Provide as much diagnostic information as possible in "panic: ..." messages.

The convention is that when the interpreter dies with an internal error, the
message starts "panic: ". Historically, many panic messages had been terse
fixed strings, which means that the out-of-range values that triggered the
panic are lost. Now we try to report these values, as such panics may not be
repeatable, and the original error message may be the only diagnostic we get
when we try to find the cause.

We can't report diagnostics when the panic message is generated by something
other than croak(), as we don't have *printf-style format strings. Don't
attempt to report values in panics related to *printf buffer overflows, as
attempting to format the values to strings may repeat or compound the
original error.

1 files changed, 21 insertions, 21 deletions

diff --git a/pod/perldiag.pod b/pod/perldiag.pod
index 544a9ed6b4..9263de2989 100644
--- a/pod/perldiag.pod
+++ b/pod/perldiag.pod
@@ -3517,15 +3517,15 @@ an ACL related-function, but that function is not available on this
 platform.  Earlier checks mean that it should not be possible to
 enter this branch on this platform.
 
-=item panic: ck_grep
+=item panic: ck_grep, type=%u
 
 (P) Failed an internal consistency check trying to compile a grep.
 
-=item panic: ck_split
+=item panic: ck_split, type=%u
 
 (P) Failed an internal consistency check trying to compile a split.
 
-=item panic: corrupt saved stack index
+=item panic: corrupt saved stack index %ld
 
 (P) The savestack was requested to restore more localized values than
 there are in the savestack.
@@ -3559,7 +3559,7 @@ failure was caught.
 
 (P) The library function frexp() failed, making printf("%f") impossible.
 
-=item panic: goto
+=item panic: goto, type=%u, ix=%ld
 
 (P) We popped the context stack to a context with the specified label,
 and then discovered it wasn't a context we know how to do a goto in.
@@ -3571,11 +3571,11 @@ repeatedly, but each time something re-created entries in the glob.
 Most likely the glob contains an object with a reference back to
 the glob and a destructor that adds a new object to the glob.
 
-=item panic: INTERPCASEMOD
+=item panic: INTERPCASEMOD, %s
 
 (P) The lexer got into a bad state at a case modifier.
 
-=item panic: INTERPCONCAT
+=item panic: INTERPCONCAT, %s
 
 (P) The lexer got into a bad state parsing a string with brackets.
 
@@ -3583,7 +3583,7 @@ the glob and a destructor that adds a new object to the glob.
 
 (F) forked child returned an incomprehensible message about its errno.
 
-=item panic: last
+=item panic: last, type=%u
 
 (P) We popped the context stack to a block context, and then discovered
 it wasn't a block context.
@@ -3593,7 +3593,7 @@ it wasn't a block context.
 (P) A writable lexical variable became read-only somehow within the
 scope.
 
-=item panic: leave_scope inconsistency
+=item panic: leave_scope inconsistency %u
 
 (P) The savestack probably got out of sync.  At least, there was an
 invalid enum on the top of it.
@@ -3603,7 +3603,7 @@ invalid enum on the top of it.
 (P) Failed an internal consistency check while trying to reset all weak
 references to an object.
 
-=item panic: malloc
+=item panic: malloc, %s
 
 (P) Something requested a negative number of bytes of malloc.
 
@@ -3611,12 +3611,12 @@ references to an object.
 
 (P) Something tried to allocate more memory than possible.
 
-=item panic: pad_alloc
+=item panic: pad_alloc, %p!=%p
 
 (P) The compiler got confused about which scratch pad it was allocating
 and freeing temporaries and lexicals from.
 
-=item panic: pad_free curpad
+=item panic: pad_free curpad, %p!=%p
 
 (P) The compiler got confused about which scratch pad it was allocating
 and freeing temporaries and lexicals from.
@@ -3625,7 +3625,7 @@ and freeing temporaries and lexicals from.
 
 (P) An invalid scratch pad offset was detected internally.
 
-=item panic: pad_reset curpad
+=item panic: pad_reset curpad, %p!=%p
 
 (P) The compiler got confused about which scratch pad it was allocating
 and freeing temporaries and lexicals from.
@@ -3634,7 +3634,7 @@ and freeing temporaries and lexicals from.
 
 (P) An invalid scratch pad offset was detected internally.
 
-=item panic: pad_swipe curpad
+=item panic: pad_swipe curpad, %p!=%p
 
 (P) The compiler got confused about which scratch pad it was allocating
 and freeing temporaries and lexicals from.
@@ -3643,7 +3643,7 @@ and freeing temporaries and lexicals from.
 
 (P) An invalid scratch pad offset was detected internally.
 
-=item panic: pp_iter
+=item panic: pp_iter, type=%u
 
 (P) The foreach iterator got called in a non-loop context frame.
 
@@ -3652,11 +3652,11 @@ and freeing temporaries and lexicals from.
 (P) The internal pp_match() routine was called with invalid operational
 data.
 
-=item panic: pp_split
+=item panic: pp_split, pm=%p, s=%p
 
 (P) Something terrible went wrong in setting up for the split.
 
-=item panic: realloc
+=item panic: realloc, %s
 
 (P) Something requested a negative number of bytes of realloc.
 
@@ -3665,17 +3665,17 @@ data.
 (P) The internal sv_replace() function was handed a new SV with a
 reference count other than 1.
 
-=item panic: restartop
+=item panic: restartop in %s
 
 (P) Some internal routine requested a goto (or something like it), and
 didn't supply the destination.
 
-=item panic: return
+=item panic: return, type=%u
 
 (P) We popped the context stack to a subroutine or eval context, and
 then discovered it wasn't a subroutine or eval context.
 
-=item panic: scan_num
+=item panic: scan_num, %s
 
 (P) scan_num() got called on something that wasn't a number.
 
@@ -3684,7 +3684,7 @@ then discovered it wasn't a subroutine or eval context.
 (P) The sv_chop() routine was passed a position that is not within the
 scalar's string buffer.
 
-=item panic: sv_insert
+=item panic: sv_insert, midend=%p, bigend=%p
 
 (P) The sv_insert() routine was told to remove more string than there
 was string.
@@ -3714,7 +3714,7 @@ to even) byte length.
 (P) Something tried to call utf16_to_utf8_reversed with an odd (as opposed
 to even) byte length.
 
-=item panic: yylex
+=item panic: yylex, %s
 
 (P) The lexer got into a bad state while processing a case modifier.