Merge upstream commit '0a2e2cae' into master

* commit '0a2e2cae7038ce519b0524c07d7135c3e520c9cd':
  Restore depfile toleration of multiple output paths on distinct lines
  Fix depfile parser handling of multiple rules
  Fix depfile parser test case line continuation
  Re-arrange depfile parser token processing logic
  Re-generate depfile parser with re2cc 1.0.1

depfile_parser.cc conflicts were handled by regenerating with re2c

The other conflicts were all fairly simple argument/option ordering.

Test: compare .ninja_deps of a full android build before and after this
      change, they're equivalent
Change-Id: I74b7fc56e035c9dbab4c987b6af17329c596a898
diff --git a/src/build.cc b/src/build.cc
index 045331b..2f8b860 100644
--- a/src/build.cc
+++ b/src/build.cc
@@ -359,7 +359,8 @@
                  int64_t start_time_millis)
     : state_(state), config_(config), status_(status),
       start_time_millis_(start_time_millis), disk_interface_(disk_interface),
-      scan_(state, build_log, deps_log, disk_interface, config.uses_phony_outputs) {
+      scan_(state, build_log, deps_log, disk_interface,
+            &config_.depfile_parser_options, config.uses_phony_outputs) {
 }
 
 Builder::~Builder() {
@@ -802,7 +803,7 @@
     if (content.empty())
       return true;
 
-    DepfileParser deps;
+    DepfileParser deps(config_.depfile_parser_options);
     if (!deps.Parse(&content, err))
       return false;
 
diff --git a/src/build.h b/src/build.h
index d5d7bc9..5c06f8b 100644
--- a/src/build.h
+++ b/src/build.h
@@ -26,6 +26,7 @@
 #include <sys/resource.h>
 #endif
 
+#include "depfile_parser.h"
 #include "graph.h"  // XXX needed for DependencyScan; should rearrange.
 #include "exit_status.h"
 #include "util.h"  // int64_t
@@ -162,6 +163,7 @@
   /// The maximum load average we must not exceed. A negative value
   /// means that we do not have any limit.
   double max_load_average;
+  DepfileParserOptions depfile_parser_options;
 
   /// Command to execute to handle build output
   const char* frontend;
diff --git a/src/depfile_parser.cc b/src/depfile_parser.cc
index 8d9345e..16403f1 100644
--- a/src/depfile_parser.cc
+++ b/src/depfile_parser.cc
@@ -14,6 +14,12 @@
 // limitations under the License.
 
 #include "depfile_parser.h"
+#include "util.h"
+
+DepfileParser::DepfileParser(DepfileParserOptions options)
+  : options_(options)
+{
+}
 
 // A note on backslashes in Makefiles, from reading the docs:
 // Backslash-newline is the line continuation character.
@@ -35,8 +41,13 @@
   // parsing_targets: whether we are parsing targets or dependencies.
   char* in = &(*content)[0];
   char* end = in + content->size();
+  bool have_target = false;
+  bool have_secondary_target_on_this_rule = false;
+  bool have_newline_since_primary_target = false;
+  bool warned_distinct_target_lines = false;
   bool parsing_targets = true;
   while (in < end) {
+    bool have_newline = false;
     // out: current output point (typically same as in, but can fall behind
     // as we de-escape backslashes).
     char* out = in;
@@ -45,6 +56,7 @@
     for (;;) {
       // start: beginning of the current parsed span.
       const char* start = in;
+      char* yymarker = NULL;
       
