diff --git a/src/defs.h b/src/defs.h
index 2c2d1350..bdbb3425 100644
--- a/src/defs.h
+++ b/src/defs.h
@@ -270,6 +270,17 @@ typedef struct {
 
 typedef struct basic_block basic_block_t;
 
+/* Definition of a dynamic array structure for sources in src/globals.c
+ * size:     Current number of elements in the array
+ * capacity: Number of elements that can be stored without resizing
+ * elements: Pointer to the array of characters
+ */
+typedef struct {
+    int size;
+    int capacity;
+    char *elements;
+} source_t;
+
 /* phase-2 IR definition */
 struct ph2_ir {
     opcode_t op;
diff --git a/src/globals.c b/src/globals.c
index a4a7e996..a4703517 100644
--- a/src/globals.c
+++ b/src/globals.c
@@ -56,8 +56,7 @@ int aliases_idx = 0;
 constant_t *CONSTANTS;
 int constants_idx = 0;
 
-char *SOURCE;
-int source_idx = 0;
+source_t *SOURCE;
 
 /* ELF sections */
 
@@ -837,6 +836,62 @@ void add_insn(block_t *block,
     bb->insn_list.tail = n;
 }
 
+source_t *create_source(int init_capacity)
+{
+    source_t *array = malloc(sizeof(source_t));
+    if (!array)
+        return NULL;
+
+    array->size = 0;
+    array->capacity = init_capacity;
+    array->elements = malloc(array->capacity * sizeof(char));
+    if (!array->elements) {
+        free(array);
+        return NULL;
+    }
+
+    return array;
+}
+
+bool source_expand(source_t *src)
+{
+    if (src->size < src->capacity)
+        return true;
+
+    src->capacity <<= 1;
+    char *new_arr = malloc(src->capacity * sizeof(char));
+
+    if (!new_arr)
+        return false;
+
+    memcpy(new_arr, src->elements, src->size * sizeof(char));
+
+    free(src->elements);
+    src->elements = new_arr;
+
+    return true;
+}
+
+bool source_push(source_t *src, char value)
+{
+    if (!source_expand(src))
+        return false;
+
+    src->elements[src->size] = value;
+    src->size++;
+
+    return true;
+}
+
+void source_release(source_t *src)
+{
+    if (!src)
+        return;
+
+    free(src->elements);
+    free(src);
+}
+
 /* This routine is required because the global variable initializations are
  * not supported now.
  */
@@ -855,7 +910,7 @@ void global_init()
     BB_ARENA = arena_init(DEFAULT_ARENA_SIZE);
     PH2_IR_FLATTEN = malloc(MAX_IR_INSTR * sizeof(ph2_ir_t *));
     LABEL_LUT = malloc(MAX_LABEL * sizeof(label_lut_t));
-    SOURCE = malloc(MAX_SOURCE);
+    SOURCE = create_source(MAX_SOURCE);
     ALIASES = malloc(MAX_ALIASES * sizeof(alias_t));
     CONSTANTS = malloc(MAX_CONSTANTS * sizeof(constant_t));
 
@@ -887,7 +942,7 @@ void global_release()
     arena_free(BB_ARENA);
     free(PH2_IR_FLATTEN);
     free(LABEL_LUT);
-    free(SOURCE);
+    source_release(SOURCE);
     free(ALIASES);
     free(CONSTANTS);
 
@@ -907,18 +962,20 @@ void error(char *msg)
     int offset, start_idx, i = 0;
     char diagnostic[512 /* MAX_LINE_LEN * 2 */];
 
-    for (offset = source_idx; offset >= 0 && SOURCE[offset] != '\n'; offset--)
+    for (offset = SOURCE->size; offset >= 0 && SOURCE->elements[offset] != '\n';
+         offset--)
         ;
 
     start_idx = offset + 1;
 
-    for (offset = 0; offset < MAX_SOURCE && SOURCE[start_idx + offset] != '\n';
+    for (offset = 0;
+         offset < MAX_SOURCE && SOURCE->elements[start_idx + offset] != '\n';
          offset++) {
-        diagnostic[i++] = SOURCE[start_idx + offset];
+        diagnostic[i++] = SOURCE->elements[start_idx + offset];
     }
     diagnostic[i++] = '\n';
 
