[RFA]: Handle multi-line versions of multi-breakpoints
Doug Evans
dje@google.com
Fri Mar 13 17:04:00 GMT 2009
Ping.
On Sun, Mar 1, 2009 at 11:53 PM, Doug Evans <dje@google.com> wrote:
> Hi.
>
> "multi-breakpoints" (multiple breakpoints for the same source line)
> don't work for constructors and inline functions where the source expression
> spans several lines (at least for the new testcases included in this patch).
>
> This patch fixes it by, if there's no exact match,
> rescanning the symtabs for all matches of the best match.
> Included are updated testcases to exercise the bug.
> The bug isn't exposed by templates, but I updated mb-templates.{cc,exp}
> anyway (if only to confirm things work there too).
>
> Ok to check in?
>
> 2009-03-01 Doug Evans <dje@google.com>
>
> * symtab.c (expand_line_sal): If we don't find an exact match,
> rescan all symtabs again to find all copies of the best match.
>
> * gdb.cp/mb-ctor.exp: Add multi-line source statement test.
> * gdb.cp/mb-ctor.cc: Ditto.
> * gdb.cp/mb-inline.exp: Add multi-line source statement test.
> * gdb.cp/mb-inline.h (multi_line_foo): New function.
> * gdb.cp/mb-inline1.cc: Call it.
> * gdb.cp/mb-inline2.cc: Ditto.
> * gdb.cp/mb-templates.exp: Add multi-line source statement test.
> * gdb.cp/mb-templates.cc (multi_line_foo): New template.
>
> Index: symtab.c
> ===================================================================
> RCS file: /cvs/src/src/gdb/symtab.c,v
> retrieving revision 1.204
> diff -u -p -r1.204 symtab.c
> --- symtab.c 2 Mar 2009 06:33:24 -0000 1.204
> +++ symtab.c 2 Mar 2009 06:39:17 -0000
> @@ -4481,7 +4481,6 @@ expand_line_sal (struct symtab_and_line
> else
> {
> struct linetable_entry *best_item = 0;
> - struct symtab *best_symtab = 0;
> int exact = 0;
>
> lineno = sal.line;
> @@ -4533,13 +4532,41 @@ expand_line_sal (struct symtab_and_line
> && (best_item == NULL || item->line < best_item->line))
> {
> best_item = item;
> - best_symtab = symtab;
> }
> }
> }
> }
> +
> if (!exact && best_item)
> - append_expanded_sal (&ret, best_symtab, lineno, best_item->pc);
> + {
> + /* We found a "good enough" match.
> + Rescan to find all such matches.
> + This is to handle constructors, templates, inline-functions
> + that have multiple breakpoints for one line number. */
> +
> + ALL_SYMTABS (objfile, symtab)
> + {
> + if (strcmp (sal.symtab->filename,
> + symtab->filename) == 0)
> + {
> + struct linetable *l;
> + int len;
> + l = LINETABLE (symtab);
> + if (!l)
> + continue;
> + len = l->nitems;
> +
> + for (j = 0; j < len; j++)
> + {
> + struct linetable_entry *item = &(l->item[j]);
> +
> + if (item->line == best_item->line)
> + append_expanded_sal (&ret, symtab, item->line,
> + item->pc);
> + }
> + }
> + }
> + }
> }
>
> /* For optimized code, compiler can scatter one source line accross
> Index: testsuite/gdb.cp/mb-ctor.cc
> ===================================================================
> RCS file: /cvs/src/src/gdb/testsuite/gdb.cp/mb-ctor.cc,v
> retrieving revision 1.1
> diff -u -p -r1.1 mb-ctor.cc
> --- testsuite/gdb.cp/mb-ctor.cc 24 Sep 2007 07:40:32 -0000 1.1
> +++ testsuite/gdb.cp/mb-ctor.cc 2 Mar 2009 06:39:17 -0000
> @@ -28,11 +28,19 @@ public:
> ~Derived();
> private:
> int i;
> + int i2;
> };
>
> Derived::Derived(int i) : Base(i)
> {
> this->i = i;
> + /* The next statement is spread over two lines on purpose to exercise
> + a bug where breakpoints set on all but the last line of a statement
> + would not get multiple breakpoints.
