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systemtap/SOURCES/systemtap-defined.patch

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commit 4eb1b10d893b8020315df7dd5215a087ebd39372
Author: Frank Ch. Eigler <fche@redhat.com>
Date: Mon May 19 16:51:42 2025 -0400
PR32964 part 1: improve diagnostics of @defined resolution
The @defined construct is special in that it is attempted to be
resolved to literal 1/0 fairly early during semantic analysis pass-2,
so that it can guard $context variable references. But this early
processing is not that systematic: not all script level constructs
properly nest with it. Those cases that don't happen to match end
up resolved to 0 as a fallback in late during pass-2, due to PR18079.
This patch adds verbosity diagnostics for some of these cases, and a
warning message for the fallback resolution path. This triggers
for the test case associated with this bugzilla report.
diff --git a/dwflpp.cxx b/dwflpp.cxx
index 1105272f2..62ae15837 100644
--- a/dwflpp.cxx
+++ b/dwflpp.cxx
@@ -4427,8 +4427,9 @@ dwflpp::literal_stmt_for_pointer (location_context &ctx,
Dwarf_Die *die_mem)
{
if (sess.verbose>2)
- clog << _F("literal_stmt_for_pointer: finding value for %s (%s)\n",
- dwarf_type_name(start_typedie).c_str(), (dwarf_diename(cu) ?: "<unknown>"));
+ clog << _("literal_stmt_for_pointer: finding value for ") << *e->tok
+ << _F(" type %s (%s)\n",
+ dwarf_type_name(start_typedie).c_str(), (dwarf_diename(cu) ?: "<unknown>"));
assert(ctx.pointer != NULL);
location *tail = ctx.translate_argument (ctx.pointer);
diff --git a/elaborate.cxx b/elaborate.cxx
index 865fe6555..023b4c08f 100644
--- a/elaborate.cxx
+++ b/elaborate.cxx
@@ -1894,7 +1894,7 @@ semantic_pass_symbols (systemtap_session& s)
assert_no_interrupts();
stapfile* dome = s.files[i];
- // Pass 1: add globals and functions to systemtap-session primart list,
+ // Pass 1: add globals and functions to systemtap-session primary list,
// so the find_* functions find them
//
// NB: tapset global/function definitions may duplicate or conflict
@@ -2796,6 +2796,8 @@ symresolution_info::visit_symbol (symbol* e)
vardecl* d = find_var (e->name, 0, e->tok);
if (d)
{
+ if (session.verbose > 4)
+ clog << "resolved variable " << *e->tok << " to " << *d->tok << endl;
e->referent = d;
e->name = d->name;
}
@@ -2814,6 +2816,8 @@ symresolution_info::visit_symbol (symbol* e)
// must be probe-condition expression
throw SEMANTIC_ERROR (_("probe condition must not reference undeclared global"), e->tok);
e->referent = v;
+ if (session.verbose > 4)
+ clog << "resolved variable " << *e->tok << " to new local" << endl;
}
}
@@ -5112,6 +5116,7 @@ const_folder::visit_defined_op (defined_op* e)
// Don't be greedy... we'll only collapse one at a time so type
// resolution can have another go at it.
relaxed_p = false;
+ session.print_warning (_F("Collapsing unresolved @define to %ld", value), e->tok);
literal_number* n = new literal_number (value);
n->tok = e->tok;
n->visit (this);
diff --git a/tapsets.cxx b/tapsets.cxx
index d25c85043..01fec29e3 100644
--- a/tapsets.cxx
+++ b/tapsets.cxx
@@ -3118,9 +3118,22 @@ var_expanding_visitor::visit_defined_op (defined_op* e)
target_symbol* tsym = dynamic_cast<target_symbol*> (e->operand);
if (tsym && tsym->saved_conversion_error) // failing
- resolved = false;
+ {
+ if (sess.verbose>3)
+ {
+ for (const semantic_error *c = tsym->saved_conversion_error;
+ c != 0;
+ c = c->get_chain()) {
+ clog << _("variable location problem [man error::dwarf]: ") << c->what() << endl;
+ }
+ }
+ resolved = false;
+ }
else if (e->operand == old_operand) // unresolved but not marked failing
{
+ if (sess.verbose>3)
+ clog << _("@defined unresolved due to un-rewritten operand ") << *e << endl;
+
// There are some visitors that won't touch certain target_symbols,
// e.g. dwarf_var_expanding_visitor won't resolve @cast. We should
// leave it for now so some other visitor can have a chance.
