Restore depfile toleration of multiple output paths on distinct lines

Prior to introduction of depfile parser handling of multiple rules,
ninja silently accepted a depfile of the form:

    out: in1 in2 in3
    other: otherIn1 otherIn2 otherIn3

and incorrectly treated `other` and `otherIn*` as additional inputs to
`out`.  Now we prefer to reject this just as we already do for a depfile
specifying multiple outputs on one line.  However, this can break
existing cases where such a depfile was silently tolerated.

Add a `-w depfilemulti={err,warn}` option to control this behavior,
and make it just a warning by default.

1 files changed, 3 insertions, 2 deletions

diff --git a/src/build.cc b/src/build.cc
index ed219fd..b392803 100644
--- a/src/build.cc
+++ b/src/build.cc
@@ -557,7 +557,8 @@ Builder::Builder(State* state, const BuildConfig& config,
                  BuildLog* build_log, DepsLog* deps_log,
                  DiskInterface* disk_interface)
     : state_(state), config_(config), disk_interface_(disk_interface),
-      scan_(state, build_log, deps_log, disk_interface) {
+      scan_(state, build_log, deps_log, disk_interface,
+            &config_.depfile_parser_options) {
   status_ = new BuildStatus(config);
 }
 
@@ -906,7 +907,7 @@ bool Builder::ExtractDeps(CommandRunner::Result* result,
     if (content.empty())
       return true;
 
-    DepfileParser deps;
+    DepfileParser deps(config_.depfile_parser_options);
     if (!deps.Parse(&content, err))
       return false;