This patch essentially causes GDB to treat inlined frames like "normal"
frames from the user's perspective. This means, for example, that when a
user sets a breakpoint in an inlined function, GDB will now actually stop
"in" that function.
Using the test case from breakpoints/17534,
3 static inline void NVIC_EnableIRQ(int IRQn)
4 {
5 volatile int y;
6 y = IRQn;
7 }
8
9 __attribute__( ( always_inline ) ) static inline void __WFI(void)
10 {
11 __asm volatile ("nop");
12 }
13
14 int main(void) {
15
16 x= 42;
17
18 if (x)
19 NVIC_EnableIRQ(16);
20 else
21 NVIC_EnableIRQ(18);
(gdb) b NVIC_EnableIRQ
Breakpoint 1 at 0x4003e4: NVIC_EnableIRQ. (2 locations)
(gdb) r
Starting program: 17534
Breakpoint 1, main () at 17534.c:19
19 NVIC_EnableIRQ(16);
Because skip_inline_frames currently skips every inlined frame, GDB "stops"
in the caller. This patch adds a new parameter to skip_inline_frames
that allows us to pass in a bpstat stop chain. The breakpoint locations
on the stop chain can be used to determine if we've stopped inside an inline
function (due to a user breakpoint). If we have, we do not elide the frame.
With this patch, GDB now reports that the inferior has stopped inside the
inlined function:
(gdb) r
Starting program: 17534
Breakpoint 1, NVIC_EnableIRQ (IRQn=16) at 17534.c:6
6 y = IRQn;
Many thanks to Jan and Pedro for guidance on this.
gdb/ChangeLog:
* breakpoint.c (build_bpstat_chain): New function, moved from
bpstat_stop_status.
(bpstat_stop_status): Add optional parameter, `stop_chain'.
If no stop chain is passed, call build_bpstat_chain to build it.
* breakpoint.h (build_bpstat_chain): Declare.
(bpstat_stop_status): Move documentation here from breakpoint.c.
* infrun.c (handle_signal_stop): Before eliding inlined frames,
build the stop chain and pass it to skip_inline_frames.
Pass this stop chain to bpstat_stop_status.
* inline-frame.c: Include breakpoint.h.
(stopped_by_user_bp_inline_frame): New function.
(skip_inline_frames): Add parameter `stop_chain'.
Move documention to inline-frame.h.
If non-NULL, use stopped_by_user_bp_inline_frame to determine
whether the frame should be elided.
* inline-frame.h (skip_inline_frames): Add parameter `stop_chain'.
Add moved documentation and update for new parameter.
gdb/testsuite/ChangeLog:
* gdb.ada/bp_inlined_func.exp: Update inlined frame locations
in expected breakpoint stop locations.
* gdb.dwarf2/implptr.exp (implptr_test_baz): Use up/down to
move to proper scope to test variable values.
* gdb.opt/inline-break.c (inline_func1, not_inline_func1)
(inline_func2, not_inline_func2, inline_func3, not_inline_func3):
New functions.
(main): Call not_inline_func3.
* gdb.opt/inline-break.exp: Start inferior and set breakpoints at
inline_func1, inline_func2, and inline_func3. Test that when each
breakpoint is hit, GDB properly reports both the stop location
and the backtrace. Repeat tests for temporary breakpoints.
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