Add git version check (2.12 is minimum supported)

6 files changed, 115 insertions, 53 deletions

diff --git a/bdep/git.cxx b/bdep/git.cxx
index c26d257..c0b48fc 100644
--- a/bdep/git.cxx
+++ b/bdep/git.cxx
@@ -4,7 +4,8 @@
 
 #include <bdep/git.hxx>
 
-#include <libbutl/filesystem.mxx>
+#include <libbutl/git.mxx>
+#include <libbutl/standard-version.mxx>
 
 #include <bdep/diagnostics.hxx>
 
@@ -12,14 +13,27 @@ using namespace butl;
 
 namespace bdep
 {
-  bool
-  git (const dir_path& d)
+  static optional<standard_version> git_ver;
+
+  void
+  git_check_version ()
   {
-    // .git can be either a directory or a file in case of a submodule.
-    //
-    return entry_exists (d / ".git",
-                         true /* follow_symlinks */,
-                         true /* ignore_errors   */);
+    if (!git_ver)
+    {
+      // Make sure that the getline() function call doesn't end up with an
+      // infinite recursion.
+      //
+      git_ver = standard_version ();
+
+      optional<string> s (git_line (false /* ignore_error */, "--version"));
+
+      if (!s || !(git_ver = git_version (*s)))
+        fail << "unable to obtain git version";
+
+      if (git_ver->version < 20120000000)
+        fail << "unsupported git version " << *git_ver <<
+          info << "minimum supported version is 2.12.0" << endf;
+    }
   }
 
   optional<string>
diff --git a/bdep/git.hxx b/bdep/git.hxx
index 1552670..ca49622 100644
--- a/bdep/git.hxx
+++ b/bdep/git.hxx
@@ -5,39 +5,49 @@
 #ifndef BDEP_GIT_HXX
 #define BDEP_GIT_HXX
 
+#include <libbutl/git.mxx>
+
 #include <bdep/types.hxx>
 #include <bdep/utility.hxx>
 
 namespace bdep
 {
-  // Return true if the specified directory is a git repository root (contains
-  // the .git filesystem entry).
-  //
-  bool
-  git (const dir_path&);
+  using butl::git_repository;
 
-  template <typename... A>
-  inline void
-  run_git (const dir_path& repo, A&&... args);
+  template <typename I, typename O, typename E, typename... A>
+  process
+  start_git (I&& in, O&& out, E&& err, A&&... args);
 
   template <typename I, typename O, typename E, typename... A>
-  inline process
-  start_git (I&& in, O&& out, E&& err, const dir_path& repo, A&&... args);
+  process
+  start_git (const dir_path& repo, I&& in, O&& out, E&& err, A&&... args);
+
+  void
+  finish_git (process& pr, bool io_read = false);
+
+  template <typename... A>
+  void
+  run_git (const dir_path& repo, A&&... args);
 
   // Return the first line of the git output. If ignore_error is true, then
   // suppress stderr, ignore (normal) error exit status, and return nullopt.
   //
   template <typename... A>
   optional<string>
+  git_line (bool ignore_error, A&&... args);
+
+  template <typename... A>
+  optional<string>
   git_line (const dir_path& repo, bool ignore_error, A&&... args);
 
   // Similar to the above but takes the already started git process with a
   // redirected output pipe.
   //
   optional<string>
-  git_line (process&& pr, fdpipe&& pipe, bool ignore_error = false);
+  git_line (process&& pr, fdpipe&& pipe, bool ignore_error);
 }
 
 #include <bdep/git.ixx>
+#include <bdep/git.txx>
 
 #endif // BDEP_GIT_HXX
diff --git a/bdep/git.ixx b/bdep/git.ixx
index e71375a..9369564 100644
--- a/bdep/git.ixx
+++ b/bdep/git.ixx
@@ -2,43 +2,31 @@
 // copyright : Copyright (c) 2014-2018 Code Synthesis Ltd
 // license   : MIT; see accompanying LICENSE file
 
-using namespace butl;
-
 namespace bdep
 {
-  template <typename... A>
-  inline void
-  run_git (const dir_path& repo, A&&... args)
+  template <typename I, typename O, typename E, typename... A>
+  inline process
+  start_git (const dir_path& repo, I&& in, O&& out, E&& err, A&&... args)
   {
-    return run ("git", "-C", repo, forward<A> (args)...);
+    return start_git (forward<I> (in),
+                      forward<O> (out),
+                      forward<E> (err),
+                      "-C", repo,
+                      forward<A> (args)...);
   }
 