@@ -3132,6 +3145,8 @@ var_expanding_visitor::visit_defined_op (defined_op* e)
resolved = true;
} catch (const semantic_error& e) {
// some uncooperative value like @perf("NO_SUCH_VALUE")
+ if (sess.verbose > 3)
+ clog << sess.build_error_msg (e);
resolved = false;
}
defined_ops.pop ();
commit b36c59692966c6207bf6f69b2f6f91079f7b89ab
Author: Frank Ch. Eigler <fche@redhat.com>
Date: Mon May 19 22:30:29 2025 -0400
PR32964 part 2: document new @defined() warning
... in [man stapprobes], though [man stap] is where autocast variable
processing is documented in the "TYPECASTING" section.
diff --git a/elaborate.cxx b/elaborate.cxx
index 023b4c08f..c09e3ddca 100644
--- a/elaborate.cxx
+++ b/elaborate.cxx
@@ -5116,7 +5116,7 @@ const_folder::visit_defined_op (defined_op* e)
// Don't be greedy... we'll only collapse one at a time so type
// resolution can have another go at it.
relaxed_p = false;
- session.print_warning (_F("Collapsing unresolved @define to %ld", value), e->tok);
+ session.print_warning (_F("Collapsing unresolved @define to %ld [stapprobes]", value), e->tok);
literal_number* n = new literal_number (value);
n->tok = e->tok;
n->visit (this);
diff --git a/man/stapprobes.3stap b/man/stapprobes.3stap
index 1f980567b..d395e3578 100644
--- a/man/stapprobes.3stap
+++ b/man/stapprobes.3stap
@@ -700,6 +700,11 @@ for use in conditionals such as
.SAMPLE
@defined($foo\->bar) ? $foo\->bar : 0
.ESAMPLE
+Use full $context variables or @cast() expressions in @define parameters
+for unambiguous processing. The TYPECAST script-level variable
+facility is incompletely supported. Simplify the parameters by reducing
+nesting or indirection, if encountering "Collapsing unresolved @define to ..."
+warnings.
.TP
@probewrite($VAR)
see the PROBES section of \fIstap\fR(1).
commit e4786671a999d47003ea62525ed829c1784c03ea
Author: Frank Ch. Eigler <fche@redhat.com>
Date: Thu May 22 17:14:53 2025 -0400
PR32964 part 3: include autocast processing in initial_typeres_pass
This type resolution pass is done early, but previously purposefully
ommitted opportunistic autocast expansion. With it done there, once
(in the usual relaxation loop), more autocast-based @defined /
@choose_defined constructs will be processed in the way a user
may expect.
diff --git a/elaborate.cxx b/elaborate.cxx
index c09e3ddca..b03f0aced 100644
--- a/elaborate.cxx
+++ b/elaborate.cxx
@@ -2602,7 +2602,7 @@ semantic_pass (systemtap_session& s)
if (rc == 0) rc = semantic_pass_symbols (s);
if (rc == 0) monitor_mode_write (s);
if (rc == 0) rc = semantic_pass_conditions (s);
- if (rc == 0) rc = semantic_pass_optimize1 (s);
+ if (rc == 0) rc = semantic_pass_optimize1 (s); // includes const_fold and last ditch @defined() processing
if (rc == 0) rc = semantic_pass_types (s);
if (rc == 0) rc = gen_dfa_table(s);
if (rc == 0) add_global_var_display (s);
@@ -6045,7 +6045,7 @@ struct initial_typeresolution_info : public typeresolution_info
static int initial_typeres_pass(systemtap_session& s)
{
// minimal type resolution based off of semantic_pass_types(), without
- // checking for complete type resolutions or autocast expanding
+ // checking for complete type resolutions, PR32964 but including autocast expanding
initial_typeresolution_info ti(s);
ti.assert_resolvability = false;
@@ -6067,6 +6067,30 @@ static int initial_typeres_pass(systemtap_session& s)
ti.current_function = fd;
ti.t = pe_unknown;
fd->body->visit (& ti);
+
+ // Check and run the autocast expanding visitor.