     {
       unsigned char yych;
@@ -84,17 +96,25 @@
       };
       yych = *in;
       if (yybm[0+yych] & 128) {
-        goto yy6;
-      }
-      if (yych <= '$') {
-        if (yych <= 0x00) goto yy2;
-        if (yych <= '#') goto yy4;
         goto yy9;
-      } else {
-        if (yych == '\\') goto yy10;
-        goto yy4;
       }
-yy2:
+      if (yych <= '\r') {
+        if (yych <= '\t') {
+          if (yych >= 0x01) goto yy4;
+        } else {
+          if (yych <= '\n') goto yy6;
+          if (yych <= '\f') goto yy4;
+          goto yy8;
+        }
+      } else {
+        if (yych <= '$') {
+          if (yych <= '#') goto yy4;
+          goto yy12;
+        } else {
+          if (yych == '\\') goto yy13;
+          goto yy4;
+        }
+      }
       ++in;
       {
         break;
@@ -108,9 +128,20 @@
         break;
       }
 yy6:
+      ++in;
+      {
+        // A newline ends the current file name and the current rule.
+        have_newline = true;
+        break;
+      }
+yy8:
+      yych = *++in;
+      if (yych == '\n') goto yy6;
+      goto yy5;
+yy9:
       yych = *++in;
       if (yybm[0+yych] & 128) {
-        goto yy6;
+        goto yy9;
       }
       {
         // Got a span of plain text.
@@ -121,41 +152,41 @@
         out += len;
         continue;
       }
-yy9:
+yy12:
       yych = *++in;
-      if (yych == '$') goto yy11;
+      if (yych == '$') goto yy14;
       goto yy5;
-yy10:
-      yych = *++in;
+yy13:
+      yych = *(yymarker = ++in);
       if (yych <= '"') {
         if (yych <= '\f') {
           if (yych <= 0x00) goto yy5;
-          if (yych == '\n') goto yy5;
-          goto yy13;
+          if (yych == '\n') goto yy18;
+          goto yy16;
         } else {
-          if (yych <= '\r') goto yy5;
-          if (yych == ' ') goto yy15;
-          goto yy13;
+          if (yych <= '\r') goto yy20;
+          if (yych == ' ') goto yy22;
+          goto yy16;
         }
       } else {
         if (yych <= 'Z') {
-          if (yych <= '#') goto yy15;
-          if (yych == '*') goto yy15;
-          goto yy13;
+          if (yych <= '#') goto yy22;
+          if (yych == '*') goto yy22;
+          goto yy16;
         } else {
-          if (yych <= ']') goto yy15;
-          if (yych == '|') goto yy15;
-          goto yy13;
+          if (yych <= ']') goto yy22;
+          if (yych == '|') goto yy22;
+          goto yy16;
         }
       }
-yy11:
+yy14:
       ++in;
       {
         // De-escape dollar character.
         *out++ = '$';
         continue;
       }
-yy13:
+yy16:
       ++in;
       {
         // Let backslash before other characters through verbatim.
@@ -163,7 +194,18 @@
         *out++ = yych;
         continue;
       }
-yy15:
+yy18:
+      ++in;
+      {
+        // A line continuation ends the current file name.
+        break;
+      }
+yy20:
+      yych = *++in;
+      if (yych == '\n') goto yy18;
+      in = yymarker;
+      goto yy5;
+yy22:
       ++in;
       {
         // De-escape backslashed character.
@@ -175,25 +217,52 @@
     }
 
     int len = (int)(out - filename);
-    const bool is_target = parsing_targets;
+    const bool is_dependency = !parsing_targets;
     if (len > 0 && filename[len - 1] == ':') {
       len--;  // Strip off trailing colon, if any.
       parsing_targets = false;
+      have_target = true;
     }
 
-    if (len == 0)
-      continue;
+    if (len > 0) {
+      if (is_dependency) {
+        if (have_secondary_target_on_this_rule) {
+          if (!have_newline_since_primary_target) {
+            *err = "depfile has multiple output paths";
+            return false;
+          } else if (options_.depfile_distinct_target_lines_action_ ==
+                     kDepfileDistinctTargetLinesActionError) {
+            *err =
+                "depfile has multiple output paths (on separate lines)"
+                " [-w depfilemulti=err]";
+            return false;
+          } else {
+            if (!warned_distinct_target_lines) {
+              warned_distinct_target_lines = true;
+              Warning("depfile has multiple output paths (on separate lines); "
+                      "continuing anyway [-w depfilemulti=warn]");
+            }
+            continue;
+          }
+        }
+        ins_.push_back(StringPiece(filename, len));
+      } else if (!out_.str_) {
+        out_ = StringPiece(filename, len);
+      } else if (out_ != StringPiece(filename, len)) {
+        have_secondary_target_on_this_rule = true;
+      }
+    }
 
