diff options
| -rw-r--r-- | gdb/ChangeLog | 6 | ||||
| -rw-r--r-- | gdb/dwarf2-frame.c | 34 |
2 files changed, 39 insertions, 1 deletions
diff --git a/gdb/ChangeLog b/gdb/ChangeLog index e154e34..99f522e 100644 --- a/gdb/ChangeLog +++ b/gdb/ChangeLog @@ -1,5 +1,11 @@ 2003-06-07 Andrew Cagney <cagney@redhat.com> + * dwarf2-frame.c (dwarf2_frame_cache): Add comments on PC_REGNUM. + Assert that PC_REGNUM is valid. + (dwarf2_frame_prev_register): Add comments on SP_REGNUM. + +2003-06-07 Andrew Cagney <cagney@redhat.com> + * gdbarch.sh (TARGET_READ_SP): Add predicate, delete default. * gdbarch.h, gdbarch.c: Regenerate. * mn10300-tdep.c: Include "gdb_assert.h". diff --git a/gdb/dwarf2-frame.c b/gdb/dwarf2-frame.c index f28fade..81eb195 100644 --- a/gdb/dwarf2-frame.c +++ b/gdb/dwarf2-frame.c @@ -544,6 +544,13 @@ dwarf2_frame_cache (struct frame_info *next_frame, void **this_cache) /* Skip the return address column. */ if (reg == fs->retaddr_column) + /* NOTE: cagney/2003-06-07: Is this right? What if the + RETADDR_COLUM corresponds to a real register (and, worse, + that isn't the PC_REGNUM)? I'm guessing that the PC_REGNUM + further down is trying to handle this. That can't be right + though - PC_REGNUM may not be valid (it can be -ve). I + think, instead when RETADDR_COLUM isn't a real register, it + should map itself onto frame_pc_unwind. */ continue; /* Use the GDB register number as index. */ @@ -558,12 +565,22 @@ dwarf2_frame_cache (struct frame_info *next_frame, void **this_cache) implies a copy from the ra column register. */ if (fs->retaddr_column < fs->regs.num_regs && fs->regs.reg[fs->retaddr_column].how != REG_UNSAVED) - cache->reg[PC_REGNUM] = fs->regs.reg[fs->retaddr_column]; + { + /* See comment above about a possibly -ve PC_REGNUM. If this + assertion fails, it's a problem with this code and not the + architecture. */ + gdb_assert (PC_REGNUM >= 0); + cache->reg[PC_REGNUM] = fs->regs.reg[fs->retaddr_column]; + } else { reg = DWARF2_REG_TO_REGNUM (fs->retaddr_column); if (reg != PC_REGNUM) { + /* See comment above about PC_REGNUM being -ve. If this + assertion fails, it's a problem with this code and not + the architecture. */ + gdb_assert (PC_REGNUM >= 0); cache->reg[PC_REGNUM].loc.reg = reg; cache->reg[PC_REGNUM].how = REG_SAVED_REG; } @@ -606,6 +623,21 @@ dwarf2_frame_prev_register (struct frame_info *next_frame, void **this_cache, /* GCC defines the CFA as the value of the stack pointer just before the call instruction is executed. Do other compilers use the same definition? */ + /* DWARF V3 Draft 7 p102: Typically, the CFA is defined to + be the value of the stack pointer at the call site in the + previous frame (which may be different from its value on + entry to the current frame). */ + /* DWARF V3 Draft 7 p103: The first column of the rules + defines the rule which computes the CFA value; it may be + either a register and a signed offset that are added + together or a DWARF expression that is evaluated. */ + /* FIXME: cagney/2003-07-07: I don't understand this. The + CFI info should have provided unwind information for the + SP register and then pointed ->cfa_reg at it, not the + reverse. Assuming that SP_REGNUM is !-ve, there is a + very real posibility that CFA is an offset from some + other register, having nothing to do with the unwound SP + value. */ *optimizedp = 0; if (valuep) { |