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Diffstat (limited to 'butl/target-triplet')
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diff --git a/butl/target-triplet b/butl/target-triplet new file mode 100644 index 0000000..d355d75 --- /dev/null +++ b/butl/target-triplet @@ -0,0 +1,155 @@ +// file : butl/target-triplet -*- C++ -*- +// copyright : Copyright (c) 2014-2017 Code Synthesis Ltd +// license : MIT; see accompanying LICENSE file + +#ifndef BUTL_TARGET_TRIPLET +#define BUTL_TARGET_TRIPLET + +#include <string> +#include <ostream> + +#include <butl/export> + +namespace butl +{ + // This is the ubiquitous 'target triplet' that loosely has the CPU-VENDOR-OS + // form which, these days, quite often takes the CPU-VENDOR-OS-ABI form. Plus + // some fields can sometimes be omitted. This looseness makes it hard to base + // any kind of decisions on the triplet without canonicalizing it and then + // splitting it into components. The way we are going to split it is like + // this: + // + // CPU + // + // This one is reasonably straightforward. Note that we always expect at + // least two components with the first being the CPU. In other words, we + // don't try to guess what just 'mingw32' might mean like config.sub does. + // + // VENDOR + // + // This can be a machine vendor as in i686-apple-darwin8, a toolchain vendor + // as in i686-lfs-linux-gnu, or something else as in arm-softfloat-linux-gnu. + // Just as we think vendor is pretty irrelevant and can be ignored, comes + // MinGW-W64 and calls itself *-w64-mingw32. While it is tempting to + // attribute w64 to OS-ABI, the MinGW-W64 folks insist it is a (presumably + // toolchain) vendor. + // + // Another example where the vendor seems to be reused for something else + // entirely is the Intel's MIC architecture: x86_64-k1om-linux. + // + // To make things more regular we also convert the information-free vendor + // names 'pc', 'unknown' and 'none' to the empty name. + // + // OS/KERNEL-OS/OS-ABI + // + // This is where things get really messy and instead of trying to guess, we + // call the entire thing SYSTEM. Except, in certain cases, we factor out the + // trailing version, again, to make SYSTEM easier to compare to. For example, + // *-darwin14.5.0 becomes 'darwin' and '14.5.0'. + // + // Again, to make things more regular, if the first component in SYSTEM is + // none, then it is removed (so *-none-eabi becomes just 'eabi'). + // + // Values for two-component systems (e.g., linux-gnu) that don't specify + // VENDOR explicitly are inherently ambiguous: is 'linux' VENDOR or part of + // SYSTEM? The only way to handle this is to recognize their specific names + // as special cases and this is what we do for some of the more common + // ones. The alternative would be to first run such names through config.sub + // which adds explicit VENDOR and this could be a reasonable fallback + // strategy for (presumably less common) cases were we don't split things + // correctly. + // + // Note also that the version splitting is only done for certain commonly- + // used targets. + // + // Some examples of canonicalization and splitting: + // + // x86_64-apple-darwin14.5.0 x86_64 apple darwin 14.5.0 + // x86_64-unknown-freebsd10.2 x86_64 freebsd 10.2 + // i686-elf i686 elf + // arm-eabi arm eabi + // arm-none-eabi arm eabi + // arm-none-linux-gnueabi arm linux-gnueabi + // arm-softfloat-linux-gnu arm softfloat linux-gnu + // i686-pc-mingw32 i686 mingw32 + // i686-w64-mingw32 i686 w64 mingw32 + // i686-lfs-linux-gnu i686 lfs linux-gnu + // x86_64-unknown-linux-gnu x86_64 linux-gnu + // x86_64-linux-gnux32 x86_64 linux-gnux32 + // x86_64-microsoft-win32-msvc14.0 x86_64 microsoft win32-msvc 14.0 + // + // Similar to version splitting, for certain commonly-used targets we also + // derive the "target class" which can be used as a shorthand, more + // convenient way to identify a targets. If the target is not recognized, + // then the special 'other' value is used. Currently the following classes + // are recognized: + // + // linux *-*-linux-* + // macosx *-apple-darwin* + // bsd *-*-(freebsd|openbsd|netbsd)* + // windows *-*-win32-* | *-*-mingw32 + // + // References: + // + // 1. The libtool repository contains the PLATFORM file that lists many known + // triplets. + // + // 2. LLVM has the Triple class with similar goals. + // + struct LIBBUTL_EXPORT target_triplet + { + std::string cpu; + std::string vendor; + std::string system; + std::string version; + std::string class_; + + // Assemble and returning the canonical (i.e., the one we round-trip) + // target triplet string. + // + std::string + string () const; + + bool + empty () const {return cpu.empty ();} + + int + compare (const target_triplet& y) const + { + int r; + return + (r = cpu.compare (y.cpu)) != 0 ? r : + (r = vendor.compare (y.vendor)) != 0 ? r : + (r = system.compare (y.system)) != 0 ? r : + ( version.compare (y.version)); + } + + // Parse the triplet throw std::invalid_argument if the triplet is not + // recognizable. + // + explicit + target_triplet (const std::string&); + + target_triplet () = default; + }; + + inline bool + operator== (const target_triplet& x, const target_triplet& y) + { + return x.compare (y) == 0; + } + + inline bool + operator!= (const target_triplet& x, const target_triplet& y) + { + return !(x == y); + } + + inline std::ostream& + operator<< (std::ostream& o, const target_triplet& x) + { + return o << x.string (); + } +}; + +#endif // BUTL_TARGET_TRIPLET |