cmGlobalNinjaGenerator: Teach WriteBuild about implicit outputs

Ninja 1.7 introduced support for implicit outputs on build statements.
Teach WriteBuild to generate the corresponding syntax.  Leave it up to
callers to decide whether implicit outputs are supported by the Ninja
version in use.  For now simply update all call sites to pass an empty
list of implicit outputs.

Source/cmGlobalNinjaGenerator.cxx

@@ -140,10 +140,10 @@ std::string cmGlobalNinjaGenerator::EncodeDepfileSpace(const std::string& path)
 
 void cmGlobalNinjaGenerator::WriteBuild(
   std::ostream& os, const std::string& comment, const std::string& rule,
-  const cmNinjaDeps& outputs, const cmNinjaDeps& explicitDeps,
+  const cmNinjaDeps& outputs, const cmNinjaDeps& implicitOuts,
-  const cmNinjaDeps& implicitDeps, const cmNinjaDeps& orderOnlyDeps,
+  const cmNinjaDeps& explicitDeps, const cmNinjaDeps& implicitDeps,
-  const cmNinjaVars& variables, const std::string& rspfile, int cmdLineLimit,
+  const cmNinjaDeps& orderOnlyDeps, const cmNinjaVars& variables,
-  bool* usedResponseFile)
+  const std::string& rspfile, int cmdLineLimit, bool* usedResponseFile)
 {
   // Make sure there is a rule.
   if (rule.empty()) {
@@ -204,6 +204,13 @@ void cmGlobalNinjaGenerator::WriteBuild(
       this->CombinedBuildOutputs.insert(EncodePath(*i));
     }
   }
+  if (!implicitOuts.empty()) {
+    build += " |";
+    for (cmNinjaDeps::const_iterator i = implicitOuts.begin();
+         i != implicitOuts.end(); ++i) {
+      build += " " + EncodeIdent(EncodePath(*i), os);
+    }
+  }
   build += ":";
 
   // Write the rule.
@@ -244,7 +251,8 @@ void cmGlobalNinjaGenerator::WritePhonyBuild(
   const cmNinjaDeps& explicitDeps, const cmNinjaDeps& implicitDeps,
   const cmNinjaDeps& orderOnlyDeps, const cmNinjaVars& variables)
 {
-  this->WriteBuild(os, comment, "phony", outputs, explicitDeps, implicitDeps,
+  this->WriteBuild(os, comment, "phony", outputs,
+                   /*implicitOuts=*/cmNinjaDeps(), explicitDeps, implicitDeps,
                    orderOnlyDeps, variables);
 }
 
@@ -288,7 +296,8 @@ void cmGlobalNinjaGenerator::WriteCustomCommandBuild(
     vars["depfile"] = depfile;
   }
   this->WriteBuild(*this->BuildFileStream, comment, "CUSTOM_COMMAND", outputs,
-                   deps, cmNinjaDeps(), orderOnly, vars);
+                   /*implicitOuts=*/cmNinjaDeps(), deps, cmNinjaDeps(),
+                   orderOnly, vars);
 
   if (this->ComputingUnknownDependencies) {
     // we need to track every dependency that comes in, since we are trying
@@ -330,7 +339,8 @@ void cmGlobalNinjaGenerator::WriteMacOSXContentBuild(const std::string& input,
   cmNinjaVars vars;
 
   this->WriteBuild(*this->BuildFileStream, "", "COPY_OSX_CONTENT", outputs,
-                   deps, cmNinjaDeps(), cmNinjaDeps(), cmNinjaVars());
+                   /*implicitOuts=*/cmNinjaDeps(), deps, cmNinjaDeps(),
+                   cmNinjaDeps(), cmNinjaVars());
 }
 
 void cmGlobalNinjaGenerator::WriteRule(
@@ -1271,6 +1281,7 @@ void cmGlobalNinjaGenerator::WriteTargetRebuildManifest(std::ostream& os)
   this->WriteBuild(os, "Re-run CMake if any of its inputs changed.",
                    "RERUN_CMAKE",
                    /*outputs=*/cmNinjaDeps(1, ninjaBuildFile),
+                   /*implicitOuts=*/cmNinjaDeps(),
                    /*explicitDeps=*/cmNinjaDeps(), implicitDeps,
                    /*orderOnlyDeps=*/cmNinjaDeps(), variables);
 