> + The second line's text for gdb_get_line_number is a subset of the
> + first line so that we don't care which line gdb prints when it stops. */
> + this->i2 = // set breakpoint here
> + i; // breakpoint here
> }
>
> Derived::~Derived()
> Index: testsuite/gdb.cp/mb-ctor.exp
> ===================================================================
> RCS file: /cvs/src/src/gdb/testsuite/gdb.cp/mb-ctor.exp,v
> retrieving revision 1.5
> diff -u -p -r1.5 mb-ctor.exp
> --- testsuite/gdb.cp/mb-ctor.exp 3 Jan 2009 05:58:04 -0000 1.5
> +++ testsuite/gdb.cp/mb-ctor.exp 2 Mar 2009 06:39:17 -0000
> @@ -43,6 +43,11 @@ gdb_start
> gdb_reinitialize_dir $srcdir/$subdir
> gdb_load ${binfile}
>
> +if ![runto_main] then {
> + perror "couldn't run to breakpoint"
> + continue
> +}
> +
> # Set a breakpoint with multiple locations
> # and a condition.
>
> @@ -50,34 +55,31 @@ gdb_test "break 'Derived::Derived(int)'"
> "Breakpoint.*at.* file .*$srcfile, line.*\\(2 locations\\).*" \
> "set-breakpoint at ctor"
>
> +gdb_breakpoint [gdb_get_line_number "set breakpoint here"]
> +
> gdb_test "break 'Derived::~Derived()'" \
> "Breakpoint.*at.* file .*$srcfile, line.*\\(2 locations\\).*" \
> "set-breakpoint at dtor"
>
> -gdb_run_cmd
> -gdb_expect {
> - -re "Breakpoint \[0-9\]+,.*Derived.*i=7.*$gdb_prompt $" {
> - pass "run to breakpoint"
> - }
> - -re "$gdb_prompt $" {
> - fail "run to breakpoint"
> - }
> - timeout {
> - fail "run to breakpoint (timeout)"
> - }
> -}
> +gdb_test "continue" \
> + ".*Breakpoint.*Derived.*i=7.*" \
> + "run to breakpoint 1 v1"
> +
> +gdb_continue_to_breakpoint "set breakpoint here" ".* breakpoint here"
>
> gdb_test "continue" \
> ".*Breakpoint.*Derived.*i=15.*" \
> - "run to breakpoint 2"
> + "run to breakpoint 1 v2"
> +
> +gdb_continue_to_breakpoint "set breakpoint here" ".* breakpoint here"
>
> gdb_test "continue" \
> ".*Breakpoint.*~Derived.*" \
> - "run to breakpoint 3"
> + "run to breakpoint 3 v1"
>
> gdb_test "continue" \
> ".*Breakpoint.*~Derived.*" \
> - "run to breakpoint 4"
> + "run to breakpoint 3 v2"
>
> gdb_test "continue" \
> ".*exited normally.*" \
> Index: testsuite/gdb.cp/mb-inline.exp
> ===================================================================
> RCS file: /cvs/src/src/gdb/testsuite/gdb.cp/mb-inline.exp,v
> retrieving revision 1.2
> diff -u -p -r1.2 mb-inline.exp
> --- testsuite/gdb.cp/mb-inline.exp 3 Jan 2009 05:58:04 -0000 1.2
> +++ testsuite/gdb.cp/mb-inline.exp 2 Mar 2009 06:39:17 -0000
> @@ -106,3 +106,25 @@ gdb_expect {
> gdb_test "continue" \
> ".*Program exited normally.*" \
> "continue with disabled breakpoint 1.2"
> +
> +# Make sure we can set a breakpoint on a source statement that spans
> +# multiple lines.
> +
> +delete_breakpoints
> +
> +set bp_location [gdb_get_line_number "set multi-line breakpoint here" $hdrfile]
> +
> +if { ![runto_main] } {
> + fail "Can't run to main for multi_line_foo tests."
