From 7149c8eaeec3efcfc9da0f89c9ae979ff2c07fd5 Mon Sep 17 00:00:00 2001
From: Boris Kolpackov <boris@codesynthesis.com>
Date: Mon, 30 Jul 2018 18:47:55 +0200
Subject: Fortify cli detection against "other" cli's (like Mono JIT compiler)

---
 build2/cli/init.cxx | 37 +++++++++++++++++++++++++------------
 1 file changed, 25 insertions(+), 12 deletions(-)

(limited to 'build2')

diff --git a/build2/cli/init.cxx b/build2/cli/init.cxx
index 8e0abdb..4ad8a1a 100644
--- a/build2/cli/init.cxx
+++ b/build2/cli/init.cxx
@@ -100,7 +100,8 @@ namespace build2
         //
         process_path pp;
 
-        // Return version or empty string if the cli executable is not found.
+        // Return version or empty string if the cli executable is not found
+        // or is not the command line interface compiler.
         //
         // @@ This needs some more thinking/cleanup. Specifically, what does
         //    it mean "cli not found"? Is it just not found in PATH? That plus
@@ -129,23 +130,35 @@ namespace build2
             {
               ifdstream is (move (pr.in_ofd), fdstream_mode::skip);
 
-              // The version should be the last word on the first line.
+              // The version should be the last word on the first line. But
+              // also check the prefix since there are other things called
+              // 'cli', for example, "Mono JIT compiler".
               //
-              string ver;
-              getline (is, ver);
-              auto p (ver.rfind (' '));
-              if (p != string::npos)
-                ver = string (ver, p + 1);
+              string v;
+              getline (is, v);
 
-              is.close (); // Don't block the other end.
-
-              if (pr.wait ())
+              if (v.compare (0, 37,
+                             "CLI (command line interface compiler)") == 0)
               {
-                if (ver.empty ())
+                size_t p (v.rfind (' '));
+
+                if (p == string::npos)
                   fail << "unexpected output from " << cli;
 
-                return ver;
+                v.erase (0, p + 1);
               }
+              else
+              {
+                if (!optional)
+                  fail << cli << " is not command line interface compiler";
+
+                v.clear ();
+              }
+
+              is.close (); // Don't block the other end.
+
+              if (pr.wait ())
+                return v;
 
               // Presumably issued diagnostics. Fall through.
             }
-- 
cgit v1.1