diff --git a/Makefile b/Makefile
index c3346c6..cd9954b 100644
--- a/Makefile
+++ b/Makefile
@@ -1,12 +1,19 @@
 CC = gcc
 CFLAGS_EXTRA = 
 CFLAGS = -Wall -Wextra -Wpedantic -std=c17 -O3
+CLANG_FORMAT_STYLE = '{ BasedOnStyle: Google, IndentWidth: 4 }'
 
-.PHONY: clean build-dir hbas example
+.PHONY: clean hbas example format check-format
 
 hbas: build/hbas
 example: build/example.hbf
 
+format:
+	clang-format --style=${CLANG_FORMAT_STYLE} -i src/*
+
+check-format:
+	clang-format --style=${CLANG_FORMAT_STYLE} -i --dry-run -Werror src/*
+
 build:
 	mkdir -p build
 
diff --git a/src/args.c b/src/args.c
index 11668dd..be74e1e 100644
--- a/src/args.c
+++ b/src/args.c
@@ -1,11 +1,11 @@
 typedef struct ArgMeta_s {
-  char chr;
-  uint8_t size;
-  // This is a bitset of acceptable overflow states,
-  // where accept signed = 1, accept unsigned = 2.
-  // 1 -> signed, 2 -> unsigned, 3 -> whatever
-  uint8_t sign;
-  uint8_t rel;
+    char chr;
+    uint8_t size;
+    // This is a bitset of acceptable overflow states,
+    // where accept signed = 1, accept unsigned = 2.
+    // 1 -> signed, 2 -> unsigned, 3 -> whatever
+    uint8_t sign;
+    uint8_t rel;
 } ArgMeta;
 const ArgMeta ARGS[] = {
     {'R', 1, 2, 0}, {'1', 1, 3, 0}, {'b', 1, 1, 0}, {'B', 1, 2, 0},
@@ -15,31 +15,31 @@ const ArgMeta ARGS[] = {
 };
 
 typedef enum Operands_e {
-  Empty = 0,
-  R,
-  RR,
-  RRR,
-  RRRR,
-  Rx8,
-  Rx16,
-  Rx32,
-  Rx64,
-  RRx8,
-  RRx16,
-  RRx32,
-  RRx64,
-  RRs32,
-  RRs64,
-  RRu8,
-  RRu16,
-  RRu64,
-  r16,
-  r32,
-  RRr16,
-  RRr32,
-  RRr16u16,
-  RRr32u16,
-  RRu64u16,
+    Empty = 0,
+    R,
+    RR,
+    RRR,
+    RRRR,
+    Rx8,
+    Rx16,
+    Rx32,
+    Rx64,
+    RRx8,
+    RRx16,
+    RRx32,
+    RRx64,
+    RRs32,
+    RRs64,
+    RRu8,
+    RRu16,
+    RRu64,
+    r16,
+    r32,
+    RRr16,
+    RRr32,
+    RRr16u16,
+    RRr32u16,
+    RRu64u16,
 } Operands;
 // R -> register,
 // 1 -> Xi8, 2 -> Xi16, 4 -> Xi32, 8 -> Xi64,
@@ -56,11 +56,11 @@ const char *TYPE_STR[] = {
 
 const size_t NARGS = sizeof(ARGS) / sizeof(ARGS[0]);
 ArgMeta arg_meta(char arg) {
-  for (size_t ii = 0; ii < NARGS; ii += 1) {
-    ArgMeta meta = ARGS[ii];
-    if (meta.chr == arg) {
-      return meta;
+    for (size_t ii = 0; ii < NARGS; ii += 1) {
+        ArgMeta meta = ARGS[ii];
+        if (meta.chr == arg) {
+            return meta;
+        }
     }
-  }
-  return ARGS[NARGS - 1];
+    return ARGS[NARGS - 1];
 }
diff --git a/src/bytevec.c b/src/bytevec.c
index ed774e8..0d87620 100644
--- a/src/bytevec.c
+++ b/src/bytevec.c
@@ -1,29 +1,29 @@
 const size_t INVALID = ~(size_t)0;
 
 typedef struct ByteVec_s {
-  char *buf;
-  size_t cap;
-  size_t len;
+    char *buf;
+    size_t cap;
+    size_t len;
 } ByteVec;
 
