Would-be fix for bug 7733: learn bridge ID from descriptor

If somebody has configured a client to use a bridge without setting
an identity digest (not recommended), learn the identity digest from
whatever bridge descriptor we have downloaded or have in our cache.
Fix configure script build with autoconf < 2.63

We added some AS_VAR_IF-based checks to detect whether we have
managed to compile (but not link) with stack-protector.  On autoconf
before 2.63, we don't have AS_VAR_IF, so we just have to let the
user get a compile error rather than a helpful "find libssp" error.

Fixes bug 12693; bugfix on 0.2.5.2-alpha (commit 21ac292820da578)
forward-port changelog from 0.2.5.7-rc
Bump maint-0.2.5 to 0.2.5.7-rc-dev
Merge remote-tracking branch 'origin/maint-0.2.5'

(Do an "ours" merge to avoid taking version number changes)
Give an example how to run the unit tests
Mention "make check" in doc/HACKING
fix typo in comment
Clear up another clangalyzer issue

"The NULL pointer warnings on the return value of
tor_addr_to_in6_addr32() are incorrect. But clang can't work this
out itself due to limited analysis depth. To teach the analyser that
the return value is safe to dereference, I applied tor_assert to the
return value."

Patch from teor.  Part of 13157.
Clean up a clangalyzer warning in directory_remove_invalid

"At this point in the code, msg has been set to a string
constant. But the tor code checks that msg is not NULL, and the
redundant NULL check confuses the analyser[...] To avoid this
spurious warning, the patch initialises msg to NULL."

Patch from teor. another part of 13157.
Don't pass invalid memory regions to digestmap_set/get in test_routerlist

Fixes bug in c887e20e6a5a2c17c65; bug in no released Tor version.
Use coccinelle scripts to clean up our unit tests

This should get rid of most of the users of the old test_*
functions.  Some are in macros and will need manual cleanup, though.

This patch is for 13119, and was automatically generated with these
scripts.  The perl scripts are there because coccinelle hates
operators as macro arguments.

------------------------------

s/==,/_X_EQ_,/g;
s/!=,/_X_NE_,/g;
s/<,/_X_LT_,/g;
s/>,/_X_GT_,/g;
s/>=,/_X_GEQ_,/g;
s/<=,/_X_LEQ_,/g;

------------------------------
@@
expression a;
identifier func;
@@
 func (...) {
<...
-test_fail_msg
+TT_DIE
 (
+(
 a
+)
 )
 ...>
 }

@@
identifier func;
@@
 func (...) {
<...
-test_fail()
+TT_DIE(("Assertion failed."))
 ...>
 }

@@
expression a;
identifier func;
@@
 func (...) {
<...
-test_assert
+tt_assert
	(a)
 ...>
 }

@@
expression a, b;
identifier func;
@@
 func (...) {
<...
-test_eq
+tt_int_op
 (a,
+_X_EQ_,
  b)
 ...>
 }

@@
expression a, b;
identifier func;
@@
 func (...) {
<...
-test_neq
+tt_int_op
 (a,
+_X_NEQ_,
  b)
 ...>
 }

@@
expression a, b;
identifier func;
@@
 func (...) {
<...
-test_streq
+tt_str_op
 (a,
+_X_EQ_,
  b)
 ...>
 }

@@
expression a, b;
identifier func;
@@
 func (...) {
<...
-test_strneq
+tt_str_op
 (a,
+_X_NEQ_,
  b)
 ...>
 }

@@
expression a, b;
identifier func;
@@
 func (...) {
<...
-test_eq_ptr
+tt_ptr_op
 (a,
+_X_EQ_,
  b)
 ...>
 }

@@
expression a, b;
identifier func;
@@
 func() {
<...
-test_neq_ptr
+tt_ptr_op
 (a,
+_X_NEQ_,
  b)
 ...>
 }

@@
expression a, b, len;
identifier func;
@@
 func (...) {
<...
-test_memeq
+tt_mem_op
 (a,
+_X_EQ_,
  b, len)
 ...>
 }

