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workaround a type handling bug in SystemTap Dtrace 1.2

It uses a construct similar to:

  __typeof__((func)) x = func;

but hek_key is a char[1] so the above becomes:

  char arg1[1] = func;

which is invalid.

Using a temporary allows an implicit conversion to const char * and
avoids possible bugs that might be hidden by an explicit cast.
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1 parent 44d8286 commit ee3ace03a45521163d0977e8a8fe5387f0193e80 @tonycoz tonycoz committed Aug 9, 2011
Showing with 25 additions and 2 deletions.
  1. +25 −2 mydtrace.h
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@@ -13,16 +13,39 @@
# include "perldtrace.h"
-# define ENTRY_PROBE(func, file, line, stash) \
+# if defined(STAP_PROBE_ADDR) && !defined(DEBUGGING)
+
+/* SystemTap 1.2 uses a construct that chokes on passing a char array
+ * as a char *, in this case hek_key in struct hek. Workaround it
+ * with a temporary.
+ */
+
+# define ENTRY_PROBE(func, file, line, stash) \
+ if (PERL_SUB_ENTRY_ENABLED()) { \
+ const char *tmp_func = func; \
+ PERL_SUB_ENTRY(tmp_func, file, line, stash); \
+ }
+
+# define RETURN_PROBE(func, file, line, stash) \
+ if (PERL_SUB_RETURN_ENABLED()) { \
+ const char *tmp_func = func; \
+ PERL_SUB_RETURN(tmp_func, file, line, stash); \
+ }
+
+# else
+
+# define ENTRY_PROBE(func, file, line, stash) \
if (PERL_SUB_ENTRY_ENABLED()) { \
PERL_SUB_ENTRY(func, file, line, stash); \
}
-# define RETURN_PROBE(func, file, line, stash) \
+# define RETURN_PROBE(func, file, line, stash) \
if (PERL_SUB_RETURN_ENABLED()) { \
PERL_SUB_RETURN(func, file, line, stash); \
}
+# endif
+
# define PHASE_CHANGE_PROBE(new_phase, old_phase) \
if (PERL_PHASE_CHANGE_ENABLED()) { \
PERL_PHASE_CHANGE(new_phase, old_phase); \

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