Refine comments

Author: jserv

src/arm-codegen.c

@@ -440,7 +440,7 @@ void emit_ph2_ir(ph2_ir_t *ph2_ir)
         emit(__and_i(__AL, rd, rn, rm));
         return;
     case OP_sign_ext:
-        /* TODO: Allow to sign extends to other types */
+        /* TODO: Support sign extension to types other than int */
         emit(__sxtb(__AL, rd, rn, 0));
         return;
     case OP_cast:

src/defs.h

@@ -111,7 +111,7 @@ typedef struct {
 
 /* lexer tokens */
 typedef enum {
-    T_start, /* FIXME: it was intended to start the state machine. */
+    T_start, /* FIXME: Unused, intended for lexer state machine init */
     T_numeric,
     T_identifier,
     T_comma,  /* , */

src/elf.c

@@ -15,8 +15,7 @@ int elf_symbol_index;
 
 void elf_write_str(strbuf_t *elf_array, const char *vals)
 {
-    /*
-     * Note that strbuf_puts() does not push the null character.
+    /* Note that strbuf_puts() does not push the null character.
      *
      * If necessary, use elf_write_byte() to append the null character
      * after calling elf_write_str().

src/globals.c

@@ -91,19 +91,16 @@ strbuf_t *SOURCE;
 hashmap_t *INCLUSION_MAP;
 
 /* ELF sections */
-strbuf_t *elf_code;
-strbuf_t *elf_data;
+strbuf_t *elf_code, *elf_data;
 strbuf_t *elf_rodata;
 strbuf_t *elf_header;
 strbuf_t *elf_symtab;
 strbuf_t *elf_strtab;
 strbuf_t *elf_section;
 int elf_header_len = 0x54; /* ELF fixed: 0x34 + 1 * 0x20 */
-int elf_code_start;
-int elf_data_start;
+int elf_code_start, elf_data_start;
 int elf_rodata_start;
-int elf_bss_start;
-int elf_bss_size;
+int elf_bss_start, elf_bss_size;
 
 /* Create a new arena block with given capacity.
  * @capacity: The capacity of the arena block. Must be positive.
@@ -1403,8 +1400,8 @@ void error(char *msg)
 
     strcpy(diagnostic + i, "^ Error occurs here");
 
-    /* TODO: Enhanced error reporting with location tracking will be added
-     * once self-hosting is stable with new token management
+    /* TODO: Implement line/column tracking for precise error location
+     * reporting. Current implementation only shows source position offset.
      */
     printf("[Error]: %s\nOccurs at source location %d.\n%s\n", msg,
            SOURCE->size, diagnostic);

src/lexer.c

@@ -839,7 +839,9 @@ token_t lex_token_impl(bool aliasing)
         if (aliasing) {
             alias = find_alias(token_str);
             if (alias) {
-                /* FIXME: comparison with string "bool" is a temporary hack */
+                /* FIXME: Special-casing _Bool alias handling is a workaround.
+                 * Should integrate properly with type system.
+                 */
                 token_t t;
 
                 if (is_numeric(alias)) {

src/parser.c

@@ -756,7 +756,9 @@ var_t *parse_global_constant_value(block_t *parent, basic_block_t **bb)
         add_insn(parent, *bb, OP_load_constant, val, NULL, NULL, 0, NULL);
     } else if (lex_peek(T_string, NULL)) {
         lex_accept(T_string);
-        /* Strings not supported in struct fields */
+        /* TODO: String fields in structs not yet supported - requires proper
+         * handling of string literals as initializers
+         */
     } else {
         error("Global array initialization requires constant values");
     }
@@ -3657,8 +3659,9 @@ bool read_global_assignment(char *token)
         if (lex_peek(T_string, NULL)) {
             /* String literal global initialization:
              * String literals are now stored in .rodata section.
-             * TODO: Full support for global pointer initialization with
-             * rodata addresses requires compile-time address resolution.
+             * TODO: Implement compile-time address resolution for global
+             * pointer initialization with rodata addresses
+             * (e.g., char *p = "str";)
              */
             read_literal_param(parent, bb);
             rs1 = opstack_pop();
@@ -4801,7 +4804,9 @@ void read_global_decl(block_t *block, bool is_const)
         lex_expect(T_semicolon);
         return;
     } else if (lex_accept(T_comma)) {
-        /* TODO: Global variable continuation syntax not yet implemented */
+        /* TODO: Implement global variable continuation syntax for multiple
+         * declarations in single statement (e.g., int a = 1, b = 2;)
+         */
         error("Global continuation not supported");
     } else if (lex_accept(T_semicolon)) {
         opstack_pop();

src/peephole.c

@@ -350,7 +350,6 @@ bool redundant_move_elim(ph2_ir_t *ph2_ir)
     return false;
 }
 
