[clang] ca495e3 - [clang] Add a new flag -fexperimental-library to enable experimental library features
Louis Dionne via cfe-commits
cfe-commits at lists.llvm.org
Tue Jul 19 12:05:48 PDT 2022
Author: Louis Dionne
Date: 2022-07-19T15:04:58-04:00
New Revision: ca495e36c1b4d4b8be47c9140647e6e934913cba
URL: https://github.com/llvm/llvm-project/commit/ca495e36c1b4d4b8be47c9140647e6e934913cba
DIFF: https://github.com/llvm/llvm-project/commit/ca495e36c1b4d4b8be47c9140647e6e934913cba.diff
LOG: [clang] Add a new flag -fexperimental-library to enable experimental library features
Based on the discussion at [1], this patch adds a Clang flag called
-fexperimental-library that controls whether experimental library
features are provided in libc++. In essence, it links against the
experimental static archive provided by libc++ and defines a feature
that can be picked up by libc++ to enable experimental features.
This ensures that users don't start depending on experimental
(and hence unstable) features unknowingly.
[1]: https://discourse.llvm.org/t/rfc-a-compiler-flag-to-enable-experimental-unstable-language-and-library-features
Differential Revision: https://reviews.llvm.org/D121141
Added:
clang/test/Driver/experimental-library-flag.cpp
clang/test/Lexer/has_feature_experimental_library.cpp
Modified:
clang/docs/ClangCommandLineReference.rst
clang/include/clang/Basic/Features.def
clang/include/clang/Basic/LangOptions.def
clang/include/clang/Driver/Options.td
clang/lib/Driver/ToolChain.cpp
clang/lib/Driver/ToolChains/AIX.cpp
clang/lib/Driver/ToolChains/BareMetal.cpp
clang/lib/Driver/ToolChains/Clang.cpp
clang/lib/Driver/ToolChains/CloudABI.cpp
clang/lib/Driver/ToolChains/CrossWindows.cpp
clang/lib/Driver/ToolChains/Darwin.cpp
clang/lib/Driver/ToolChains/FreeBSD.cpp
clang/lib/Driver/ToolChains/Fuchsia.cpp
clang/lib/Driver/ToolChains/Hexagon.cpp
clang/lib/Driver/ToolChains/MipsLinux.cpp
clang/lib/Driver/ToolChains/NaCl.cpp
clang/lib/Driver/ToolChains/OpenBSD.cpp
clang/lib/Driver/ToolChains/VEToolchain.cpp
clang/lib/Driver/ToolChains/WebAssembly.cpp
Removed:
clang/test/Driver/unstable-flag.cpp
clang/test/Lexer/has_feature_cxx_unstable.cpp
################################################################################
diff --git a/clang/docs/ClangCommandLineReference.rst b/clang/docs/ClangCommandLineReference.rst
index 223990e0517f1..6d1b6000484ce 100644
--- a/clang/docs/ClangCommandLineReference.rst
+++ b/clang/docs/ClangCommandLineReference.rst
@@ -1761,6 +1761,10 @@ Enable support for exception handling
.. option:: -fexec-charset=<arg>
+.. option:: -fexperimental-library, -fno-experimental-library
+
+Control whether unstable and experimental library features are enabled. This option enables various library features that are either experimental (also known as TSes), or have been but are not stable yet in the selected Standard Library implementation. It is not recommended to use this option in production code, since neither ABI nor API stability are guaranteed. This is intended to provide a preview of features that will ship in the future for experimentation purposes
+
.. option:: -fexperimental-new-constant-interpreter
Enable the experimental new constant interpreter
@@ -2637,10 +2641,6 @@ Turn on loop unroller
.. option:: -funsigned-char, -fno-unsigned-char, --unsigned-char
-.. option:: -funstable, -fno-unstable
-
-Enable unstable and experimental features
-
.. option:: -funwind-tables, -fno-unwind-tables
.. option:: -fuse-cxa-atexit, -fno-use-cxa-atexit
diff --git a/clang/include/clang/Basic/Features.def b/clang/include/clang/Basic/Features.def
index a7f0ae03e0beb..7151e923ae9cf 100644
--- a/clang/include/clang/Basic/Features.def
+++ b/clang/include/clang/Basic/Features.def
@@ -179,7 +179,6 @@ FEATURE(cxx_thread_local,
FEATURE(cxx_trailing_return, LangOpts.CPlusPlus11)
FEATURE(cxx_unicode_literals, LangOpts.CPlusPlus11)
FEATURE(cxx_unrestricted_unions, LangOpts.CPlusPlus11)
-FEATURE(cxx_unstable, LangOpts.Unstable)
FEATURE(cxx_user_literals, LangOpts.CPlusPlus11)
FEATURE(cxx_variadic_templates, LangOpts.CPlusPlus11)
// C++14 features
@@ -235,6 +234,7 @@ FEATURE(shadow_call_stack,
LangOpts.Sanitize.has(SanitizerKind::ShadowCallStack))
FEATURE(tls, PP.getTargetInfo().isTLSSupported())
FEATURE(underlying_type, LangOpts.CPlusPlus)
+FEATURE(experimental_library, LangOpts.ExperimentalLibrary)
// C11 features supported by other languages as extensions.
