proper handling of runtime errors

src/logging.c

@@ -130,7 +130,7 @@ u6a_err_bad_bc_ver(const char* stage, const char* filename, int ver_major, int v
 
 U6A_COLD void
 u6a_err_vm_pool_oom(const char* stage) {
-    fprintf(stderr, "%s: [%s] VM object pool memory exhausted.\n", stage, prog_name);
+    fprintf(stderr, "%s: [%s] VM object pool memory exhausted.\n", prog_name, stage);
 }
 
 U6A_COLD void

src/runtime.c

@@ -27,6 +27,7 @@
 #include <string.h>
 #include <inttypes.h>
 #include <arpa/inet.h>
+#include <setjmp.h>
 
 static struct u6a_vm_ins*      text;
 static        uint32_t         text_len;
@@ -35,6 +36,7 @@ static        uint32_t         rodata_len;
 static        bool             force_exec;
 static struct u6a_vm_stack_ctx stack_ctx;
 static struct u6a_vm_pool_ctx  pool_ctx;
+static        jmp_buf          jmp_ctx;
 
 static const struct u6a_vm_ins text_subst[] = {
     { .opcode = u6a_vo_la  },
@@ -181,10 +183,10 @@ u6a_runtime_init(struct u6a_runtime_options* options) {
     if (UNLIKELY(rodata_len != fread(rodata, sizeof(char), rodata_len, options->istream))) {
         goto runtime_init_failed;
     }
-    if (UNLIKELY(!u6a_vm_stack_init(&stack_ctx, options->stack_segment_size, err_runtime))) {
+    if (UNLIKELY(!u6a_vm_stack_init(&stack_ctx, options->stack_segment_size, &jmp_ctx, err_runtime))) {
         goto runtime_init_failed;
     }
-    if (UNLIKELY(!u6a_vm_pool_init(&pool_ctx, options->pool_size, text_len, err_runtime))) {
+    if (UNLIKELY(!u6a_vm_pool_init(&pool_ctx, options->pool_size, text_len, &jmp_ctx, err_runtime))) {
         goto runtime_init_failed;
     }
     stack_ctx.pool_ctx = &pool_ctx;
@@ -209,6 +211,9 @@ u6a_runtime_execute(FILE* restrict istream, FILE* restrict ostream) {
     int current_char = EOF;
     struct u6a_vm_var_tuple tuple;
     void* cont;
+    if (setjmp(jmp_ctx)) {
+        goto runtime_error;
+    }
     while (true) {
         switch (ins->opcode) {
             case u6a_vo_app:

src/vm_defs.h

@@ -110,4 +110,6 @@ struct u6a_vm_var_tuple {
 #define U6A_VM_MIN_POOL_SIZE                16
 #define U6A_VM_MAX_POOL_SIZE              ( 16 * 1024 * 1024 )
 
+#define U6A_VM_ERR(ctx)                     longjmp(*(ctx)->jmp_ctx, -1)
+
 #endif

src/vm_pool.c

@@ -24,7 +24,7 @@
 #include <stdlib.h>
 
 bool
-u6a_vm_pool_init(struct u6a_vm_pool_ctx* ctx, uint32_t pool_len, uint32_t ins_len, const char* err_stage) {
+u6a_vm_pool_init(struct u6a_vm_pool_ctx* ctx, uint32_t pool_len, uint32_t ins_len, jmp_buf* jmp_ctx, const char* err_stage) {
     const uint32_t pool_size = sizeof(struct u6a_vm_pool) + pool_len * sizeof(struct u6a_vm_pool_elem);
     ctx->active_pool = malloc(pool_size);
     if (UNLIKELY(ctx->active_pool == NULL)) {
@@ -49,6 +49,7 @@ u6a_vm_pool_init(struct u6a_vm_pool_ctx* ctx, uint32_t pool_len, uint32_t ins_le
     ctx->active_pool->pos = UINT32_MAX;
     ctx->holes->pos = UINT32_MAX;
     ctx->pool_len = pool_len;
+    ctx->jmp_ctx = jmp_ctx;
     ctx->err_stage = err_stage;
     return true;
 }

