVMLibCCompileOptionRules.cmake
@@ -106,6 +106,10 @@ function(_get_compile_options_from_config output_var)
list(APPEND config_options "-DLIBC_MATH=${LIBC_CONF_MATH_OPTIMIZATIONS}")
endif()
+ if(LIBC_CONF_ERRNO_MODE)
+ set(APPEND config_options "-DLIBC_ERRNO_MODE=${LIBC_CONF_ERRNO_MODE}")
+ endif()
+
set(${output_var} ${config_options} PARENT_SCOPE)
endfunction(_get_compile_options_from_config)
diff --git a/libc/cmake/modules/LLVMLibCTestRules.cmake b/libc/cmake/modules/LLVMLibCTestRules.cmake
index 3f804694b5bae..0bef0763ec999 100644
--- a/libc/cmake/modules/LLVMLibCTestRules.cmake
+++ b/libc/cmake/modules/LLVMLibCTestRules.cmake
@@ -1,5 +1,6 @@
function(_get_common_test_compile_options output_var c_test flags)
_get_compile_options_from_flags(compile_flags ${flags})
+ _get_compile_options_from_config(config_flags)
# Remove -fno-math-errno if it was added.
if(LIBC_ADD_FNO_MATH_ERRNO)
@@ -9,7 +10,8 @@ function(_get_common_test_compile_options output_var c_test flags)
set(compile_options
${LIBC_COMPILE_OPTIONS_DEFAULT}
${LIBC_TEST_COMPILE_OPTIONS_DEFAULT}
- ${compile_flags})
+ ${compile_flags}
+ ${config_flags})
if(LLVM_LIBC_COMPILER_IS_GCC_COMPATIBLE)
list(APPEND compile_options "-fpie")
diff --git a/libc/docs/configure.rst b/libc/docs/configure.rst
index 8d53390ae19bf..dee9a63101eb9 100644
--- a/libc/docs/configure.rst
+++ b/libc/docs/configure.rst
@@ -33,7 +33,7 @@ to learn about the defaults for your platform and target.
* **"general" options**
- ``LIBC_ADD_NULL_CHECKS``: Add nullptr checks in the library's implementations to some functions for which passing nullptr is undefined behavior.
* **"math" options**
- - ``LIBC_CONF_FREXP_INF_NAN_EXPONENT``: The value written back to the second parameter when calling frexp/frexpf/frexpl` with `+/-Inf`/`NaN` is unspecified. Configure an explicit exp value for Inf/NaN inputs.
+ - ``LIBC_CONF_FREXP_INF_NAN_EXPONENT``: The value written back to the second parameter when calling frexp/frexpf/frexpl` with `+/-Inf`/`NaN` is unspecified. Configue an explicit exp value for Inf/NaN inputs.
- ``LIBC_CONF_MATH_OPTIMIZATIONS``: Configures optimizations for math functions. Values accepted are LIBC_MATH_SKIP_ACCURATE_PASS, LIBC_MATH_SMALL_TABLES, LIBC_MATH_NO_ERRNO, LIBC_MATH_NO_EXCEPT, and LIBC_MATH_FAST.
* **"printf" options**
- ``LIBC_CONF_PRINTF_DISABLE_FIXED_POINT``: Disable printing fixed point values in printf and friends.
diff --git a/libc/docs/dev/code_style.rst b/libc/docs/dev/code_style.rst
index 0bd3a69ae3ffe..86247966552f9 100644
--- a/libc/docs/dev/code_style.rst
+++ b/libc/docs/dev/code_style.rst
@@ -101,7 +101,7 @@ test infrastructure itself can be affected. To avoid perturbing the unit test
infrastructure around the setting of ``errno``, the following rules are to be
followed:
-#. A special macro named ``libc_errno`` defined in ``src/errno/libc_errno.h``
+#. A special macro named ``libc_errno`` defined in ``src/__support/libc_errno.h``
should be used when setting ``errno`` from libc runtime code. For example,
code to set ``errno`` to ``EINVAL`` should be:
@@ -117,7 +117,7 @@ followed:
`ErrorOr <https://github.com/llvm/llvm-project/blob/main/libc/src/__support/error_or.h>`_
to return error values.
-#. The header file ``src/errno/libc_errno.h`` is shipped as part of the target
+#. The header file ``src/__support/libc_errno.h`` is shipped as part of the target
corresponding to the ``errno`` entrypoint ``libc.src.errno.errno``. We do
not in general allow dependencies between entrypoints. However, the ``errno``
entrypoint is the only exceptional entrypoint on which other entrypoints
diff --git a/libc/shared/math.h b/libc/shared/math.h
new file mode 100644
index 0000000000000..19c49bb23bc39
--- /dev/null
+++ b/libc/shared/math.h
@@ -0,0 +1,22 @@
+//===-- Floating point math functions ---------------------------*- C++ -*-===//
+//
+// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
+// See https://llvm.org/LICENSE.txt for license information.
+// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
+//
+//===----------------------------------------------------------------------===//
+
+#ifndef LLVM_LIBC_SHARED_MATH_H
+#define LLVM_LIBC_SHARED_MATH_H
+
+#include "src/__support/math/expf.h"
+
+namespace LIBC_NAMESPACE_DECL {
+namespace shared {
+
+using math::expf;
+
+} // namespace shared
+} // namespace LIBC_NAMESPACE_DECL
+
+#endif // LLVM_LIBC_SHARED_FP_BITS_H
diff --git a/libc/src/__support/CMakeLists.txt b/libc/src/__support/CMakeLists.txt
index f92499fdbf451..e4a3a7983e4de 100644
--- a/libc/src/__support/CMakeLists.txt
+++ b/libc/src/__support/CMakeLists.txt
@@ -381,3 +381,5 @@ add_subdirectory(HashTable)
add_subdirectory(fixed_point)
add_subdirectory(time)
+
+add_subdirectory(math)
diff --git a/libc/src/__support/FPUtil/FEnvImpl.h b/libc/src/__support/FPUtil/FEnvImpl.h
index 4c8f34a435bdf..50a101f833c55 100644
--- a/libc/src/__support/FPUtil/FEnvImpl.h
+++ b/libc/src/__support/FPUtil/FEnvImpl.h
@@ -12,10 +12,10 @@
#include "hdr/fenv_macros.h"
#include "hdr/math_macros.h"
#include "hdr/types/fenv_t.h"
+#include "src/__support/libc_errno.h"
#include "src/__support/macros/attributes.h" // LIBC_INLINE
#include "src/__support/macros/config.h"
#include "src/__support/macros/properties/architectures.h"
-#include "src/errno/libc_errno.h"
#if defined(LIBC_TARGET_ARCH_IS_AARCH64) && defined(__ARM_FP)
#if defined(__APPLE__)
diff --git a/libc/src/__support/File/dir.cpp b/libc/src/__support/File/dir.cpp
index 21b0106f70106..aea8862c15f7f 100644
--- a/libc/src/__support/File/dir.cpp
+++ b/libc/src/__support/File/dir.cpp
@@ -11,8 +11,8 @@
#include "src/__support/CPP/mutex.h" // lock_guard
#include "src/__support/CPP/new.h"
#include "src/__support/error_or.h"
+#include "src/__support/libc_errno.h" // For error macros
#include "src/__support/macros/config.h"
-#include "src/errno/libc_errno.h" // For error macros
namespace LIBC_NAMESPACE_DECL {
diff --git a/libc/src/__support/File/file.cpp b/libc/src/__support/File/file.cpp
index 528542cccf324..303852dbbb717 100644
--- a/libc/src/__support/File/file.cpp
+++ b/libc/src/__support/File/file.cpp
@@ -13,8 +13,8 @@
#include "hdr/types/off_t.h"
#include "src/__support/CPP/new.h"
#include "src/__support/CPP/span.h"
+#include "src/__support/libc_errno.h" // For error macros
#include "src/__support/macros/config.h"
-#include "src/errno/libc_errno.h" // For error macros
namespace LIBC_NAMESPACE_DECL {
diff --git a/libc/src/__support/File/linux/file.cpp b/libc/src/__support/File/linux/file.cpp
index 824c1f200e8c5..761e352f74ead 100644
--- a/libc/src/__support/File/linux/file.cpp
+++ b/libc/src/__support/File/linux/file.cpp
@@ -15,8 +15,8 @@
#include "src/__support/File/linux/lseekImpl.h"
#include "src/__support/OSUtil/fcntl.h"
#include "src/__support/OSUtil/syscall.h" // For internal syscall function.
+#include "src/__support/libc_errno.h" // For error macros
#include "src/__support/macros/config.h"
-#include "src/errno/libc_errno.h" // For error macros
#include "hdr/fcntl_macros.h" // For mode_t and other flags to the open syscall
#include <sys/stat.h> // For S_IS*, S_IF*, and S_IR* flags.
diff --git a/libc/src/__support/File/linux/lseekImpl.h b/libc/src/__support/File/linux/lseekImpl.h
index a034913d9f6ec..300e5c5dd55bf 100644
--- a/libc/src/__support/File/linux/lseekImpl.h
+++ b/libc/src/__support/File/linux/lseekImpl.h
@@ -13,8 +13,8 @@
#include "src/__support/OSUtil/syscall.h" // For internal syscall function.
