wcc/cgen: GAP-A.ptr global-array base — LEAQ name(SB) not (BP) (#11, both stages)

A global fixed array's .ptr (= &A[0]) must take the SB base, but cstage
emitted frame-relative LEAQ off(BP) for BOTH let- and def-global arrays
-> *A.ptr read frame garbage (0 instead of the element). cstage-SILENT;
wwstage def-global was a loud link-error. The .ptr read arm now gates
off==0 && (let_islet || def_isarraydef) -> LEAQ name(SB), reusing the
def-array index base predicate (cgen.c:4367, the #94/#231/#48 class).
Locals (off != 0) stay BP-relative -- the 14 toolchain backing-ptr sites
unaffected.

wwstage let-global was already correct; this adds the missing def-global
arm (cgenexpr.ww), converging cstage/wwstage byte-identical across all
three flavors (local / let-global / def-global) and closing a latent
cstage-only let-global cs!=ww divergence.

Byte-id 990-997 8/8 (corpus has no global .ptr); w6c/w6c_ww binaries move
(cgen changed). test/wcc/818 table-driven, build+run+byte-id per flavor.
This commit is contained in:
2026-06-08 17:39:45 +09:00
parent 1c87881bda
commit 267e81b89e
6 changed files with 300 additions and 10 deletions

View File

@@ -244,6 +244,7 @@ TESTS = $(BIN)/test_smoke $(BIN)/test_lex $(BIN)/test_parse $(BIN)/test_check \
$(BIN)/test_arr_tagged_elem \
$(BIN)/test_arr_infer_len \
$(BIN)/test_arr_cap_reject \
$(BIN)/test_arr_ptr_global \
$(BIN)/test_def_arr_infer_len \
$(BIN)/test_def_arr_len \
$(BIN)/test_slice_str_global_zero \
@@ -642,6 +643,12 @@ $(BIN)/test_arr_cap_reject: test/wcc/817_arr_cap_reject.c $(BIN)/ww \
$(LIB)/libwwrt.a | $(BIN)
$(CC) $(CFLAGS) -o $@ $<
$(BIN)/test_arr_ptr_global: test/wcc/818_arr_ptr_global.c $(BIN)/ww \
$(BIN)/w6c $(BIN)/w6a $(BIN)/w6l \
$(BIN)/ww_ww $(BIN)/w6c_ww $(BIN)/w6a_ww $(BIN)/w6l_ww \
$(LIB)/libwwrt.a | $(BIN)
$(CC) $(CFLAGS) -o $@ $<
$(BIN)/test_def_arr_infer_len: test/wcc/814_def_arr_infer_len.c $(BIN)/ww \
$(BIN)/w6c $(BIN)/w6a $(BIN)/w6l \
$(BIN)/ww_ww $(BIN)/w6c_ww $(BIN)/w6a_ww $(BIN)/w6l_ww \

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@@ -11123,7 +11123,21 @@ cgexpr(Cg *c, Node *n, Local *locals)
break;
}
if (ptrfld) {
ins2(c, A_LEAQ, amem(D_BP, off), areg(D_AX));
/* The array's backing pointer = address of its
* element 0 (array.ptr ≡ &A[0], drew #13). A LOCAL
* array IS its frame slot — LEAQ off(BP). A module
* GLOBAL (let or def array) lives at name(SB): off==0
* here would LEAQ the frame's first slot = garbage
* (*p→0), the GAP-A.ptr silent miscompile. Same
* off==0/global base-selection as the def-array index
* base (cgen.c:4367) and #231/#48. */
if (off == 0 && (let_islet(n->lhs->str)
|| def_isarraydef(n->lhs->str)))
ins2(c, A_LEAQ, masym(c, n->lhs->str),
areg(D_AX));
else
ins2(c, A_LEAQ, amem(D_BP, off),
areg(D_AX));
break;
}
}

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@@ -24981,11 +24981,24 @@ fn cgdot(c: *cgen, n: *node) void = {
// SB fallback → MOVQ len(SB) (w6l: undefined 'len'). cstage cgen.c
// emits MOVQ $alen here. defvartnode is the def-side mirror of
// letvartnode (returns dtnode = the N_TARRAY whose .rhs length child
// is #11-stamped). `.ptr`/`.cap` are NOT mirrored: cstage's def .ptr
// is itself buggy (LEAQ (BP), task GAP-A.ptr) and arrays have no
// .cap (cstage rejects, task GAP-A.cap).
// is #11-stamped). `.ptr` mirrors the let-global arm above: the
// array's backing pointer ≡ &A[0] = LEAQ name(SB) (drew #13,
// .ai/drew-gapa-ptr-ruling.md; GAP-A.ptr now fixed cstage-side too,
// so both stages byte-id). `.cap` stays unmirrored — arrays have no
// .cap (both checkers reject, task GAP-A.cap).
if (lhs != nil) {
if (lhs.kind == nkind.N_IDENT) {
if (streq(fld, "ptr")) {
let dtn: *node = defvartnode(c, lhs.str);
if (dtn != nil) {
if (dtn.kind == nkind.N_TARRAY) {
emitline("\tLEAQ\t");
emitsymname(c, lhs.str);
emitline("(SB), AX\n");
return;
};
};
};
if (streq(fld, "len")) {
let dtn: *node = defvartnode(c, lhs.str);
if (dtn != nil) {