src/vm_pool.h

@@ -25,6 +25,7 @@
 
 #include <stdint.h>
 #include <stdbool.h>
+#include <setjmp.h>
 
 struct u6a_vm_pool_elem {
     struct u6a_vm_var_tuple values;
@@ -51,6 +52,7 @@ struct u6a_vm_pool_ctx {
     struct u6a_vm_stack_ctx*      stack_ctx;
     uint32_t                      pool_len;
     uint32_t                      fstack_top;
+    jmp_buf*                      jmp_ctx;
     const char*                   err_stage;
 };
 
@@ -88,7 +90,7 @@ u6a_vm_pool_elem_alloc_(struct u6a_vm_pool_ctx* ctx) {
     if (ctx->holes->pos == UINT32_MAX) {
         if (UNLIKELY(++pool->pos == ctx->pool_len)) {
             u6a_err_vm_pool_oom(ctx->err_stage);
-            return NULL;
+            U6A_VM_ERR(ctx);
         }
         new_elem = pool->elems + pool->pos;
     } else {
@@ -101,22 +103,16 @@ u6a_vm_pool_elem_alloc_(struct u6a_vm_pool_ctx* ctx) {
 static inline struct u6a_vm_pool_elem*
 u6a_vm_pool_elem_dup_(struct u6a_vm_pool_ctx* ctx, struct u6a_vm_pool_elem* elem) {
     struct u6a_vm_pool_elem* new_elem = u6a_vm_pool_elem_alloc_(ctx);
-    if (UNLIKELY(new_elem == NULL)) {
-        return NULL;
-    }
     *new_elem = *elem;
     return new_elem;
 }
 
 bool
-u6a_vm_pool_init(struct u6a_vm_pool_ctx* ctx, uint32_t pool_len, uint32_t ins_len, const char* err_stage);
+u6a_vm_pool_init(struct u6a_vm_pool_ctx* ctx, uint32_t pool_len, uint32_t ins_len, jmp_buf* jmp_ctx, const char* err_stage);
 
 static inline uint32_t
 u6a_vm_pool_alloc1(struct u6a_vm_pool_ctx* ctx, struct u6a_vm_var_fn v1) {
     struct u6a_vm_pool_elem* elem = u6a_vm_pool_elem_alloc_(ctx);
-    if (UNLIKELY(elem == NULL)) {
-        return UINT32_MAX;
-    }
     elem->values = (struct u6a_vm_var_tuple) { .v1.fn = v1, .v2.ptr = NULL };
     elem->flags = 0;
     return elem - ctx->active_pool->elems;
@@ -125,9 +121,6 @@ u6a_vm_pool_alloc1(struct u6a_vm_pool_ctx* ctx, struct u6a_vm_var_fn v1) {
 static inline uint32_t
 u6a_vm_pool_alloc2(struct u6a_vm_pool_ctx* ctx, struct u6a_vm_var_fn v1, struct u6a_vm_var_fn v2) {
     struct u6a_vm_pool_elem* elem = u6a_vm_pool_elem_alloc_(ctx);
-    if (UNLIKELY(elem == NULL)) {
-        return UINT32_MAX;
-    }
     elem->values = (struct u6a_vm_var_tuple) { .v1.fn = v1, .v2.fn = v2 };
     elem->flags = 0;
     return elem - ctx->active_pool->elems;
@@ -136,9 +129,6 @@ u6a_vm_pool_alloc2(struct u6a_vm_pool_ctx* ctx, struct u6a_vm_var_fn v1, struct
 static inline uint32_t
 u6a_vm_pool_alloc2_ptr(struct u6a_vm_pool_ctx* ctx, void* v1, void* v2) {
     struct u6a_vm_pool_elem* elem = u6a_vm_pool_elem_alloc_(ctx);
-    if (UNLIKELY(elem == NULL)) {
-        return UINT32_MAX;
-    }
     elem->values = (struct u6a_vm_var_tuple) { .v1.ptr = v1, .v2.ptr = v2 };
     elem->flags = U6A_VM_POOL_ELEM_HOLDS_PTR;
     return elem - ctx->active_pool->elems;