-    if (!is_target) {
-      ins_.push_back(StringPiece(filename, len));
-    } else if (!out_.str_) {
-      out_ = StringPiece(filename, len);
-    } else if (out_ != StringPiece(filename, len)) {
-      *err = "depfile has multiple output paths";
-      return false;
+    if (have_newline) {
+      // A newline ends a rule so the next filename will be a new target.
+      parsing_targets = true;
+      have_secondary_target_on_this_rule = false;
+      if (have_target) {
+        have_newline_since_primary_target = true;
+      }
     }
   }
-  if (parsing_targets) {
+  if (!have_target) {
     *err = "expected ':' in depfile";
     return false;
   }
diff --git a/src/depfile_parser.h b/src/depfile_parser.h
index 1e6ebb5..be20374 100644
--- a/src/depfile_parser.h
+++ b/src/depfile_parser.h
@@ -21,8 +21,24 @@
 
 #include "string_piece.h"
 
+enum DepfileDistinctTargetLinesAction {
+  kDepfileDistinctTargetLinesActionWarn,
+  kDepfileDistinctTargetLinesActionError,
+};
+
+struct DepfileParserOptions {
+  DepfileParserOptions()
+      : depfile_distinct_target_lines_action_(
+          kDepfileDistinctTargetLinesActionWarn) {}
+  DepfileDistinctTargetLinesAction
+    depfile_distinct_target_lines_action_;
+};
+
 /// Parser for the dependency information emitted by gcc's -M flags.
 struct DepfileParser {
+  explicit DepfileParser(DepfileParserOptions options =
+                         DepfileParserOptions());
+
   /// Parse an input file.  Input must be NUL-terminated.
   /// Warning: may mutate the content in-place and parsed StringPieces are
   /// pointers within it.
@@ -30,6 +46,7 @@
 
   StringPiece out_;
   vector<StringPiece> ins_;
+  DepfileParserOptions options_;
 };
 
 #endif // NINJA_DEPFILE_PARSER_H_
diff --git a/src/depfile_parser.in.cc b/src/depfile_parser.in.cc
index 464efda..f8c94b3 100644
--- a/src/depfile_parser.in.cc
+++ b/src/depfile_parser.in.cc
@@ -13,6 +13,12 @@
 // limitations under the License.
 
 #include "depfile_parser.h"
+#include "util.h"
+
+DepfileParser::DepfileParser(DepfileParserOptions options)
+  : options_(options)
+{
+}
 
 // A note on backslashes in Makefiles, from reading the docs:
 // Backslash-newline is the line continuation character.
@@ -34,8 +40,13 @@
   // parsing_targets: whether we are parsing targets or dependencies.
   char* in = &(*content)[0];
   char* end = in + content->size();
+  bool have_target = false;
+  bool have_secondary_target_on_this_rule = false;
+  bool have_newline_since_primary_target = false;
+  bool warned_distinct_target_lines = false;
   bool parsing_targets = true;
   while (in < end) {
+    bool have_newline = false;
     // out: current output point (typically same as in, but can fall behind
     // as we de-escape backslashes).
     char* out = in;
@@ -44,10 +55,12 @@
     for (;;) {
       // start: beginning of the current parsed span.
       const char* start = in;
+      char* yymarker = NULL;
       /*!re2c
       re2c:define:YYCTYPE = "unsigned char";
       re2c:define:YYCURSOR = in;
       re2c:define:YYLIMIT = end;
+      re2c:define:YYMARKER = yymarker;
 
       re2c:yyfill:enable = 0;
 
@@ -56,6 +69,7 @@
 
       nul = "\000";
       escape = [ \\#*[|\]];
+      newline = '\r'?'\n';
 
