Rework and rename target_triplet

6 files changed, 97 insertions, 48 deletions

diff --git a/butl/buildfile b/butl/buildfile
index 9168774..dd2e6bb 100644
--- a/butl/buildfile
+++ b/butl/buildfile
@@ -24,8 +24,8 @@ lib{butl}:                               \
 {hxx         cxx}{ sha256              } \
 {hxx            }{ small-vector        } \
 {hxx     txx    }{ string-table        } \
+{hxx         cxx}{ target-triplet      } \
 {hxx         cxx}{ timestamp           } \
-{hxx         cxx}{ triplet             } \
 {hxx ixx     cxx}{ utility             } \
 {hxx            }{ vector-view         } \
 {hxx            }{ version             }
diff --git a/butl/triplet b/butl/target-triplet
index 0d1b7f4..d355d75 100644
--- a/butl/triplet
+++ b/butl/target-triplet
@@ -1,11 +1,12 @@
-// file      : butl/triplet -*- C++ -*-
+// file      : butl/target-triplet -*- C++ -*-
 // copyright : Copyright (c) 2014-2017 Code Synthesis Ltd
 // license   : MIT; see accompanying LICENSE file
 
-#ifndef BUTL_TRIPLET
-#define BUTL_TRIPLET
+#ifndef BUTL_TARGET_TRIPLET
+#define BUTL_TARGET_TRIPLET
 
 #include <string>
+#include <ostream>
 
 #include <butl/export>
 
@@ -15,7 +16,7 @@ namespace butl
   // 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
+  // splitting it into components. The way we are going to split it is like
   // this:
   //
   // CPU
@@ -95,7 +96,7 @@ namespace butl
   //
   // 2. LLVM has the Triple class with similar goals.
   //
-  struct LIBBUTL_EXPORT triplet
+  struct LIBBUTL_EXPORT target_triplet
   {
     std::string cpu;
     std::string vendor;
@@ -103,14 +104,52 @@ namespace butl
     std::string version;
     std::string class_;
 
-    // Parse the triplet optionally returning the canonicalized string. Throw
-    // std::invalid_argument if the triplet is not recognizable.
+    // 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
-    triplet (const std::string&, std::string* canon = nullptr);
-    triplet (const std::string& s, std::string& canon): triplet (s, &canon) {}
-    triplet () = default;
+    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_TRIPLET
+#endif // BUTL_TARGET_TRIPLET
diff --git a/butl/triplet.cxx b/butl/target-triplet.cxx
index 2177717..f7da724 100644
--- a/butl/triplet.cxx
+++ b/butl/target-triplet.cxx
@@ -1,8 +1,8 @@
-// file      : butl/triplet.cxx -*- C++ -*-
+// file      : butl/target-triplet.cxx -*- C++ -*-
 // copyright : Copyright (c) 2014-2017 Code Synthesis Ltd
 // license   : MIT; see accompanying LICENSE file
 
-#include <butl/triplet>
+#include <butl/target-triplet>
 
 #include <stdexcept> // invalid_argument
 
@@ -10,9 +10,11 @@ using namespace std;
 
 namespace butl
 {
-  triplet::
-  triplet (const string& s, string* c)
+  target_triplet::
+  target_triplet (const std::string& s)
   {
+    using std::string;
+
     auto bad = [](const char* m) {throw invalid_argument (m);};
 
     // Find the first and the last components. The first is CPU and the last is
@@ -25,9 +27,6 @@ namespace butl
 
     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.
@@ -75,15 +74,7 @@ namespace butl
         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;
-          }
-        }
       }
     }
 
@@ -97,12 +88,6 @@ namespace butl
     if (system.front () == '-' || system.back () == '-')
       bad ("invalid os/kernel/abi");
 
-    if (c != nullptr)
-    {
-      *c += '-';
-      *c += system;
-    }
-
     // Extract VERSION for some recognized systems.
     //
     string::size_type v (0);
@@ -132,4 +117,29 @@ namespace butl
     else
       class_ = "other";
   }
+
+  std::string target_triplet::
+  string () const
+  {
+    std::string r (cpu);
+
+    if (!vendor.empty ())
+    {
+      if (!r.empty ()) r += '-';
+      r += vendor;
+    }
+
+    if (!system.empty ())
+    {
+      if (!r.empty ()) r += '-';
+      r += system;
+    }
+
+    if (!version.empty ())
+    {
+      r += version;
+    }
+
+    return r;
+  }
 }
diff --git a/tests/buildfile b/tests/buildfile
index 7259717..8608ed9 100644
--- a/tests/buildfile
+++ b/tests/buildfile
@@ -4,7 +4,7 @@
 
 d = base64/ cpfile/ dir-iterator/ fdstream/ link/ manifest-parser/ \
     manifest-serializer/ manifest-roundtrip/ pager/ path/ prefix-map/ \
-    process/ sha256/ small-vector/ strcase/ timestamp/ triplet/
+    process/ sha256/ small-vector/ strcase/ timestamp/ target-triplet/
 
 ./: $d
 include $d
diff --git a/tests/triplet/buildfile b/tests/target-triplet/buildfile
index 7724f4c..ca8365d 100644
--- a/tests/triplet/buildfile
+++ b/tests/target-triplet/buildfile
@@ -1,4 +1,4 @@
-# file      : tests/triplet/buildfile
+# file      : tests/target-triplet/buildfile
 # copyright : Copyright (c) 2014-2017 Code Synthesis Ltd
 # license   : MIT; see accompanying LICENSE file
 
diff --git a/tests/triplet/driver.cxx b/tests/target-triplet/driver.cxx
index 96d76cd..fe055db 100644
--- a/tests/triplet/driver.cxx
+++ b/tests/target-triplet/driver.cxx
@@ -1,4 +1,4 @@
-// file      : tests/triplet/driver.cxx -*- C++ -*-
+// file      : tests/target-triplet/driver.cxx -*- C++ -*-
 // copyright : Copyright (c) 2014-2017 Code Synthesis Ltd
 // license   : MIT; see accompanying LICENSE file
 
@@ -6,7 +6,7 @@
 #include <iostream>
 #include <stdexcept> // invalid_argument
 
-#include <butl/triplet>
+#include <butl/target-triplet>
 
 using namespace std;
 using namespace butl;
@@ -118,21 +118,21 @@ test (const char* s,
       const char* version,
       const char* class_)
 {
-  string c;
-  triplet t (s, c);
+  target_triplet t (s);
+  string c (t.string ());
 
   auto cmp = [] (const string& a, const char* e, const char* n) -> bool
+  {
+    if (a != e)
     {
-      if (a != e)
-      {
-        cerr << n << " actual: " << a << endl
-             << n << " expect: " << e << endl;
+      cerr << n << " actual: " << a << endl
+           << n << " expect: " << e << endl;
 
-        return false;
-      }
+      return false;
+    }
 
-      return true;
-    };
+    return true;
+  };
 
   return
     cmp (c, canon, "canonical") &&
@@ -148,7 +148,7 @@ fail (const char* s)
 {
   try
   {
-    triplet t (s);
+    target_triplet t (s);
     cerr << "nofail: " << s << endl;
     return false;
   }