> + return 0
> +}
> +
> +gdb_test "break $hdrfile:$bp_location" \
> + "Breakpoint.*at.* file .*$hdrfile, line.*\\(2 locations\\).*" \
> + "set multi_line_foo breakpoint"
> +gdb_test "continue" \
> + ".*Breakpoint.*multi_line_foo \\(i=0\\).*" \
> + "run to multi_line_foo breakpoint 4 afn"
> +gdb_test "continue" \
> + ".*Breakpoint.*multi_line_foo \\(i=1\\).*" \
> + "run to multi_line_foo breakpoint 4 bfn"
> Index: testsuite/gdb.cp/mb-inline.h
> ===================================================================
> RCS file: /cvs/src/src/gdb/testsuite/gdb.cp/mb-inline.h,v
> retrieving revision 1.2
> diff -u -p -r1.2 mb-inline.h
> --- testsuite/gdb.cp/mb-inline.h 3 Jan 2009 05:58:04 -0000 1.2
> +++ testsuite/gdb.cp/mb-inline.h 2 Mar 2009 06:39:17 -0000
> @@ -26,5 +26,12 @@ foo (int i)
> return i; // set breakpoint here
> }
>
> +static int
> +multi_line_foo (int i)
> +{
> + return // set multi-line breakpoint here
> + i;
> +}
> +
> extern int afn ();
> extern int bfn ();
> Index: testsuite/gdb.cp/mb-inline1.cc
> ===================================================================
> RCS file: /cvs/src/src/gdb/testsuite/gdb.cp/mb-inline1.cc,v
> retrieving revision 1.2
> diff -u -p -r1.2 mb-inline1.cc
> --- testsuite/gdb.cp/mb-inline1.cc 3 Jan 2009 05:58:04 -0000 1.2
> +++ testsuite/gdb.cp/mb-inline1.cc 2 Mar 2009 06:39:17 -0000
> @@ -23,7 +23,7 @@
> int
> afn ()
> {
> - return foo (0);
> + return foo (0) + multi_line_foo (0);
> }
>
> int
> Index: testsuite/gdb.cp/mb-inline2.cc
> ===================================================================
> RCS file: /cvs/src/src/gdb/testsuite/gdb.cp/mb-inline2.cc,v
> retrieving revision 1.2
> diff -u -p -r1.2 mb-inline2.cc
> --- testsuite/gdb.cp/mb-inline2.cc 3 Jan 2009 05:58:04 -0000 1.2
> +++ testsuite/gdb.cp/mb-inline2.cc 2 Mar 2009 06:39:17 -0000
> @@ -21,5 +21,5 @@
> int
> bfn ()
> {
> - return foo (1);
> + return foo (1) + multi_line_foo (1);
> }
> Index: testsuite/gdb.cp/mb-templates.cc
> ===================================================================
> RCS file: /cvs/src/src/gdb/testsuite/gdb.cp/mb-templates.cc,v
> retrieving revision 1.1
> diff -u -p -r1.1 mb-templates.cc
> --- testsuite/gdb.cp/mb-templates.cc 24 Sep 2007 07:40:32 -0000 1.1
> +++ testsuite/gdb.cp/mb-templates.cc 2 Mar 2009 06:39:17 -0000
> @@ -8,6 +8,13 @@ void foo(T i)
> std::cout << "hi\n"; // set breakpoint here
> }
>
> +template<class T>
> +void multi_line_foo(T i)
> +{
> + std::cout // set multi-line breakpoint here
> + << "hi\n";
> +}
> +
> int main()
> {
> foo<int>(0);
> @@ -16,4 +23,9 @@ int main()
> foo<double>(1);
> foo<int>(2);
> foo<double>(2);
> +
> + multi_line_foo<int>(0);
> + multi_line_foo<double>(0);
> +
> + return 0;
> }
> Index: testsuite/gdb.cp/mb-templates.exp
> ===================================================================
> RCS file: /cvs/src/src/gdb/testsuite/gdb.cp/mb-templates.exp,v
> retrieving revision 1.5
> diff -u -p -r1.5 mb-templates.exp
> --- testsuite/gdb.cp/mb-templates.exp 3 Jan 2009 05:58:04 -0000 1.5
> +++ testsuite/gdb.cp/mb-templates.exp 2 Mar 2009 06:39:17 -0000
> @@ -165,3 +165,25 @@ gdb_test "continue" \
> ".*Breakpoint.*foo<int> \\(i=1\\).*" \
> "instantiation: run to breakpoint 2"
>
> +
> +# Make sure we can set a breakpoint on a source statement that spans
> +# multiple lines.
> +
> +delete_breakpoints
> +
> +set bp_location [gdb_get_line_number "set multi-line breakpoint here"]
> +
> +if { ![runto_main] } {
> + fail "Can't run to main for multi_line_foo tests."
> + return 0
> +}
> +
> +gdb_test "break $srcfile:$bp_location" \
> + "Breakpoint.*at.* file .*$srcfile, line.*\\(2 locations\\).*" \
> + "set multi_line_foo breakpoint"
> +gdb_test "continue" \
> + ".*Breakpoint.*multi_line_foo<int> \\(i=0\\).*" \
> + "run to multi_line_foo breakpoint 2 <int>"
> +gdb_test "continue" \
> + ".*Breakpoint.*multi_line_foo<double> \\(i=0\\).*" \
> + "run to multi_line_foo breakpoint 2 <double>"
>
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