boot2

commit 0fd2a385eff1429fab658443cb8c57f015cc3b1f
parent 4e861efba1981b1b0be51750f604825520dceff1
Author: Ryan Sepassi <rsepassi@gmail.com>
Date:   Sun, 26 Apr 2026 22:26:42 -0700

cc tests: switch / case / default with fall-through (§F.3)

Validates the existing swctx machinery: cg-switch-begin spills the
controlling expression, cg-switch-case + cg-switch-default record
labels, and cg-switch-end emits the dispatch table at the bottom.
Fall-through is the natural default since cases emit no break.

Diffstat:
A
tests/cc-cg/64-switch.expected-exit
 | 
1
+
A
tests/cc-cg/64-switch.scm
 | 
73
+++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
A
tests/cc-parse/65-switch.c
 | 
13
+++++++++++++
A
tests/cc-parse/65-switch.expected-exit
 | 
1
+

4 files changed, 88 insertions(+), 0 deletions(-)
diff --git a/tests/cc-cg/64-switch.expected-exit b/tests/cc-cg/64-switch.expected-exit
@@ -0,0 +1 @@
+9
diff --git a/tests/cc-cg/64-switch.scm b/tests/cc-cg/64-switch.scm
@@ -0,0 +1,73 @@
+;; tests/cc-cg/64-switch.scm — switch with case + default + fall-through (§F.3).
+;; Models:
+;;   int main(void) {
+;;       int x = 2; int s = 0;
+;;       switch (x) {
+;;           case 1: s = s + 1;          /* fall through */
+;;           case 2: s = s + 10;         /* fall through */
+;;           case 3: s = s + 100;        /* fall through */
+;;           default: s = s + 1000;
+;;       }
+;;       return s;  /* x=2 -> 10 + 100 + 1000 = 1110, but exit code low byte = 86 */
+;;   }
+;; To stay within exit-code range we rewrite to small contributions and
+;; pick x=2 hitting case 2 + 3 + default = 7. Final exit = 7.
+;;
+;; Body sketch (small ints only):
+;;   x=2; s=0;
+;;   case 1: s+=1   (skipped, x=2)
+;;   case 2: s+=2   (taken)
+;;   case 3: s+=3   (fall-through)
+;;   default: s+=4  (fall-through)
+;; Result: 2 + 3 + 4 = 9
+;; Exit = 9.
+
+(let* ((cg     (cg-init))
+       (params (cg-fn-begin cg "main" '() %t-i32))
+       (x-sl   (cg-alloc-slot cg 4 4))
+       (s-sl   (cg-alloc-slot cg 4 4))
+       (x-sym  (%sym "x" 'var 'auto %t-i32 x-sl))
+       (s-sym  (%sym "s" 'var 'auto %t-i32 s-sl)))
+  ;; x = 2; s = 0;
+  (cg-push-sym cg x-sym) (cg-push-imm cg %t-i32 2)
+  (cg-assign cg) (cg-pop cg)
+  (cg-push-sym cg s-sym) (cg-push-imm cg %t-i32 0)
+  (cg-assign cg) (cg-pop cg)
+
+  ;; switch (x) { ... }
+  (cg-push-sym cg x-sym) (cg-load cg)
+  (let ((sw (cg-switch-begin cg)))
+    ;; case 1: s = s + 1;
+    (cg-switch-case cg sw 1)
+    (cg-push-sym cg s-sym)
+    (cg-push-sym cg s-sym) (cg-load cg)
+    (cg-push-imm cg %t-i32 1)
+    (cg-binop cg 'add)
+    (cg-assign cg) (cg-pop cg)
+    ;; case 2: s = s + 2;
+    (cg-switch-case cg sw 2)
+    (cg-push-sym cg s-sym)
+    (cg-push-sym cg s-sym) (cg-load cg)
+    (cg-push-imm cg %t-i32 2)
+    (cg-binop cg 'add)
+    (cg-assign cg) (cg-pop cg)
+    ;; case 3: s = s + 3;
+    (cg-switch-case cg sw 3)
+    (cg-push-sym cg s-sym)
+    (cg-push-sym cg s-sym) (cg-load cg)
+    (cg-push-imm cg %t-i32 3)
+    (cg-binop cg 'add)
+    (cg-assign cg) (cg-pop cg)
+    ;; default: s = s + 4;
+    (cg-switch-default cg sw)
+    (cg-push-sym cg s-sym)
+    (cg-push-sym cg s-sym) (cg-load cg)
+    (cg-push-imm cg %t-i32 4)
+    (cg-binop cg 'add)
+    (cg-assign cg) (cg-pop cg)
+    (cg-switch-end cg sw))
+
+  (cg-push-sym cg s-sym) (cg-load cg)
+  (cg-return cg)
+  (cg-fn-end cg)
+  (write-bv-fd 1 (cg-finish cg)))
diff --git a/tests/cc-parse/65-switch.c b/tests/cc-parse/65-switch.c
@@ -0,0 +1,13 @@
+int main(void) {
+    int x; int s;
+    x = 2;
+    s = 0;
+    switch (x) {
+        case 1: s = s + 1;
+        case 2: s = s + 2;
+        case 3: s = s + 3;
+        default: s = s + 4;
+    }
+    /* x = 2 hits case 2; falls through case 3 + default; s = 2+3+4 = 9 */
+    return s;
+}
diff --git a/tests/cc-parse/65-switch.expected-exit b/tests/cc-parse/65-switch.expected-exit
@@ -0,0 +1 @@
+9