py/mpconfig.h: Add note that using computed gotos in VM is not C99.

2017-09-18 23:53:33 +10:00 · 2017-09-18 23:53:33 +10:00 · 44f0a4d1e7
parent fdb2aa81b7
commit 44f0a4d1e7
1 changed files with 2 additions and 0 deletions
--- a/py/mpconfig.h
+++ b/py/mpconfig.h
@ -383,6 +383,8 @@

 // Whether to use computed gotos in the VM, or a switch
 // Computed gotos are roughly 10% faster, and increase VM code size by a little
+// Note: enabling this will use the gcc-specific extensions of ranged designated
+// initialisers and addresses of labels, which are not part of the C99 standard.
 #ifndef MICROPY_OPT_COMPUTED_GOTO
 #define MICROPY_OPT_COMPUTED_GOTO (0)
 #endif