       '\\' escape {
         // De-escape backslashed character.
@@ -85,6 +99,15 @@
       nul {
         break;
       }
+      '\\' newline {
+        // A line continuation ends the current file name.
+        break;
+      }
+      newline {
+        // A newline ends the current file name and the current rule.
+        have_newline = true;
+        break;
+      }
       [^] {
         // For any other character (e.g. whitespace), swallow it here,
         // allowing the outer logic to loop around again.
@@ -94,25 +117,52 @@
     }
 
     int len = (int)(out - filename);
-    const bool is_target = parsing_targets;
+    const bool is_dependency = !parsing_targets;
     if (len > 0 && filename[len - 1] == ':') {
       len--;  // Strip off trailing colon, if any.
       parsing_targets = false;
+      have_target = true;
     }
 
-    if (len == 0)
-      continue;
+    if (len > 0) {
+      if (is_dependency) {
+        if (have_secondary_target_on_this_rule) {
+          if (!have_newline_since_primary_target) {
+            *err = "depfile has multiple output paths";
+            return false;
+          } else if (options_.depfile_distinct_target_lines_action_ ==
+                     kDepfileDistinctTargetLinesActionError) {
+            *err =
+                "depfile has multiple output paths (on separate lines)"
+                " [-w depfilemulti=err]";
+            return false;
+          } else {
+            if (!warned_distinct_target_lines) {
+              warned_distinct_target_lines = true;
+              Warning("depfile has multiple output paths (on separate lines); "
+                      "continuing anyway [-w depfilemulti=warn]");
+            }
+            continue;
+          }
+        }
+        ins_.push_back(StringPiece(filename, len));
+      } else if (!out_.str_) {
+        out_ = StringPiece(filename, len);
+      } else if (out_ != StringPiece(filename, len)) {
+        have_secondary_target_on_this_rule = true;
+      }
+    }
 