 AsmError ensure_push(ByteVec *vec, size_t el_size, size_t extra) {
-  if (vec->len + extra < vec->len) {
-    return ErrOutOfMemory;
-  }
-  while (vec->len + extra > vec->cap) {
-    if ((~(size_t)0) / 2 < vec->cap) {
-      return ErrOutOfMemory;
+    if (vec->len + extra < vec->len) {
+        return ErrOutOfMemory;
     }
-    vec->cap *= 2;
-    // multiply overflow
-    if ((~(size_t)0) / el_size < vec->cap) {
-      return ErrOutOfMemory;
+    while (vec->len + extra > vec->cap) {
+        if ((~(size_t)0) / 2 < vec->cap) {
+            return ErrOutOfMemory;
+        }
+        vec->cap *= 2;
+        // multiply overflow
+        if ((~(size_t)0) / el_size < vec->cap) {
+            return ErrOutOfMemory;
+        }
+        vec->buf = realloc(vec->buf, el_size * vec->cap);
+        if (vec->buf == NULL) {
+            vec->cap = 0;
+            return ErrOutOfMemory;
+        }
     }
-    vec->buf = realloc(vec->buf, el_size * vec->cap);
-    if (vec->buf == NULL) {
-      vec->cap = 0;
-      return ErrOutOfMemory;
-    }
-  }
-  return 0;
+    return 0;
 }
diff --git a/src/einfo.h b/src/einfo.h
index d52021c..1dcad3f 100644
--- a/src/einfo.h
+++ b/src/einfo.h
@@ -1,5 +1,5 @@
 typedef struct EInfo_s {
-  Token token;
-  size_t line;
-  size_t line_start;
+    Token token;
+    size_t line;
+    size_t line_start;
 } EInfo;
diff --git a/src/error.h b/src/error.h
index f1d6e35..d0b293d 100644
--- a/src/error.h
+++ b/src/error.h
@@ -1,23 +1,23 @@
 typedef enum AsmError_e {
-  ErrOk = 0,
-  ErrBadRegister,
-  ErrImmediateOverflow,
-  ErrInvalidToken,
-  ErrBadArgumentMeta,
-  ErrNeedCommaAfterArgument,
-  ErrLabelImmediate,
-  ErrNumberImmediate,
-  ErrBadNumOverflow,
-  ErrBadNumDigit,
-  ErrBadNumNoDigit,
-  ErrLabelAfterLabel,
-  ErrOutOfMemory,
-  ErrDuplicateLabel,
-  ErrTrailingLine,
-  ErrNeedDirectiveAfterDot,
-  ErrDirectiveNotImplemented,
-  ErrUnexpectedToken,
-  ErrTriedNegateNonNumber,
+    ErrOk = 0,
+    ErrBadRegister,
+    ErrImmediateOverflow,
+    ErrInvalidToken,
+    ErrBadArgumentMeta,
+    ErrNeedCommaAfterArgument,
+    ErrLabelImmediate,
+    ErrNumberImmediate,
+    ErrBadNumOverflow,
+    ErrBadNumDigit,
+    ErrBadNumNoDigit,
+    ErrLabelAfterLabel,
+    ErrOutOfMemory,
+    ErrDuplicateLabel,
+    ErrTrailingLine,
+    ErrNeedDirectiveAfterDot,
+    ErrDirectiveNotImplemented,
+    ErrUnexpectedToken,
+    ErrTriedNegateNonNumber,
 } AsmError;
 char *ERRORS[] = {
     "Success",
diff --git a/src/hash.c b/src/hash.c
index 34d74ef..21d1d0f 100644
--- a/src/hash.c
+++ b/src/hash.c
@@ -1,57 +1,57 @@
 // Instruction Hash table, for faster lookups
 typedef struct InstHtNode_s {
-  uint8_t index1;
-  uint8_t index2;
+    uint8_t index1;
+    uint8_t index2;
 } InstHtNode;
 typedef InstHtNode *InstHt;
 
 uint32_t inst_hash(const char *s, size_t len) {
-  uint32_t hash = 0;
-  uint32_t mul = 75;
-  for (size_t ii = 0; ii < len; ii += 1) {
-    hash ^= s[ii] * mul;
-    hash *= mul;
-  }
-  return hash;
+    uint32_t hash = 0;
+    uint32_t mul = 75;
+    for (size_t ii = 0; ii < len; ii += 1) {
+        hash ^= s[ii] * mul;
+        hash *= mul;
+    }
+    return hash;
 }
 