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@@ -3461,11 +3461,24 @@ fn cgdot(c: *cgen, n: *node) void = {
// SB fallback → MOVQ len(SB) (w6l: undefined 'len'). cstage cgen.c
// emits MOVQ $alen here. defvartnode is the def-side mirror of
// letvartnode (returns dtnode = the N_TARRAY whose .rhs length child
// is #11-stamped). `.ptr`/`.cap` are NOT mirrored: cstage's def .ptr
// is itself buggy (LEAQ (BP), task GAP-A.ptr) and arrays have no
// .cap (cstage rejects, task GAP-A.cap).
// is #11-stamped). `.ptr` mirrors the let-global arm above: the
// array's backing pointer ≡ &A[0] = LEAQ name(SB) (drew #13,
// .ai/drew-gapa-ptr-ruling.md; GAP-A.ptr now fixed cstage-side too,
// so both stages byte-id). `.cap` stays unmirrored — arrays have no
// .cap (both checkers reject, task GAP-A.cap).
if (lhs != nil) {
if (lhs.kind == nkind.N_IDENT) {
if (streq(fld, "ptr")) {
let dtn: *node = defvartnode(c, lhs.str);
if (dtn != nil) {
if (dtn.kind == nkind.N_TARRAY) {
emitline("\tLEAQ\t");
emitsymname(c, lhs.str);
emitline("(SB), AX\n");
return;
};
};
};
if (streq(fld, "len")) {
let dtn: *node = defvartnode(c, lhs.str);
if (dtn != nil) {

View File

@@ -24981,11 +24981,24 @@ fn cgdot(c: *cgen, n: *node) void = {
// SB fallback → MOVQ len(SB) (w6l: undefined 'len'). cstage cgen.c
// emits MOVQ $alen here. defvartnode is the def-side mirror of
// letvartnode (returns dtnode = the N_TARRAY whose .rhs length child
// is #11-stamped). `.ptr`/`.cap` are NOT mirrored: cstage's def .ptr
// is itself buggy (LEAQ (BP), task GAP-A.ptr) and arrays have no
// .cap (cstage rejects, task GAP-A.cap).
// is #11-stamped). `.ptr` mirrors the let-global arm above: the
// array's backing pointer ≡ &A[0] = LEAQ name(SB) (drew #13,
// .ai/drew-gapa-ptr-ruling.md; GAP-A.ptr now fixed cstage-side too,
// so both stages byte-id). `.cap` stays unmirrored — arrays have no
// .cap (both checkers reject, task GAP-A.cap).
if (lhs != nil) {
if (lhs.kind == nkind.N_IDENT) {
if (streq(fld, "ptr")) {
let dtn: *node = defvartnode(c, lhs.str);
if (dtn != nil) {
if (dtn.kind == nkind.N_TARRAY) {
emitline("\tLEAQ\t");
emitsymname(c, lhs.str);
emitline("(SB), AX\n");
return;
};
};
};
if (streq(fld, "len")) {
let dtn: *node = defvartnode(c, lhs.str);
if (dtn != nil) {

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@@ -0,0 +1,230 @@
/*
* 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 <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <unistd.h>
#include <sys/stat.h>
#include <sys/wait.h>
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 src[64], tmpdir[64], cmd[1024];
snprintf(src, sizeof src, "/tmp/apg_%d_%d.ww", getpid(), i);
snprintf(tmpdir, sizeof tmpdir, "/tmp/apg_%d_d_%d", getpid(), i);
FILE *f = fopen(src, "wb");
if (!f) return -1;
fputs(r->src, f);
fclose(f);
mkdir(tmpdir, 0755);
snprintf(cmd, sizeof cmd, "cd %s && %s build %s 2>/dev/null",
tmpdir, driver, src);
if (runwait(cmd) != 0) {
fprintf(stderr, "row[%s]: build via %s failed\n",
r->label, driver);
unlink(src); rmdir(tmpdir);
return -1;
}
const char *base = strrchr(src, '/');
base = base ? base + 1 : src;
char outbin[128];
snprintf(outbin, sizeof outbin, "%s/%s", tmpdir, base);
char *dot = strrchr(outbin, '.');
if (dot && strcmp(dot, ".ww") == 0) *dot = '\0';
int got = runwait(outbin);
unlink(src); unlink(outbin); rmdir(tmpdir);
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;
}