Compiler — zsdcc

Binary: z88dk-zsdcc (via zcc -compiler=sdcc or target -clib=sdcc_*). Sources / patches: src/zsdcc/. Pin: root Makefile SDCC_VERSION.

Agent facts

Topic	Detail
Common clibs	sdcc_ix, sdcc_iy (IY reserved in many newlib configs)
World	Prefer newlib (-clib=new / sdcc clibs), not classic 8085
Calling	Do not mix sccz80 and sdcc objects carelessly
Opts	SDCC-specific peephole rules under lib/sdcc/
Preprocessor	ucpp (not stock sdcpp)

Version (this tree)

Item	Value
SDCC baseline	4.6.0 r16639 (final release tag; changelog.txt v2.5)
Current patch	src/zsdcc/sdcc-z88dk.patch
Snapshot name	src/zsdcc/sdcc-16639-z88dk.patch
Makefile pin	SDCC_VERSION=16639
CI / HTTP tarball	zsdcc_r16639_src.tar.gz (nightly http://nightly.z88dk.org/zsdcc/)

Historical snapshots stay under src/zsdcc/sdcc-*-z88dk.patch for rebuild of older pins. Human notes: src/zsdcc/readme.md.

Select via zcc

Flag	Meaning
-clib=sdcc_iy	Preferred on many targets; adds --reserve-regs-iy
-clib=sdcc_ix	SDCC with IX frame conventions as defined by cfg

zcc +cpm -clib=sdcc_iy -vn hi.c -o hi

Limits

• Intended for Z80-class work in this toolchain.
• For 8080 / 8085 / gbz80 classic products, prefer sccz80 (or 80cc), not zsdcc.
• Library directory is often still lib/clibs/sdcc_ix even for sdcc_iy. Read lib/config/<target>.cfg.
• Vanilla SDCC (sdcc from svn, __sdcccall(1), banner #16608) is a different toolchain. Bench recipes: methodology-sdcc-vanilla. Do not write vanilla numbers into zsdcc RESULT blocks.

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Generating / upgrading the zsdcc patch

Use this when SDCC releases (or z88dk moves pin). Product docs: issue #2974 / PR class “prepare patch and tarball”.

Layout

Path	Role
Makefile SDCC_VERSION	svn revision checked out or tarball name
src/zsdcc/sdcc-z88dk.patch	Default patch applied by make (non-HTTP build)
src/zsdcc/sdcc-<rev>-z88dk.patch	Frozen copy for that rev (keep previous revs)
src/sdcc-build/	Working tree (gitignored); svn checkout or tarball extract
zsdcc_r<rev>_src.tar.gz	Pre-patched sources for CI (BUILD_SDCC_HTTP=1); gitignored unless force-added for upload

Build without HTTP: svn checkout -r $(SDCC_VERSION) …/trunk/sdcc then patch -p0 < sdcc-z88dk.patch. HTTP: extract tarball (already patched).

Required patch components (keep all of these)

These are z88dk-specific; they do not belong upstream as a unit.

1. ABI revision = 0 (src/z80/main.c)

Every Z80-family port descriptor must use:

0,                            /* ABI revision */   /* was 1 */

Stock SDCC defaults to ABI 1 (__sdcccall(1)). z88dk libraries and classic/newlib bridges expect ABI 0 (traditional stack / __z88dk_callee / __z88dk_fastcall world with __sdcccall(0)). Do not “fix” PORT stack vectors when regenerating — only the ABI field is intentional. Context lines around { -1, 0, 0, 4, 0, 3, 0 } etc. may move between SDCC revs; they are not z88dk edits.

Optional parity with older patches: first vector may keep // Stack options comment.

2. User-facing version string (src/SDCCmain.c printVersionInfo)

Replace stock “SDCC : port/port …” banner with z88dk identity, for example:

ZSDCC IS A MODIFICATION OF SDCC FOR Z88DK
Build: <SDCC_VERSION_STR> #<build> (env) <date>
sdcc website: https://sourceforge.net/projects/sdcc/
patch details: https://github.com/z88dk/z88dk/blob/master/src/zsdcc/sdcc-z88dk.patch

#<build> comes from SDCC’s build-number machinery (see ChangeLog below).

3. ChangeLog $Revision$ — fix the reported build number

Important: SDCC’s svn tree does not update ChangeLog’s $Revision: … $ keyword on every commit. The tag/checkout revision (e.g. 16639) often disagrees with the string at the end of ChangeLog (e.g. 16608).

version.awk / getBuildNumber() read that keyword → z88dk-zsdcc --version shows the wrong #NNNN unless the patch forces it.

Always add a ChangeLog hunk that sets:

$Revision: <SDCC_VERSION> $

to the same revision as Makefile SDCC_VERSION (the pin you actually build). Historical example: sdcc-14648-z88dk.patch header. If svn diff ignores the keyword edit, hand-write the unified hunk (keyword expansion can hide the change from svn status).