+ if (ti.num_available_autocasts > 0)
+ {
+ autocast_expanding_visitor aev (s, ti);
+ aev.replace (fd->body);
+
+ // PR18079, rerun the const-folder / dead-block-remover
+ // if autocast evaluation enabled a @defined()
+ if (! aev.relaxed())
+ {
+ bool relaxed_p = true;
+ const_folder cf (s, relaxed_p);
+ cf.replace (fd->body);
+ if (! s.unoptimized)
+ {
+ dead_control_remover dc (s, relaxed_p);
+ fd->body->visit (&dc);
+ }
+ (void) relaxed_p; // we judge success later by num_still_unresolved, not this flag
+ }
+
+ ti.num_available_autocasts = 0;
+ }
}
for (unsigned j=0; j<s.probes.size(); j++)
@@ -6079,6 +6103,24 @@ static int initial_typeres_pass(systemtap_session& s)
ti.t = pe_unknown;
pn->body->visit (& ti);
+ // Check and run the autocast expanding visitor.
+ if (ti.num_available_autocasts > 0)
+ {
+ autocast_expanding_visitor aev (s, ti);
+ var_expand_const_fold_loop (s, pn->body, aev);
+ // PR18079, rerun the const-folder / dead-block-remover
+ // if autocast evaluation enabled a @defined()
+ if (! s.unoptimized)
+ {
+ bool relaxed_p;
+ dead_control_remover dc (s, relaxed_p);
+ pn->body->visit (&dc);
+ (void) relaxed_p; // we judge success later by num_still_unresolved, not this flag
+ }
+
+ ti.num_available_autocasts = 0;
+ }
+
probe_point* pp = pn->sole_location();
if (pp->condition)
{
@@ -6147,30 +6189,8 @@ semantic_pass_types (systemtap_session& s)
// ti.unresolved (fd->tok);
for (unsigned i=0; i < fd->locals.size(); ++i)
ti.check_local (fd->locals[i]);
-
- // Check and run the autocast expanding visitor.
- if (ti.num_available_autocasts > 0)
- {
- autocast_expanding_visitor aev (s, ti);
- aev.replace (fd->body);
-
- // PR18079, rerun the const-folder / dead-block-remover
- // if autocast evaluation enabled a @defined()
- if (! aev.relaxed())
- {
- bool relaxed_p = true;
- const_folder cf (s, relaxed_p);
- cf.replace (fd->body);
- if (! s.unoptimized)
- {
- dead_control_remover dc (s, relaxed_p);
- fd->body->visit (&dc);
- }
- (void) relaxed_p; // we judge success later by num_still_unresolved, not this flag
- }
- ti.num_available_autocasts = 0;
- }
+ // PR32964: autocast resolution is now done early in initial_typeres_pass
}
catch (const semantic_error& e)
{
@@ -6191,24 +6211,8 @@ semantic_pass_types (systemtap_session& s)
pn->body->visit (& ti);
for (unsigned i=0; i < pn->locals.size(); ++i)
ti.check_local (pn->locals[i]);
-
- // Check and run the autocast expanding visitor.
