propagate much more source info through compilation

* module/language/ghil/compile-glil.scm (codegen): Record source location
  for offset 0 into a lambda, if we can.

* module/language/scheme/compile-ghil.scm (translate-1)
  (define-scheme-translator): In the retrans procedures, propagate the
  location information from the enclosing expression if the subexpression
  has no location information. Gives source information to many more
  expressions.
  (location): Just propagate the source properties as they are, the
  glil->assembly compiler will interpret them.

* module/language/glil.scm (<glil>): Change glil-source to take "props"
  and not "loc", as it's the source properties that we're interested in.

* module/language/glil/compile-assembly.scm (limn-sources): New function,
  takes a list of addr-source property pairs and "compresses" them for
  serialization to disk.
  (glil->assembly): Limn the sources before writing them to disk. Avoid
  non-tail recursion when determining total byte length of code.

* module/system/vm/program.scm (source:file, source:line, source:column):
  Update for new source representation.
  (program-source): Export.
  (write-program): Nicer pretty-printing of anonymous procedures.

* libguile/backtrace.c (display_backtrace_get_file_line): Update for the
  new VM source representation.

* libguile/programs.h:
* libguile/programs.c (scm_program_sources): Update for the new
  serialized source representation, where the filename is not in the
  stream unless it changes.
  (scm_program_source): New exported function, looks up the source for a
  given ip offset.
  (scm_c_program_source): Update to return the last source information
  that was <= the given IP, because we only serialize source info when it
  changes.

1 files changed, 7 insertions, 7 deletions

diff --git a/libguile/backtrace.c b/libguile/backtrace.c
index 418b6d777..a8afcdf34 100644
--- a/libguile/backtrace.c
+++ b/libguile/backtrace.c
@@ -473,14 +473,14 @@ display_backtrace_get_file_line (SCM frame, SCM *file, SCM *line)
       *file = scm_source_property (source, scm_sym_filename);
       *line = scm_source_property (source, scm_sym_line);
     }
-  else if (scm_is_vector (source))
+  else if (scm_is_pair (source)
+           && scm_is_pair (scm_cdr (source))
+           && scm_is_pair (scm_cddr (source))
+           && !scm_is_pair (scm_cdddr (source)))
     {
-      /* #(line column file), from VM compilation */
-      size_t len = scm_c_vector_length (source);
-      if (len >= 3)
-        *file = scm_c_vector_ref (source, 2);
-      if (len >= 1)
-        *line = scm_c_vector_ref (source, 0);
+      /* (addr . (filename . (line . column))), from vm compilation */
+      *file = scm_cadr (source);
+      *line = scm_caddr (source);
     }
 }