Support multiple declarators in struct member decl

This commit allows struct members to be declared with multiple variables
on the same line, matching standard C syntax. For example:

    struct node {
        struct node *next, *prev;  // Now supported
        int value;
    };

The fix handles comma-separated declarators by parsing additional
variables after the first one, inheriting the base type while parsing
pointer levels and array dimensions independently for each declarator.

Author: jserv

lib/c.c

@@ -576,8 +576,7 @@ int fputc(int c, FILE *stream)
 #define IS_CHUNK_GET_FREED(size) (size & CHUNK_SIZE_FREED_MASK)
 
 typedef struct chunk {
-    struct chunk *next;
-    struct chunk *prev;
+    struct chunk *next, *prev;
     int size;
 } chunk_t;
 

src/defs.h

@@ -266,8 +266,7 @@ typedef struct {
 typedef struct ref_block ref_block_t;
 
 struct ref_block_list {
-    ref_block_t *head;
-    ref_block_t *tail;
+    ref_block_t *head, *tail;
 };
 
 typedef struct ref_block_list ref_block_list_t;
@@ -276,8 +275,7 @@ typedef struct insn insn_t;
 
 typedef struct use_chain_node {
     insn_t *insn;
-    struct use_chain_node *next;
-    struct use_chain_node *prev;
+    struct use_chain_node *next, *prev;
 } use_chain_t;
 
 typedef struct var var_t;
@@ -306,8 +304,7 @@ struct var {
     int subscripts_idx;
     rename_t rename;
     ref_block_list_t ref_block_list; /* blocks which kill variable */
-    use_chain_t *users_head;
-    use_chain_t *users_tail;
+    use_chain_t *users_head, *users_tail;
     struct insn *last_assign;
     int consumed;
     bool is_ternary_ret;
@@ -408,8 +405,7 @@ struct phi_operand {
 typedef struct phi_operand phi_operand_t;
 
 struct insn {
-    struct insn *next;
-    struct insn *prev;
+    struct insn *next, *prev;
     int idx;
     opcode_t opcode;
     var_t *rd;
@@ -423,13 +419,11 @@ struct insn {
 };
 
 typedef struct {
-    insn_t *head;
-    insn_t *tail;
+    insn_t *head, *tail;
 } insn_list_t;
 
 typedef struct {
-    ph2_ir_t *head;
-    ph2_ir_t *tail;
+    ph2_ir_t *head, *tail;
 } ph2_ir_list_t;
 
 typedef enum { NEXT, ELSE, THEN } bb_connection_type_t;
@@ -448,8 +442,7 @@ struct symbol {
 typedef struct symbol symbol_t;
 
 typedef struct {
-    symbol_t *head;
-    symbol_t *tail;
+    symbol_t *head, *tail;
 } symbol_list_t;
 
 struct basic_block {
@@ -519,8 +512,7 @@ struct func {
 };
 
 typedef struct {
-    func_t *head;
-    func_t *tail;
+    func_t *head, *tail;
 } func_list_t;
 
 typedef struct {

src/parser.c

@@ -2870,6 +2870,31 @@ void read_global_statement(void)
             read_full_var_decl(v, 0, 1);
             v->offset = size;
             size += size_var(v);
+
+            /* Handle multiple variable declarations with same base type */
+            while (lex_accept(T_comma)) {
+                if (i >= MAX_FIELDS)
+                    error("Too many struct fields");
+
+                var_t *nv = &type->fields[i++];
+                nv->type = v->type;
+                nv->var_name[0] = '\0';
+                nv->is_ptr = 0;
+                nv->is_func = false;
+                nv->is_global = false;
+                nv->array_size = 0;
+                nv->offset = 0;
+                nv->init_val = 0;
+                nv->liveness = 0;
+                nv->in_loop = 0;
+                nv->base = NULL;
+                nv->subscript = 0;
+                nv->subscripts_idx = 0;
+                read_inner_var_decl(nv, 0, 1);
+                nv->offset = size;
+                size += size_var(nv);
+            }
+
             lex_expect(T_semicolon);
         } while (!lex_accept(T_close_curly));
 
@@ -2922,6 +2947,32 @@ void read_global_statement(void)
                     read_full_var_decl(v, 0, 1);
                     v->offset = size;
                     size += size_var(v);
+
+                    /* Handle multiple variable declarations with same base type
+                     */
+                    while (lex_accept(T_comma)) {
+                        if (i >= MAX_FIELDS)
+                            error("Too many struct fields");
+
+                        var_t *nv = &type->fields[i++];
+                        nv->type = v->type;
+                        nv->var_name[0] = '\0';
+                        nv->is_ptr = 0;
+                        nv->is_func = false;
+                        nv->is_global = false;
+                        nv->array_size = 0;
+                        nv->offset = 0;
+                        nv->init_val = 0;
+                        nv->liveness = 0;
+                        nv->in_loop = 0;
+                        nv->base = NULL;
+                        nv->subscript = 0;
+                        nv->subscripts_idx = 0;
+                        read_inner_var_decl(nv, 0, 1);
+                        nv->offset = size;
+                        size += size_var(nv);
+                    }
+
                     lex_expect(T_semicolon);
                 } while (!lex_accept(T_close_curly));
             }

tests/driver.sh

@@ -423,6 +423,20 @@ int main() {
 }
 EOF
 
+# struct with multiple pointer declarations in same line
+try_ 42 << EOF
+typedef struct chunk {
+    struct chunk *next, *prev;
+    int size;
+} chunk_t;
+
+int main() {
+    chunk_t c;
+    c.size = 42;
+    return c.size;
+}
+EOF
+
 # arrays
 try_ 12 << EOF
 int nth_of(int *a, int i) {