Filter gratuitous VC cl.exe and link.exe messages

3 files changed, 119 insertions, 18 deletions

diff --git a/build2/cxx/compile.cxx b/build2/cxx/compile.cxx
index c737ce7..5e7a1b2 100644
--- a/build2/cxx/compile.cxx
+++ b/build2/cxx/compile.cxx
@@ -7,6 +7,7 @@
 #include <map>
 #include <limits>   // numeric_limits
 #include <cstdlib>  // exit()
+#include <iostream> // cerr
 
 #include <butl/path-map>
 
@@ -1211,7 +1212,7 @@ namespace build2
               // we need to copy the diagnostics for the user to see.
               //
               if (!is.eof () && cid == "msvc" && bad_error)
-                *diag_stream << is.rdbuf ();
+                cerr << is.rdbuf ();
 
               is.close ();
 
@@ -1248,6 +1249,11 @@ namespace build2
       }
     }
 
+    // Filter cl.exe noise (msvc.cxx).
+    //
+    void
+    msvc_filter_cl (ifdstream&, const path& src);
+
     target_state compile::
     perform_update (action a, target& xt)
     {
@@ -1406,19 +1412,38 @@ namespace build2
 
       try
       {
-        // @@ VC prints file name being compiled to stdout as the first
-        //    line, would be good to weed it out (but check if it is
-        //    always printed, for example if the file does not exist).
-        //    Seems always. The same story with link.exe when creating
-        //    the DLL.
+        // VC cl.exe sends diagnostics to stdout. It also prints the file name
+        // being compiled as the first line. So for cl.exe we redirect stdout
+        // to a pipe, filter that noise out, and send the rest to stderr.
         //
-
-        // VC++ cl.exe sends diagnostics to stdout. To fix this (and any other
-        // insane compilers that may want to do something like this) we are
-        // going to always redirect stdout to stderr. For sane compilers this
-        // should be harmless.
+        // For other compilers redirect stdout to stderr, in case any of them
+        // tries to pull off something similar. For sane compilers this should
+        // be harmless.
         //
-        process pr (args.data (), 0, 2);
+        bool filter (cid == "msvc");
+
+        process pr (args.data (), 0, (filter ? -1 : 2));
+
+        if (filter)
+        {
+          try
+          {
+            ifdstream is (pr.in_ofd, fdstream_mode::text, ifdstream::badbit);
+
+            msvc_filter_cl (is, rels);
+
+            // If anything remains in the stream, send it all to stderr. Note
+            // that the eos check is important: if the stream is at eos, this
+            // and all subsequent writes to cerr will fail (and you won't see
+            // a thing).
+            //
+            if (is.peek () != ifdstream::traits_type::eof ())
+              cerr << is.rdbuf ();
+
+            is.close ();
+          }
+          catch (const ifdstream::failure&) {} // Assume exits with error.
+        }
 
         if (!pr.wait ())
           throw failed ();
diff --git a/build2/cxx/link.cxx b/build2/cxx/link.cxx
index 9ee84ce..1624f5d 100644
--- a/build2/cxx/link.cxx
+++ b/build2/cxx/link.cxx
@@ -4,7 +4,8 @@
 
 #include <build2/cxx/link>
 
-#include <cstdlib> // exit()
+#include <cstdlib>  // exit()
+#include <iostream> // cerr
 
 #include <butl/path-map>
 
@@ -1079,6 +1080,11 @@ namespace build2
     const char*
     msvc_machine (const string& cpu); // msvc.cxx
 
+    // Filter link.exe noise (msvc.cxx).
+    //
+    void
+    msvc_filter_link (ifdstream&, const file&, otype);
+
     target_state link::
     perform_update (action a, target& xt)
     {
@@ -1686,12 +1692,39 @@ namespace build2
 
       try
       {
-        // VC++ (cl.exe, lib.exe, and link.exe) sends diagnostics to stdout.
-        // To fix this (and any other insane compilers that may want to do
-        // something like this) we are going to always redirect stdout to
-        // stderr. For sane compilers this should be harmless.
+        // VC tools (both lib.exe and link.exe) send diagnostics to stdout.
+        // Also, link.exe likes to print various gratuitous messages. So for
+        // link.exe we redirect stdout to a pipe, filter that noise out, and
+        // send the rest to stderr.
+        //
+        // For lib.exe (and any other insane compiler that may try to pull off
+        // something like this) we are going to redirect stdout to stderr. For
+        // sane compilers this should be harmless.
         //
-        process pr (args.data (), 0, 2);
+        bool filter (cid == "msvc" && lt != otype::a);
+
+        process pr (args.data (), 0, (filter ? -1 : 2));
+
+        if (filter)
+        {
+          try
+          {
+            ifdstream is (pr.in_ofd, fdstream_mode::text, ifdstream::badbit);
+
+            msvc_filter_link (is, t, lt);
+
+            // If anything remains in the stream, send it all to stderr. Note
+            // that the eos check is important: if the stream is at eos, this
+            // and all subsequent writes to cerr will fail (and you won't see
+            // a thing).
+            //
+            if (is.peek () != ifdstream::traits_type::eof ())
+              cerr << is.rdbuf ();
+
+            is.close ();
+          }
+          catch (const ifdstream::failure&) {} // Assume exits with error.
+        }
 
         if (!pr.wait ())
           throw failed ();
diff --git a/build2/cxx/msvc.cxx b/build2/cxx/msvc.cxx
index 294ac03..dcf7fee 100644
--- a/build2/cxx/msvc.cxx
+++ b/build2/cxx/msvc.cxx
@@ -2,6 +2,8 @@
 // copyright : Copyright (c) 2014-2016 Code Synthesis Ltd
 // license   : MIT; see accompanying LICENSE file
 
+#include <iostream> // cerr
+
 #include <build2/scope>
 #include <build2/target>
 #include <build2/context>
@@ -37,6 +39,47 @@ namespace build2
       return m;
     }
 
+    // Filter cl.exe and link.exe noise.
+    //
+    void
+    msvc_filter_cl (ifdstream& is, const path& src)
+    {
+      // While it appears VC always prints the source name (event if the
+      // file does not exist), let's do a sanity check.
+      //
+      string l;
+      if (getline (is, l) && l != src.leaf ().string ())
+        cerr << l << endl;
+    }
+
+    void
+    msvc_filter_link (ifdstream& is, const file& t, otype lt)
+    {
+      // Filter lines until we encounter something we don't recognize. We also
+      // have to assume the messages can be translated.
+      //
+      for (string l; getline (is, l); )
+      {
+        // "   Creating library foo\foo.dll.lib and object foo\foo.dll.exp"
+        //
+        if (lt == otype::s && l.compare (0, 3, "   ") == 0)
+        {
+          path imp (static_cast<file*> (t.member)->path ().leaf ());
+
+          if (l.find (imp.string ()) != string::npos &&
+              l.find (imp.base ().string () + ".exp") != string::npos)
+            continue;
+        }
+
+        // /INCREMENTAL causes linker to sometimes issue messages but now I
+        // can't quite reproduce it.
+        //
+
+        cerr << l << endl;
+        break;
+      }
+    }
+
     // Extract system library search paths from MSVC.
     //
     void