[PATCH] gdb: fix debug expression dumping of function call expressions
Andrew Burgess
andrew.burgess@embecosm.com
Fri Nov 6 18:18:59 GMT 2020
In commit:
commit 6d81691950f8c4be4a49a85a672255c140e82468
CommitDate: Sat Sep 19 09:44:58 2020 +0100
gdb/fortran: Move Fortran expression handling into f-lang.c
A bug was introduced that broke GDB's ability to perform debug dumps
of expressions containing function calls. For example this would no
longer work:
(gdb) set debug expression 1
(gdb) print call_me (&val)
Dump of expression @ 0x4eced60, before conversion to prefix form:
Language c, 12 elements, 16 bytes each.
Index Opcode Hex Value String Value
0 OP_VAR_VALUE 40 (...............
1 OP_M2_STRING 79862864 P...............
2 unknown opcode: 224 79862240 ................
3 OP_VAR_VALUE 40 (...............
4 OP_VAR_VALUE 40 (...............
5 OP_RUST_ARRAY 79861600 `...............
6 UNOP_PREDECREMENT 79861312 @...............
7 OP_VAR_VALUE 40 (...............
8 UNOP_ADDR 61 =...............
9 OP_FUNCALL 46 ................
10 BINOP_ADD 1 ................
11 OP_FUNCALL 46 ................
Dump of expression @ 0x4eced60, after conversion to prefix form:
Expression: `call_me (&main::val, VAL(Aborted (core dumped)
The situation was even worse for Fortran function calls, or array
indexes, which both make use of the same expression opcode.
The problem was that in a couple of places the index into the
expression array was handled incorrectly causing GDB to interpret
elements incorrectly. These issues are fixed in this commit.
There are already some tests to check GDB when 'set debug expression
1' is set, these can be found in gdb.*/debug-expr.exp. Unfortunately
the cases above were not covered.
In this commit I have cleaned up all of the debug-expr.exp files a
little, there was a helper function that had clearly been copied into
each file, this is now moved into lib/gdb.exp.
I've added a gdb.fortran/debug-expr.exp test file, and extended
gdb.base/debug-expr.exp to cover the function call case.
gdb/ChangeLog:
* expprint.c (print_subexp_funcall): Increment expression position
after reading argument count.
* f-lang.c (print_subexp_f): Skip over opcode before calling
common function.
(dump_subexp_body_f): Likewise.
gdb/testsuite/ChangeLog:
* gdb.base/debug-expr.c: Add extra function to allow for an
additional test.
* gdb.base/debug-expr.exp (test_debug_expr): Delete, replace calls
to this proc with gdb_test_debug_expr. Add an extra test.
* gdb.cp/debug-expr.exp (test_debug_expr): Delete, replace calls
to this proc with gdb_test_debug_expr, give the tests names
* gdb.dlang/debug-expr.exp (test_debug_expr): Delete, replace
calls to this proc with gdb_test_debug_expr, give the tests names
* gdb.fortran/debug-expr.exp: New file.
* gdb.fortran/debug-expr.f90: New file.
* lib/gdb.exp (gdb_test_debug_expr): New proc.