@@
expression a, b, len;
identifier func;
@@
 func (...) {
<...
-test_memneq
+tt_mem_op
 (a,
+_X_NEQ_,
  b, len)
 ...>
 }

------------------------------
@@
char a, b;
identifier func;
@@
 func (...) {
<...
-tt_assert
+tt_int_op
 (
-a == b
+a, _X_EQ_, b
 )
 ...>
}

@@
int a, b;
identifier func;
@@
 func (...) {
<...
-tt_assert
+tt_int_op
 (
-a == b
+a, _X_EQ_, b
 )
 ...>
}

@@
long a, b;
identifier func;
@@
 func (...) {
<...
-tt_assert
+tt_int_op
 (
-a == b
+a, _X_EQ_, b
 )
 ...>
}

@@
unsigned int a, b;
identifier func;
@@
 func (...) {
<...
-tt_assert
+tt_uint_op
 (
-a == b
+a, _X_EQ_, b
 )
 ...>
}

@@
unsigned long a, b;
identifier func;
@@
 func (...) {
<...
-tt_assert
+tt_uint_op
 (
-a == b
+a, _X_EQ_, b
 )
 ...>
}

@@
char a, b;
identifier func;
@@
 func (...) {
<...
-tt_assert
+tt_int_op
 (
-a != b
+a, _X_NEQ_, b
 )
 ...>
}

@@
int a, b;
identifier func;
@@
 func (...) {
<...
-tt_assert
+tt_int_op
 (
-a != b
+a, _X_NEQ_, b
 )
 ...>
}

@@
long a, b;
identifier func;
@@
 func (...) {
<...
-tt_assert
+tt_int_op
 (
-a != b
+a, _X_NEQ_, b
 )
 ...>
}

@@
unsigned int a, b;
identifier func;
@@
 func (...) {
<...
-tt_assert
+tt_uint_op
 (
-a != b
+a, _X_NEQ_, b
 )
 ...>
}

@@
unsigned long a, b;
identifier func;
@@
 func (...) {
<...
-tt_assert
+tt_uint_op
 (
-a != b
+a, _X_NEQ_, b
 )
 ...>
}

@@
char a, b;
identifier func;
@@
 func (...) {
<...
-tt_assert
+tt_int_op
 (
-a >= b
+a, _X_GEQ_, b
 )
 ...>
}

@@
int a, b;
identifier func;
@@
 func (...) {
<...
-tt_assert
+tt_int_op
 (
-a >= b
+a, _X_GEQ_, b
 )
 ...>
}

@@
long a, b;
identifier func;
@@
 func (...) {
<...
-tt_assert
+tt_int_op
 (
-a >= b
+a, _X_GEQ_, b
 )
 ...>
}

@@
unsigned int a, b;
identifier func;
@@
 func (...) {
<...
-tt_assert
+tt_uint_op
 (
-a >= b
+a, _X_GEQ_, b
 )
 ...>
}

@@
unsigned long a, b;
identifier func;
@@
 func (...) {
<...
-tt_assert
+tt_uint_op
 (
-a >= b
+a, _X_GEQ_, b
 )
 ...>
}

@@
char a, b;
identifier func;
@@
 func (...) {
<...
-tt_assert
+tt_int_op
 (
-a <= b
+a, _X_LEQ_, b
 )
 ...>
}

@@
int a, b;
identifier func;
@@
 func (...) {
<...
-tt_assert
+tt_int_op
 (
-a <= b
+a, _X_LEQ_, b
 )
 ...>
}

@@
long a, b;
identifier func;
@@
 func (...) {
<...
-tt_assert
+tt_int_op
 (
-a <= b
+a, _X_LEQ_, b
 )
 ...>
}

@@
unsigned int a, b;
identifier func;
@@
 func (...) {
<...
-tt_assert
+tt_uint_op
 (
-a <= b
+a, _X_LEQ_, b
 )
 ...>
}

@@
unsigned long a, b;
identifier func;
@@
 func (...) {
<...
-tt_assert
+tt_uint_op
 (
-a <= b
+a, _X_LEQ_, b
 )
 ...>
}