-  template <typename I, typename O, typename E, typename... A>
-  inline process
-  start_git (I&& in, O&& out, E&& err, const dir_path& repo, A&&... args)
+  inline void
+  finish_git (process& pr, bool io_read)
   {
-    return start (forward<I> (in),
-                  forward<O> (out),
-                  forward<E> (err),
-                  "git",
-                  "-C", repo,
-                  forward<A> (args)...);
+    finish ("git", pr, io_read);
   }
 
   template <typename... A>
   inline optional<string>
   git_line (const dir_path& repo, bool ie, A&&... args)
   {
-    fdpipe pipe (fdopen_pipe ());
-    auto_fd null (ie ? fdnull () : auto_fd ());
-
-    process pr (start (0                     /* stdin  */,
-                       pipe                  /* stdout */,
-                       ie ?  null.get () : 2 /* stderr */,
-                       "git",
-                       "-C", repo,
-                       forward<A> (args)...));
-
-    return git_line (move (pr), move (pipe), ie);
+    return git_line (ie,
+                     "-C", repo,
+                     forward<A> (args)...);
   }
 }
diff --git a/bdep/git.txx b/bdep/git.txx
new file mode 100644
index 0000000..aef5f3d
--- /dev/null
+++ b/bdep/git.txx
@@ -0,0 +1,50 @@
+// file      : bdep/git.txx -*- C++ -*-
+// copyright : Copyright (c) 2014-2018 Code Synthesis Ltd
+// license   : MIT; see accompanying LICENSE file
+
+namespace bdep
+{
+  template <typename... A>
+  void
+  run_git (const dir_path& repo, A&&... args)
+  {
+    process pr (start_git (repo,
+                           0 /* stdin  */,
+                           1 /* stdout */,
+                           2 /* stderr */,
+                           forward<A> (args)...));
+
+    finish_git (pr);
+  }
+
+  void
+  git_check_version ();
+
+  template <typename I, typename O, typename E, typename... A>
+  process
+  start_git (I&& in, O&& out, E&& err, A&&... args)
+  {
+    git_check_version ();
+
+    return start (forward<I> (in),
+                  forward<O> (out),
+                  forward<E> (err),
+                  "git",
+                  forward<A> (args)...);
+  }
+
+  template <typename... A>
+  optional<string>
+  git_line (bool ie, A&&... args)
+  {
+    fdpipe pipe (fdopen_pipe ());
+    auto_fd null (ie ? fdnull () : auto_fd ());
+
+    process pr (start_git (0                    /* stdin  */,
+                           pipe                 /* stdout */,
+                           ie ? null.get () : 2 /* stderr */,
+                           forward<A> (args)...));
+
+    return git_line (move (pr), move (pipe), ie);
+  }
+}
diff --git a/bdep/project-email.cxx b/bdep/project-email.cxx
index 2b836f2..6216d28 100644
--- a/bdep/project-email.cxx
+++ b/bdep/project-email.cxx
@@ -27,7 +27,7 @@ namespace bdep
 
     // See if this is a VCS repository we recognize.
     //
-    if (git (prj))
+    if (git_repository (prj))
     {
       // In git the author email can be specified with the GIT_AUTHOR_EMAIL
       // environment variable after which things fall back to the committer
diff --git a/bdep/publish.cxx b/bdep/publish.cxx
index 3650381..40a1724 100644
--- a/bdep/publish.cxx
+++ b/bdep/publish.cxx
@@ -44,7 +44,7 @@ namespace bdep
   static url
   control_url (const dir_path& prj)
   {
-    if (git (prj))
+    if (git_repository (prj))
     {
       // First try remote.origin.build2ControlUrl which can be used to specify
       // a custom URL (e.g., if a correct one cannot be automatically derived
@@ -890,7 +890,7 @@ namespace bdep
     //
     // See if this is a VCS repository we recognize.
     //
-    if (ctrl && git (prj))
+    if (ctrl && git_repository (prj))
     {
       // Checkout the build2-control branch into a separate working tree not
       // to interfere with the user's stuff.
@@ -919,10 +919,10 @@ namespace bdep
         bool q (verb < 2);
         auto_fd null (q ? fdnull () : auto_fd ());
 
-        process pr (start_git (0                   /* stdin  */,
+        process pr (start_git (prj,
+                               0                   /* stdin  */,
                                q ? null.get () : 1 /* stdout */,
                                q ? null.get () : 2 /* stderr */,
-                               prj,
                                "worktree",
                                "add",
                                wd,
@@ -1003,15 +1003,15 @@ namespace bdep
           auto_fd null (fdnull ());
           fdpipe pipe (fdopen_pipe ());
 
-          process pr (start_git (null.get () /* stdin  */,
+          process pr (start_git (prj,
+                                 null.get () /* stdin  */,
                                  pipe        /* stdout */,
                                  2           /* stderr */,
-                                 prj,
                                  "hash-object",
                                  "-wt", "tree",
                                  "--stdin"));
 
-          optional<string> tree (git_line (move (pr), move (pipe)));
+          optional<string> tree (git_line (move (pr), move (pipe), false));
 
           if (!tree)
             fail << "unable to create git tree object for build2-control";