-    for (offset = start_idx; offset < source_idx; offset++) {
+    for (offset = start_idx; offset < SOURCE->size; offset++) {
         diagnostic[i++] = ' ';
     }
 
@@ -927,7 +984,8 @@ void error(char *msg)
     /* TODO: figure out the corresponding C source file path and report line
      * number.
      */
-    printf("Error %s at source location %d\n%s\n", msg, source_idx, diagnostic);
+    printf("Error %s at source location %d\n%s\n", msg, SOURCE->size,
+           diagnostic);
     abort();
 }
 
diff --git a/src/lexer.c b/src/lexer.c
index 4933ea63..7b3cadba 100644
--- a/src/lexer.c
+++ b/src/lexer.c
@@ -158,13 +158,14 @@ void skip_whitespace()
 {
     while (true) {
         if (is_linebreak(next_char)) {
-            source_idx += 2;
-            next_char = SOURCE[source_idx];
+            SOURCE->size += 2;
+            next_char = SOURCE->elements[SOURCE->size];
             continue;
         }
         if (is_whitespace(next_char) ||
             (skip_newline && is_newline(next_char))) {
-            next_char = SOURCE[++source_idx];
+            SOURCE->size++;
+            next_char = SOURCE->elements[SOURCE->size];
             continue;
         }
         break;
@@ -173,7 +174,8 @@ void skip_whitespace()
 
 char read_char(bool is_skip_space)
 {
-    next_char = SOURCE[++source_idx];
+    SOURCE->size++;
+    next_char = SOURCE->elements[SOURCE->size];
     if (is_skip_space)
         skip_whitespace();
     return next_char;
@@ -181,7 +183,7 @@ char read_char(bool is_skip_space)
 
 char peek_char(int offset)
 {
-    return SOURCE[source_idx + offset];
+    return SOURCE->elements[SOURCE->size + offset];
 }
 
 /* Lex next token and returns its token type. Parameter 'aliasing' is used for
@@ -601,8 +603,8 @@ token_t lex_token_internal(bool aliasing)
      */
     if (next_char == '\n') {
         if (macro_return_idx) {
-            source_idx = macro_return_idx;
-            next_char = SOURCE[source_idx];
+            SOURCE->size = macro_return_idx;
+            next_char = SOURCE->elements[SOURCE->size];
         } else
             next_char = read_char(true);
         return lex_token_internal(aliasing);
diff --git a/src/parser.c b/src/parser.c
index ad18b5d5..cfa0100c 100644
--- a/src/parser.c
+++ b/src/parser.c
@@ -408,7 +408,7 @@ bool read_preproc_directive()
             if (lex_accept(T_elipsis))
                 macro->is_variadic = true;
 
-            macro->start_source_idx = source_idx;
+            macro->start_source_idx = SOURCE->size;
             skip_macro_body();
         } else {
             /* Empty alias, may be dummy alias serves as include guard */
@@ -891,8 +891,8 @@ void read_expr_operand(block_t *parent, basic_block_t **bb)
         macro_t *mac = find_macro(token);
 
         if (!strcmp(token, "__VA_ARGS__")) {
-            /* 'source_idx' has pointed at the character after __VA_ARGS__ */
-            int remainder, t = source_idx;
+            /* 'size' has pointed at the character after __VA_ARGS__ */
+            int remainder, t = SOURCE->size;
             macro_t *macro = parent->macro;
 
             if (!macro)
@@ -902,13 +902,13 @@ void read_expr_operand(block_t *parent, basic_block_t **bb)
 
             remainder = macro->num_params - macro->num_param_defs;
             for (int i = 0; i < remainder; i++) {
-                source_idx = macro->params[macro->num_params - remainder + i];
-                next_char = SOURCE[source_idx];
+                SOURCE->size = macro->params[macro->num_params - remainder + i];
+                next_char = SOURCE->elements[SOURCE->size];
                 next_token = lex_token();
                 read_expr(parent, bb);
             }
-            source_idx = t;
-            next_char = SOURCE[source_idx];
+            SOURCE->size = t;
+            next_char = SOURCE->elements[SOURCE->size];
             next_token = lex_token();
         } else if (mac) {
             if (parent->macro)
@@ -918,18 +918,18 @@ void read_expr_operand(block_t *parent, basic_block_t **bb)
             mac->num_params = 0;
             lex_expect(T_identifier);
 