- if (ti.num_available_autocasts > 0)
- {
- autocast_expanding_visitor aev (s, ti);
- var_expand_const_fold_loop (s, pn->body, aev);
- // PR18079, rerun the const-folder / dead-block-remover
- // if autocast evaluation enabled a @defined()
- if (! s.unoptimized)
- {
- bool relaxed_p;
- dead_control_remover dc (s, relaxed_p);
- pn->body->visit (&dc);
- (void) relaxed_p; // we judge success later by num_still_unresolved, not this flag
- }
- ti.num_available_autocasts = 0;
- }
+ // PR32964: autocast resolution is now done early in initial_typeres_pass
probe_point* pp = pn->sole_location();
if (pp->condition)
commit 3122ff592bdfcf553afa6683724e90c359f3c5c9
Author: Frank Ch. Eigler <fche@redhat.com>
Date: Fri May 30 17:50:10 2025 -0400
PR32964 part 4: let autocast pass propagate vardecl/symbol type_details
The initial_typeres_pass now communicates relaxed status,
and its autocast_expanding_visitor now passes vardecl type_details
to the symbols. This way, the existing const_folder etc. visitors
can deduce enough type info for @defined(an_autocast_var->foo->bar)
constructs, and early enough, that @defined() works as intended.
New testsuite/semok/definedautocast.stp tests a simple case.
diff --git a/elaborate.cxx b/elaborate.cxx
index b03f0aced..7a1609f1b 100644
--- a/elaborate.cxx
+++ b/elaborate.cxx
@@ -5163,7 +5163,7 @@ const_folder::visit_target_symbol (target_symbol* e)
}
}
-static int initial_typeres_pass(systemtap_session& s);
+static int initial_typeres_pass(systemtap_session& s, bool& relaxed_p);
static int semantic_pass_const_fold (systemtap_session& s, bool& relaxed_p)
{
// attempt an initial type resolution pass to see if there are any type
@@ -5171,7 +5171,7 @@ static int semantic_pass_const_fold (systemtap_session& s, bool& relaxed_p)
// with a const.
// return if the initial type resolution pass reported errors (type mismatches)
- int rc = initial_typeres_pass(s);
+ int rc = initial_typeres_pass(s, relaxed_p);
if (rc)
{
relaxed_p = true;
@@ -5994,6 +5994,25 @@ struct autocast_expanding_visitor: public var_expanding_visitor
}
}
+ void visit_symbol (symbol* e) // propagate referent exp_type
+ {
+ // PR32964: mimic typeresolution_info::resolve_details, for case
+ // where the symbol (autocast_op operand) is within a @defined().
+
+ if (e->referent && e->referent->type_details && !e->type_details)
+ {
+ const exp_type_ptr &src = e->referent->type_details;
+ exp_type_ptr &dest = e->type_details;
+ dest = src;
+ ti.num_newly_resolved++;
+ relaxed_p = false;
+ if (sess.verbose > 4)
+ clog << "resolved early type details " << *dest << " to " << *e->tok << endl;
+ }
+ var_expanding_visitor::visit_symbol (e);
+ }
+
+
void visit_autocast_op (autocast_op* e)
{
const bool lvalue = is_active_lvalue (e);
@@ -6004,7 +6023,7 @@ struct autocast_expanding_visitor: public var_expanding_visitor
if (fc)
{
ti.num_newly_resolved++;
-
+ relaxed_p = false;
resolve_functioncall (fc);
// NB: at this stage, the functioncall object has one
// argument too few if we're in lvalue context. It will
@@ -6042,7 +6061,7 @@ struct initial_typeresolution_info : public typeresolution_info
void visit_cast_op (cast_op*) {}
};
-static int initial_typeres_pass(systemtap_session& s)
+static int initial_typeres_pass(systemtap_session& s, bool& relaxed_p)
{
// minimal type resolution based off of semantic_pass_types(), without
// checking for complete type resolutions, PR32964 but including autocast expanding
@@ -6069,7 +6088,7 @@ static int initial_typeres_pass(systemtap_session& s)
fd->body->visit (& ti);
// Check and run the autocast expanding visitor.