-    if (!is_target) {
-      ins_.push_back(StringPiece(filename, len));
-    } else if (!out_.str_) {
-      out_ = StringPiece(filename, len);
-    } else if (out_ != StringPiece(filename, len)) {
-      *err = "depfile has multiple output paths";
-      return false;
+    if (have_newline) {
+      // A newline ends a rule so the next filename will be a new target.
+      parsing_targets = true;
+      have_secondary_target_on_this_rule = false;
+      if (have_target) {
+        have_newline_since_primary_target = true;
+      }
     }
   }
-  if (parsing_targets) {
+  if (!have_target) {
     *err = "expected ':' in depfile";
     return false;
   }
diff --git a/src/depfile_parser_test.cc b/src/depfile_parser_test.cc
index 824073f..52fe7cd 100644
--- a/src/depfile_parser_test.cc
+++ b/src/depfile_parser_test.cc
@@ -119,10 +119,10 @@
   // https://github.com/google/libcxx/tree/master/test/iterators/stream.iterators/istreambuf.iterator/
   string err;
   EXPECT_TRUE(Parse(
-"C:/Program\\ Files\\ (x86)/Microsoft\\ crtdefs.h: \n"
-" en@quot.header~ t+t-x!=1 \n"
-" openldap/slapd.d/cn=config/cn=schema/cn={0}core.ldif\n"
-" Fu\303\244ball\n"
+"C:/Program\\ Files\\ (x86)/Microsoft\\ crtdefs.h: \\\n"
+" en@quot.header~ t+t-x!=1 \\\n"
+" openldap/slapd.d/cn=config/cn=schema/cn={0}core.ldif\\\n"
+" Fu\303\244ball\\\n"
 " a\\[1\\]b@2%c",
       &err));
   ASSERT_EQ("", err);
@@ -158,3 +158,133 @@
   EXPECT_FALSE(Parse("foo bar: x y z", &err));
   ASSERT_EQ("depfile has multiple output paths", err);
 }
+
+TEST_F(DepfileParserTest, MultipleEmptyRules) {
+  string err;
+  EXPECT_TRUE(Parse("foo: x\n"
+                    "foo: \n"
+                    "foo:\n", &err));
+  ASSERT_EQ("foo", parser_.out_.AsString());
+  ASSERT_EQ(1u, parser_.ins_.size());
+  EXPECT_EQ("x", parser_.ins_[0].AsString());
+}
+
+TEST_F(DepfileParserTest, UnifyMultipleRulesLF) {
+  string err;
+  EXPECT_TRUE(Parse("foo: x\n"
+                    "foo: y\n"
+                    "foo \\\n"
+                    "foo: z\n", &err));
+  ASSERT_EQ("foo", parser_.out_.AsString());
+  ASSERT_EQ(3u, parser_.ins_.size());
+  EXPECT_EQ("x", parser_.ins_[0].AsString());
+  EXPECT_EQ("y", parser_.ins_[1].AsString());
+  EXPECT_EQ("z", parser_.ins_[2].AsString());
+}
+
+TEST_F(DepfileParserTest, UnifyMultipleRulesCRLF) {
+  string err;
+  EXPECT_TRUE(Parse("foo: x\r\n"
+                    "foo: y\r\n"
+                    "foo \\\r\n"
+                    "foo: z\r\n", &err));
+  ASSERT_EQ("foo", parser_.out_.AsString());
+  ASSERT_EQ(3u, parser_.ins_.size());
+  EXPECT_EQ("x", parser_.ins_[0].AsString());
+  EXPECT_EQ("y", parser_.ins_[1].AsString());
+  EXPECT_EQ("z", parser_.ins_[2].AsString());
+}
+
+TEST_F(DepfileParserTest, UnifyMixedRulesLF) {
+  string err;
+  EXPECT_TRUE(Parse("foo: x\\\n"
+                    "     y\n"
+                    "foo \\\n"
+                    "foo: z\n", &err));
+  ASSERT_EQ("foo", parser_.out_.AsString());
+  ASSERT_EQ(3u, parser_.ins_.size());
+  EXPECT_EQ("x", parser_.ins_[0].AsString());
+  EXPECT_EQ("y", parser_.ins_[1].AsString());
+  EXPECT_EQ("z", parser_.ins_[2].AsString());
+}
+
+TEST_F(DepfileParserTest, UnifyMixedRulesCRLF) {
+  string err;
+  EXPECT_TRUE(Parse("foo: x\\\r\n"
+                    "     y\r\n"
+                    "foo \\\r\n"
+                    "foo: z\r\n", &err));
+  ASSERT_EQ("foo", parser_.out_.AsString());
+  ASSERT_EQ(3u, parser_.ins_.size());
+  EXPECT_EQ("x", parser_.ins_[0].AsString());
+  EXPECT_EQ("y", parser_.ins_[1].AsString());
+  EXPECT_EQ("z", parser_.ins_[2].AsString());
+}
+
+TEST_F(DepfileParserTest, IndentedRulesLF) {
+  string err;
+  EXPECT_TRUE(Parse(" foo: x\n"
+                    " foo: y\n"
+                    " foo: z\n", &err));
+  ASSERT_EQ("foo", parser_.out_.AsString());
+  ASSERT_EQ(3u, parser_.ins_.size());
+  EXPECT_EQ("x", parser_.ins_[0].AsString());
+  EXPECT_EQ("y", parser_.ins_[1].AsString());
+  EXPECT_EQ("z", parser_.ins_[2].AsString());
+}
+
+TEST_F(DepfileParserTest, IndentedRulesCRLF) {
+  string err;
+  EXPECT_TRUE(Parse(" foo: x\r\n"
+                    " foo: y\r\n"
+                    " foo: z\r\n", &err));
+  ASSERT_EQ("foo", parser_.out_.AsString());
+  ASSERT_EQ(3u, parser_.ins_.size());
+  EXPECT_EQ("x", parser_.ins_[0].AsString());
+  EXPECT_EQ("y", parser_.ins_[1].AsString());
+  EXPECT_EQ("z", parser_.ins_[2].AsString());
+}
+
+TEST_F(DepfileParserTest, TolerateMP) {
+  string err;
+  EXPECT_TRUE(Parse("foo: x y z\n"
+                    "x:\n"
+                    "y:\n"
+                    "z:\n", &err));
+  ASSERT_EQ("foo", parser_.out_.AsString());
+  ASSERT_EQ(3u, parser_.ins_.size());
+  EXPECT_EQ("x", parser_.ins_[0].AsString());
+  EXPECT_EQ("y", parser_.ins_[1].AsString());
+  EXPECT_EQ("z", parser_.ins_[2].AsString());
+}
+
+TEST_F(DepfileParserTest, MultipleRulesTolerateMP) {
+  string err;
+  EXPECT_TRUE(Parse("foo: x\n"
+                    "x:\n"
+                    "foo: y\n"
+                    "y:\n"
+                    "foo: z\n"
+                    "z:\n", &err));
+  ASSERT_EQ("foo", parser_.out_.AsString());
+  ASSERT_EQ(3u, parser_.ins_.size());
+  EXPECT_EQ("x", parser_.ins_[0].AsString());
+  EXPECT_EQ("y", parser_.ins_[1].AsString());
+  EXPECT_EQ("z", parser_.ins_[2].AsString());
+}
+
+TEST_F(DepfileParserTest, MultipleRulesRejectDifferentOutputs) {
+  // check that multiple different outputs are rejected by the parser
+  // when spread across multiple rules
+  DepfileParserOptions parser_opts;
+  parser_opts.depfile_distinct_target_lines_action_ =
+      kDepfileDistinctTargetLinesActionError;
+  DepfileParser parser(parser_opts);
+  string err;
+  string input =
+      "foo: x y\n"
+      "bar: y z\n";
+  EXPECT_FALSE(parser.Parse(&input, &err));
+  ASSERT_EQ("depfile has multiple output paths (on separate lines)"
+            " [-w depfilemulti=err]", err);
+}
diff --git a/src/disk_interface_test.cc b/src/disk_interface_test.cc
index 33462fe..090adc4 100644
--- a/src/disk_interface_test.cc
+++ b/src/disk_interface_test.cc
@@ -213,7 +213,7 @@
 
