/* * 818_arr_ptr_global — `.ptr` on a fixed-size array is the sanctioned ww * spelling for &A[0] (task #13 divergence-record, drew ruling * .ai/drew-gapa-ptr-ruling.md). For a LOCAL array the backing pointer is the * frame slot (LEAQ off(BP)); for a module GLOBAL array (let or def) it is the * symbol address (LEAQ name(SB)). cstage cgen emitted LEAQ off(BP) for BOTH * flavours — and for a global, off==0, so `*A.ptr` read the frame's first * slot = stack garbage (the GAP-A.ptr silent miscompile, task #11; the * off==0/global base-selection class of #231/#48). * * The fix (cmd/w6c/cgen.c N_DOT array .ptr arm + selfhost cgenexpr.ww def * arm): when off==0 and the operand is a module global (let_islet || * def_isarraydef), emit LEAQ name(SB) instead of LEAQ (BP), mirroring the * def-array index base at cgen.c:4367. wwstage's LET-global `.ptr` was * already correct (LEAQ name(SB)); only the DEF-global arm was missing. * After this commit local / let-global / def-global `.ptr` are byte- * IDENTICAL across both stages. * * row | shape | want * -----------------+-----------------------------------------+------ * def_glob_ptr | def A:[3]int, *A.ptr (THE regression) | 10 * let_glob_ptr | let G:[3]int, *G.ptr (BP→SB converge) | 5 * local_ptr | local [3]int, (a.ptr)[2] (unchanged) | 3 * * def_glob_ptr / let_glob_ptr are the mutation-sane rows: pre-fix they read * stack garbage. local_ptr guards the 14 live local-`.ptr` consumers (cgen * unchanged for locals). A byte-id row pins cstage==wwstage `.s` for the * def-global `.ptr` source (the convergence the fix delivers). */ #include #include #include #include #include static int runwait(const char *cmd) { int rc = system(cmd); if (rc == -1) return -1; if (WIFEXITED(rc)) return WEXITSTATUS(rc); return -1; } struct row { const char *label; const char *src; int want; }; static const struct row rows[] = { /* def_glob_ptr — THE regression pin: pre-fix `*A.ptr` reads stack * garbage because cstage LEAQ (BP)'d the def-global base. */ { "def_glob_ptr", "package main;\n" "def A: [3]int = [10, 20, 30];\n" "export fn main() i32 = {\n" "\tlet p: *int = A.ptr;\n" "\treturn (*p): i32;\n" "};\n", 10 }, /* let_glob_ptr — pins the cstage BP→SB convergence (wwstage was * already right for let-global, so this closes the latent cs≠ww). */ { "let_glob_ptr", "package main;\n" "let G: [3]int = [5, 6, 7];\n" "export fn main() i32 = {\n" "\tlet p: *int = G.ptr;\n" "\treturn (*p): i32;\n" "};\n", 5 }, /* local_ptr — the 14-site regression guard; cgen unchanged for a * LOCAL array (off!=0 → LEAQ off(BP)). p[2] strides element 2. */ { "local_ptr", "package main;\n" "export fn main() i32 = {\n" "\tlet a: [3]int = [1, 2, 3];\n" "\tlet p: *int = a.ptr;\n" "\treturn p[2]: i32;\n" "};\n", 3 }, }; static int run_driver(const char *driver, const struct row *r, int i) { char tmpdir[64], src[128], outbin[128], rmcmd[160], cmd[1024]; snprintf(tmpdir, sizeof tmpdir, "/tmp/apg_%d_d_%d", getpid(), i); mkdir(tmpdir, 0755); snprintf(src, sizeof src, "%s/apg_%d_%d.ww", tmpdir, getpid(), i); snprintf(outbin, sizeof