 InstHt build_lookup(void) {
-  const size_t size = 256;
-  InstHt table = (InstHt)malloc(size * sizeof(InstHtNode));
-  if (table == NULL) {
-    return table;
-  }
-  for (size_t ii = 0; ii < size; ii += 1) {
-    table[ii] = (InstHtNode){0xff, 0xff};
-  }
-  for (size_t ii = 0; ii < INST_CNT; ii += 1) {
-    const char *mnemonic = INST[ii].mnemonic;
-    uint32_t hash = inst_hash(mnemonic, strlen(mnemonic));
-    InstHtNode *node = &table[hash & 0xff];
-    if (node->index1 == 0xff) {
-      node->index1 = ii;
-    } else if (node->index2 == 0xff) {
-      node->index2 = ii;
-    } else {
-      fprintf(stderr, "more than 1 collision in hash table\n");
-      exit(1);
+    const size_t size = 256;
+    InstHt table = (InstHt)malloc(size * sizeof(InstHtNode));
+    if (table == NULL) {
+        return table;
     }
-  }
-  return table;
+    for (size_t ii = 0; ii < size; ii += 1) {
+        table[ii] = (InstHtNode){0xff, 0xff};
+    }
+    for (size_t ii = 0; ii < INST_CNT; ii += 1) {
+        const char *mnemonic = INST[ii].mnemonic;
+        uint32_t hash = inst_hash(mnemonic, strlen(mnemonic));
+        InstHtNode *node = &table[hash & 0xff];
+        if (node->index1 == 0xff) {
+            node->index1 = ii;
+        } else if (node->index2 == 0xff) {
+            node->index2 = ii;
+        } else {
+            fprintf(stderr, "more than 1 collision in hash table\n");
+            exit(1);
+        }
+    }
+    return table;
 }
 
 size_t inst_lookup(InstHt ht, const char *s, size_t len) {
-  uint32_t hash = inst_hash(s, len);
-  uint8_t *node = (uint8_t *)&ht[(size_t)(hash & 0xff)];
-  for (size_t ii = 0; ii < 2; ii += 1) {
-    size_t idx = (size_t)node[ii];
-    if (idx == 0xff) {
-      break;
+    uint32_t hash = inst_hash(s, len);
+    uint8_t *node = (uint8_t *)&ht[(size_t)(hash & 0xff)];
+    for (size_t ii = 0; ii < 2; ii += 1) {
+        size_t idx = (size_t)node[ii];
+        if (idx == 0xff) {
+            break;
+        }
+        const char *mnemonic = INST[idx].mnemonic;
+        if (strncmp(s, mnemonic, len) == 0 && mnemonic[len] == 0) {
+            return idx;
+        }
     }
-    const char *mnemonic = INST[idx].mnemonic;
-    if (strncmp(s, mnemonic, len) == 0 && mnemonic[len] == 0) {
-      return idx;
-    }
-  }
-  return INVALID;
+    return INVALID;
 }
diff --git a/src/hbas.c b/src/hbas.c
index 453c446..7c08e11 100644
--- a/src/hbas.c
+++ b/src/hbas.c
@@ -40,376 +40,379 @@ SOFTWARE.
 #include "einfo.h"
 
 void hd(char *data, size_t len) {
-  for (size_t ii = 0; ii < len; ii += 1) {
-    if (ii > 0 && (ii & 15) == 0) {
-      printf("\n");
+    for (size_t ii = 0; ii < len; ii += 1) {
+        if (ii > 0 && (ii & 15) == 0) {
+            printf("\n");
+        }
+        printf("%02x", (uint8_t)data[ii]);
     }
-    printf("%02x", (uint8_t)data[ii]);
-  }
-  printf("\n");
+    printf("\n");
 }
 
 #define MIN_SIZE 4096
 
 int slurp(FILE *fd, ByteVec *out) {
-  ByteVec rv = {malloc(MIN_SIZE), MIN_SIZE, 0};
-  size_t bread = 1;
-  int err = 0;
-  if (rv.buf == NULL) {
-    rv.cap = 0;
-    err = ErrOutOfMemory;
-    bread = 0;
-  }
-  while (bread > 0) {
-    if (ensure_push(&rv, 1, 1) != 0) {
-      err = ErrOutOfMemory;
-      break;
+    ByteVec rv = {malloc(MIN_SIZE), MIN_SIZE, 0};
+    size_t bread = 1;
+    int err = 0;
+    if (rv.buf == NULL) {
+        rv.cap = 0;
+        err = ErrOutOfMemory;
+        bread = 0;
     }
-    bread = fread(&rv.buf[rv.len], 1, rv.cap - rv.len, fd);
-    rv.len += bread;
-  }
-  *out = rv;
-  if (err == 0) {
-    err = ferror(fd);
-  }
-  return err;
+    while (bread > 0) {
+        if (ensure_push(&rv, 1, 1) != 0) {
+            err = ErrOutOfMemory;
+            break;
+        }
+        bread = fread(&rv.buf[rv.len], 1, rv.cap - rv.len, fd);
+        rv.len += bread;
+    }
+    *out = rv;
+    if (err == 0) {
+        err = ferror(fd);
+    }
+    return err;
 }
 
