This patch fixes PR 4643 by allowing symbols in the LENGTH and ORIGIN
fields of MEMORY regions. Previously, only constants and constant
expressions are allowed.
For the AVR target, this helps define memory constraints more
accurately (per device), without having to create a ton of device
specific linker scripts.
ld/
PR 4643
* ldexp.c (fold_name): Fold LENGTH only after
lang_first_phase_enum.
* ldgram.y (memory_spec): Don't evaluate ORIGIN and LENGTH
rightaway.
* ldlang.h (struct memory_region_struct): Add origin_exp and
length_exp fields.
* ldlang.c (lang_do_memory_regions): New.
(lang_memory_region_lookup): Initialize origin_exp and
length_exp fields.
(lang_process): Call lang_do_memory_regions.
ld/testsuite/
* ld-scripts/memory.t: Define new symbol tred.
* ld-scripts/memory_sym.t: New.
* ld-scripts/script.exp: Perform MEMORY with symbols test, and
conditionally check values of linker symbols.
* NEWS: Mention change in linker script expression evaluation.
ld/
* ld.texinfo (Expression Section): Detail expression evaluation.
(Builtin Functions <ADDR>): Correct.
(Builtin Functions <LOADADDR>): Don't mention LOADADDR normally
the same as ADDR.
(Builtin Functions <SEGMENT_START>): Typo fix.
* ldexp.c (new_number): New function.
(make_abs, exp_get_abs_int): Cope with NULL expld.result.section.
(fold_unary <'~', '!', '-'>): Don't make_abs.
(fold_binary): Simplify result section logic. Return NULL section
for logical ops.
(fold_binary <SEGMENT_START>): Use new_rel_from_abs to set value to
a consistent result.
(fold_name <SIZEOF_HEADERS>): Return new_number, not new_abs.
(fold_name <DEFINED, SIZEOF, ALIGNOF, LENGTH, CONSTANT>): Likewise.
(fold_name <NAME>): No need to handle absolute symbols differently
from relative ones.
(fold_name <ORIGIN>): Don't return valid result when
lang_first_phase_enum. Return new_rel_from_abs, not new_abs.
(exp_fold_tree_1 <etree_value>): Return new_number, not new_rel.
(exp_fold_tree_1): Ajust for NULL expld.result.section. When assigning
a plain number to dot, assume the value is relative to expld.section.
Make terms not in an output section, absolute.
* ldlang.c (print_assignment): Fix style nit.
(lang_size_sections_1): Cope with NULL expld.result.section.
(lang_do_assignments_1): Likewise.
ld/testsuite/
* ld-scripts/memory.t: Remove ORIGIN fudge.
* ldlang.c: Likewise.
* ldlang.h: Likewise.
* ldlex.l: Likewise.
* NEWS: Mention the new feature.
* ld.texinfo: Document the new feature.
* ld-scripts/regions-alias-1.t: New file.
* ld-scripts/regions-alias-2.t: New file.
* ld-scripts/regions-alias-3.t: New file.
* ld-scripts/regions-alias-4.t: New file.
* ld-scripts/script.exp: Run region alias tests.