src/vm_stack.c

@@ -83,8 +83,9 @@ vm_stack_free(struct u6a_vm_stack_ctx* ctx, struct u6a_vm_stack* vs) {
 }
 
 bool
-u6a_vm_stack_init(struct u6a_vm_stack_ctx* ctx, uint32_t stack_seg_len, const char* err_stage) {
+u6a_vm_stack_init(struct u6a_vm_stack_ctx* ctx, uint32_t stack_seg_len, jmp_buf* jmp_ctx, const char* err_stage) {
     ctx->stack_seg_len = stack_seg_len;
+    ctx->jmp_ctx = jmp_ctx;
     ctx->err_stage = err_stage;
     ctx->active_stack = vm_stack_create(ctx, NULL, UINT32_MAX);
     return ctx->active_stack != NULL;
@@ -92,34 +93,32 @@ u6a_vm_stack_init(struct u6a_vm_stack_ctx* ctx, uint32_t stack_seg_len, const ch
 
 // Boilerplates below. If only we have C++ templates here... (macros just make things nastier)
 
-U6A_HOT bool
+U6A_HOT void
 u6a_vm_stack_push1_split_(struct u6a_vm_stack_ctx* ctx, struct u6a_vm_var_fn v0) {
     struct u6a_vm_stack* vs = ctx->active_stack;
     ctx->active_stack = vm_stack_create(ctx, vs, 0);
     if (UNLIKELY(ctx->active_stack == NULL)) {
         ctx->active_stack = vs;
-        return false;
+        U6A_VM_ERR(ctx);
     }
     ++vs->refcnt;
     ctx->active_stack->elems[0] = v0;
-    return true;
 }
 
-U6A_HOT bool
+U6A_HOT void
 u6a_vm_stack_push2_split_(struct u6a_vm_stack_ctx* ctx, struct u6a_vm_var_fn v0, struct u6a_vm_var_fn v1) {
     struct u6a_vm_stack* vs = ctx->active_stack;
     ctx->active_stack = vm_stack_create(ctx, vs, 1);
     if (UNLIKELY(ctx->active_stack == NULL)) {
         ctx->active_stack = vs;
-        return false;
+        U6A_VM_ERR(ctx);
     }
     ++vs->refcnt;
     ctx->active_stack->elems[0] = v0;
     ctx->active_stack->elems[1] = v1;
-    return true;
 }
 
-U6A_HOT bool
+U6A_HOT void
 u6a_vm_stack_push3_split_(struct u6a_vm_stack_ctx* ctx, struct u6a_vm_var_fn v0, struct u6a_vm_var_fn v1,
                           struct u6a_vm_var_fn v2)
 {
@@ -127,16 +126,15 @@ u6a_vm_stack_push3_split_(struct u6a_vm_stack_ctx* ctx, struct u6a_vm_var_fn v0,
     ctx->active_stack = vm_stack_create(ctx, vs, 2);
     if (UNLIKELY(ctx->active_stack == NULL)) {
         ctx->active_stack = vs;
-        return false;
+        U6A_VM_ERR(ctx);
     }
     ++vs->refcnt;
     ctx->active_stack->elems[0] = v0;
     ctx->active_stack->elems[1] = v1;
     ctx->active_stack->elems[2] = v2;
-    return true;
 }
 
-U6A_HOT bool
+U6A_HOT void
 u6a_vm_stack_push4_split_(struct u6a_vm_stack_ctx* ctx, struct u6a_vm_var_fn v0, struct u6a_vm_var_fn v1,
                           struct u6a_vm_var_fn v2, struct u6a_vm_var_fn v3)
 {
@@ -144,35 +142,33 @@ u6a_vm_stack_push4_split_(struct u6a_vm_stack_ctx* ctx, struct u6a_vm_var_fn v0,
     ctx->active_stack = vm_stack_create(ctx, vs, 3);
     if (UNLIKELY(ctx->active_stack == NULL)) {
         ctx->active_stack = vs;
-        return false;
+        U6A_VM_ERR(ctx);
     }
     ++vs->refcnt;
     ctx->active_stack->elems[0] = v0;
     ctx->active_stack->elems[1] = v1;
     ctx->active_stack->elems[2] = v2;
     ctx->active_stack->elems[3] = v3;
-    return true;
 }
 
