Set build tags with config option (#199)

.plzconfig

@@ -147,5 +147,10 @@ Type = bool
 DefaultValue = true
 Help = Generate pkg info for Go targets
 
+[PluginConfig "build_tags"]
+Repeatable = true
+Optional = true
+Help = Build tags to pass to the Go compiler
+
 [Plugin "shell"]
 Target = //plugins:shell

build_defs/go.build_defs

@@ -1218,11 +1218,14 @@ def go_repo(module: str, version:str='', download:str=None, name:str=None, insta
     if version:
         labels += [f"go_module:{module}@{version}"]
     requirements = " ".join(requirements)
+
+    build_tags = '--build_tag ' + ' --build_tag '.join(CONFIG.GO.BUILD_TAGS) if CONFIG.GO.BUILD_TAGS else ''
+
     repo = build_rule(
         name = name,
         tag = "repo" if install else None,
         srcs =  srcs,
-        cmd  = f"rm -rf $SRCS_DOWNLOAD/.plzconfig && find $SRCS_DOWNLOAD -name BUILD -delete && $TOOL generate {modFileArg} --module {module} --version '{version}' --src_root=$SRCS_DOWNLOAD --third_part_folder='{third_party_path}' {install_args} {requirements} && mv $SRCS_DOWNLOAD $OUT",
+        cmd  = f"rm -rf $SRCS_DOWNLOAD/.plzconfig && find $SRCS_DOWNLOAD -name BUILD -delete && $TOOL generate {modFileArg} --module {module} --version '{version}' {build_tags} --src_root=$SRCS_DOWNLOAD --third_part_folder='{third_party_path}' {install_args} {requirements} && mv $SRCS_DOWNLOAD $OUT",
         outs = [subrepo_name],
         tools = [CONFIG.GO.PLEASE_GO_TOOL],
         env= {
@@ -1576,7 +1579,12 @@ def _set_go_env():
 
 def _go_library_cmds(name, import_path:str="", complete=True, all_srcs=False, cover=True, filter_srcs=True, abi=False, embedcfg=None, pgo_file=None):
     """Returns the commands to run for building a Go library."""
-    filter_cmd = 'export SRCS_GO="$(\"${TOOLS_PLEASE_GO}\" filter ${SRCS_GO})"; ' if filter_srcs else ''
+    if filter_srcs:
+        build_tags = '-t ' + ' -t '.join(CONFIG.GO.BUILD_TAGS) if CONFIG.GO.BUILD_TAGS else ''
+        filter_cmd = f'export SRCS_GO="$(\"${TOOLS_PLEASE_GO}\" filter {build_tags} $SRCS_GO)"; '
+    else:
+        filter_cmd = ''
+
     # Invokes the Go compiler.
     complete_flag = '-complete ' if complete else ''
     embed_flag = ' -embedcfg $SRCS_EMBED' if embedcfg else ''

tools/please_go/ChangeLog

@@ -1,3 +1,8 @@
+Version 1.8.0
+-------------
+    * Add --build_tag flag to `generate` subcommand to allow specifying a build tag to use when
+      generating the BUILD files (#199)
+
 Version 1.7.0
 -------------
     * Allow selecting the pkg-config tool via PKG_CONFIG_TOOL env var

tools/please_go/VERSION

@@ -1 +1 @@
-1.7.0
+1.8.0

tools/please_go/generate/generate.go

@@ -31,14 +31,18 @@ type Generate struct {
 	install            []string
 }
 
-func New(srcRoot, thirdPartyFolder, modFile, module, version string, buildFileNames, moduleDeps, install []string) *Generate {
+func New(srcRoot, thirdPartyFolder, modFile, module, version string, buildFileNames, moduleDeps, install []string, buildTags []string) *Generate {
 	moduleArg := module
 	if version != "" {
 		moduleArg += "@" + version
 	}
+
+	ctxt := build.Default
+	ctxt.BuildTags = buildTags
+
 	return &Generate{
 		srcRoot:            srcRoot,
-		buildContext:       build.Default,
+		buildContext:       ctxt,
 		buildFileNames:     buildFileNames,
 		moduleDeps:         moduleDeps,
 		modFile:            modFile,
@@ -54,17 +58,17 @@ func New(srcRoot, thirdPartyFolder, modFile, module, version string, buildFileNa
 // files. This is primarily intended to generate a please subrepo for third party code.
 func (g *Generate) Generate() error {
 	if err := g.readGoMod(g.modFile); err != nil {
-		return err
+		return fmt.Errorf("failed to read go.mod: %w", err)
 	}
 	if err := g.writeConfig(); err != nil {
-		return err
+		return fmt.Errorf("failed to write config: %w", err)
 	}
 	if err := g.parseImportConfigs(); err != nil {
-		return err
+		return fmt.Errorf("failed to parse import configs: %w", err)
 	}
 
 	if err := g.generateAll(g.srcRoot); err != nil {
-		return err
+		return fmt.Errorf("failed to generate BUILD files: %w", err)
 	}
 	return g.writeInstallFilegroup()
 }
@@ -274,6 +278,20 @@ func (g *Generate) generate(dir string) error {
 		return err
 	}
 
+	// filter out pkg.GoFiles based on build tags
+	var goFiles []string
+	for _, f := range pkg.GoFiles {
+		match, err := g.buildContext.MatchFile(pkg.Dir, f)
+		if err != nil {
+			return err
+		}
+		if match {
+			goFiles = append(goFiles, f)
+		}
+	}
+
+	pkg.GoFiles = goFiles
+
 	lib := g.ruleForPackage(pkg, dir)
 	if lib == nil {
 		return nil

tools/please_go/please_go.go

@@ -98,6 +98,7 @@ var opts = struct {
 		Module           string   `long:"module" description:"The name of the current module"`
 		Version          string   `long:"version" description:"The version of the current module"`
 		Install          []string `long:"install" description:"The packages to add to the :install alias"`
+		BuildTags        []string `long:"build_tag" description:"Any build tags to apply to the build"`
 		Args             struct {
 			Requirements []string `positional-arg-name:"requirements" description:"Any module requirements not included in the go.mod"`
 		} `positional-args:"true"`
@@ -179,7 +180,7 @@ var subCommands = map[string]func() int{
 		return 0
 	},
 	"generate": func() int {
-		g := generate.New(opts.Generate.SrcRoot, opts.Generate.ThirdPartyFolder, opts.Generate.ModFile, opts.Generate.Module, opts.Generate.Version, []string{"BUILD", "BUILD.plz"}, opts.Generate.Args.Requirements, opts.Generate.Install)
+		g := generate.New(opts.Generate.SrcRoot, opts.Generate.ThirdPartyFolder, opts.Generate.ModFile, opts.Generate.Module, opts.Generate.Version, []string{"BUILD", "BUILD.plz"}, opts.Generate.Args.Requirements, opts.Generate.Install, opts.Generate.BuildTags)
 		if err := g.Generate(); err != nil {
 			log.Fatalf("failed to generate go rules: %v", err)
 		}