 typedef struct Hole_s {
-  size_t location;
-  size_t origin;
-  char *str;
-  size_t len;
-  size_t size;
+    size_t location;
+    size_t origin;
+    char *str;
+    size_t len;
+    size_t size;
 } Hole;
 typedef struct HoleVec_s {
-  Hole *buf;
-  size_t cap;
-  size_t len;
+    Hole *buf;
+    size_t cap;
+    size_t len;
 } HoleVec;
 typedef struct Label_s {
-  size_t location;
-  char *str;
-  size_t len;
+    size_t location;
+    char *str;
+    size_t len;
 } Label;
 typedef struct LabelVec_s {
-  Label *buf;
-  size_t cap;
-  size_t len;
+    Label *buf;
+    size_t cap;
+    size_t len;
 } LabelVec;
 
 size_t label_lookup(LabelVec *labels, char *name, size_t len) {
-  size_t nlabels = labels->len;
-  Label *buf = labels->buf;
-  for (size_t ii = 0; ii < nlabels; ii += 1) {
-    if (len == buf->len && strncmp(buf->str, name, len) == 0) {
-      return ii;
+    size_t nlabels = labels->len;
+    Label *buf = labels->buf;
+    for (size_t ii = 0; ii < nlabels; ii += 1) {
+        if (len == buf->len && strncmp(buf->str, name, len) == 0) {
+            return ii;
+        }
+        buf += 1;
     }
-    buf += 1;
-  }
-  return INVALID;
+    return INVALID;
 }
 
 // safety: assumes the buffer has enough place for specified integer size.
 // `sign` is a bitset, where bit `1` indicates that value accepts a signed int,
 // and bit `2` indicates that value accepts an unsigned int.
 AsmError push_int_le(char *buf, uint64_t val, size_t size, uint8_t sign) {
-  // Unsigned integers must have all upper bits set to zero. To check this,
-  // we shift the value right by the integer size and verify it equals zero.
-  int valid_uint = (val >> (size * 8)) == 0;
+    // Unsigned integers must have all upper bits set to zero. To check this,
+    // we shift the value right by the integer size and verify it equals zero.
+    int valid_uint = (val >> (size * 8)) == 0;
 
-  // For signed integers, the sign-extended high bits must match the sign bit.
-  // By shifting right by one less than the total bit size (size * 8 - 1),
-  // we isolate the sign bit and any sign-extended bits. For a value fitting
-  // in the signed range, this operation results in either 0 (for non-negative
-  // values) or -1 (for negative values due to sign extension).
-  int64_t int_shifted = ((int64_t)val) >> (size * 8 - 1);
+    // For signed integers, the sign-extended high bits must match the sign bit.
+    // By shifting right by one less than the total bit size (size * 8 - 1),
+    // we isolate the sign bit and any sign-extended bits. For a value fitting
+    // in the signed range, this operation results in either 0 (for non-negative
+    // values) or -1 (for negative values due to sign extension).
+    int64_t int_shifted = ((int64_t)val) >> (size * 8 - 1);
 
-  // To unify the check for both positive and negative cases, we adjust
-  // non-zero values (-1) by incrementing by 1.  This turns -1 into 0,
-  // enabling a single check for 0 to validate both cases.  This adjustment
-  // simplifies the validation logic, allowing us to use a single condition to
-  // check for proper sign extension or zero extension in the original value.
-  int_shifted += int_shifted != 0;
+    // To unify the check for both positive and negative cases, we adjust
+    // non-zero values (-1) by incrementing by 1.  This turns -1 into 0,
+    // enabling a single check for 0 to validate both cases.  This adjustment
+    // simplifies the validation logic, allowing us to use a single condition to
+    // check for proper sign extension or zero extension in the original value.
+    int_shifted += int_shifted != 0;
 
-  // A valid signed integer will have `int_shifted` equal to 0
-  // after adjustment, indicating proper sign extension. 
-  int valid_int = int_shifted == 0;
+    // A valid signed integer will have `int_shifted` equal to 0
+    // after adjustment, indicating proper sign extension.
+    int valid_int = int_shifted == 0;
 
-  // Validity bitmask to represents whether the value
-  // fits as signed, unsigned, or both.
-  int validity = valid_int | (valid_uint << 1);
+    // Validity bitmask to represents whether the value
+    // fits as signed, unsigned, or both.
+    int validity = valid_int | (valid_uint << 1);
 