-U6A_HOT bool
+U6A_HOT void
 u6a_vm_stack_pop_split_(struct u6a_vm_stack_ctx* ctx) {
     struct u6a_vm_stack* vs = ctx->active_stack;
     ctx->active_stack = vs->prev;
     if (UNLIKELY(ctx->active_stack == NULL)) {
         u6a_err_stack_underflow(ctx->err_stage);
         ctx->active_stack = vs;
-        return false;
+        U6A_VM_ERR(ctx);
     }
     if (--ctx->active_stack->refcnt > 0) {
         ctx->active_stack = vm_stack_dup(ctx, ctx->active_stack);
     }
     if (UNLIKELY(ctx->active_stack == NULL)) {
         ctx->active_stack = vs;
-        return false;
+        U6A_VM_ERR(ctx);
     }
     free(vs);
     --ctx->active_stack->top;
-    return true;
 }
 
 U6A_HOT struct u6a_vm_var_fn
@@ -183,12 +179,12 @@ u6a_vm_stack_xch_split_(struct u6a_vm_stack_ctx* ctx, struct u6a_vm_var_fn v0) {
     struct u6a_vm_stack* prev = vs->prev;
     if (UNLIKELY(prev == NULL)) {
         u6a_err_stack_underflow(ctx->err_stage);
-        return U6A_VM_VAR_FN_EMPTY;
+        U6A_VM_ERR(ctx);
     }
     if (--prev->refcnt > 0) {
         prev = vm_stack_dup(ctx, prev);
         if (UNLIKELY(prev == NULL)) {
-            return U6A_VM_VAR_FN_EMPTY;
+            U6A_VM_ERR(ctx);
         }
     }
     if (vs->top == 0) {

src/vm_stack.h

@@ -25,6 +25,7 @@
 
 #include <stdint.h>
 #include <stdbool.h>
+#include <setjmp.h>
 
 struct u6a_vm_stack {
     struct u6a_vm_stack* prev;
@@ -34,14 +35,15 @@ struct u6a_vm_stack {
 };
 
 struct u6a_vm_stack_ctx {
-    struct u6a_vm_stack* active_stack;
+    struct u6a_vm_stack*    active_stack;
-    uint32_t             stack_seg_len;
+    uint32_t                stack_seg_len;
-    struct u6a_vm_pool_ctx*  pool_ctx;
+    struct u6a_vm_pool_ctx* pool_ctx;
-    const char*          err_stage;
+    jmp_buf*                jmp_ctx;
+    const char*             err_stage;
 };
 
 bool
-u6a_vm_stack_init(struct u6a_vm_stack_ctx* ctx, uint32_t stack_seg_len, const char* err_stage);
+u6a_vm_stack_init(struct u6a_vm_stack_ctx* ctx, uint32_t stack_seg_len, jmp_buf* jmp_ctx, const char* err_stage);
 
 static inline struct u6a_vm_var_fn
 u6a_vm_stack_top(struct u6a_vm_stack_ctx* ctx) {
@@ -49,45 +51,45 @@ u6a_vm_stack_top(struct u6a_vm_stack_ctx* ctx) {
     if (UNLIKELY(vs->top == UINT32_MAX)) {
         vs = vs->prev;
         if (UNLIKELY(vs == NULL)) {
-            return U6A_VM_VAR_FN_EMPTY;
+            U6A_VM_ERR(ctx);
         }
         ctx->active_stack = vs;
     }
     return vs->elems[vs->top];
 }
 
-bool
+void
 u6a_vm_stack_push1_split_(struct u6a_vm_stack_ctx* ctx, struct u6a_vm_var_fn v0);
 
