Provide (abs) top srcdir directly (and not via Rd).

git-svn-id: https://svn.r-project.org/R/trunk@89133 00db46b3-68df-0310-9c12-caf00c1e9a41

Author: hornik

src/library/tools/Makefile.in

@@ -34,6 +34,8 @@ all: Makefile DESCRIPTION
 	@$(ECHO) "building package '$(pkg)'"
 	@$(MKINSTALLDIRS) $(top_builddir)/library/$(pkg)
 	@$(MKINSTALLDIRS) $(top_builddir)/library/$(pkg)/misc
+	@$(ECHO) $(abs_top_srcdir) \
+	  > $(top_builddir)/library/$(pkg)/misc/top.txt
 	@$(MAKE) mkR1 mkdesc2  $(WRE_DATA)
 	@$(MAKE) mksrc
 	@if ! test -f $(top_builddir)/library/$(pkg)/R/$(pkg); then \

src/library/tools/R/zzz.R

@@ -61,3 +61,10 @@ rm(C_parseLatex)
     toset <- !(names(op.tools) %in% names(.Options))
     if(any(toset)) options(op.tools[toset])
 }
+
+.R_top_srcdir_file_path <-
+    system.file("misc", "top.txt", package = "tools")
+.R_top_srcdir <- if(nzchar(.R_top_srcdir_file_path)) {
+                     readLines(.R_top_srcdir_file_path)
+                 } else ""
+rm(.R_top_srcdir_file_path)