#include "src/__support/common.h"
#include "src/__support/error_or.h"
+#include "src/__support/libc_errno.h"
#include "src/__support/macros/config.h"
-#include "src/errno/libc_errno.h"
#include <stdint.h> // For uint64_t.
#include <sys/syscall.h> // For syscall numbers.
diff --git a/libc/src/__support/HashTable/randomness.h b/libc/src/__support/HashTable/randomness.h
index 244dd41be3eec..6b58a4125f785 100644
--- a/libc/src/__support/HashTable/randomness.h
+++ b/libc/src/__support/HashTable/randomness.h
@@ -14,7 +14,7 @@
#include "src/__support/macros/attributes.h"
#include "src/__support/macros/config.h"
#if defined(LIBC_HASHTABLE_USE_GETRANDOM)
-#include "src/errno/libc_errno.h"
+#include "src/__support/libc_errno.h"
#include "src/sys/random/getrandom.h"
#endif
diff --git a/libc/src/__support/OSUtil/linux/fcntl.cpp b/libc/src/__support/OSUtil/linux/fcntl.cpp
index 4742b2a00220b..99e16ad58c918 100644
--- a/libc/src/__support/OSUtil/linux/fcntl.cpp
+++ b/libc/src/__support/OSUtil/linux/fcntl.cpp
@@ -15,8 +15,8 @@
#include "hdr/types/struct_flock64.h"
#include "src/__support/OSUtil/syscall.h" // For internal syscall function.
#include "src/__support/common.h"
+#include "src/__support/libc_errno.h"
#include "src/__support/macros/config.h"
-#include "src/errno/libc_errno.h"
#include <stdarg.h>
#include <sys/syscall.h> // For syscall numbers.
diff --git a/libc/src/__support/OSUtil/linux/vdso.cpp b/libc/src/__support/OSUtil/linux/vdso.cpp
index 8c9bd3e1bcc72..e4e53c3c2a0f2 100644
--- a/libc/src/__support/OSUtil/linux/vdso.cpp
+++ b/libc/src/__support/OSUtil/linux/vdso.cpp
@@ -11,9 +11,9 @@
#include "src/__support/CPP/array.h"
#include "src/__support/CPP/optional.h"
#include "src/__support/CPP/string_view.h"
+#include "src/__support/libc_errno.h"
#include "src/__support/threads/callonce.h"
#include "src/__support/threads/linux/futex_word.h"
-#include "src/errno/libc_errno.h"
#include "src/sys/auxv/getauxval.h"
#include <linux/auxvec.h>
diff --git a/libc/src/__support/StringUtil/tables/linux_extension_errors.h b/libc/src/__support/StringUtil/tables/linux_extension_errors.h
index 425590f6e91c9..de637d60bea97 100644
--- a/libc/src/__support/StringUtil/tables/linux_extension_errors.h
+++ b/libc/src/__support/StringUtil/tables/linux_extension_errors.h
@@ -10,8 +10,8 @@
#define LLVM_LIBC_SRC___SUPPORT_STRINGUTIL_TABLES_LINUX_EXTENSION_ERRORS_H
#include "src/__support/StringUtil/message_mapper.h"
+#include "src/__support/libc_errno.h"
#include "src/__support/macros/config.h"
-#include "src/errno/libc_errno.h"
namespace LIBC_NAMESPACE_DECL {
diff --git a/libc/src/__support/libc_errno.h b/libc/src/__support/libc_errno.h
new file mode 100644
index 0000000000000..cf971d0bd1ae3
--- /dev/null
+++ b/libc/src/__support/libc_errno.h
@@ -0,0 +1,93 @@
+//===-- Implementation header for libc_errno --------------------*- C++ -*-===//
+//
+// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
+// See https://llvm.org/LICENSE.txt for license information.
+// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
+//
+//===----------------------------------------------------------------------===//
+
+#ifndef LLVM_LIBC_SRC___SUPPORT_LIBC_ERRNO_H
+#define LLVM_LIBC_SRC___SUPPORT_LIBC_ERRNO_H
+
+#include "src/__support/macros/attributes.h"
+#include "src/__support/macros/config.h"
+#include "src/__support/macros/properties/architectures.h"
+
+#include "hdr/errno_macros.h"
+
+// This header is to be consumed by internal implementations, in which all of
+// them should refer to `libc_errno` instead of using `errno` directly from
+// <errno.h> header.
+
+// Unit and hermetic tests should:
+// - #include "src/__support/libc_errno.h"
+// - NOT #include <errno.h>
+// - Only use `libc_errno` in the code
+// - Depend on libc.src.errno.errno
+
+// Integration tests should:
+// - NOT #include "src/__support/libc_errno.h"
+// - #include <errno.h>
+// - Use regular `errno` in the code
+// - Still depend on libc.src.errno.errno
+
+// libc uses a fallback default value, either system or thread local.