-static inline bool
+static inline void
 u6a_vm_stack_push1(struct u6a_vm_stack_ctx* ctx, struct u6a_vm_var_fn v0) {
     struct u6a_vm_stack* vs = ctx->active_stack;
     if (LIKELY(vs->top + 1 < ctx->stack_seg_len)) {
         vs->elems[++vs->top] = v0;
-        return true;
+    } else {
+        u6a_vm_stack_push1_split_(ctx, v0);
     }
-    return u6a_vm_stack_push1_split_(ctx, v0);
 }
 
-bool
+void
 u6a_vm_stack_push2_split_(struct u6a_vm_stack_ctx* ctx, struct u6a_vm_var_fn v0, struct u6a_vm_var_fn v1);
 
-static inline bool
+static inline void
 u6a_vm_stack_push2(struct u6a_vm_stack_ctx* ctx, struct u6a_vm_var_fn v0, struct u6a_vm_var_fn v1) {
     struct u6a_vm_stack* vs = ctx->active_stack;
     if (LIKELY(vs->top + 2 < ctx->stack_seg_len)) {
         vs->elems[++vs->top] = v0;
         vs->elems[++vs->top] = v1;
-        return true;
+    } else {
+        u6a_vm_stack_push2_split_(ctx, v0, v1);
     }
-    return u6a_vm_stack_push2_split_(ctx, v0, v1);
 }
 
-bool
+void
 u6a_vm_stack_push3_split_(struct u6a_vm_stack_ctx* ctx, struct u6a_vm_var_fn v0, struct u6a_vm_var_fn v1,
                           struct u6a_vm_var_fn v2);
 
-static inline bool
+static inline void
 u6a_vm_stack_push3(struct u6a_vm_stack_ctx* ctx, struct u6a_vm_var_fn v0, struct u6a_vm_var_fn v1,
                    struct u6a_vm_var_fn v2)
 {
@@ -96,16 +98,16 @@ u6a_vm_stack_push3(struct u6a_vm_stack_ctx* ctx, struct u6a_vm_var_fn v0, struct
         vs->elems[++vs->top] = v0;
         vs->elems[++vs->top] = v1;
         vs->elems[++vs->top] = v2;
-        return true;
+    } else {
+        return u6a_vm_stack_push3_split_(ctx, v0, v1, v2);
     }
-    return u6a_vm_stack_push3_split_(ctx, v0, v1, v2);
 }
 
-bool
+void
 u6a_vm_stack_push4_split_(struct u6a_vm_stack_ctx* ctx, struct u6a_vm_var_fn v0, struct u6a_vm_var_fn v1,
                           struct u6a_vm_var_fn v2, struct u6a_vm_var_fn v3);
 
-static inline bool
+static inline void
 u6a_vm_stack_push4(struct u6a_vm_stack_ctx* ctx, struct u6a_vm_var_fn v0, struct u6a_vm_var_fn v1,
                    struct u6a_vm_var_fn v2, struct u6a_vm_var_fn v3)
 {
@@ -115,21 +117,20 @@ u6a_vm_stack_push4(struct u6a_vm_stack_ctx* ctx, struct u6a_vm_var_fn v0, struct
         vs->elems[++vs->top] = v1;
         vs->elems[++vs->top] = v2;
         vs->elems[++vs->top] = v3;
-        return true;
+    } else {
+        u6a_vm_stack_push4_split_(ctx, v0, v1, v2, v3);
     }
-    return u6a_vm_stack_push4_split_(ctx, v0, v1, v2, v3);
 }
 
-bool
+void
 u6a_vm_stack_pop_split_(struct u6a_vm_stack_ctx* ctx);
 
-static inline bool
+static inline void
 u6a_vm_stack_pop(struct u6a_vm_stack_ctx* ctx) {
     struct u6a_vm_stack* vs = ctx->active_stack;
-    if (LIKELY(vs->top-- != UINT32_MAX)) {
+    if (UNLIKELY(vs->top-- == UINT32_MAX)) {
-        return true;
+        u6a_vm_stack_pop_split_(ctx);
     }
-    return u6a_vm_stack_pop_split_(ctx);
 }
 
 struct u6a_vm_var_fn