EXTENSION(c_alignas, true)
diff --git a/clang/include/clang/Basic/LangOptions.def b/clang/include/clang/Basic/LangOptions.def
index ba6ce4e9250f4..6fb31c5655abf 100644
--- a/clang/include/clang/Basic/LangOptions.def
+++ b/clang/include/clang/Basic/LangOptions.def
@@ -155,7 +155,7 @@ LANGOPT(GNUAsm , 1, 1, "GNU-style inline assembly")
LANGOPT(Coroutines , 1, 0, "C++20 coroutines")
LANGOPT(DllExportInlines , 1, 1, "dllexported classes dllexport inline methods")
LANGOPT(RelaxedTemplateTemplateArgs, 1, 0, "C++17 relaxed matching of template template arguments")
-LANGOPT(Unstable , 1, 0, "Enable unstable and experimental features")
+LANGOPT(ExperimentalLibrary, 1, 0, "enable unstable and experimental library features")
LANGOPT(DoubleSquareBracketAttributes, 1, 0, "'[[]]' attributes extension for all language standard modes")
diff --git a/clang/include/clang/Driver/Options.td b/clang/include/clang/Driver/Options.td
index 94b5f6656de07..88b675ee8a2cb 100644
--- a/clang/include/clang/Driver/Options.td
+++ b/clang/include/clang/Driver/Options.td
@@ -1189,9 +1189,13 @@ defm coroutines_ts : BoolFOption<"coroutines-ts",
PosFlag<SetTrue, [CC1Option], "Enable support for the C++ Coroutines TS">,
NegFlag<SetFalse>>;
-defm unstable : BoolFOption<"unstable",
- LangOpts<"Unstable">, DefaultFalse,
- PosFlag<SetTrue, [CC1Option, CoreOption], "Enable unstable and experimental features">,
+defm experimental_library : BoolFOption<"experimental-library",
+ LangOpts<"ExperimentalLibrary">, DefaultFalse,
+ PosFlag<SetTrue, [CC1Option, CoreOption], "Control whether unstable and experimental library features are enabled. "
+ "This option enables various library features that are either experimental (also known as TSes), or have been "
+ "but are not stable yet in the selected Standard Library implementation. It is not recommended to use this option "
+ "in production code, since neither ABI nor API stability are guaranteed. This is intended to provide a preview "
+ "of features that will ship in the future for experimentation purposes">,
NegFlag<SetFalse>>;
def fembed_offload_object_EQ : Joined<["-"], "fembed-offload-object=">,
diff --git a/clang/lib/Driver/ToolChain.cpp b/clang/lib/Driver/ToolChain.cpp
index 5130eb9b72c13..7a4319ea680f9 100644
--- a/clang/lib/Driver/ToolChain.cpp
+++ b/clang/lib/Driver/ToolChain.cpp
@@ -1013,6 +1013,8 @@ void ToolChain::AddCXXStdlibLibArgs(const ArgList &Args,
switch (Type) {
case ToolChain::CST_Libcxx:
CmdArgs.push_back("-lc++");
+ if (Args.hasArg(options::OPT_fexperimental_library))
+ CmdArgs.push_back("-lc++experimental");
break;
case ToolChain::CST_Libstdcxx:
diff --git a/clang/lib/Driver/ToolChains/AIX.cpp b/clang/lib/Driver/ToolChains/AIX.cpp
index 878b84a777027..19054ae53d7bb 100644
--- a/clang/lib/Driver/ToolChains/AIX.cpp
+++ b/clang/lib/Driver/ToolChains/AIX.cpp
@@ -275,6 +275,8 @@ void AIX::AddCXXStdlibLibArgs(const llvm::opt::ArgList &Args,
