X-Git-Url: http://git.shadowcat.co.uk/gitweb/gitweb.cgi?a=blobdiff_plain;f=scope.h;h=debe1f88a7fc903f22342cdf78070011a83897ec;hb=ae77835f9b08444f73b593d4cdc0758132dbbf00;hp=d0931b1c58c51020a9c8669bf60195b51a442ccf;hpb=4fdae80067c447c675a6ac92c7959d2206e207ba;p=p5sagit%2Fp5-mst-13.2.git

diff --git a/scope.h b/scope.h
index d0931b1..debe1f8 100644
--- a/scope.h
+++ b/scope.h
@@ -70,3 +70,52 @@
     SSPUSHINT(SAVEt_STACK_POS);		\
  } STMT_END
 
+
+/* A jmpenv packages the state required to perform a proper non-local jump.
+ * Note that there is a start_env initialized when perl starts, and top_env
+ * points to this initially, so top_env should always be non-null.
+ *
+ * Existence of a non-null top_env->je_prev implies it is valid to call
+ * longjmp() at that runlevel (we make sure start_env.je_prev is always
+ * null to ensure this).
+ *
+ * je_mustcatch, when set at any runlevel to TRUE, means eval ops must
+ * establish a local jmpenv to handle exception traps.  Care must be taken
+ * to restore the previous value of je_mustcatch before exiting the
+ * stack frame iff JMPENV_PUSH was not called in that stack frame.
+ * GSAR 97-03-27
+ */
+
+struct jmpenv {
+    struct jmpenv *	je_prev;
+    Sigjmp_buf		je_buf;		
+    int			je_ret;		/* return value of last setjmp() */
+    bool		je_mustcatch;	/* longjmp()s must be caught locally */
+};
+
+typedef struct jmpenv JMPENV;
+
+#define dJMPENV		JMPENV cur_env
+#define JMPENV_PUSH(v) \
+    STMT_START {					\
+	cur_env.je_prev = top_env;			\
+	cur_env.je_ret = Sigsetjmp(cur_env.je_buf, 1);	\
+	top_env = &cur_env;				\
+	cur_env.je_mustcatch = FALSE;			\
+	(v) = cur_env.je_ret;				\
+    } STMT_END
+#define JMPENV_POP \
+    STMT_START { top_env = cur_env.je_prev; } STMT_END
+#define JMPENV_JUMP(v) \
+    STMT_START {						\
+	if (top_env->je_prev)					\
+	    Siglongjmp(top_env->je_buf, (v));			\
+	if ((v) == 2)						\
+	    exit(STATUS_NATIVE_EXPORT);				\
+	PerlIO_printf(PerlIO_stderr(), "panic: top_env\n");	\
+	exit(1);						\
+    } STMT_END
+   
+#define CATCH_GET	(top_env->je_mustcatch)
+#define CATCH_SET(v)	(top_env->je_mustcatch = (v))
+