-
 /* Load/store elimination for consecutive memory operations.
  * Removes redundant loads and dead stores that access the same memory location.
  * Conservative implementation to maintain bootstrap stability.
@@ -820,7 +819,7 @@ bool triple_pattern_optimization(ph2_ir_t *ph2_ir)
         return true;
     }
 
-    /* FIXME: Additional patterns for future implementation:
+    /* FIXME: Additional optimization patterns to implement:
      *
      * Pattern 3: Load-op-store with same location
      * {load r1, [addr]; op r2, r1, ...; store r2, [addr]}

src/reg-alloc.c

@@ -8,8 +8,8 @@
 /* Allocate registers from IR. The linear-scan algorithm now expects a minimum
  * of 7 available registers (typical for RISC-style architectures).
  *
- * TODO: Implement the "-O level" option. This allocator now always drops the
- * dead variable and does NOT wrtie it back to the stack.
+ * TODO: Implement "-O level" optimization control. Currently the allocator
+ * always performs dead variable elimination without writing back to stack.
  */
 
 #include "defs.h"
@@ -390,7 +390,9 @@ void extend_liveness(basic_block_t *bb, insn_t *insn, var_t *var, int offset)
 
 void reg_alloc(void)
 {
-    /* TODO: .bss and .data section */
+    /* TODO: Add proper .bss and .data section support for uninitialized /
+     * initialized globals
+     */
     for (insn_t *global_insn = GLOBAL_FUNC->bbs->insn_list.head; global_insn;
          global_insn = global_insn->next) {
         ph2_ir_t *ir;
@@ -710,8 +712,10 @@ void reg_alloc(void)
                         ir->src0 = src0;
                         strcpy(ir->func_name, insn->rs2->var_name);
                     } else {
-                        /* FIXME: Avoid outdated content in register after
-                         * storing, but causing some redundant spilling.
+                        /* FIXME: Register content becomes stale after store
+                         * operation. Current workaround causes redundant
+                         * spilling - need better register invalidation
+                         * strategy.
                          */
                         spill_alive(bb, insn);
                         src0 = prepare_operand(bb, insn->rs1, -1);

src/riscv-codegen.c

@@ -425,11 +425,11 @@ void emit_ph2_ir(ph2_ir_t *ph2_ir)
         emit(__andi(rd, rs1, rs2));
         return;
     case OP_sign_ext:
-        /* TODO: Allow to sign extends to other types */
+        /* TODO: Support sign extension to types other than int */
         emit(__andi(rd, rs1, 0xFF));
         emit(__slli(rd, rd, 24));
         emit(__srai(rd, rd, 24));
-        /* TODO: Allow user to switch to Zbb extension if needed */
+        /* TODO: Consider Zbb extension for improved bit manipulation */
         /* emit(__sext_b(rd, rs1)); */
         return;
     case OP_cast:

src/ssa.c

@@ -799,7 +799,9 @@ void solve_phi_params(void)
 {
     for (func_t *func = FUNC_LIST.head; func; func = func->next) {
         for (int i = 0; i < func->num_params; i++) {
-            /* FIXME: Rename arguments directly, might be not good here. */
+            /* FIXME: Direct argument renaming in SSA construction phase may
+             * interfere with later optimization passes
+             */
             var_t *var = require_var(func->bbs->scope);
             var_t *base = &func->param_defs[i];
             memcpy(var, base, sizeof(var_t));
@@ -857,7 +859,8 @@ void bb_unwind_phi(func_t *func, basic_block_t *bb)
         for (phi_operand_t *operand = insn->phi_ops; operand;
              operand = operand->next)
             append_unwound_phi_insn(operand->from, insn->rd, operand->var);
-        /* TODO: Release dangling phi instruction */
+        /* TODO: Release memory allocated for phi instruction to prevent leaks
+         */
     }
 
     bb->insn_list.head = insn;