syscfg: Write defs for each APIs provided by included packages

This adds symbols in syscfg.h for each API provided by packages included
in build. The symbol name has "MYNEWT_API_" prefix followed with sanitized
API name, all illegal characters in resulting name are replaced with "_".

This allows to check if any package included in build provides specific
API. Could be useful if some API is not strictly required, but we can
use it if provided by some package.

newt/builder/targetbuild.go

@@ -292,7 +292,11 @@ func (t *TargetBuilder) validateAndWriteCfg() error {
  srcDir := GeneratedSrcDir(t.target.FullName())
 
  lpkgs := resolve.RpkgSliceToLpkgSlice(t.res.MasterSet.Rpkgs)
- if err := syscfg.EnsureWritten(t.res.Cfg, incDir, lpkgs); err != nil {
+ apis := []string{}
+ for api := range t.res.ApiMap {
+ apis = append(apis, api)
+ }
+ if err := syscfg.EnsureWritten(t.res.Cfg, incDir, lpkgs, apis); err != nil {
  return err
  }
 

newt/syscfg/syscfg.go

@@ -1599,7 +1599,19 @@ func writePackages(lpkgs []*pkg.LocalPackage, w io.Writer) {
  }
 }
 
-func write(cfg Cfg, lpkgs []*pkg.LocalPackage, w io.Writer) {
+func writeApis(apis []string, w io.Writer) {
+ for i, api := range apis {
+ apis[i] = cfgPkgIllegalChar.ReplaceAllLiteralString(api, "_")
+ }
+ sort.Strings(apis)
+
+ fmt.Fprintf(w, "/*** Included APIs */\n")
+ for _, name := range apis {
+ fmt.Fprintf(w, "#define MYNEWT_API_%s 1\n", name)
+ }
+}
+
+func write(cfg Cfg, lpkgs []*pkg.LocalPackage, apis []string, w io.Writer) {
  fmt.Fprintf(w, newtutil.GeneratedPreamble())
 
  fmt.Fprintf(w, "#ifndef H_MYNEWT_SYSCFG_\n")
@@ -1619,10 +1631,13 @@ func write(cfg Cfg, lpkgs []*pkg.LocalPackage, w io.Writer) {
  writePackages(lpkgs, w)
  fmt.Fprintf(w, "\n")
 
+ writeApis(apis, w)
+ fmt.Fprintf(w, "\n")
+
  fmt.Fprintf(w, "#endif\n")
 }
 
-func EnsureWritten(cfg Cfg, includeDir string, lpkgs []*pkg.LocalPackage) error {
+func EnsureWritten(cfg Cfg, includeDir string, lpkgs []*pkg.LocalPackage, apis []string) error {
  // XXX: Detect these problems at error text generation time.
  if err := calcPriorities(cfg, CFG_SETTING_TYPE_TASK_PRIO,
  SYSCFG_TASK_PRIO_MAX, false); err != nil {
@@ -1631,7 +1646,7 @@ func EnsureWritten(cfg Cfg, includeDir string, lpkgs []*pkg.LocalPackage) error
  }
 
  buf := bytes.Buffer{}
- write(cfg, lpkgs, &buf)
+ write(cfg, lpkgs, apis, &buf)
 
  path := includeDir + "/" + HEADER_PATH