From ddfe970e6bec29f779a60b071f12590e53cfe6eb Mon Sep 17 00:00:00 2001 From: Keith Seitz Date: Thu, 17 May 2018 12:15:11 -0700 Subject: Don't elide all inlined frames 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. --- gdb/inline-frame.h | 11 ++++++++--- 1 file changed, 8 insertions(+), 3 deletions(-) (limited to 'gdb/inline-frame.h') diff --git a/gdb/inline-frame.h b/gdb/inline-frame.h index 1d2e251..d66ad44 100644 --- a/gdb/inline-frame.h +++ b/gdb/inline-frame.h @@ -22,16 +22,21 @@ struct frame_info; struct frame_unwind; +struct bpstats; /* The inline frame unwinder. */ extern const struct frame_unwind inline_frame_unwind; /* Skip all inlined functions whose call sites are at the current PC. - Frames for the hidden functions will not appear in the backtrace until the - user steps into them. */ -void skip_inline_frames (ptid_t ptid); + If non-NULL, STOP_CHAIN is used to determine whether a stop was caused by + a user breakpoint. In that case, do not skip that inlined frame. This + allows the inlined frame to be treated as if it were non-inlined from the + user's perspective. GDB will stop "in" the inlined frame instead of + the caller. */ + +void skip_inline_frames (ptid_t ptid, struct bpstats *stop_chain); /* Forget about any hidden inlined functions in PTID, which is new or about to be resumed. If PTID is minus_one_ptid, forget about all -- cgit v1.1