Merge pull request sysprog21#176 from ChAoSUnItY/refactor/reduce-blocks-alloc

Replace fixed size blocks with linked list

Author: jserv

src/defs.h

@@ -21,7 +21,6 @@
 #define MAX_FIELDS 64
 #define MAX_FUNCS 512
 #define MAX_FUNC_TRIES 2160
-#define MAX_BLOCKS 2048
 #define MAX_TYPES 64
 #define MAX_IR_INSTR 50000
 #define MAX_BB_PRED 128
@@ -227,11 +226,16 @@ struct block {
     func_t *func;
     macro_t *macro;
     int locals_size;
-    int index;
+    struct block *next;
 };
 
 typedef struct block block_t;
 
+typedef struct {
+    block_t *head;
+    block_t *tail;
+} block_list_t;
+
 /* phase-1 IR definition */
 typedef struct {
     opcode_t op;

src/globals.c

@@ -7,8 +7,7 @@
 
 /* Global objects */
 
-block_t *BLOCKS;
-int blocks_idx = 0;
+block_list_t BLOCKS;
 
 macro_t *MACROS;
 int macros_idx = 0;
@@ -226,8 +225,16 @@ int find_label_offset(char name[])
 
 block_t *add_block(block_t *parent, func_t *func, macro_t *macro)
 {
-    block_t *blk = &BLOCKS[blocks_idx];
-    blk->index = blocks_idx++;
+    block_t *blk = malloc(sizeof(block_t));
+
+    if (!BLOCKS.head) {
+        BLOCKS.head = blk;
+        BLOCKS.tail = BLOCKS.head;
+    } else {
+        BLOCKS.tail->next = blk;
+        BLOCKS.tail = blk;
+    }
+
     blk->parent = parent;
     blk->func = func;
     blk->macro = macro;
@@ -394,7 +401,7 @@ var_t *find_local_var(char *token, block_t *block)
 
 var_t *find_global_var(char *token)
 {
-    block_t *block = &BLOCKS[0];
+    block_t *block = BLOCKS.head;
 
     for (int i = 0; i < block->next_local; i++) {
         if (!strcmp(block->locals[i].var_name, token))
@@ -587,7 +594,8 @@ void global_init()
 {
     elf_code_start = ELF_START + elf_header_len;
 
-    BLOCKS = malloc(MAX_BLOCKS * sizeof(block_t));
+    BLOCKS.head = NULL;
+    BLOCKS.tail = NULL;
     MACROS = malloc(MAX_ALIASES * sizeof(macro_t));
     FUNCS = malloc(MAX_FUNCS * sizeof(func_t));
     FUNC_TRIES = malloc(MAX_FUNC_TRIES * sizeof(trie_t));
@@ -613,7 +621,11 @@ void global_init()
 
 void global_release()
 {
-    free(BLOCKS);
+    while (BLOCKS.head) {
+        block_t *next = BLOCKS.head->next;
+        free(BLOCKS.head);
+        BLOCKS.head = next;
+    }
     free(MACROS);
     free(FUNCS);
     free(FUNC_TRIES);

src/parser.c

@@ -2153,7 +2153,7 @@ bool read_global_assignment(char *token)
 {
     ph1_ir_t *ph1_ir;
     var_t *vd;
-    block_t *parent = &BLOCKS[0];
+    block_t *parent = BLOCKS.head;
 
     /* global initialization must be constant */
     var_t *var = find_global_var(token);
@@ -3182,7 +3182,7 @@ void read_global_decl(block_t *block)
 void read_global_statement()
 {
     char token[MAX_ID_LEN];
-    block_t *block = &BLOCKS[0]; /* global block */
+    block_t *block = BLOCKS.head; /* global block */
 
     if (lex_accept(T_struct)) {
         int i = 0, size = 0;