+#define LIBC_ERRNO_MODE_DEFAULT 0
+// libc never stores a value; `errno` macro uses get link-time failure.
+#define LIBC_ERRNO_MODE_UNDEFINED 1
+// libc maintains per-thread state (requires C++ `thread_local` support).
+#define LIBC_ERRNO_MODE_THREAD_LOCAL 2
+// libc maintains shared state used by all threads, contrary to standard C
+// semantics unless always single-threaded; nothing prevents data races.
+#define LIBC_ERRNO_MODE_SHARED 3
+// libc doesn't maintain any internal state, instead the embedder must define
+// `int *__llvm_libc_errno(void);` C function.
+#define LIBC_ERRNO_MODE_EXTERNAL 4
+// libc uses system `<errno.h>` `errno` macro directly in the overlay mode; in
+// fullbuild mode, effectively the same as `LIBC_ERRNO_MODE_EXTERNAL`.
+#define LIBC_ERRNO_MODE_SYSTEM 5
+
+#if !defined(LIBC_ERRNO_MODE) || LIBC_ERRNO_MODE == LIBC_ERRNO_MODE_DEFAULT
+#undef LIBC_ERRNO_MODE
+#if defined(LIBC_FULL_BUILD) || !defined(LIBC_COPT_PUBLIC_PACKAGING)
+#define LIBC_ERRNO_MODE LIBC_ERRNO_MODE_THREAD_LOCAL
+#else
+#define LIBC_ERRNO_MODE LIBC_ERRNO_MODE_SYSTEM
+#endif
+#endif // LIBC_ERRNO_MODE
+
+#if LIBC_ERRNO_MODE != LIBC_ERRNO_MODE_DEFAULT && \
+ LIBC_ERRNO_MODE != LIBC_ERRNO_MODE_UNDEFINED && \
+ LIBC_ERRNO_MODE != LIBC_ERRNO_MODE_THREAD_LOCAL && \
+ LIBC...
[truncated]
|
vonosmas
reviewed
May 21, 2025
| @@ -83,14 +45,11 @@ Errno::operator int() { return shared_errno; } | |||
| void Errno::operator=(int a) { *__llvm_libc_errno() = a; } | |||
| Errno::operator int() { return *__llvm_libc_errno(); } | |||
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| #elif LIBC_ERRNO_MODE == LIBC_ERRNO_MODE_SYSTEM | |||
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I think it may be cleaner to add this elif in place, and just leave nothing inside, with a comment that in this case the implementation is provided by support header.
| @@ -33,7 +33,7 @@ to learn about the defaults for your platform and target. | |||
| * **"general" options** | |||
| - ``LIBC_ADD_NULL_CHECKS``: Add nullptr checks in the library's implementations to some functions for which passing nullptr is undefined behavior. | |||
| * **"math" options** | |||
| - ``LIBC_CONF_FREXP_INF_NAN_EXPONENT``: The value written back to the second parameter when calling frexp/frexpf/frexpl` with `+/-Inf`/`NaN` is unspecified. Configure an explicit exp value for Inf/NaN inputs. | |||
| - ``LIBC_CONF_FREXP_INF_NAN_EXPONENT``: The value written back to the second parameter when calling frexp/frexpf/frexpl` with `+/-Inf`/`NaN` is unspecified. Configue an explicit exp value for Inf/NaN inputs. | |||
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Does this reverts a landed fix to docs?
| @@ -117,7 +117,7 @@ followed: | |||
| `ErrorOr <https://github.com/llvm/llvm-project/blob/main/libc/src/__support/error_or.h>`_ | |||
| to return error values. | |||
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| #. The header file ``src/errno/libc_errno.h`` is shipped as part of the target | |||
| #. The header file ``src/__support/libc_errno.h`` is shipped as part of the target | |||
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Should this bullet point be revisited? I think that if we're using system errno, targets no longer need to depend on errno. For full-build, conversely, system errno shouldn't be feasible?
| namespace LIBC_NAMESPACE_DECL { | ||
| namespace shared { | ||
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| using math::expf; |
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I wonder if there's any value in having a per-function (or per-function-group) header? E.g. libc/shared/math/exp.h . Otherwise the user who wants to use just one function will include header with all of them, potentially pulling in a bunch of deps they don't want (or won't work on their system).
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I think the |
Yes, I do plan to split the commits into their own PRs. But probably I should go ahead and do the libc_errno refactoring first to reduce the noise for this proof-of-concept PR. |
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A draft PR to make
__builtin_expfconstexpr using LLVM libc math implementation.TODO: Split the commits into their own PRs.