Move logic out of symbol_find_demangled_name

This patch moves most of the demangling logic out of
symbol_find_demangled_name into the various language_defn objects.

The simplest way to do this seemed to be to add a new method to
language_defn.  This is shame given the existing la_demangle, but
given Ada's unusual needs, and the differing demangling options
between languages, la_demangle didn't seem to fit.

In order to make this work, I made enum language order-sensitive.
This helps preserve the current ordering of demangling operations.

2016-06-23  Tom Tromey  <tom@tromey.com>

	* symtab.c (symbol_find_demangled_name): Loop over languages and
	use language_sniff_from_mangled_name.
	* rust-lang.c (rust_sniff_from_mangled_name): New function.
	(rust_language_defn): Update.
	* p-lang.c (pascal_language_defn): Update.
	* opencl-lang.c (opencl_language_defn): Update.
	* objc-lang.c (objc_sniff_from_mangled_name): New function.
	(objc_language_defn): Update.
	* m2-lang.c (m2_language_defn): Update.
	* language.h (struct language_defn) <la_sniff_from_mangled_name>: New
	field.
	(language_sniff_from_mangled_name): Declare.
	* language.c (language_sniff_from_mangled_name): New function.
	(unknown_language_defn, auto_language_defn, local_language_defn):
	Update.
	* jv-lang.c (java_sniff_from_mangled_name): New function.
	(java_language_defn): Use it.
	* go-lang.c (go_sniff_from_mangled_name): New function.
	(go_language_defn): Use it.
	* f-lang.c (f_language_defn): Update.
	* defs.h (enum language): Reorder.
	* d-lang.c (d_sniff_from_mangled_name): New function.
	(d_language_defn): Use it.
	* cp-support.h (gdb_sniff_from_mangled_name): Declare.
	* cp-support.c (gdb_sniff_from_mangled_name): New function.
	* c-lang.c (c_language_defn, cplus_language_defn)
	(asm_language_defn, minimal_language_defn): Update.
	* ada-lang.c (ada_sniff_from_mangled_name): New function.
	(ada_language_defn): Use it.

1 files changed, 14 insertions, 4 deletions

diff --git a/gdb/defs.h b/gdb/defs.h
index b81de46..5088390 100644
--- a/gdb/defs.h
+++ b/gdb/defs.h
@@ -194,26 +194,36 @@ extern void quit_serial_event_clear (void);
 /* * Languages represented in the symbol table and elsewhere.
    This should probably be in language.h, but since enum's can't
    be forward declared to satisfy opaque references before their
-   actual definition, needs to be here.  */
+   actual definition, needs to be here.
+
+   The constants here are in priority order.  In particular,
+   demangling is attempted according to this order.
+
+   Note that there's ambiguity between the mangling schemes of some of
+   these languages, so some symbols could be successfully demangled by
+   several languages.  For that reason, the constants here are sorted
+   in the order we'll attempt demangling them.  For example: Java and
+   Rust use C++ mangling, so must come after C++; Ada must come last
+   (see ada_sniff_from_mangled_name).  */
 
 enum language
   {
     language_unknown,		/* Language not known */
     language_auto,		/* Placeholder for automatic setting */
     language_c,			/* C */
+    language_objc,		/* Objective-C */
     language_cplus,		/* C++ */
+    language_java,		/* Java */
     language_d,			/* D */
     language_go,		/* Go */
-    language_objc,		/* Objective-C */
-    language_java,		/* Java */
     language_fortran,		/* Fortran */
     language_m2,		/* Modula-2 */
     language_asm,		/* Assembly language */
     language_pascal,		/* Pascal */
-    language_ada,		/* Ada */
     language_opencl,		/* OpenCL */
     language_rust,		/* Rust */
     language_minimal,		/* All other languages, minimal support only */
+    language_ada,		/* Ada */
     nr_languages
   };