 struct StatTest : public StateTestWithBuiltinRules,
                   public DiskInterface {
-  StatTest() : scan_(&state_, NULL, NULL, this, false) {}
+  StatTest() : scan_(&state_, NULL, NULL, this, NULL, false) {}
 
   // DiskInterface implementation.
   virtual TimeStamp Stat(const string& path, string* err) const;
diff --git a/src/graph.cc b/src/graph.cc
index 13fa85c..6c773aa 100644
--- a/src/graph.cc
+++ b/src/graph.cc
@@ -856,7 +856,9 @@
     return false;
   }
 
-  DepfileParser depfile;
+  DepfileParser depfile(depfile_parser_options_
+                        ? *depfile_parser_options_
+                        : DepfileParserOptions());
   string depfile_err;
   if (!depfile.Parse(&content, &depfile_err)) {
     *err = path + ": " + depfile_err;
diff --git a/src/graph.h b/src/graph.h
index 21c95eb..b648947 100644
--- a/src/graph.h
+++ b/src/graph.h
@@ -26,6 +26,7 @@
 #include "util.h"
 
 struct BuildLog;
+struct DepfileParserOptions;
 struct DiskInterface;
 struct DepsLog;
 struct Edge;
@@ -460,8 +461,10 @@
 /// "depfile" attribute in build files.
 struct ImplicitDepLoader {
   ImplicitDepLoader(State* state, DepsLog* deps_log,
-                    DiskInterface* disk_interface)
-      : state_(state), disk_interface_(disk_interface), deps_log_(deps_log) {}
+                    DiskInterface* disk_interface,
+                    DepfileParserOptions const* depfile_parser_options)
+      : state_(state), disk_interface_(disk_interface), deps_log_(deps_log),
+        depfile_parser_options_(depfile_parser_options) {}
 