-            /* 'source_idx' has pointed at the first parameter */
+            /* 'size' has pointed at the first parameter */
             while (!lex_peek(T_close_bracket, NULL)) {
-                mac->params[mac->num_params++] = source_idx;
+                mac->params[mac->num_params++] = SOURCE->size;
                 do {
                     next_token = lex_token();
                 } while (next_token != T_comma &&
                          next_token != T_close_bracket);
             }
-            /* move 'source_idx' to the macro body */
-            macro_return_idx = source_idx;
-            source_idx = mac->start_source_idx;
-            next_char = SOURCE[source_idx];
+            /* move 'size' to the macro body */
+            macro_return_idx = SOURCE->size;
+            SOURCE->size = mac->start_source_idx;
+            next_char = SOURCE->elements[SOURCE->size];
             lex_expect(T_close_bracket);
 
             skip_newline = 0;
@@ -941,13 +941,13 @@ void read_expr_operand(block_t *parent, basic_block_t **bb)
             macro_return_idx = 0;
         } else if (macro_param_idx) {
             /* "expand" the argument from where it comes from */
-            int t = source_idx;
-            source_idx = macro_param_idx;
-            next_char = SOURCE[source_idx];
+            int t = SOURCE->size;
+            SOURCE->size = macro_param_idx;
+            next_char = SOURCE->elements[SOURCE->size];
             next_token = lex_token();
             read_expr(parent, bb);
-            source_idx = t;
-            next_char = SOURCE[source_idx];
+            SOURCE->size = t;
+            next_char = SOURCE->elements[SOURCE->size];
             next_token = lex_token();
         } else if (con) {
             ph1_ir = add_ph1_ir(OP_load_constant);
@@ -3075,17 +3075,17 @@ basic_block_t *read_body_statement(block_t *parent, basic_block_t *bb)
         mac->num_params = 0;
         lex_expect(T_identifier);
 
-        /* 'source_idx' has pointed at the first parameter */
+        /* 'size' has pointed at the first parameter */
         while (!lex_peek(T_close_bracket, NULL)) {
-            mac->params[mac->num_params++] = source_idx;
+            mac->params[mac->num_params++] = SOURCE->size;
             do {
                 next_token = lex_token();
             } while (next_token != T_comma && next_token != T_close_bracket);
         }
-        /* move 'source_idx' to the macro body */
-        macro_return_idx = source_idx;
-        source_idx = mac->start_source_idx;
-        next_char = SOURCE[source_idx];
+        /* move 'size' to the macro body */
+        macro_return_idx = SOURCE->size;
+        SOURCE->size = mac->start_source_idx;
+        next_char = SOURCE->elements[SOURCE->size];
         lex_expect(T_close_bracket);
 
         skip_newline = 0;
@@ -3377,8 +3377,8 @@ void parse_internal()
     GLOBAL_FUNC.fn->bbs = calloc(1, sizeof(basic_block_t));
 
     /* lexer initialization */
-    source_idx = 0;
-    next_char = SOURCE[0];
+    SOURCE->size = 0;
+    next_char = SOURCE->elements[0];
     lex_expect(T_start);
 
     do {
@@ -3415,8 +3415,8 @@ void load_source_file(char *file)
             snprintf(path + c + 1, inclusion_path_len, "%s", buffer + 10);
             load_source_file(path);
         } else {
-            strcpy(SOURCE + source_idx, buffer);
-            source_idx += strlen(buffer);
+            strcpy(SOURCE->elements + SOURCE->size, buffer);
+            SOURCE->size += strlen(buffer);
         }
     }
     fclose(f);
diff --git a/tools/inliner.c b/tools/inliner.c
index 920fd849..952c412c 100644
--- a/tools/inliner.c
+++ b/tools/inliner.c
@@ -95,7 +95,7 @@ int main(int argc, char *argv[])
      */
     write_str("void __c(char *src) {\n");
     write_str("    for (int i = 0; src[i]; i++)\n");
-    write_str("        SOURCE[source_idx++] = src[i];\n");
+    write_str("        source_push(SOURCE, src[i]);\n");
     write_str("}\n");
 
     write_str("void libc_generate() {\n");