-  // If the value's validity doesn't match the `sign` requirements,
-  // we report an overflow.
-  if ((validity & sign) == 0) {
-    return ErrImmediateOverflow;
-  }
+    // If the value's validity doesn't match the `sign` requirements,
+    // we report an overflow.
+    if ((validity & sign) == 0) {
+        return ErrImmediateOverflow;
+    }
 
-  // Write out the bytes of the integer to the buffer in little-endian order,
-  // starting with the lowest byte first.
-  for (size_t ii = 0; ii < size; ii += 1) {
-    buf[ii] = val & 0xff;
-    val >>= 8;
-  }
-  return ErrOk;
+    // Write out the bytes of the integer to the buffer in little-endian order,
+    // starting with the lowest byte first.
+    for (size_t ii = 0; ii < size; ii += 1) {
+        buf[ii] = val & 0xff;
+        val >>= 8;
+    }
+    return ErrOk;
 }
 
 AsmError assemble_instr(InstHt ht, char *input, size_t len, Token *tok,
                         ByteVec *rv, HoleVec *holes) {
-  const InstDesc *inst;
-  const char *type_str;
-  size_t nargs;
-  size_t size;
-  size_t idx = inst_lookup(ht, &input[tok->start], tok->len);
-  size_t inst_start = rv->len;
-  if (idx == INVALID) {
-    return ErrInvalidToken;
-  }
-  inst = &INST[idx];
-  type_str = TYPE_STR[inst->type];
-  nargs = strlen(type_str);
-  size = 1;
-  for (size_t ii = 0; ii < nargs; ii += 1) {
-    char chr = type_str[ii];
-    ArgMeta meta = arg_meta(chr);
-    if (meta.chr == 0) {
-      return ErrBadArgumentMeta;
+    const InstDesc *inst;
+    const char *type_str;
+    size_t nargs;
+    size_t size;
+    size_t idx = inst_lookup(ht, &input[tok->start], tok->len);
+    size_t inst_start = rv->len;
+    if (idx == INVALID) {
+        return ErrInvalidToken;
     }
-    size += meta.size;
-  }
-  if (ensure_push(rv, 1, size) != 0) {
-    return ErrOutOfMemory;
-  }
-  rv->buf[rv->len] = inst->opcode;
-  rv->len += 1;
-  for (size_t ii = 0; ii < nargs; ii += 1) {
-    if (ii > 0) {
-      *tok = token(input, len, tok->start + tok->len);
-      if (tok->kind != TokComma) {
-        return ErrNeedCommaAfterArgument;
-      }
+    inst = &INST[idx];
+    type_str = TYPE_STR[inst->type];
+    nargs = strlen(type_str);
+    size = 1;
+    for (size_t ii = 0; ii < nargs; ii += 1) {
+        char chr = type_str[ii];
+        ArgMeta meta = arg_meta(chr);
+        if (meta.chr == 0) {
+            return ErrBadArgumentMeta;
+        }
+        size += meta.size;
     }
-    char chr = type_str[ii];
-    ArgMeta meta = arg_meta(chr);
-    uint64_t is_negative = 0;
-    *tok = token(input, len, tok->start + tok->len);
-    if (tok->kind == TokNeg) {
-      *tok = token(input, len, tok->start + tok->len);
-      if (tok->kind != TokNumber) {
-        return ErrTriedNegateNonNumber;
-      }
-      is_negative -= 1;
+    if (ensure_push(rv, 1, size) != 0) {
+        return ErrOutOfMemory;
     }
-    if (chr == 'R') {
-      int reg = parse_register(&input[tok->start], tok->len);
-      if (reg > 255) {
-        return ErrBadRegister;
-      }
-      rv->buf[rv->len] = (char)(reg & 0xff);
-      rv->len += 1;
-    } else {
-      uint64_t num_to_write;
-      if (meta.rel == 1 || meta.size == 8) {
-        if (tok->kind == TokIdent) {
-          if (ensure_push((ByteVec*)holes, sizeof(Hole), 1) != 0) {
-            return ErrOutOfMemory;
-          }
-          holes->buf[holes->len] = (Hole) {
-              .location = rv->len,
-              .origin = inst_start,
-              .str = &input[tok->start],
-              .len = tok->len,
-              .size = (size_t)meta.size,
-          };
-          holes->len += 1;
-          num_to_write = 0;
-        } else if (tok->kind == TokNumber) {
-          num_to_write = tok->num;
+    rv->buf[rv->len] = inst->opcode;
+    rv->len += 1;
+    for (size_t ii = 0; ii < nargs; ii += 1) {
+        if (ii > 0) {
+            *tok = token(input, len, tok->start + tok->len);
+            if (tok->kind != TokComma) {
+                return ErrNeedCommaAfterArgument;
+            }
+        }
+        char chr = type_str[ii];
+        ArgMeta meta = arg_meta(chr);
+        uint64_t is_negative = 0;
+        *tok = token(input, len, tok->start + tok->len);
+        if (tok->kind == TokNeg) {
+            *tok = token(input, len, tok->start + tok->len);
+            if (tok->kind != TokNumber) {
+                return ErrTriedNegateNonNumber;
+            }
+            is_negative -= 1;
+        }
+        if (chr == 'R') {
+            int reg = parse_register(&input[tok->start], tok->len);
+            if (reg > 255) {
+                return ErrBadRegister;
+            }
+            rv->buf[rv->len] = (char)(reg & 0xff);
+            rv->len += 1;
         } else {
-          return ErrLabelImmediate;
+            uint64_t num_to_write;
+            if (meta.rel == 1 || meta.size == 8) {
+                if (tok->kind == TokIdent) {
+                    if (ensure_push((ByteVec *)holes, sizeof(Hole), 1) != 0) {
+                        return ErrOutOfMemory;
+                    }
+                    holes->buf[holes->len] = (Hole){
+                        .location = rv->len,
+                        .origin = inst_start,
+                        .str = &input[tok->start],
+                        .len = tok->len,
+                        .size = (size_t)meta.size,
+                    };
+                    holes->len += 1;
+                    num_to_write = 0;
+                } else if (tok->kind == TokNumber) {
+                    num_to_write = tok->num;
+                } else {
+                    return ErrLabelImmediate;
+                }
+            } else if (tok->kind == TokNumber) {
+                num_to_write = tok->num;
+            } else {
+                return ErrNumberImmediate;
+            }
+            // num_to_write = num_to_write ^ is_negative - is_negative;
+            if (is_negative) {
+                int64_t tmp = -(int64_t)num_to_write;
+                if (tmp > 0) {
+                    return ErrBadNumOverflow;
+                }
+                num_to_write = (uint64_t)tmp;
+            }
+            AsmError err = push_int_le(&rv->buf[rv->len], num_to_write,
+                                       meta.size, meta.sign);
+            if (err != ErrOk) {
+                return err;
+            }
+            rv->len += meta.size;
         }
-      } else if (tok->kind == TokNumber) {
-        num_to_write = tok->num;
-      } else {
-        return ErrNumberImmediate;
-      }
-      // num_to_write = num_to_write ^ is_negative - is_negative;
-      if (is_negative) {
-        int64_t tmp = -(int64_t)num_to_write;
-        if (tmp > 0) {
-          return ErrBadNumOverflow;
-        }
-        num_to_write = (uint64_t)tmp;
-      }
-      AsmError err =
-          push_int_le(&rv->buf[rv->len], num_to_write, meta.size, meta.sign);
-      if (err != ErrOk) {
-        return err;
-      }
-      rv->len += meta.size;
     }
-  }
 