outbin, "%s/apg_%d_%d", tmpdir, getpid(), i); snprintf(rmcmd, sizeof rmcmd, "rm -rf %s", tmpdir); FILE *f = fopen(src, "wb"); if (!f) { runwait(rmcmd); return -1; } fputs(r->src, f); fclose(f); snprintf(cmd, sizeof cmd, "%s build -o %s %s 2>/dev/null", driver, outbin, src); if (runwait(cmd) != 0) { fprintf(stderr, "row[%s]: build via %s failed\n", r->label, driver); runwait(rmcmd); return -1; } int got = runwait(outbin); runwait(rmcmd); return got; } /* asm_byte_identical — w6c vs w6c_ww .s for the same source must match. */ static int asm_byte_identical(const char *bin, const struct row *r, int i) { char src[64], cs[64], ws[64], cmd[1024]; snprintf(src, sizeof src, "/tmp/apg_asm_%d_%d.ww", getpid(), i); snprintf(cs, sizeof cs, "/tmp/apg_asm_%d_%d_c.s", getpid(), i); snprintf(ws, sizeof ws, "/tmp/apg_asm_%d_%d_w.s", getpid(), i); FILE *f = fopen(src, "wb"); if (!f) return -1; fputs(r->src, f); fclose(f); snprintf(cmd, sizeof cmd, "%s/w6c -o %s %s 2>/dev/null", bin, cs, src); if (runwait(cmd) != 0) { fprintf(stderr, "row[%s]: w6c errored\n", r->label); unlink(src); return -1; } snprintf(cmd, sizeof cmd, "%s/w6c_ww -o %s %s 2>/dev/null", bin, ws, src); if (runwait(cmd) != 0) { fprintf(stderr, "row[%s]: w6c_ww errored\n", r->label); unlink(src); unlink(cs); return -1; } FILE *fc = fopen(cs, "rb"); FILE *fw = fopen(ws, "rb"); int rc = 0; if (!fc || !fw) { rc = -1; } else { for (;;) { int a = fgetc(fc); int b = fgetc(fw); if (a != b) { rc = -1; break; } if (a == EOF) break; } } if (fc) fclose(fc); if (fw) fclose(fw); if (rc != 0) fprintf(stderr, "row[%s]: cstage vs wwstage asm differs\n", r->label); unlink(src); unlink(cs); unlink(ws); return rc; } int main(void) { const char *bin = getenv("BIN"); if (!bin) bin = "out/bin"; char absbin[1024]; if (bin[0] != '/') { char cwd[1024]; if (getcwd(cwd, sizeof cwd) == NULL) return 1; snprintf(absbin, sizeof absbin, "%s/%s", cwd, bin); bin = absbin; } char cdrv[1024]; snprintf(cdrv, sizeof cdrv, "%s/ww", bin); char wdrv[1024]; snprintf(wdrv, sizeof wdrv, "%s/ww_ww", bin); struct { const char *name; const char *path; int gated_on_existence; } drivers[] = { { "cstage", cdrv, 0 }, { "wwstage", wdrv, 1 }, { NULL, NULL, 0 }, }; int n = (int)(sizeof rows / sizeof rows[0]); int total = 0, fail = 0; for (int d = 0; drivers[d].name; d++) { if (drivers[d].gated_on_existence && access(drivers[d].path, X_OK) != 0) { fprintf(stderr, "arr_ptr_global: skip %s (no %s)\n", drivers[d].name, drivers[d].path); continue; } for (int i = 0; i < n; i++) { int got = run_driver(drivers[d].path, &rows[i], i); total++; if (got != rows[i].want) { fprintf(stderr, "arr_ptr_global[%s][%s]: exit=%d want=%d\n", drivers[d].name, rows[i].label, got, rows[i].want); fail++; } } } if (access(wdrv, X_OK) == 0) { for (int i = 0; i < n; i++) { total++; if (asm_byte_identical(bin, &rows[i], i) != 0) fail++; } } if (fail) { fprintf(stderr, "arr_ptr_global: %d/%d fixtures failed\n", fail, total); return 1; } printf("arr_ptr_global: %d/%d ok\n", total, total); return 0; }