llvm::report_fatal_error("linking libstdc++ unimplemented on AIX");
case ToolChain::CST_Libcxx:
CmdArgs.push_back("-lc++");
+ if (Args.hasArg(options::OPT_fexperimental_library))
+ CmdArgs.push_back("-lc++experimental");
CmdArgs.push_back("-lc++abi");
return;
}
diff --git a/clang/lib/Driver/ToolChains/BareMetal.cpp b/clang/lib/Driver/ToolChains/BareMetal.cpp
index cd07692be3583..5f1638a159d52 100644
--- a/clang/lib/Driver/ToolChains/BareMetal.cpp
+++ b/clang/lib/Driver/ToolChains/BareMetal.cpp
@@ -276,6 +276,8 @@ void BareMetal::AddCXXStdlibLibArgs(const ArgList &Args,
switch (GetCXXStdlibType(Args)) {
case ToolChain::CST_Libcxx:
CmdArgs.push_back("-lc++");
+ if (Args.hasArg(options::OPT_fexperimental_library))
+ CmdArgs.push_back("-lc++experimental");
CmdArgs.push_back("-lc++abi");
break;
case ToolChain::CST_Libstdcxx:
diff --git a/clang/lib/Driver/ToolChains/Clang.cpp b/clang/lib/Driver/ToolChains/Clang.cpp
index 881ba3fba44ea..9a4b643c19510 100644
--- a/clang/lib/Driver/ToolChains/Clang.cpp
+++ b/clang/lib/Driver/ToolChains/Clang.cpp
@@ -5858,12 +5858,7 @@ void Clang::ConstructJob(Compilation &C, const JobAction &JA,
CmdArgs.push_back(A->getValue());
}
- if (Args.hasArg(options::OPT_funstable)) {
- CmdArgs.push_back("-funstable");
- if (!Args.hasArg(options::OPT_fno_coroutines_ts))
- CmdArgs.push_back("-fcoroutines-ts");
- CmdArgs.push_back("-fmodules-ts");
- }
+ Args.AddLastArg(CmdArgs, options::OPT_fexperimental_library);
if (Args.hasArg(options::OPT_fexperimental_new_constant_interpreter))
CmdArgs.push_back("-fexperimental-new-constant-interpreter");
diff --git a/clang/lib/Driver/ToolChains/CloudABI.cpp b/clang/lib/Driver/ToolChains/CloudABI.cpp
index 501e3a382ec1f..9fd0529a32974 100644
--- a/clang/lib/Driver/ToolChains/CloudABI.cpp
+++ b/clang/lib/Driver/ToolChains/CloudABI.cpp
@@ -117,6 +117,8 @@ void CloudABI::addLibCxxIncludePaths(const llvm::opt::ArgList &DriverArgs,
void CloudABI::AddCXXStdlibLibArgs(const ArgList &Args,
ArgStringList &CmdArgs) const {
CmdArgs.push_back("-lc++");
+ if (Args.hasArg(options::OPT_fexperimental_library))
+ CmdArgs.push_back("-lc++experimental");
CmdArgs.push_back("-lc++abi");
CmdArgs.push_back("-lunwind");
}
diff --git a/clang/lib/Driver/ToolChains/CrossWindows.cpp b/clang/lib/Driver/ToolChains/CrossWindows.cpp
index 2b043fbeecdaf..681a6824dad1e 100644
--- a/clang/lib/Driver/ToolChains/CrossWindows.cpp
+++ b/clang/lib/Driver/ToolChains/CrossWindows.cpp
@@ -273,8 +273,11 @@ AddClangCXXStdlibIncludeArgs(const llvm::opt::ArgList &DriverArgs,
void CrossWindowsToolChain::
AddCXXStdlibLibArgs(const llvm::opt::ArgList &Args,
llvm::opt::ArgStringList &CmdArgs) const {
- if (GetCXXStdlibType(Args) == ToolChain::CST_Libcxx)
+ if (GetCXXStdlibType(Args) == ToolChain::CST_Libcxx) {
CmdArgs.push_back("-lc++");
+ if (Args.hasArg(options::OPT_fexperimental_library))