-  return ErrOk;
+    return ErrOk;
 }
 
-AsmError assemble(InstHt ht, char *input, size_t len, ByteVec *out, EInfo *einfo) {
-  ByteVec rv = {malloc(MIN_SIZE), MIN_SIZE, 0};
-  HoleVec holes = {malloc(MIN_SIZE * sizeof(Hole)), MIN_SIZE, 0};
-  LabelVec labels = {malloc(MIN_SIZE * sizeof(Label)), MIN_SIZE, 0};
-  size_t line = 0;
-  size_t line_start = 0;
-  size_t pos = 0;
-  // init=0, label=1, instruction=2, comment=3, newline -> 0
-  size_t line_state = 0;
-  AsmError err = ErrOk;
+AsmError assemble(InstHt ht, char *input, size_t len, ByteVec *out,
+                  EInfo *einfo) {
+    ByteVec rv = {malloc(MIN_SIZE), MIN_SIZE, 0};
+    HoleVec holes = {malloc(MIN_SIZE * sizeof(Hole)), MIN_SIZE, 0};
+    LabelVec labels = {malloc(MIN_SIZE * sizeof(Label)), MIN_SIZE, 0};
+    size_t line = 0;
+    size_t line_start = 0;
+    size_t pos = 0;
+    // init=0, label=1, instruction=2, comment=3, newline -> 0
+    size_t line_state = 0;
+    AsmError err = ErrOk;
 