---
gdb/ChangeLog | 8 +++++
gdb/expprint.c | 2 +-
gdb/f-lang.c | 3 +-
gdb/testsuite/ChangeLog | 14 ++++++++
gdb/testsuite/gdb.base/debug-expr.c | 10 +++++-
gdb/testsuite/gdb.base/debug-expr.exp | 26 +++++---------
gdb/testsuite/gdb.cp/debug-expr.exp | 24 ++++---------
gdb/testsuite/gdb.dlang/debug-expr.exp | 19 ++---------
gdb/testsuite/gdb.fortran/debug-expr.exp | 43 ++++++++++++++++++++++++
gdb/testsuite/gdb.fortran/debug-expr.f90 | 38 +++++++++++++++++++++
gdb/testsuite/lib/gdb.exp | 28 +++++++++++++++
11 files changed, 160 insertions(+), 55 deletions(-)
create mode 100644 gdb/testsuite/gdb.fortran/debug-expr.exp
create mode 100644 gdb/testsuite/gdb.fortran/debug-expr.f90
diff --git a/gdb/expprint.c b/gdb/expprint.c
index f4668aa297d..29e6237ab4d 100644
--- a/gdb/expprint.c
+++ b/gdb/expprint.c
@@ -60,8 +60,8 @@ void
print_subexp_funcall (struct expression *exp, int *pos,
struct ui_file *stream)
{
- (*pos) += 2;
unsigned nargs = longest_to_int (exp->elts[*pos].longconst);
+ (*pos) += 2;
print_subexp (exp, pos, stream, PREC_SUFFIX);
fputs_filtered (" (", stream);
for (unsigned tem = 0; tem < nargs; tem++)
diff --git a/gdb/f-lang.c b/gdb/f-lang.c
index d3391d9442f..b775fae2e79 100644
--- a/gdb/f-lang.c
+++ b/gdb/f-lang.c
@@ -614,6 +614,7 @@ print_subexp_f (struct expression *exp, int *pos,
return;
case OP_F77_UNDETERMINED_ARGLIST:
+ (*pos)++;
print_subexp_funcall (exp, pos, stream);
return;
}
@@ -660,7 +661,7 @@ dump_subexp_body_f (struct expression *exp,
break;
case OP_F77_UNDETERMINED_ARGLIST:
- return dump_subexp_body_funcall (exp, stream, elt);
+ return dump_subexp_body_funcall (exp, stream, elt + 1);
}
elt += oplen;
diff --git a/gdb/testsuite/gdb.base/debug-expr.c b/gdb/testsuite/gdb.base/debug-expr.c
index 9b32c52576a..f7c3dbc5b8e 100644
--- a/gdb/testsuite/gdb.base/debug-expr.c
+++ b/gdb/testsuite/gdb.base/debug-expr.c
@@ -1,7 +1,15 @@
char array[4];
+int
+call_me (int *arg)
+{
+ return (*arg) - 1;
+}
+
+int val = 1;
+
int
main ()
{
- return 0;
+ return call_me (&val);
}
diff --git a/gdb/testsuite/gdb.base/debug-expr.exp b/gdb/testsuite/gdb.base/debug-expr.exp
index 95c2185773d..b0318bcd946 100644
--- a/gdb/testsuite/gdb.base/debug-expr.exp
+++ b/gdb/testsuite/gdb.base/debug-expr.exp
@@ -33,21 +33,6 @@ if ![runto_main] {
return -1
}
-# Test whether the expression debug machinery accepts the expression.
-
-proc test_debug_expr { cmd output } {
- global gdb_prompt
-
- gdb_test_multiple $cmd "" {
- -re ".*Invalid expression.*\r\n$gdb_prompt $" {
- fail $cmd
- }
- -re ".*\[\r\n\]$output\r\n$gdb_prompt $" {
- pass $cmd
- }
- }
-}
-
for { set i 0 } { $i < 4 } { incr i } {
gdb_test_no_output "set variable array\[$i\] = $i"
}
@@ -55,10 +40,15 @@ for { set i 0 } { $i < 4 } { incr i } {
gdb_test_no_output "set debug expression 1"
# This caused gdb to segfault.
-test_debug_expr "print /x {char\[4\]} array" \
+gdb_test_debug_expr "print /x {char\[4\]} array" \
"\[$\]$decimal = \\{0x0, 0x1, 0x2, 0x3\\}"
# This caused gdb to output garbage and possibly segfault
-gdb_test "print \"hello\"" \
- ".*OP_STRING\[^\r\n\]*Language-specific string type: 0.*\[\r\n\]\\$$decimal = \"hello\"\[\r\n\].*" \
+gdb_test_debug_expr "print \"hello\"" \
+ ".*OP_STRING\[^\r\n\]*Language-specific string type: 0.*\[\r\n\]\\$$decimal = \"hello\"" \
"string evaluation with debug expr"
+
+# An expression using a function call.
