diff options
Diffstat (limited to 'gdb/block.h')
| -rw-r--r-- | gdb/block.h | 44 |
1 files changed, 32 insertions, 12 deletions
diff --git a/gdb/block.h b/gdb/block.h index c3babad..3bd2c51 100644 --- a/gdb/block.h +++ b/gdb/block.h @@ -179,27 +179,35 @@ struct block : public allocate_on_obstack<block> /* Return the "entry PC" of this block. - The entry PC is the lowest (start) address for the block when all addresses - within the block are contiguous. If non-contiguous, then use the start - address for the first range in the block. - - At the moment, this almost matches what DWARF specifies as the entry - pc. (The missing bit is support for DW_AT_entry_pc which should be - preferred over range data and the low_pc.) + If the entry PC has been set to a specific value then this is + returned. Otherwise, the entry PC is the lowest (start) address for + the block when all addresses within the block are contiguous. If + non-contiguous, then use the start address for the first range in the + block. - Once support for DW_AT_entry_pc is added, I expect that an entry_pc - field will be added to one of these data structures. Once that's done, - the entry_pc field can be set from the dwarf reader (and other readers - too). ENTRY_PC can then be redefined to be less DWARF-centric. */ + This almost matches what DWARF specifies as the entry pc, except that + the final case, using the first address of the first range, is a GDB + extension. However, the DWARF reader sets the specific entry PC + wherever possible, so this non-standard fallback case is only used as + a last resort. */ CORE_ADDR entry_pc () const { - if (this->is_contiguous ()) + if (m_entry_pc != 0) + return m_entry_pc; + else if (this->is_contiguous ()) return this->start (); else return this->ranges ()[0].start (); } + /* Set this block's entry PC. */ + + void set_entry_pc (CORE_ADDR addr) + { + m_entry_pc = addr; + } + /* Return the objfile of this block. */ struct objfile *objfile () const; @@ -344,6 +352,18 @@ private: startaddr and endaddr above. */ struct blockranges *m_ranges = nullptr; + + /* The entry address for this block. The value 0 is special and + indicates that the entry address has not been set. + + Using 0 as a special value is not ideal, targets for which 0 is a + valid code address might run into problems if they want to use 0 as a + block's entry address, but the alternative is to carry a flag + indicating if m_entry_pc is valid or not, but that would make 'struct + block' even bigger, and we want to keep 'struct block' as small as + possible (we might have a lot of blocks). */ + + CORE_ADDR m_entry_pc = 0; }; /* The global block is singled out so that we can provide a back-link |