- if (ti.num_available_autocasts > 0)
+ if (true || ti.num_available_autocasts > 0)
{
autocast_expanding_visitor aev (s, ti);
aev.replace (fd->body);
@@ -6078,7 +6097,7 @@ static int initial_typeres_pass(systemtap_session& s)
// if autocast evaluation enabled a @defined()
if (! aev.relaxed())
{
- bool relaxed_p = true;
+ // bool relaxed_p = true;
const_folder cf (s, relaxed_p);
cf.replace (fd->body);
if (! s.unoptimized)
@@ -6086,7 +6105,7 @@ static int initial_typeres_pass(systemtap_session& s)
dead_control_remover dc (s, relaxed_p);
fd->body->visit (&dc);
}
- (void) relaxed_p; // we judge success later by num_still_unresolved, not this flag
+ // (void) relaxed_p; // we judge success later by num_still_unresolved, not this flag
}
ti.num_available_autocasts = 0;
@@ -6104,7 +6123,7 @@ static int initial_typeres_pass(systemtap_session& s)
pn->body->visit (& ti);
// Check and run the autocast expanding visitor.
- if (ti.num_available_autocasts > 0)
+ if (true || ti.num_available_autocasts > 0)
{
autocast_expanding_visitor aev (s, ti);
var_expand_const_fold_loop (s, pn->body, aev);
@@ -6112,10 +6131,10 @@ static int initial_typeres_pass(systemtap_session& s)
// if autocast evaluation enabled a @defined()
if (! s.unoptimized)
{
- bool relaxed_p;
+ // bool relaxed_p;
dead_control_remover dc (s, relaxed_p);
pn->body->visit (&dc);
- (void) relaxed_p; // we judge success later by num_still_unresolved, not this flag
+ // (void) relaxed_p; // we judge success later by num_still_unresolved, not this flag
}
ti.num_available_autocasts = 0;
diff --git a/testsuite/semok/definedautocast.stp b/testsuite/semok/definedautocast.stp
new file mode 100755
index 000000000..b28be6118
--- /dev/null
+++ b/testsuite/semok/definedautocast.stp
@@ -0,0 +1,6 @@
+#! stap -Wp2
+
+probe kernel.function("do_exit") {
+ x = & @cast(0, "struct block_device")
+ println(@defined(x->__bd_flags->counter))
+}
commit 778ba67e356dc1820acc8ecdaa2c4b608c2eb184
Author: Frank Ch. Eigler <fche@redhat.com>
Date: Fri May 30 22:10:36 2025 -0400
PR32964 part 5: tweak type inference propagation
Because some type inference is now performed earlier than before,
coupled with early const-folding (so dead code elimination), tests
like semko/binexpr_infer_type.stp started passing with immediately
prior code. That's because constructs like (foo*0) got quietly
replaced by 0, even if foo was typed pe_string. This patch
compensates for this change in behaviour by:
- typeresolution_info::resolve_2types now propagates types
more aggressively & recursively in its three-way inference,
so that the unknown x string x long case is detected in one
incoming invocation of the function, instead of being
deferred to some unknown later relaxation-iteration round.
- typeresolution_info::mismatch reporting errors, independent
of "assert_resolvability". That flag was most likely meant
for detection & rejection of pe_unknown types at the end of
all the optimization stuff, not for ignoring outright known
conflicts.
