Load the debug information during runtime startup if OCAMLRUNPARAM=b=2.
This guards against the specific case of running out of fds, since the
debug information can't then be loaded.
The previous mechanism worked for C calls that raise an exception, but not for C calls that call back into OCaml code which raises an exception.
This commit addresses the issue by saving the PC in the interpreter stack before a C call, so that the backtrace mechanism always sees it.
However, if an external is declared in the .ml file and exposed in the .mli file as a val, then ocamlc generates a wrapper that adds a spurious entry in the stack frame. In this PR, this change in behavior results in the re-declaration of Printexc.get_callstack as an external instead of a val, so that the spurious stack frame does not appear in call stacks obtained from Printexc.get_callstack.
* Fix free identifiers in spacetime
* Fix free identifiers in tools/gdb-macros
* [minor] Fix Caml_state fields in comments, and other comment updates
* Changes
Since we cannot access backtrace position in cmmgen.ml anymore,
Cmm.raise_kind in removed. Instead, we use Lambda.raise_kind. When
assembly code is generated, we reset the backtrace position to 0 in the
case of regular raise. Importantly, the semantics remains the same.
David Allsopp
Gabriel Scherer
Jacques-Henri Jourdan
Guillaume Munch-Maccagnoni
KC Sivaramakrishnan
Sébastien Hinderer