+gdb_test_debug_expr "print call_me ( &val )" \
+ ".*OP_FUNCALL\[^\r\n\]*Number of args: 1.*\[\r\n\]\\$$decimal = 0.*" \
+ "function call expression"
diff --git a/gdb/testsuite/gdb.cp/debug-expr.exp b/gdb/testsuite/gdb.cp/debug-expr.exp
index 79ba0bc377f..77462c5b3f2 100644
--- a/gdb/testsuite/gdb.cp/debug-expr.exp
+++ b/gdb/testsuite/gdb.cp/debug-expr.exp
@@ -21,23 +21,11 @@ gdb_start
gdb_test_no_output "set language c++"
gdb_test_no_output "set debug expression 1"
-# Test whether the expression debug machinery accepts the expression.
-
-proc test_debug_expr { cmd output } {
- global gdb_prompt
-
- gdb_test_multiple $cmd "" {
- -re ".*Invalid expression.*\r\n$gdb_prompt $" {
- fail $cmd
- }
- -re ".*\[\r\n\]$output\r\n$gdb_prompt $" {
- pass $cmd
- }
- }
-}
-
set void_star_zero_regex "\[$\]$decimal = \\(void \[*\]\\) 0x0"
-test_debug_expr "print static_cast<void*>(0)" "$void_star_zero_regex"
-test_debug_expr "print reinterpret_cast<void*>(0)" "$void_star_zero_regex"
-test_debug_expr "print dynamic_cast<void*>(0)" "$void_star_zero_regex"
+gdb_test_debug_expr "print static_cast<void*>(0)" \
+ "$void_star_zero_regex" "static_cast of zero to void*"
+gdb_test_debug_expr "print reinterpret_cast<void*>(0)" \
+ "$void_star_zero_regex" "reinterpret_cast of zero to void*"
+gdb_test_debug_expr "print dynamic_cast<void*>(0)" \
+ "$void_star_zero_regex" "dynamic_cast of zero to void*"
diff --git a/gdb/testsuite/gdb.dlang/debug-expr.exp b/gdb/testsuite/gdb.dlang/debug-expr.exp
index 8d12d33a47f..6b8ad0cb09f 100644
--- a/gdb/testsuite/gdb.dlang/debug-expr.exp
+++ b/gdb/testsuite/gdb.dlang/debug-expr.exp
@@ -21,20 +21,7 @@ gdb_start
gdb_test_no_output "set language d"
gdb_test_no_output "set debug expression 1"
-# Test whether the expression debug machinery accepts the expression.
-
-proc test_debug_expr { cmd output } {
- global gdb_prompt
-
- gdb_test_multiple $cmd "" {
- -re ".*Invalid expression.*\r\n$gdb_prompt $" {
- fail $cmd
- }
- -re ".*\[\r\n\]$output\r\n$gdb_prompt $" {
- pass $cmd
- }
- }
-}
-
# This caused gdb to segfault.
-test_debug_expr "print *(int*)(0)" "Cannot access memory at address 0x0"
+gdb_test_debug_expr "print *(int*)(0)" \
+ "Cannot access memory at address 0x0" \
+ "dereference a null pointer"
diff --git a/gdb/testsuite/gdb.fortran/debug-expr.exp b/gdb/testsuite/gdb.fortran/debug-expr.exp
new file mode 100644
index 00000000000..19df7bdecbc
--- /dev/null
+++ b/gdb/testsuite/gdb.fortran/debug-expr.exp
@@ -0,0 +1,43 @@
+# Copyright 2020 Free Software Foundation, Inc.
+
+# This program is free software; you can redistribute it and/or modify
+# it under the terms of the GNU General Public License as published by
+# the Free Software Foundation; either version 3 of the License, or
+# (at your option) any later version.
+#
+# This program is distributed in the hope that it will be useful,
+# but WITHOUT ANY WARRANTY; without even the implied warranty of
+# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+# GNU General Public License for more details.
