Finishes Phase E4. `process.exit` / `assert` now report the caller's location.
#caller_location + Source_Location:
- new `hash_caller_location` token (lexer) + a leaf `caller_location` AST node
(parser primary-expr; sema + lsp arms).
- `Source_Location :: struct { file; line; col; func }` in std.sx.
- expandCallDefaults rewrites a `#caller_location` param default to a marker
carrying the CALL site's span + source_file.
- lowerCallerLocation synthesizes the struct: file + line:col via
errors.SourceLoc.compute over the diagnostics file→source map, stamped with
the enclosing (caller) function name. inferExprType resolves it to
Source_Location. Explicitly forwarding a Source_Location through an inner
call preserves the outermost site.
namespaced default-param expansion (pre-existing crash): expandCallDefaults
bailed on field_access callees, so `mod.fn(args)` with an omitted defaulted
param passed too few args → LLVM "incorrect number of arguments". Now resolves
the namespace fd (by field / qualified name); method-on-value calls (where
`self` shifts the count) stay excluded. Prerequisite for process.exit/assert
(always called namespaced) taking `loc = #caller_location`.
comptime flush: interp.callForeign flushes the interpreter's buffered print
output before invoking any host symbol, so a comptime diagnostic emitted just
before a terminating `_exit` (process.exit at comptime) survives.
process.exit/assert take `loc: Source_Location = #caller_location`; assert
prints `ASSERTION FAILED at <file>:<line>: <msg>`. examples 250 (assert
file:line), 251 (caller-location + forwarding). The two ffi-objc *.ir
snapshots are regenerated — adding Source_Location to std.sx renumbers the
global string pool the type/field-name tables index (benign, identical IR).
Stdlib slice of Phase E4, plus the noreturn codegen fix that enables it.
noreturn codegen (the enabling bug): E1.4c made `noreturn` type-system-only;
this is its first backend consumer and it crashed LLVM verification. Fixed:
- lower.zig: a `-> noreturn` body lowers as statements ending in `unreachable`
(ensureTerminator emits unreachable; the two body-lowering sites no longer
treat the last expr as a `ret`).
- emit_llvm.zig: a `void`/`noreturn` call result stays unnamed (direct +
foreign call sites) — LLVM rejects a named void value.
- finishCatchHandler: a `noreturn` value-carrying catch body (which is not an
IR terminator) closes the handler with `unreachable` instead of feeding a
bad value into the merge phi. Shared by lowerCatch + lowerCatchOverChain.
is_comptime(): new nullary `.is_comptime` IR op (inst/print/interp/emit_llvm) —
interp evaluates true, emit_llvm emits constant false, so `if is_comptime()`
dead-codes out of compiled binaries. Recognized by name in
tryLowerReflectionCall + inferExprType (no std.sx decl, which would emit a
spurious `declare @is_comptime` into every module).
library/modules/log.sx: warn/info/debug/err — interpolate like print, write
`LEVEL: <msg>` to stderr. (`error` is reserved → the level is `log.err`.)
process.exit(code) -> noreturn + assert(cond, msg) in process.sx. `exit` is
POSIX `_exit(2)` (immediate, no cleanup; sx print is unbuffered so nothing is
lost), bound to "_exit" which also avoids a link-level clash with the sx `exit`
function's own name.
examples 248 (exit 0), 249 (exit 42), 250 (exit 1). #caller_location, the
comptime-exit diagnostic flush, and trace.print_interpreter_frames deferred to
E4.1b.