-  while (1) {
-    Token tok = token(input, len, pos);
-    einfo->token = tok;
-    pos = tok.start + tok.len;
-    if (tok.kind == TokInvalid || tok.kind == TokBadNumber) {
-      if (tok.num) {
-        err = (AsmError)tok.num;
-      } else {
-        err = ErrInvalidToken;
-      }
-      break;
-    }
-    if (tok.kind == TokEOF) {
-      break;
-    }
-    if (tok.kind == TokComment) {
-      line_state = 3;
-      continue;
-    }
-    if (tok.kind == TokNewline) {
-      line += 1;
-      line_start = tok.start + tok.len;
-      line_state = 0;
-      continue;
-    }
-    if (tok.kind == TokDot) {
-      Token next = token(input, len, pos);
-      if (next.kind == TokIdent) {
-        err = ErrDirectiveNotImplemented;
-        goto end;
-      } else {
-        err = ErrNeedDirectiveAfterDot;
-        goto end;
-      }
-      continue;
-    }
-    if (tok.kind == TokIdent) {
-      Token next = token(input, len, pos);
-      if (next.kind == TokColon) {
-        // Label
-        pos = next.start + next.len;
-        if (line_state >= 1) {
-          err = ErrLabelAfterLabel;
-          einfo->token = next;
-          goto end;
-        }
-        line_state = 1;
-        if (ensure_push((ByteVec *)&labels, sizeof(Label), 1) != 0) {
-          err = ErrOutOfMemory;
-          goto end;
-        }
-        size_t idx = label_lookup(&labels, &input[tok.start], tok.len);
-        if (idx != INVALID) {
-          err = ErrDuplicateLabel;
-          goto end;
-        }
-        labels.buf[labels.len] = (Label){
-            .location = rv.len,
-            .str = &input[tok.start],
-            .len = tok.len,
-        };
-        labels.len += 1;
-      } else {
-        // Instruction
-        if (line_state >= 2) {
-          err = ErrTrailingLine;
-          goto end;
-        }
-        line_state = 2;
-        err = assemble_instr(ht, input, len, &tok, &rv, &holes);
+    while (1) {
+        Token tok = token(input, len, pos);
+        einfo->token = tok;
         pos = tok.start + tok.len;
-        if (err != 0) {
-          goto end;
+        if (tok.kind == TokInvalid || tok.kind == TokBadNumber) {
+            if (tok.num) {
+                err = (AsmError)tok.num;
+            } else {
+                err = ErrInvalidToken;
+            }
+            break;
         }
-      }
-      continue;
+        if (tok.kind == TokEOF) {
+            break;
+        }
+        if (tok.kind == TokComment) {
+            line_state = 3;
+            continue;
+        }
+        if (tok.kind == TokNewline) {
+            line += 1;
+            line_start = tok.start + tok.len;
+            line_state = 0;
+            continue;
+        }
+        if (tok.kind == TokDot) {
+            Token next = token(input, len, pos);
+            if (next.kind == TokIdent) {
+                err = ErrDirectiveNotImplemented;
+                goto end;
+            } else {
+                err = ErrNeedDirectiveAfterDot;
+                goto end;
+            }
+            continue;
+        }
+        if (tok.kind == TokIdent) {
+            Token next = token(input, len, pos);
+            if (next.kind == TokColon) {
+                // Label
+                pos = next.start + next.len;
+                if (line_state >= 1) {
+                    err = ErrLabelAfterLabel;
+                    einfo->token = next;
+                    goto end;
+                }
+                line_state = 1;
+                if (ensure_push((ByteVec *)&labels, sizeof(Label), 1) != 0) {
+                    err = ErrOutOfMemory;
+                    goto end;
+                }
+                size_t idx = label_lookup(&labels, &input[tok.start], tok.len);
+                if (idx != INVALID) {
+                    err = ErrDuplicateLabel;
+                    goto end;
+                }
+                labels.buf[labels.len] = (Label){
+                    .location = rv.len,
+                    .str = &input[tok.start],
+                    .len = tok.len,
+                };
+                labels.len += 1;
+            } else {
+                // Instruction
+                if (line_state >= 2) {
+                    err = ErrTrailingLine;
+                    goto end;
+                }
+                line_state = 2;
+                err = assemble_instr(ht, input, len, &tok, &rv, &holes);
+                pos = tok.start + tok.len;
+                if (err != 0) {
+                    goto end;
+                }
+            }
+            continue;
+        }
+        err = ErrUnexpectedToken;
+        goto end;
     }
-    err = ErrUnexpectedToken;
-    goto end;
-  }
 
