Motiejus
b3cf6644a7
Add source_dir to Sema for resolving relative imports. When a field_call cannot find its callee locally, attempt cross-module resolution: extract import path from the declaration's value body, load and parse the imported file, generate its ZIR, and find the target function. Also add comptime tracker, comptime handlers (zirTypeof, zirTypeInfoComptime, zirFieldValComptime), explicit handlers for RET_TYPE (with TYPE_NONE guard) and SAVE_ERR_RET_INDEX (void mapping), and source_dir wiring in stages_test.zig. neghf2.zig still needs comptime @Type/reify + struct_init support. Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>
About
zig0 aspires to be an interpreter of zig 0.15.2 written in C.
This is written with help from LLM:
- Lexer:
- Datastructures 100% human.
- Helper functions 100% human.
- Lexing functions 50/50 human/bot.
- Parser:
- Datastructures 100% human.
- Helper functions 50/50.
- Parser functions 5/95 human/bot.
- AstGen: TBD.
Testing
Quick test:
./zig-out/bin/zig build fmt-zig0 test-zig0
Full test and static analysis with all supported compilers and valgrind (run before commit, takes a while):
./zig-out/bin/zig build all-zig0 -Dvalgrind
Debugging tips
Test runs infinitely? Build the test program executable:
$ ./zig-out/bin/zig build test-zig0 -Dzig0-no-exec
And then run it, capturing the stack trace:
gdb -batch \
-ex "python import threading; threading.Timer(1.0, lambda: gdb.post_event(lambda: gdb.execute('interrupt'))).start()" \
-ex run \
-ex "bt full" \
-ex quit \
zig-out/bin/test
You are welcome to replace -ex "bt full" with anything other of interest.
Float handling
Float literals are parsed with strtold() (C11 standard, portable). On
x86-64 Linux, long double is 80-bit extended precision (63 fraction bits).
When a float doesn't round-trip through f64, it's emitted as f128 (ZIR
float128 instruction). The 80-bit extended value is converted to IEEE 754
binary128 encoding by bit manipulation — both formats share the same 15-bit
exponent with bias 16383. The top 63 of binary128's 112 fraction bits come
from the 80-bit value; the bottom 49 are zero-padded.
This means float128 literals lose ~49 bits of precision compared to the
upstream Zig implementation (which uses native f128). This is acceptable
because stage0 is a bootstrap tool — the real Zig compiler re-parses all
source with full f128 precision in later stages. The test comparison mask
in astgen_test.zig skips float128 payloads to account for this.
Previous approach used __float128/strtof128 (GCC/glibc extensions) for
full precision, but these are not portable to TCC and other C11 compilers.
Rebuilding zig
If you need to rebuild zig-out/bin/zig for some reason, here's how:
~/code/zig-bootstrap/out-0.15.2/zig-x86_64-linux-musl-x86_64_v3/zig build \
--zig-lib-dir lib/ -Dtarget=x86_64-linux-musl -Dcpu=x86_64_v3 \
-Dstatic-llvm --search-prefix \
$HOME/code/zig-bootstrap/out-0.15.2/x86_64-linux-musl-x86_64_v3/ \
-Ddebug-extensions=true -Dlog=false -Doptimize=ReleaseSafe