4. z88dk intrinsic / special call awareness (src/z80/peep.c)

Stock peep does not know z88dk helper register contracts. The patch inserts special_funcs[][3]:

Column	Meaning
[0]	Exact asm call text, e.g. "call\t____sdcc_ll_…"
[1]	Input regs used as parms (dehl, bcdehl, …)
[2]	Regs preserved across the call

Hooks in z80MightBeParmInCallFromCurrentFunction / destroy/preserve helpers so peep does not break around:

• ____sdcc_ll_* — long long load/store/shift/add/sub helpers
• ____sdcc_4_* / ____sdcc_2_* — 32/16-bit mem helpers
• ____sdcc_ldi*, ____sdcc_outi* — block move / I/O
• ____sdcc_cpu_push_di / ____sdcc_cpu_pop_ei
• ____sdcc_lib_setmem_hl, ____sdcc_load_*, ____sdcc_store_*

When regenerating: re-apply the whole table; only extend it when new z88dk runtime helpers appear. Upstream may rename ISINST → lineIsInst — attach hooks to the current API, do not resurrect old macro names blindly.

5. Other required hunks (carry forward)

File	Change
src/SDCCasm.c	Temp labels l%N_%05d$; extern → .globl
src/SDCCglue.c	Emit/track externs; skip !ds for pure externs
src/SDCCopt.c	Builtin memcpy name _memcpy (not ___memcpy) — both call sites
src/z80/main.c	legacyBanking: port->stack.banked_overhead = 0 in _finaliseOptions
src/SDCCmain.c	c1-mode adb: if (options.debug && (fullSrcFileName || options.c1mode)) so --c1mode + debug still writes .adb

6. Optional / historical

Item	Note
sdas/linksrc/aslink.h elf(int i)	Fedora / GCC C23 fix (#2717). Already fixed in SDCC 4.6.0 (void elf(int i)). Re-check on new revs; only re-add if upstream regresses. Prefer this tiny prototype fix over forcing -std=c17 on the whole build.

Procedure (new pin)

# 1. Pin
#    Edit Makefile SDCC_VERSION=<rev>   # e.g. 16639

# 2. Clean tree
rm -rf src/sdcc-build
svn checkout -r <rev> https://svn.code.sf.net/p/sdcc/code/trunk/sdcc -q src/sdcc-build

# 3. Apply previous patch (may need fuzz/offsets)
patch -d src/sdcc-build -p0 < src/zsdcc/sdcc-z88dk.patch
# Fix rejects; ensure every component above is present.

# 4. Force ChangeLog revision string to <rev>
#    Edit last $Revision: … $ line → $Revision: <rev> $

# 5. Regenerate unified patch from clean base
cd src/sdcc-build
svn revert -R .   # if regenerating from edits; or diff working tree vs pristine
# Prefer: start from pristine checkout, re-apply all edits, then:
svn diff src/SDCCasm.c src/SDCCglue.c src/SDCCmain.c src/SDCCopt.c \
         src/z80/main.c src/z80/peep.c > /tmp/zsdcc-body.patch
# Hand-prepend ChangeLog hunk if svn omits keyword-only ChangeLog.
# Install:
cp /tmp/zsdcc-full.patch ../../src/zsdcc/sdcc-z88dk.patch
cp /tmp/zsdcc-full.patch ../../src/zsdcc/sdcc-<rev>-z88dk.patch

# 6. Round-trip
svn revert -R .
patch -p0 --dry-run < ../../src/zsdcc/sdcc-z88dk.patch   # must be clean
patch -p0 < ../../src/zsdcc/sdcc-z88dk.patch

# 7. Tarball for nightly / CI (from z88dk root; no .o/.a)
cd ../..
tar --exclude=.svn --exclude='*.o' --exclude='*.a' \
  -czf zsdcc_r<rev>_src.tar.gz src/sdcc-build
# Upload to nightly server; force-add only if packaging in git: git add -f zsdcc_r<rev>_src.tar.gz

# 8. Smoke
#    configure (same flags as Makefile BUILD_SDCC), make -j2
#    ./src/sdcc-build/src/sdcc --version   # expect #=<rev>
#    cp to bin/z88dk-zsdcc

Checklist before calling the upgrade done

• SDCC_VERSION == snapshot filename rev == ChangeLog $Revision$ == --version #NNNN
• All Z80-family ports: ABI field 0
• printVersionInfo z88dk banner + patch URL
• special_funcs table present; peep hooks compile
• legacyBanking overhead fix present
• c1-mode adb condition present
• SDCCasm / glue / opt memcpy hunks present
• patch -p0 clean on pristine checkout
• Tarball extracts to src/sdcc-build/ and configures
• changelog.txt + src/zsdcc/readme.md version lines updated

Pitfalls

1. Diff of old patch vs new patch looks like PORT vectors “changed” — usually context only; only ABI 1→0 is required.
2. Skipping ChangeLog → wrong #NNNN in CI reports and support mail.
3. Tarball full of .o after a local build → run make distclean / delete objects before packing.
4. Dropping legacyBanking or peep table when “regenerating from RC” — re-diff against last good sdcc-*-z88dk.patch net adds.
5. Untracked local .agents/ can block git merge master (master owns .agents/). Move or remove incomplete local trees first.

Related

• src/zsdcc/readme.md, root Makefile (BUILD_SDCC, BUILD_SDCC_HTTP)
• tool/zcc, library/newlib, lib/sdcc/
• Wiki: wiki/tools/Tool---zsdcc.md (keep baseline in sync)
• library-newlib, tool-zcc, wiki learning/Compilers.md