@@
char a, b;
identifier func;
@@
 func (...) {
<...
-tt_assert
+tt_int_op
 (
-a > b
+a, _X_GT_, b
 )
 ...>
}

@@
int a, b;
identifier func;
@@
 func (...) {
<...
-tt_assert
+tt_int_op
 (
-a > b
+a, _X_GT_, b
 )
 ...>
}

@@
long a, b;
identifier func;
@@
 func (...) {
<...
-tt_assert
+tt_int_op
 (
-a > b
+a, _X_GT_, b
 )
 ...>
}

@@
unsigned int a, b;
identifier func;
@@
 func (...) {
<...
-tt_assert
+tt_uint_op
 (
-a > b
+a, _X_GT_, b
 )
 ...>
}

@@
unsigned long a, b;
identifier func;
@@
 func (...) {
<...
-tt_assert
+tt_uint_op
 (
-a > b
+a, _X_GT_, b
 )
 ...>
}

@@
char a, b;
identifier func;
@@
 func (...) {
<...
-tt_assert
+tt_int_op
 (
-a < b
+a, _X_LT_, b
 )
 ...>
}

@@
int a, b;
identifier func;
@@
 func (...) {
<...
-tt_assert
+tt_int_op
 (
-a < b
+a, _X_LT_, b
 )
 ...>
}

@@
long a, b;
identifier func;
@@
 func (...) {
<...
-tt_assert
+tt_int_op
 (
-a < b
+a, _X_LT_, b
 )
 ...>
}

@@
unsigned int a, b;
identifier func;
@@
 func (...) {
<...
-tt_assert
+tt_uint_op
 (
-a < b
+a, _X_LT_, b
 )
 ...>
}

@@
unsigned long a, b;
identifier func;
@@
 func (...) {
<...
-tt_assert
+tt_uint_op
 (
-a < b
+a, _X_LT_, b
 )
 ...>
}

------------------------------

s/_X_NEQ_/!=/g;
s/_X_NE_/!=/g;
s/_X_EQ_/==/g;
s/_X_GT_/>/g;
s/_X_LT_/</g;
s/_X_GEQ_/>=/g;
s/_X_LEQ_/<=/g;

s/test_mem_op\(/tt_mem_op\(/g;
Make not even macros use test_fail_msg.
Replace the remaining test_n?eq_ptr calls
Replace remaining uses of deprecated test_mem* functions
remove two unused test_* macros
Replace the remaining test_assert instances
Replace all uses of test_{str,}eq
Add a changes file for 13119
Remove the legacy_test_helper and legacy_setup wrappers

These wrappers went into place when the default type for our unit
test functions changed from "void fn(void)" to "void fn(void *arg)".

To generate this patch, I did the same hokey-pokey as before with
replacing all operators used as macro arguments, then I ran a
coccinelle script, then I ran perl script to fix up everything that
used legacy_test_helper, then I manually removed the
legacy_test_helper functions, then I ran a final perl script to put
the operators back how they were.

==============================
 #!/usr/bin/perl -w -i -p

s/==,/_X_EQ_,/g;
s/!=,/_X_NE_,/g;
s/<,/_X_LT_,/g;
s/>,/_X_GT_,/g;
s/>=,/_X_GEQ_,/g;
s/<=,/_X_LEQ_,/g;

--------------------

@@
identifier func =~ "test_.*$";
statement S, S2;
@@
 static void func (
-void
+void *arg
 )
 {
 ... when != S2
+(void) arg;
 S
 ...
 }

--------------------
 #!/usr/bin/perl -w -i -p

s/, *legacy_test_helper, *([^,]+), *\&legacy_setup, *([^\}]+) *}/, $2, $1, NULL, NULL }/g;

--------------------
 #!/usr/bin/perl -w -i -p

s/_X_NEQ_/!=/g;
s/_X_NE_/!=/g;
s/_X_EQ_/==/g;
s/_X_GT_/>/g;
s/_X_LT_/</g;
s/_X_GEQ_/>=/g;
s/_X_LEQ_/<=/g;

--------------------