A 'char *&' (a reference to a char pointer) was only marshalled as a string by
C#, D, Go, Java and PHP; every other language treated it as an opaque char **
pointer. Add char *& string typemaps to the languages that were missing them,
so a char *& function argument, return value or variable is marshalled as a
string in every target language. SWIG's const reference stripping means this
also covers char *const&.
- Lib/typemaps/strings.swg: add Char *& to the %typemaps_string in, freearg,
out, typecheck and director typemaps. This gives char *& to the languages
that use the Unified Typemap Library (Python, Ruby, Perl, Tcl, Octave, Scilab,
R and JavaScript). The shared in typemap now casts &buf to $1_ltype so that a
const char * reference hidden behind a typedef also compiles.
- Lib/lua/luatypemaps.swg, Lib/guile/typemaps.i, Lib/ocaml/ocaml.swg: these
define their own char * string typemaps; give each char *& and const char *&
in/out/freearg typemaps too.
- Lib/r/rtype.swg: the C wrapper returned the char *& string correctly but the R
proxy wrapped it as an undefined _p_p_char S4 class; add char *& to the
scoerceout char list so it is returned as a plain character value.
char_strings.i is now exercised by a runme in every target language, all testing
the same set of functions (get/set/pingpong/global variables and all four char *&
functions), giving complete char *& typemap coverage and testing.
Where a language genuinely cannot support part of the char array portion of the
test (a char[] global has no varin typemap in most scripting languages, a char[16]
parameter is bounds checked, and Guile/OCaml reject char[] parameters), that one
assertion is adapted or skipped with an inline comment; the char *& coverage is
complete everywhere.
Assisted-by: Claude Code (Opus 4.8)
The Go 'in' typemap for char * wrote the null terminator through $1, which
fails to compile as C++ when the matched type is const char *, as happens
with a typedef such as 'typedef const char *MyString'. Allocate and write
the terminator through a char * temp, assign to $1 via $1_ltype, and cast
in the freearg so a const char * buffer can still be freed. Freeing $1
(rather than the temp) keeps the freearg working when char * is remapped
with %apply SWIGTYPE[], which overrides the in typemap but not the freearg.
Add coverage to the common char_strings.i test, which is compiled for
every language, rather than a Go only test: a typedef'd const char * setter
plus a runtime assertion in each language that has a char_strings runme
(c, csharp, d, java, javascript, lua, perl5, php).
See #3290.
Assisted-by: Claude Code (Opus 4.8)
William S Fulton