+ CmdArgs.push_back("-lc++experimental");
+ }
}
clang::SanitizerMask CrossWindowsToolChain::getSupportedSanitizers() const {
diff --git a/clang/lib/Driver/ToolChains/Darwin.cpp b/clang/lib/Driver/ToolChains/Darwin.cpp
index c9e773701ac3f..71b0c5bc9c710 100644
--- a/clang/lib/Driver/ToolChains/Darwin.cpp
+++ b/clang/lib/Driver/ToolChains/Darwin.cpp
@@ -2448,6 +2448,7 @@ void DarwinClang::AddClangCXXStdlibIncludeArgs(
break;
}
}
+
void DarwinClang::AddCXXStdlibLibArgs(const ArgList &Args,
ArgStringList &CmdArgs) const {
CXXStdlibType Type = GetCXXStdlibType(Args);
@@ -2455,6 +2456,8 @@ void DarwinClang::AddCXXStdlibLibArgs(const ArgList &Args,
switch (Type) {
case ToolChain::CST_Libcxx:
CmdArgs.push_back("-lc++");
+ if (Args.hasArg(options::OPT_fexperimental_library))
+ CmdArgs.push_back("-lc++experimental");
break;
case ToolChain::CST_Libstdcxx:
diff --git a/clang/lib/Driver/ToolChains/FreeBSD.cpp b/clang/lib/Driver/ToolChains/FreeBSD.cpp
index 1476d11cd16d5..fec80f85e2787 100644
--- a/clang/lib/Driver/ToolChains/FreeBSD.cpp
+++ b/clang/lib/Driver/ToolChains/FreeBSD.cpp
@@ -430,6 +430,8 @@ void FreeBSD::AddCXXStdlibLibArgs(const ArgList &Args,
switch (Type) {
case ToolChain::CST_Libcxx:
CmdArgs.push_back(Profiling ? "-lc++_p" : "-lc++");
+ if (Args.hasArg(options::OPT_fexperimental_library))
+ CmdArgs.push_back("-lc++experimental");
break;
case ToolChain::CST_Libstdcxx:
diff --git a/clang/lib/Driver/ToolChains/Fuchsia.cpp b/clang/lib/Driver/ToolChains/Fuchsia.cpp
index f96cfde8e9570..d63c69c63b1fc 100644
--- a/clang/lib/Driver/ToolChains/Fuchsia.cpp
+++ b/clang/lib/Driver/ToolChains/Fuchsia.cpp
@@ -417,6 +417,8 @@ void Fuchsia::AddCXXStdlibLibArgs(const ArgList &Args,
switch (GetCXXStdlibType(Args)) {
case ToolChain::CST_Libcxx:
CmdArgs.push_back("-lc++");
+ if (Args.hasArg(options::OPT_fexperimental_library))
+ CmdArgs.push_back("-lc++experimental");
break;
case ToolChain::CST_Libstdcxx:
diff --git a/clang/lib/Driver/ToolChains/Hexagon.cpp b/clang/lib/Driver/ToolChains/Hexagon.cpp
index ed07e710fc49b..0e47704ab636a 100644
--- a/clang/lib/Driver/ToolChains/Hexagon.cpp
+++ b/clang/lib/Driver/ToolChains/Hexagon.cpp
@@ -616,6 +616,8 @@ void HexagonToolChain::AddCXXStdlibLibArgs(const ArgList &Args,
CmdArgs.push_back("-lc++");
CmdArgs.push_back("-lc++abi");
CmdArgs.push_back("-lunwind");
+ if (Args.hasArg(options::OPT_fexperimental_library))
+ CmdArgs.push_back("-lc++experimental");
break;
case ToolChain::CST_Libstdcxx:
diff --git a/clang/lib/Driver/ToolChains/MipsLinux.cpp b/clang/lib/Driver/ToolChains/MipsLinux.cpp
index 41b7b839f3b32..9c58583bca770 100644
--- a/clang/lib/Driver/ToolChains/MipsLinux.cpp
+++ b/clang/lib/Driver/ToolChains/MipsLinux.cpp
@@ -112,6 +112,8 @@ void MipsLLVMToolChain::AddCXXStdlibLibArgs(const ArgList &Args,
"Only -lc++ (aka libxx) is supported in this toolchain.");
CmdArgs.push_back("-lc++");
