Create a lookup table for magic vtables from magic type, PL_magic_data.

Use it to eliminate the large switch statement in Perl_sv_magic().

As the table needs to be keyed on magic type, which is expressed as C character
constants, the order depends on the compiler's character set. Frustratingly,
EBCDIC variants don't agree on the code points for '~' and ']', which we use
here. Instead of having (at least) 4 tables, get the local runtime to sort the
table for us. Hence the regen script writes out the (unsorted) mg_raw.h, which
generate_uudmap sorts to generate mg_data.h

1 files changed, 9 insertions, 0 deletions

diff --git a/perl.h b/perl.h
index 9c0012022f..6b688b6ff6 100644
--- a/perl.h
+++ b/perl.h
@@ -5072,6 +5072,15 @@ START_EXTERN_C
 #endif
 
 #include "mg_vtable.h"
+
+#ifdef DOINIT
+EXTCONST U8 PL_magic_data[256] =
+#include "mg_data.h"
+;
+#else
+EXTCONST U8 PL_magic_data[256];
+#endif
+
 #include "overload.h"
 
 END_EXTERN_C