@@ -1308,6 +1319,7 @@ void cmGlobalNinjaGenerator::WriteTargetClean(std::ostream& os)
             /*generator=*/false);
   WriteBuild(os, "Clean all the built files.", "CLEAN",
              /*outputs=*/cmNinjaDeps(1, this->NinjaOutputPath("clean")),
+             /*implicitOuts=*/cmNinjaDeps(),
              /*explicitDeps=*/cmNinjaDeps(),
              /*implicitDeps=*/cmNinjaDeps(),
              /*orderOnlyDeps=*/cmNinjaDeps(),
@@ -1327,6 +1339,7 @@ void cmGlobalNinjaGenerator::WriteTargetHelp(std::ostream& os)
             /*generator=*/false);
   WriteBuild(os, "Print all primary targets available.", "HELP",
              /*outputs=*/cmNinjaDeps(1, this->NinjaOutputPath("help")),
+             /*implicitOuts=*/cmNinjaDeps(),
              /*explicitDeps=*/cmNinjaDeps(),
              /*implicitDeps=*/cmNinjaDeps(),
              /*orderOnlyDeps=*/cmNinjaDeps(),

Source/cmGlobalNinjaGenerator.h

@@ -106,6 +106,7 @@ public:
    */
   void WriteBuild(std::ostream& os, const std::string& comment,
                   const std::string& rule, const cmNinjaDeps& outputs,
+                  const cmNinjaDeps& implicitOuts,
                   const cmNinjaDeps& explicitDeps,
                   const cmNinjaDeps& implicitDeps,
                   const cmNinjaDeps& orderOnlyDeps,

Source/cmNinjaNormalTargetGenerator.cxx

@@ -691,7 +691,8 @@ void cmNinjaNormalTargetGenerator::WriteLinkStatement()
   // Write the build statement for this target.
   bool usedResponseFile = false;
   globalGen.WriteBuild(this->GetBuildFileStream(), comment.str(),
-                       this->LanguageLinkerRule(), outputs, explicitDeps,
+                       this->LanguageLinkerRule(), outputs,
+                       /*implicitOuts=*/cmNinjaDeps(), explicitDeps,
                        implicitDeps, orderOnlyDeps, vars, rspfile,
                        commandLineLengthLimit, &usedResponseFile);
   this->WriteLinkRule(usedResponseFile);
@@ -702,7 +703,8 @@ void cmNinjaNormalTargetGenerator::WriteLinkStatement()
         this->GetBuildFileStream(),
         "Create executable symlink " + targetOutput,
         "CMAKE_SYMLINK_EXECUTABLE", cmNinjaDeps(1, targetOutput),
-        cmNinjaDeps(1, targetOutputReal), emptyDeps, emptyDeps, symlinkVars);
+        /*implicitOuts=*/cmNinjaDeps(), cmNinjaDeps(1, targetOutputReal),
+        emptyDeps, emptyDeps, symlinkVars);
     } else {
       cmNinjaDeps symlinks;
       std::string const soName =
@@ -717,7 +719,8 @@ void cmNinjaNormalTargetGenerator::WriteLinkStatement()
       symlinks.push_back(targetOutput);
       globalGen.WriteBuild(
         this->GetBuildFileStream(), "Create library symlink " + targetOutput,
-        "CMAKE_SYMLINK_LIBRARY", symlinks, cmNinjaDeps(1, targetOutputReal),
+        "CMAKE_SYMLINK_LIBRARY", symlinks,
+        /*implicitOuts=*/cmNinjaDeps(), cmNinjaDeps(1, targetOutputReal),
         emptyDeps, emptyDeps, symlinkVars);
     }
   }

Source/cmNinjaTargetGenerator.cxx

@@ -607,8 +607,9 @@ void cmNinjaTargetGenerator::WriteObjectBuildStatement(
   std::string const rspfile = objectFileName + ".rsp";
 
   this->GetGlobalGenerator()->WriteBuild(
-    this->GetBuildFileStream(), comment, rule, outputs, explicitDeps,
+    this->GetBuildFileStream(), comment, rule, outputs,
-    implicitDeps, orderOnlyDeps, vars, rspfile, commandLineLengthLimit);
+    /*implicitOuts=*/cmNinjaDeps(), explicitDeps, implicitDeps, orderOnlyDeps,
+    vars, rspfile, commandLineLengthLimit);
 
   if (const char* objectOutputs = source->GetProperty("OBJECT_OUTPUTS")) {
     std::vector<std::string> outputList;