+ if (Args.hasArg(options::OPT_fexperimental_library))
+ CmdArgs.push_back("-lc++experimental");
CmdArgs.push_back("-lc++abi");
CmdArgs.push_back("-lunwind");
}
diff --git a/clang/lib/Driver/ToolChains/NaCl.cpp b/clang/lib/Driver/ToolChains/NaCl.cpp
index 753459cb230b7..38151735ee51f 100644
--- a/clang/lib/Driver/ToolChains/NaCl.cpp
+++ b/clang/lib/Driver/ToolChains/NaCl.cpp
@@ -308,6 +308,8 @@ void NaClToolChain::AddCXXStdlibLibArgs(const ArgList &Args,
// if the value is libc++, and emits an error for other values.
GetCXXStdlibType(Args);
CmdArgs.push_back("-lc++");
+ if (Args.hasArg(options::OPT_fexperimental_library))
+ CmdArgs.push_back("-lc++experimental");
}
void NaClToolChain::addLibCxxIncludePaths(
diff --git a/clang/lib/Driver/ToolChains/OpenBSD.cpp b/clang/lib/Driver/ToolChains/OpenBSD.cpp
index cd50582c30e84..44cc9dee67f4d 100644
--- a/clang/lib/Driver/ToolChains/OpenBSD.cpp
+++ b/clang/lib/Driver/ToolChains/OpenBSD.cpp
@@ -331,6 +331,8 @@ void OpenBSD::AddCXXStdlibLibArgs(const ArgList &Args,
bool Profiling = Args.hasArg(options::OPT_pg);
CmdArgs.push_back(Profiling ? "-lc++_p" : "-lc++");
+ if (Args.hasArg(options::OPT_fexperimental_library))
+ CmdArgs.push_back("-lc++experimental");
CmdArgs.push_back(Profiling ? "-lc++abi_p" : "-lc++abi");
CmdArgs.push_back(Profiling ? "-lpthread_p" : "-lpthread");
}
diff --git a/clang/lib/Driver/ToolChains/VEToolchain.cpp b/clang/lib/Driver/ToolChains/VEToolchain.cpp
index 1e43796be1ff8..9be239262db8d 100644
--- a/clang/lib/Driver/ToolChains/VEToolchain.cpp
+++ b/clang/lib/Driver/ToolChains/VEToolchain.cpp
@@ -141,6 +141,8 @@ void VEToolChain::AddCXXStdlibLibArgs(const ArgList &Args,
tools::addArchSpecificRPath(*this, Args, CmdArgs);
CmdArgs.push_back("-lc++");
+ if (Args.hasArg(options::OPT_fexperimental_library))
+ CmdArgs.push_back("-lc++experimental");
CmdArgs.push_back("-lc++abi");
CmdArgs.push_back("-lunwind");
// libc++ requires -lpthread under glibc environment
diff --git a/clang/lib/Driver/ToolChains/WebAssembly.cpp b/clang/lib/Driver/ToolChains/WebAssembly.cpp
index c5e4d569793c3..b051bff875127 100644
--- a/clang/lib/Driver/ToolChains/WebAssembly.cpp
+++ b/clang/lib/Driver/ToolChains/WebAssembly.cpp
@@ -444,6 +444,8 @@ void WebAssembly::AddCXXStdlibLibArgs(const llvm::opt::ArgList &Args,
switch (GetCXXStdlibType(Args)) {
case ToolChain::CST_Libcxx:
CmdArgs.push_back("-lc++");
+ if (Args.hasArg(options::OPT_fexperimental_library))
+ CmdArgs.push_back("-lc++experimental");
CmdArgs.push_back("-lc++abi");
break;
case ToolChain::CST_Libstdcxx:
diff --git a/clang/test/Driver/experimental-library-flag.cpp b/clang/test/Driver/experimental-library-flag.cpp
new file mode 100644
index 0000000000000..f3986bc1415a7
--- /dev/null
+++ b/clang/test/Driver/experimental-library-flag.cpp
@@ -0,0 +1,15 @@
+// On Windows, -stdlib=libc++ is currently ignored, so -lc++experimental is not added.