diff --git a/elaborate.cxx b/elaborate.cxx
index 7a1609f1b..d93a83eca 100644
--- a/elaborate.cxx
+++ b/elaborate.cxx
@@ -6683,21 +6683,21 @@ void resolve_2types (Referrer* referrer, Referent* referent,
// propagate from upstream
re_type = t;
r->resolved (re_tok, re_type);
- // catch re_type/te_type mismatch later
+ resolve_2types (referrer, referent, r, t, accept_unknown);
}
else if (re_type == pe_unknown && te_type != pe_unknown)
{
// propagate from referent
re_type = te_type;
r->resolved (re_tok, re_type);
- // catch re_type/t mismatch later
+ resolve_2types (referrer, referent, r, t, accept_unknown);
}
else if (re_type != pe_unknown && te_type == pe_unknown)
{
// propagate to referent
te_type = re_type;
r->resolved (re_tok, re_type, referent);
- // catch re_type/t mismatch later
+ resolve_2types (referrer, referent, r, t, accept_unknown);
}
else if (! accept_unknown)
r->unresolved (re_tok);
@@ -7636,14 +7636,14 @@ typeresolution_info::mismatch (const binary_expression* e)
{
num_still_unresolved ++;
- if (assert_resolvability && mismatch_complexity <= 1)
+ if (mismatch_complexity <= 1)
{
stringstream msg;
msg << _F("type mismatch: left and right sides don't agree (%s vs %s)",
lex_cast(e->left->type).c_str(), lex_cast(e->right->type).c_str());
session.print_error (SEMANTIC_ERROR (msg.str(), e->tok));
}
- else if (!assert_resolvability)
+ else
mismatch_complexity = max(1, mismatch_complexity);
}
@@ -7656,7 +7656,7 @@ typeresolution_info::mismatch (const token* tok, exp_type t1, exp_type t2)
{
num_still_unresolved ++;
- if (assert_resolvability && mismatch_complexity <= 2)
+ if (mismatch_complexity <= 2)
{
stringstream msg;
msg << _F("type mismatch: expected %s", lex_cast(t1).c_str());
@@ -7664,7 +7664,7 @@ typeresolution_info::mismatch (const token* tok, exp_type t1, exp_type t2)
msg << _F(" but found %s", lex_cast(t2).c_str());
session.print_error (SEMANTIC_ERROR (msg.str(), tok));
}
- else if (!assert_resolvability)
+ else
mismatch_complexity = max(2, mismatch_complexity);
}
@@ -7679,7 +7679,7 @@ typeresolution_info::mismatch (const token *tok, exp_type type,
{
num_still_unresolved ++;
- if (assert_resolvability && mismatch_complexity <= 3)
+ if (mismatch_complexity <= 3)
{
assert(decl != NULL);
@@ -7737,7 +7737,7 @@ typeresolution_info::mismatch (const token *tok, exp_type type,
err.set_chain(chain);
session.print_error (err);
}
- else if (!assert_resolvability)
+ else
mismatch_complexity = max(3, mismatch_complexity);
}
commit fd4322e38d1e6504341b67329e112ccc1af387b6
Author: Frank Ch. Eigler <fche@redhat.com>
Date: Sat May 31 09:15:33 2025 -0400
PR32964 part 6: NEWS & old testcase
It turns out there was one old testcase that relied on type
non-checking upon elided variables. This test has been removed, and
the change mentioned in NEWS. Unfortunately, this is is hard to make
conditional on --compatible=XXXX, so hypothetical old (arguably buggy)
scripts may get hit.
diff --git a/NEWS b/NEWS
index 01b74a671..f1d78e8fa 100644
--- a/NEWS
+++ b/NEWS
@@ -1,3 +1,11 @@
+* What's new in version 5.4
+
+- Type checking and autocast processing have been made more thorough,
+ so elided variables are checked more and @defined() tests may be
+ more complicated. Preexisting scripts that rely on elision for
+ bypassing type violations may now get caught. No --compatible
+ option exists to suppress this new behaviour.
+
* What's new in version 5.3, 2025-05-02
- Updated to support drastic linux 6.13 kbuild changes, numerous
diff --git a/testsuite/semok/pr30570.stp b/testsuite/semok/pr30570.stp
index b711b214c..dda7d027c 100755
--- a/testsuite/semok/pr30570.stp
+++ b/testsuite/semok/pr30570.stp
@@ -24,13 +24,16 @@ probe oneshot {
}
# error var and the try block are elided which means
-# it's not an issue to use e4 as a long here
-global e4 = 10
-probe oneshot {
- try { }
- catch (e4)
- { }
-}
+# it's not an issue to use e4 as a long here ...
+# except after PR32964, type checking is done more
+# systematically on even elided variables, so this
+# would be an error!
+# global e4 = 10
+# probe oneshot {
+# try { }
+# catch (e4)
+# { }
+# }
# e5 can be a global string
global e5 = "foo"
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