Initial import of exception handling code

Import exception handling code from WSS, modified to fit into the
fitz world.

With this code we have 'real' fz_try/fz_catch/fz_rethrow functions,
handling a fz_except type. We therefore rename the existing fz_throw/
fz_catch/fz_rethrow to be fz_error_make/fz_error_handle/fz_error_note.

We don't actually use fz_try/fz_catch/fz_rethrow yet...

1 files changed, 46 insertions, 0 deletions

diff --git a/fitz/except.h b/fitz/except.h
new file mode 100644
index 00000000..a964b94e
--- /dev/null
+++ b/fitz/except.h
@@ -0,0 +1,46 @@
+#ifndef EXCEPT_H
+#define EXCEPT_H
+
+#include "fitz.h"
+
+typedef struct fz_except {
+  char mess[256];
+} fz_except;
+
+#include "exceptxxx.h"
+/*
+    Macros for fz_try and fz_catch are defined in exceptxxx.h,
+    but their definitions are best ignored.  Just use them as follows:
+
+    fz_var(..);
+    fz_var(..);
+
+    fz_try(ctx)
+    {
+       .
+       .
+       .
+    }
+    fz_catch(ctx)
+    {
+       .
+       .
+       .
+    }
+
+    and don't return from within the try clause.
+*/
+
+void fz_throw(fz_context *, char *, ...);
+
+fz_except *fz_caught(fz_context *);
+
+void fz_rethrow(fz_context *);
+
+#define fz_var(A) fz_var_xxx((void *)&(A))
+
+void fz_var_xxx(void *x);
+
+void fz_except_init(fz_context *);
+
+#endif /* EXCEPT */