Extend FASTBuild bff generator to support CustomFileBuildStep.AdditionalInputs. (#443)

For some reason Sharpmake currently doesn't support having multiple inputs for the FASTBuild .Exec function generated from CustomFileBuildStep whereas it does for the .Exec function generated from the custom pre or post build exe steps. FASTBuild .Exec supports multiple input files, so it's fairly trivial to support this and it's useful for correct dependency checking of per-file custom build steps.

Co-authored-by: Martin Ecker <[email protected]>

Author: martinecker-ATVI

Sharpmake.Generators/FastBuild/Bff.Util.cs

@@ -859,9 +859,16 @@ internal static void WriteCustomBuildStepAsGenericExecutable(string projectRoot,
                     return relativePath;
             });
 
+            Strings inputFiles = new();
+            inputFiles.Add(relativeBuildStep.KeyInput);
+            foreach (string inputFile in relativeBuildStep.AdditionalInputs)
+            {
+                inputFiles.Add(inputFile);
+            }
+
             using (bffGenerator.Declare("fastBuildPreBuildName", relativeBuildStep.Description))
             using (bffGenerator.Declare("fastBuildPrebuildExeFile", relativeBuildStep.Executable))
-            using (bffGenerator.Declare("fastBuildPreBuildInputFiles", FBuildFormatSingleListItem(relativeBuildStep.KeyInput)))
+            using (bffGenerator.Declare("fastBuildPreBuildInputFiles", FBuildFormatList(inputFiles.ToList(), 26)))
             using (bffGenerator.Declare("fastBuildPreBuildOutputFile", relativeBuildStep.Output))
             using (bffGenerator.Declare("fastBuildPreBuildArguments", string.IsNullOrWhiteSpace(relativeBuildStep.ExecutableArguments) ? FileGeneratorUtilities.RemoveLineTag : relativeBuildStep.ExecutableArguments))
             // This is normally the project directory.

Sharpmake/Project.Configuration.cs

@@ -2360,7 +2360,6 @@ public enum ProjectFilter
                 public string OutputItemType = "";
 
                 /// <summary>
-                /// Not supported by FASTBuild.
                 /// Additional files that will cause a re-run of this custom build step can be be specified here.
                 /// </summary>
                 public Strings AdditionalInputs = new Strings();

samples/CustomBuildStep/CustomBuildStep.sharpmake.cs

@@ -14,7 +14,7 @@ public CustomBuildStepProject()
             SourceRootPath = @"[project.SharpmakeCsPath]\codebase";
             SourceFilesExtensions.Add(".bat");
 
-            // need to add it explicitly since it's gonna be generated it doesn't exist yet
+            // need to add generated files explicitly since they don't exist yet
             SourceFiles.Add(@"[project.SourceRootPath]\main.cpp");
             SourceFiles.Add(@"[project.SourceRootPath]\secondaryfile.cpp");
 
@@ -33,6 +33,7 @@ public CustomBuildStepProject()
         [Configure]
         public void ConfigureAll(Configuration conf, Target target)
         {
+            // A simple custom build step that generates main.cpp via a .bat file
             conf.CustomFileBuildSteps.Add(
                 new Configuration.CustomFileBuildStep
                 {
@@ -41,13 +42,17 @@ public void ConfigureAll(Configuration conf, Target target)
                     Description = $"Generate main.cpp",
                     Executable = "generatemain.bat"
                 });
+            // Demonstrates a custom file build step that has two inputs and one output
             conf.CustomFileBuildSteps.Add(
                 new Configuration.CustomFileBuildStep
                 {
                     KeyInput = "generatesecondaryfile.bat",
                     Output = "secondaryfile.cpp",
                     Description = $"Generate secondaryfile.cpp",
-                    Executable = "generatesecondaryfile.bat"
+                    Executable = "generatesecondaryfile.bat",
+                    ExecutableArguments = "../codebase/concatenate_file1.in ../codebase/concatenate_file2.in",
+                    AdditionalInputs = { "[project.SourceRootPath]\\concatenate_file1.in", "[project.SourceRootPath]\\concatenate_file2.in" }
+				
                 });
 
             conf.ProjectFileName = "[project.Name]_[target.DevEnv]_[target.Platform]";

samples/CustomBuildStep/codebase/concatenate_file1.in

@@ -0,0 +1,6 @@
+#include <stdio.h>
+
+const char *GetFile1Content()
+{
+    return "This is the content of file 1.\n";
+}

samples/CustomBuildStep/codebase/concatenate_file2.in

@@ -0,0 +1,10 @@
+const char *GetFile2Content()
+{
+    return "This is the content of file 2.\n";
+}
+
+void PrintSecondaryFileContent()
+{
+    printf("%s", GetFile1Content());
+    printf("%s", GetFile2Content());
+}

samples/CustomBuildStep/codebase/generatesecondaryfile.bat

@@ -1,15 +1,18 @@
 @echo off
 setlocal
 
-set OUTPUT=%~dp0secondaryfile.cpp
-echo Generating %OUTPUT%
-
-:: Note: ^ is used to escape < and >
-> "%OUTPUT%" echo #include ^<stdio.h^>
->>"%OUTPUT%" echo void PrintSecondaryFileContent()
->>"%OUTPUT%" echo {
->>"%OUTPUT%" echo     printf("This is secondary file\n");
->>"%OUTPUT%" echo }
-
-echo Done
-goto :eof
+if "%~2"=="" goto :usage
+
+set OUTPUT=%~dp0\secondaryfile.cpp
+
+echo Concatenating "%~f1" + "%~f2" into "%OUTPUT%"
+>"%OUTPUT%" type "%~f1"
+>>"%OUTPUT%" type "%~f2"
+
+echo Done.
+goto :eof
+
+:usage
+echo Usage: %~n0 file1.cpp file2.cpp
+echo Concatenates file1.cpp and file2.cpp into %~dp0concatenated.cpp
+exit /b 1