Remove `-w dupbuild` from error message and help output

This is step 4 on #931.

3 files changed, 7 insertions, 10 deletions

diff --git a/src/manifest_parser.cc b/src/manifest_parser.cc
index 54ad3f4..f77109f 100644
--- a/src/manifest_parser.cc
+++ b/src/manifest_parser.cc
@@ -323,15 +323,14 @@ bool ManifestParser::ParseEdge(string* err) {
       return lexer_.Error(path_err, err);
     if (!state_->AddOut(edge, path, slash_bits)) {
       if (options_.dupe_edge_action_ == kDupeEdgeActionError) {
-        lexer_.Error("multiple rules generate " + path + " [-w dupbuild=err]",
-                     err);
+        lexer_.Error("multiple rules generate " + path, err);
         return false;
       } else {
         if (!quiet_) {
-          Warning("multiple rules generate %s. "
-                  "builds involving this target will not be correct; "
-                  "continuing anyway [-w dupbuild=warn]",
-                  path.c_str());
+          Warning(
+              "multiple rules generate %s. builds involving this target will "
+              "not be correct; continuing anyway",
+              path.c_str());
         }
         if (e - i <= static_cast<size_t>(implicit_outs))
           --implicit_outs;
diff --git a/src/manifest_parser_test.cc b/src/manifest_parser_test.cc
index ec2eeed..5b0eddf 100644
--- a/src/manifest_parser_test.cc
+++ b/src/manifest_parser_test.cc
@@ -365,7 +365,7 @@ TEST_F(ParserTest, DuplicateEdgeWithMultipleOutputsError) {
   ManifestParser parser(&state, &fs_, parser_opts);
   string err;
   EXPECT_FALSE(parser.ParseTest(kInput, &err));
-  EXPECT_EQ("input:5: multiple rules generate out1 [-w dupbuild=err]\n", err);
+  EXPECT_EQ("input:5: multiple rules generate out1\n", err);
 }
 
 TEST_F(ParserTest, DuplicateEdgeInIncludedFile) {
@@ -382,8 +382,7 @@ TEST_F(ParserTest, DuplicateEdgeInIncludedFile) {
   ManifestParser parser(&state, &fs_, parser_opts);
   string err;
   EXPECT_FALSE(parser.ParseTest(kInput, &err));
-  EXPECT_EQ("sub.ninja:5: multiple rules generate out1 [-w dupbuild=err]\n",
-            err);
+  EXPECT_EQ("sub.ninja:5: multiple rules generate out1\n", err);
 }
 
 TEST_F(ParserTest, PhonySelfReferenceIgnored) {
diff --git a/src/ninja.cc b/src/ninja.cc
index 45fc8ea..1cff6e8 100644
--- a/src/ninja.cc
+++ b/src/ninja.cc
@@ -1104,7 +1104,6 @@ bool DebugEnable(const string& name) {
 bool WarningEnable(const string& name, Options* options) {
   if (name == "list") {
     printf("warning flags:\n"
-"  dupbuild={err,warn}  multiple build lines for one target\n"
 "  phonycycle={err,warn}  phony build statement references itself\n"
     );
     return false;