Hojun-Cho
10de5a5e0e
wwstage cgdot lacked a TY_FN branch for module-qualified N_DOT
rvalues. `let p = mod1.ping` fell through to the MOVQ/LEAQ-narrow
fallback, loading 8 prologue bytes from the fn's first instruction
instead of taking its address. Cstage cgdot already handled this
case (wired during #9, f1440bf).
Mirror cstage: gate on fnretlookup(c, fld) before the localloadop
fallback; emit `LEAQ <module>.<name>(SB), AX` via emitfnname with
the hint from lhs.str.
Extend 706_fnlabel_mangle: pos.ww now stores mod1.ping/mod2.ping
into local fn-pointer slots and dispatches through them in addition
to the existing direct calls. Expected exit 56 → 112. Regression
shape: without the new branch, MOVQ leaf(SB) loads the prologue
bytes; indirect call jumps into garbage → SIGSEGV.
ww2 == ww3 == ww4 byte-identical at the new emit.
123 lines
3.8 KiB
C
123 lines
3.8 KiB
C
/*
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* 706_fnlabel_mangle — cgen mangles fn labels by module so two
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* modules can each `export fn ping` (and each define a private
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* `fn helper`) without colliding at link time.
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*
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* The fixture in test/wcc/data/fnlabelmangle/ pins all four
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* label-emit sites #9 / #12 touch:
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* mod{1,2}/mod{1,2}.ww
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* export fn ping = bareval + helper() + fpi();
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* fn helper — private, same-leaf across modules
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* fn fpi — `let h = helper; h();` pins LEAQ N_IDENT
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* pos.ww
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* let p1 = mod1.ping; let p2 = mod2.ping; // LEAQ N_DOT × 2
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* return mod1.ping() + mod2.ping() // CALL N_DOT × 2
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* + p1() + p2(); // through fn ptr
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*
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* mod1.ping = 3 + 11 + 11 = 25
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* mod2.ping = 5 + 13 + 13 = 31
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* total = 25 + 31 + 25 + 31 = 112
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*
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* Pre-#9 (cgen emitted bare `TEXT ping` for both modules' exports),
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* the linker collapsed both `ping` symbols and one dispatch landed
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* on the wrong body. The bare-IDENT helper / `let h = helper` call-
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* sites would also pick whichever module the lookup found first,
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* silently miscompiling fpi's intra-module call.
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*
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* Pre-#12 wwstage cgdot's `let p = mod.ping` fell through to the
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* MOVQ leaf(SB) module-qualified-value fallback, loading 8 bytes
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* of fn-prologue into AX; `p()` then jumped into mid-prologue
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* garbage. Cstage cgdot already had a TY_FN LEAQ branch from #9.
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*
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* Coverage notes:
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* - The skip rule's three remaining cases (@symbol / main / empty-
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* module) are not pinned by a dedicated row because every passing
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* run of `make test` already exercises them: the bootstrap and
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* stdlib pull through `@symbol("rt_syscall")` bindings (lib/fmt,
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* lib/log), every test program links a bare `main`, and the inline-
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* source tests (700, 701, ...) compile fixtures with no module
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* directive. A regression in any of those rules would cascade
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* across the suite, not show up here.
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*
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* Both stages run the positive case — cstage and wwstage cgen must
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* agree on the mangling rule for ww2/ww3/ww4 byte-identity to hold.
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*/
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#include <stdio.h>
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#include <stdlib.h>
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#include <string.h>
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#include <unistd.h>
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#include <sys/stat.h>
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#include <sys/wait.h>
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static int
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runwait(const char *cmd)
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{
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int rc = system(cmd);
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if (rc == -1) return -1;
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if (WIFEXITED(rc)) return WEXITSTATUS(rc);
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return -1;
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}
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static int
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run_pos(const char *driver, const char *fixdir, const char *tag)
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{
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char cmd[2048];
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snprintf(cmd, sizeof cmd,
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"cd %s && %s build pos.ww >/dev/null 2>&1", fixdir, driver);
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if (runwait(cmd) != 0) {
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fprintf(stderr,
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"fnlabel_mangle[%s]: pos.ww build failed\n", tag);
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return 1;
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}
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char bin[2048];
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snprintf(bin, sizeof bin, "%s/pos", fixdir);
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int got = runwait(bin);
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unlink(bin);
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if (got != 112) {
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fprintf(stderr,
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"fnlabel_mangle[%s]: pos.ww exit=%d want=112 — "
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"fn labels likely collapsed at link, or LEAQ-of-fn "
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"N_DOT branch missing in cgdot\n", tag, got);
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return 1;
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}
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return 0;
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}
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int
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main(void)
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{
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const char *bin = getenv("BIN");
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if (!bin) bin = "out/bin";
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char absbin[1024];
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if (bin[0] != '/') {
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char cwd[1024];
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if (getcwd(cwd, sizeof cwd) == NULL) return 1;
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snprintf(absbin, sizeof absbin, "%s/%s", cwd, bin);
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bin = absbin;
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}
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char cdrv[1024];
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snprintf(cdrv, sizeof cdrv, "%s/ww", bin);
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char wdrv[1024];
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snprintf(wdrv, sizeof wdrv, "%s/ww_ww", bin);
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char fixdir[1024];
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if (getcwd(fixdir, sizeof fixdir) == NULL) return 1;
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size_t cwd_n = strlen(fixdir);
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const char *rel = "/test/wcc/data/fnlabelmangle";
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if (cwd_n + strlen(rel) + 1 >= sizeof fixdir) return 1;
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memcpy(fixdir + cwd_n, rel, strlen(rel) + 1);
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int fail = 0;
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fail += run_pos(cdrv, fixdir, "cstage");
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fail += run_pos(wdrv, fixdir, "wwstage");
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if (fail) {
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fprintf(stderr,
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"fnlabel_mangle: %d case(s) failed\n", fail);
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return 1;
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}
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printf("fnlabel_mangle: 2/2 ok\n");
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return 0;
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}
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