+#
+# You should have received a copy of the GNU General Public License
+# along with this program. If not, see <http://www.gnu.org/licenses/>.
+
+# Test "set debug expr 1" on Fortran expressions.
+
+if { [skip_fortran_tests] } { return -1 }
+
+# Test relies on checking gdb debug output. Do not run if gdb debug is
+# enabled as any debug will be redirected to the log.
+if [gdb_debug_enabled] {
+ untested "debug is enabled"
+ return 0
+}
+
+standard_testfile .f90
+load_lib fortran.exp
+
+if {[prepare_for_testing "failed to prepare" $testfile $srcfile {debug f90}]} {
+ return -1
+}
+
+if ![fortran_runto_main] {
+ fail "run to main"
+ return -1
+}
+
+gdb_breakpoint [gdb_get_line_number "Break Here"]
+gdb_continue_to_breakpoint "Break Here"
+
+gdb_test_no_output "set debug expression 1"
+gdb_test_debug_expr "print obj%three(1)%two(1)%one(1)%i" "\\\$$decimal = 1"
diff --git a/gdb/testsuite/gdb.fortran/debug-expr.f90 b/gdb/testsuite/gdb.fortran/debug-expr.f90
new file mode 100644
index 00000000000..8071f1b8d18
--- /dev/null
+++ b/gdb/testsuite/gdb.fortran/debug-expr.f90
@@ -0,0 +1,38 @@
+! Copyright 2020 Free Software Foundation, Inc.
+
+! This program is free software; you can redistribute it and/or modify
+! it under the terms of the GNU General Public License as published by
+! the Free Software Foundation; either version 3 of the License, or
+! (at your option) any later version.
+!
+! This program is distributed in the hope that it will be useful,
+! but WITHOUT ANY WARRANTY; without even the implied warranty of
+! MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+! GNU General Public License for more details.
+!
+! You should have received a copy of the GNU General Public License
+! along with this program. If not, see <http://www.gnu.org/licenses/>.
+
+program main
+ type data_item
+ integer(kind=4) i, j, k
+ end type data_item
+
+ type level_one
+ type(data_item) :: one(3)
+ end type level_one
+
+ type level_two
+ type(level_one) :: two(3)
+ end type level_two
+
+ type level_three
+ type(level_two) :: three(3)
+ end type level_three
+
+ type (level_three) obj
+
+ obj%three(1)%two(1)%one(1)%i = 1
+
+ print *, obj ! Break Here
+end program
diff --git a/gdb/testsuite/lib/gdb.exp b/gdb/testsuite/lib/gdb.exp
index 6c98ae0729b..55154db6a50 100644
--- a/gdb/testsuite/lib/gdb.exp
+++ b/gdb/testsuite/lib/gdb.exp
@@ -1656,6 +1656,34 @@ proc gdb_test_stdio {command inferior_pattern {gdb_pattern ""} {message ""}} {
return $res
}
+# Wrapper around gdb_test_multiple to be used when testing expression
+# evaluation while 'set debug expression 1' is in effect.
+# Looks for some patterns that indicates the expression was rejected.
+#
+# CMD is the command to execute, which should include an expression
+# that GDB will need to parse.
+#
+# OUTPUT is the expected output pattern.
+#
+# TESTNAME is the name to be used for the test, defaults to CMD if not
+# given.
+proc gdb_test_debug_expr { cmd output {testname "" }} {
+ global gdb_prompt
+
+ if { ${testname} == "" } {
+ set testname $cmd
+ }
+
+ gdb_test_multiple $cmd $testname {
+ -re ".*Invalid expression.*\r\n$gdb_prompt $" {
+ fail $gdb_test_name
+ }
+ -re ".*\[\r\n\]$output\r\n$gdb_prompt $" {
+ pass $gdb_test_name
+ }
+ }
+}
+
# get_print_expr_at_depths EXP OUTPUTS
#
# Used for testing 'set print max-depth'. Prints the expression EXP
--
2.25.4
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