+// Once -stdlib=libc++ works on Windows, this XFAIL can be removed.
+// XFAIL: windows
+
+// RUN: %clangxx -fexperimental-library -stdlib=libc++ -### %s 2>&1 | FileCheck --check-prefixes=CHECK,CHECK-LIBCXX %s
+// RUN: %clangxx -fexperimental-library -stdlib=libstdc++ -### %s 2>&1 | FileCheck --check-prefixes=CHECK,CHECK-LIBSTDCXX %s
+// RUN: %clangxx -fexperimental-library -stdlib=libc++ -nostdlib++ -### %s 2>&1 | FileCheck --check-prefixes=CHECK,CHECK-NOSTDLIB %s
+
+// -fexperimental-library must be passed to CC1.
+// CHECK: -fexperimental-library
+
+// Depending on the stdlib in use, we should (or not) pass -lc++experimental.
+// CHECK-LIBCXX: -lc++experimental
+// CHECK-LIBSTDCXX-NOT: -lc++experimental
+// CHECK-NOSTDLIB-NOT: -lc++experimental
diff --git a/clang/test/Driver/unstable-flag.cpp b/clang/test/Driver/unstable-flag.cpp
deleted file mode 100644
index 7e241facf76e5..0000000000000
--- a/clang/test/Driver/unstable-flag.cpp
+++ /dev/null
@@ -1,5 +0,0 @@
-// RUN: %clang -funstable -### %s 2>&1 | FileCheck %s
-
-// CHECK: -funstable
-// CHECK: -fcoroutines-ts
-// CHECK: -fmodules-ts
diff --git a/clang/test/Lexer/has_feature_cxx_unstable.cpp b/clang/test/Lexer/has_feature_cxx_unstable.cpp
deleted file mode 100644
index c4ce45a93075d..0000000000000
--- a/clang/test/Lexer/has_feature_cxx_unstable.cpp
+++ /dev/null
@@ -1,10 +0,0 @@
-// RUN: %clang_cc1 -funstable -E %s -o - | FileCheck --check-prefix=CHECK-UNSTABLE %s
-// RUN: %clang_cc1 -E %s -o - | FileCheck --check-prefix=CHECK-NO-UNSTABLE %s
-
-#if __has_feature(cxx_unstable)
-int has_cxx_unstable();
-#else
-int has_no_cxx_unstable();
-#endif
-// CHECK-UNSTABLE: int has_cxx_unstable();
-// CHECK-NO-UNSTABLE: int has_no_cxx_unstable();
diff --git a/clang/test/Lexer/has_feature_experimental_library.cpp b/clang/test/Lexer/has_feature_experimental_library.cpp
new file mode 100644
index 0000000000000..98921ef62afcc
--- /dev/null
+++ b/clang/test/Lexer/has_feature_experimental_library.cpp
@@ -0,0 +1,10 @@
+// RUN: %clang_cc1 -E -fexperimental-library %s -o - | FileCheck --check-prefix=CHECK-EXPERIMENTAL %s
+// RUN: %clang_cc1 -E %s -o - | FileCheck --check-prefix=CHECK-NO-EXPERIMENTAL %s
+
+#if __has_feature(experimental_library)
+int has_experimental_library();
+#else
+int has_no_experimental_library();
+#endif
+// CHECK-EXPERIMENTAL: int has_experimental_library();
+// CHECK-NO-EXPERIMENTAL: int has_no_experimental_library();
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