Yay, more refactoring of the section assignment… This version of the linker will allocate sections by their alignment, and then by their size (largest first, in both cases).
In future, this may be improved by using dense packing (as suggested by #83).
Aligned sections can now be created with out_NewAlignedSection(). This information is stored in created object files, and read by the linker.
The names of each section are also included in the object file, enabling potential improvements to error messages in the future.
Instead of reading into a pre-sized buffer, this function now uses malloc to create a buffer, and resizes it if necessary.
This reduces the risk of memory issues if a long string (< 255 chars) was encountered.
Deduplicates and generalises a lot of code in assign.c:
- Replace area_AllocAbs*AnyBank() with area_AllocAbsAnyBank() function
that accepts a section type parameter
- Replace area_Alloc*AnyBank() with area_AllocAnyBank()
- Replace FindLargest*() with FindLargestSection()
- Replace Assign*Sections() with AssignBankedSections()
- Add VerifyAndSetBank(), which enables bank checks (and addition with
BANK_*) to be centralised
- Refactor the initialisation of AssignSections(), removing some magic
numbers and only setting MaxAvail[i] once
- Overhaul the duplicated cases throughout AssignSections()
Previously, if BANK is used when defining a section that’s not ROMX,
WRMAX, SRAM or VRAM, a second error message would appear, e.g. “(null)
bank value $1 out of range $5d to $0”.
This would appear due to the usage of uninitialised variables. This
change ensures that the uninitialised variables are not accessed when
using an invalid section.
This also silences compiler warnings about usage of uninitialised
variables.
GNU make actually looks for ‘GNUmakefile’, not ‘GNUMakefile’.
Consequently, GNU make would erroneously attempt to use the standard
makefile, instead of the GNU-specific one. This would cause an error
when attempting to import png.h, due to PNGFLAGS not being correctly
set.
Increase number of include paths that can be passed through the
command line interface. The previous number, 16, is only good enough
for small projects. 128 is still an arbitrary number, but it is harder
to reach.
The code that adds an include path to the array of paths doesn't check
the lenght of the path (which can cause overflows because of strcpy).
It doesn't check if the max number of paths has been reached, either.
This patch adds error messages for such cases, giving the user more
information than before and crashing the assembly instead of
continuing and failing when it can't find a file to include.
GNU Make 3.x doesn't support the "!=" syntax for shell assignment,
although 4.x does, BSD Makes do, and it has been submitted to POSIX
for possible inclusion in the standard. Unfortunately, GNU Make 3.x
is still in common use, so provide an alternative makefile (GNU Make
reads "GNUmakefile" instead of "Makefile" by default) that sets the
variables and then reuses the rest of the default Makefile.
Fixed as follows: if the symbol doesn't exist, don't add it to the relocation
table. The functions calling createpatch will nevertheless increment PC
correctly.
Test case:
SECTION "CODE", CODE
glob:
jp .loc
; from test/asm/banknoexist.asm:
SECTION "sec", ROM0
db BANK(noexist)
See also issue #68
If a macro arg came in the middle of a symbol or at the end, e.g. "SYM\1", it would say that the symbol was not defined. This was because it wasn't looking up the macro arg's value correctly.
