Hello,
I am getting compile error addressed Swift Float80 when building Swift on macOS cross-compile host targeted Android Intel x86 and x86_64 targets: #error "Are you certain 'long double' on this platform is really Intel 80-bit extended precision?". See details below:
cd /swift-everywhere-toolchain/ToolChain/Build/darwin/swift && ninja -j3 swiftGlibc-android-i686 swiftCore-android-i686 swiftSwiftOnoneSupport-android-i686
[33/75] Building CXX object stdlib/public/runtime/CMakeFiles/swiftRuntime-android-i686.dir/SwiftDtoa.cpp.o
FAILED: stdlib/public/runtime/CMakeFiles/swiftRuntime-android-i686.dir/SwiftDtoa.cpp.o
/swift-everywhere-toolchain/ToolChain/Build/darwin/llvm/./bin/clang++ \
-DCMARK_STATIC_DEFINE -DGTEST_HAS_RTTI=0 -D_DEBUG -D__STDC_CONSTANT_MACROS \
-D__STDC_FORMAT_MACROS -D__STDC_LIMIT_MACROS -Istdlib/public/runtime \
-I/swift-everywhere-toolchain/ToolChain/Sources/swift/stdlib/public/runtime \
-Iinclude -I/swift-everywhere-toolchain/ToolChain/Sources/swift/include \
-I/swift-everywhere-toolchain/ToolChain/Sources/llvm/include \
-I/swift-everywhere-toolchain/ToolChain/Build/darwin/llvm/include \
-I/swift-everywhere-toolchain/ToolChain/Sources/llvm/tools/clang/include \
-I/swift-everywhere-toolchain/ToolChain/Build/darwin/llvm/tools/clang/include \
-I/swift-everywhere-toolchain/ToolChain/Sources/cmark/src \
-I/swift-everywhere-toolchain/ToolChain/Build/darwin/cmark/src \
-Wno-unknown-warning-option -Werror=unguarded-availability-new -fno-stack-protector \
-fPIC -fvisibility-inlines-hidden -Werror=date-time -Werror=unguarded-availability-new -std=c++11 -Wall -Wextra -Wno-unused-parameter \
-Wwrite-strings -Wcast-qual -Wmissing-field-initializers -Wimplicit-fallthrough -Wcovered-switch-default -Wno-class-memaccess \
-Wno-noexcept-type -Wnon-virtual-dtor -Wdelete-non-virtual-dtor -Wstring-conversion -fdiagnostics-color -Werror=switch -Wdocumentation \
-Wimplicit-fallthrough -Wunreachable-code -Woverloaded-virtual -DOBJC_OLD_DISPATCH_PROTOTYPES=0 \
-fno-sanitize=all -DLLVM_DISABLE_ABI_BREAKING_CHECKS_ENFORCING=1 -O3 \
-isysroot /Volumes/Data/Applications/Xcode.app/Contents/Developer/Platforms/MacOSX.platform/Developer/SDKs/MacOSX.sdk \
-UNDEBUG -fno-exceptions -fno-rtti -Wall -Wglobal-constructors -Wexit-time-destructors -fvisibility=hidden -DswiftCore_EXPORTS \
-I/swift-everywhere-toolchain/ToolChain/Sources/swift/include -DSWIFT_TARGET_LIBRARY_NAME=swiftRuntime \
-target i686-unknown-linux-android \
--sysroot=/Users/vova/Library/Android/sdk/ndk-bundle/platforms/android-24/arch-x86 \
-B /Users/vova/Library/Android/sdk/ndk-bundle/toolchains/x86-4.9/prebuilt/darwin-x86_64/i686-linux-android/bin \
-O2 -momit-leaf-frame-pointer -g0 -DNDEBUG -I/ndk-bundle/sources/cxx-stl/llvm-libc++/include \
/ndk-bundle/sysroot/usr/include/i686-linux-android -D__ANDROID_API__=24 \
-isystem /swift-everywhere-toolchain/ToolChain/Sources/icu/icu4c/source/common \
-isystem /swift-everywhere-toolchain/ToolChain/Sources/icu/icu4c/source/i18n \
-MD -MT stdlib/public/runtime/CMakeFiles/swiftRuntime-android-i686.dir/SwiftDtoa.cpp.o \
-MF stdlib/public/runtime/CMakeFiles/swiftRuntime-android-i686.dir/SwiftDtoa.cpp.o.d \
-o stdlib/public/runtime/CMakeFiles/swiftRuntime-android-i686.dir/SwiftDtoa.cpp.o \
-c /swift-everywhere-toolchain/ToolChain/Sources/swift/stdlib/public/runtime/SwiftDtoa.cpp
/swift-everywhere-toolchain/ToolChain/Sources/swift/stdlib/public/runtime/SwiftDtoa.cpp:148:2: error: "Are you certain `long double` on this platform is really Intel 80-bit extended precision?"
#error "Are you certain `long double` on this platform is really Intel 80-bit extended precision?"
^
1 error generated.
This error can be eliminated by disabling Float80 support:
diff --git a/include/swift/Runtime/SwiftDtoa.h b/include/swift/Runtime/SwiftDtoa.h
index c309d2e97985ef70d6c714ca802e00831f113fe9..07670af400c2b6a137b18b73b34406dd41002a8e 100644
--- a/include/swift/Runtime/SwiftDtoa.h
+++ b/include/swift/Runtime/SwiftDtoa.h
@@ -37,6 +37,10 @@
#endif
#endif
+#if defined(__ANDROID__) && (defined(__i386) || defined(__x86_64__))
+ #undef SWIFT_DTOA_FLOAT80_SUPPORT
+#endif
+
#ifdef __cplusplus
extern "C" {
#endif
Plus similar changes in various places inside stdlib:
diff --git a/stdlib/public/core/FloatingPoint.swift b/stdlib/public/core/FloatingPoint.swift
index a5ecdf598395e5d0b4515dc5455fdd9f4fbc4b44..03a3e9d364ff22958af623bfec7a91bb1ff7dcac 100644
--- a/stdlib/public/core/FloatingPoint.swift
+++ b/stdlib/public/core/FloatingPoint.swift
@@ -1491,7 +1491,7 @@ public protocol BinaryFloatingPoint: FloatingPoint, ExpressibleByFloatLiteral {
/// - Parameter value: A floating-point value to be converted.
init(_ value: Double)
-#if !os(Windows) && (arch(i386) || arch(x86_64))
+#if !(os(Windows) || os(Android)) && (arch(i386) || arch(x86_64))
/// Creates a new instance from the given value, rounded to the closest
/// possible representation.
///
Is it a good idea to disable Float80 support for Android Intel x86 and x86_64 targets (i.e. Android Simulators) to avoid build errors?
I want to clarify this before making Pull Request.
Thanks!