Add support for parsing cpu-vendor-os target triplets

1 files changed, 121 insertions, 0 deletions

diff --git a/butl/triplet.cxx b/butl/triplet.cxx
new file mode 100644
index 0000000..3208375
--- /dev/null
+++ b/butl/triplet.cxx
@@ -0,0 +1,121 @@
+// file      : butl/triplet.cxx -*- C++ -*-
+// copyright : Copyright (c) 2014-2016 Code Synthesis Ltd
+// license   : MIT; see accompanying LICENSE file
+
+#include <butl/triplet>
+
+#include <stdexcept> // invalid_argument
+
+using namespace std;
+
+namespace butl
+{
+  triplet::
+  triplet (const string& s, string* c)
+  {
+    auto bad = [](const char* m) {throw invalid_argument (m);};
+
+    // Find the first and the last components. The first is CPU and the last is
+    // (part of) SYSTEM, that we know for sure.
+    //
+    string::size_type f (s.find ('-')), l (s.rfind ('-'));
+
+    if (f == 0 || f == string::npos)
+      bad ("missing cpu");
+
+    cpu.assign (s, 0, f);
+
+    if (c != nullptr)
+      *c = cpu;
+
+    // If we have something in between, then the first component after CPU is
+    // VENDOR. Unless it is a first component of two-component system, as in
+    // i686-linux-gnu.
+    //
+    if (f != l)
+    {
+      // [f, p) is VENDOR.
+      //
+      string::size_type p (s.find ('-', ++f)), n (p - f);
+
+      if (n == 0)
+        bad ("empty vendor");
+
+      // Do we have all four components? If so, then we don't need to do any
+      // special recognition of two-component systems.
+      //
+      if (l != p)
+      {
+        l = s.rfind ('-', --l);
+
+        if (l != p)
+          bad ("too many components");
+
+        // Handle the none-* case here.
+        //
+        if (s.compare (l + 1, 5, "none-") == 0)
+          l += 5;
+      }
+      else
+      {
+        // See if this is one of the well-known non-vendors.
+        //
+        if (s.compare (f, n, "linux") == 0 ||
+            s.compare (f, n, "kfreebsd") == 0)
+        {
+          l = f - 1;
+          n = 0; // No VENDOR.
+        }
+      }
+
+      // Handle special VENDOR values.
+      //
+      if (n != 0)
+      {
+        if (s.compare (f, n, "pc") != 0 &&
+            s.compare (f, n, "none") != 0 &&
+            s.compare (f, n, "unknown") != 0)
+        {
+          vendor.assign (s, f, n);
+
+          if (c != nullptr)
+          {
+            *c += '-';
+            *c += vendor;
+          }
+        }
+      }
+    }
+
+    // (l, npos) is SYSTEM
+    //
+    system.assign (s, ++l, string::npos);
+
+    if (system.empty ())
+      bad ("missing os/kernel/abi");
+
+    if (system.front () == '-' || system.back () == '-')
+      bad ("invalid os/kernel/abi");
+
+    if (c != nullptr)
+    {
+      *c += '-';
+      *c += system;
+    }
+
+    // Finally, extract VERSION for some recognized systems.
+    //
+    string::size_type v (0);
+    if (system.compare (0, (v = 6), "darwin") == 0  ||
+        system.compare (0, (v = 7), "freebsd") == 0 ||
+        system.compare (0, (v = 7), "openbsd") == 0 ||
+        system.compare (0, (v = 7), "netbsd") == 0  ||
+        system.compare (0, (v = 7), "solaris") == 0 ||
+        system.compare (0, (v = 7), "aix") == 0     ||
+        system.compare (0, (v = 7), "hpux") == 0)
+    {
+      version.assign (system, v, string::npos);
+      system.resize (system.size () - version.size ());
+    }
+  }
+}