   /// Load implicit dependencies for \a edge.
   /// @return false on error (without filling \a err if info is just missing
@@ -493,6 +496,7 @@
   State* state_;
   DiskInterface* disk_interface_;
   DepsLog* deps_log_;
+  DepfileParserOptions const* depfile_parser_options_;
 };
 
 
@@ -500,10 +504,12 @@
 /// and updating the dirty/outputs_ready state of all the nodes and edges.
 struct DependencyScan {
   DependencyScan(State* state, BuildLog* build_log, DepsLog* deps_log,
-                 DiskInterface* disk_interface, bool missing_phony_is_err)
+                 DiskInterface* disk_interface,
+                 DepfileParserOptions const* depfile_parser_options,
+                 bool missing_phony_is_err)
       : build_log_(build_log),
         disk_interface_(disk_interface),
-        dep_loader_(state, deps_log, disk_interface),
+        dep_loader_(state, deps_log, disk_interface, depfile_parser_options),
         missing_phony_is_err_(missing_phony_is_err) {}
 
   /// Used for tests.
diff --git a/src/graph_test.cc b/src/graph_test.cc
index b50d79f..a957513 100644
--- a/src/graph_test.cc
+++ b/src/graph_test.cc
@@ -18,7 +18,7 @@
 #include "test.h"
 
 struct GraphTest : public StateTestWithBuiltinRules {
-  GraphTest() : scan_(&state_, NULL, NULL, &fs_, false) {}
+  GraphTest() : scan_(&state_, NULL, NULL, &fs_, NULL, false) {}
 
   VirtualFileSystem fs_;
   DependencyScan scan_;
@@ -510,7 +510,7 @@
   EXPECT_TRUE(GetNode("foo")->dirty());
 
   state_.Reset();
-  DependencyScan scan(&state_, NULL, NULL, &fs_, true);
+  DependencyScan scan(&state_, NULL, NULL, &fs_, NULL, true);
   EXPECT_FALSE(scan.RecomputeDirty(GetNode("foo"), NULL, &err));
   EXPECT_EQ("output foo of phony edge doesn't exist. Missing 'phony_output = true'?", err);
 }
diff --git a/src/ninja.cc b/src/ninja.cc
index 701eb7a..ac5cb7e 100644
--- a/src/ninja.cc
+++ b/src/ninja.cc
@@ -84,6 +84,10 @@
   /// Whether phony cycles should warn or print an error.
   bool phony_cycle_should_err;
 
+  /// Whether a depfile with multiple targets on separate lines should
+  /// warn or print an error.
+  bool depfile_distinct_target_lines_should_err;
+
   /// Whether to remain persistent.
   bool persistent;
 };
@@ -1115,6 +1119,7 @@
     printf("warning flags:\n"
 "  dupbuild={err,warn}  multiple build lines for one target\n"
 "  phonycycle={err,warn}  phony build statement references itself\n"
+"  depfilemulti={err,warn}  depfile has multiple output paths on separate lines\n"
 "  missingdepfile={err,warn}  how to treat missing depfiles\n"
 "\n"
 " requires -o usesphonyoutputs=yes\n"
@@ -1134,6 +1139,12 @@
   } else if (name == "phonycycle=warn") {
     options->phony_cycle_should_err = false;
     return true;
+  } else if (name == "depfilemulti=err") {
+    options->depfile_distinct_target_lines_should_err = true;
+    return true;
+  } else if (name == "depfilemulti=warn") {
+    options->depfile_distinct_target_lines_should_err = false;
+    return true;
   } else if (name == "missingdepfile=err") {
     config->missing_depfile_should_err = true;
     return true;
@@ -1514,6 +1525,11 @@
   if (exit_code >= 0)
     exit(exit_code);
 
+  if (options.depfile_distinct_target_lines_should_err) {
+    config.depfile_parser_options.depfile_distinct_target_lines_action_ =
+        kDepfileDistinctTargetLinesActionError;
+  }
+
   if (options.working_dir) {
     // The formatting of this string, complete with funny quotes, is
     // so Emacs can properly identify that the cwd has changed for