-  for (size_t ii = 0; ii < holes.len; ii += 1) {
-    Hole *hole = &holes.buf[ii];
-    size_t idx = label_lookup(&labels, hole->str, hole->len);
-    uint64_t num_to_write = labels.buf[idx].location;
-    uint8_t sign = 2;
-    if (hole->size != 8) {
-      sign = 1;
-      num_to_write -= hole->origin;
+    for (size_t ii = 0; ii < holes.len; ii += 1) {
+        Hole *hole = &holes.buf[ii];
+        size_t idx = label_lookup(&labels, hole->str, hole->len);
+        uint64_t num_to_write = labels.buf[idx].location;
+        uint8_t sign = 2;
+        if (hole->size != 8) {
+            sign = 1;
+            num_to_write -= hole->origin;
+        }
+        err = push_int_le(&rv.buf[hole->location], num_to_write, hole->size,
+                          sign);
+        if (err != 0) {
+            goto end;
+        }
     }
-    err = push_int_le(&rv.buf[hole->location], num_to_write, hole->size, sign);
-    if (err != 0) {
-      goto end;
-    }
-  }
 end:
-  free(holes.buf);
-  free(labels.buf);
-  *out = rv;
-  einfo->line = line + 1;
-  einfo->line_start = line_start;
-  return err;
+    free(holes.buf);
+    free(labels.buf);
+    *out = rv;
+    einfo->line = line + 1;
+    einfo->line_start = line_start;
+    return err;
 }
 
 int main(int argc, char **argv) {
-  int hex_out = 0;
-  if (argc >= 2 && strcmp(argv[1], "--hex") == 0) {
-    hex_out = 1;
-  }
+    int hex_out = 0;
+    if (argc >= 2 && strcmp(argv[1], "--hex") == 0) {
+        hex_out = 1;
+    }
 
-  int err = 0;
-  InstHt ht = NULL;
-  ByteVec input;
+    int err = 0;
+    InstHt ht = NULL;
+    ByteVec input;
 
-  err = slurp(stdin, &input);
-  if (err != 0) {
-    fprintf(stderr, "failed to read the file: %d\n", err);
-    goto done;
-  }
-  ht = build_lookup();
-  if (ht == NULL) {
-    err = ErrOutOfMemory;
-    fprintf(stderr, "failed to init hash table: %d\n", err);
-    goto done;
-  }
+    err = slurp(stdin, &input);
+    if (err != 0) {
+        fprintf(stderr, "failed to read the file: %d\n", err);
+        goto done;
+    }
+    ht = build_lookup();
+    if (ht == NULL) {
+        err = ErrOutOfMemory;
+        fprintf(stderr, "failed to init hash table: %d\n", err);
+        goto done;
+    }
 
-  ByteVec out;
-  EInfo einfo;
-  err = assemble(ht, input.buf, input.len, &out, &einfo);
-  if (err != 0) {
-    size_t column = einfo.token.start - einfo.line_start + 1;
-    fprintf(stderr, "failed to assemble, %s, line=%zu, col=%zu token=%.*s\n",
-            ERRORS[err], einfo.line, column, (int)einfo.token.len,
-            &input.buf[einfo.token.start]);
-    goto done;
-  }
-  if (hex_out) {
-    hd(out.buf, out.len);
-  } else {
-    fwrite(out.buf, 1, out.len, stdout);
-  }
+    ByteVec out;
+    EInfo einfo;
+    err = assemble(ht, input.buf, input.len, &out, &einfo);
+    if (err != 0) {
+        size_t column = einfo.token.start - einfo.line_start + 1;
+        fprintf(stderr,
+                "failed to assemble, %s, line=%zu, col=%zu token=%.*s\n",
+                ERRORS[err], einfo.line, column, (int)einfo.token.len,
+                &input.buf[einfo.token.start]);
+        goto done;
+    }
+    if (hex_out) {
+        hd(out.buf, out.len);
+    } else {
+        fwrite(out.buf, 1, out.len, stdout);
+    }
 
 done:
-  free(ht);
-  free(input.buf);
-  free(out.buf);
-  return err;
+    free(ht);
+    free(input.buf);
+    free(out.buf);
+    return err;
 }
diff --git a/src/instructions.c b/src/instructions.c
index 44f2e02..1af9d08 100644
--- a/src/instructions.c
+++ b/src/instructions.c
@@ -1,7 +1,7 @@
 typedef struct InstDesc_s {
-  char *mnemonic;
-  unsigned char opcode;
-  Operands type;
+    char *mnemonic;
+    unsigned char opcode;
+    Operands type;
 } InstDesc;
 
 const InstDesc INST[] = {
@@ -68,11 +68,11 @@ const InstDesc INST[] = {
 
 const size_t INST_CNT = sizeof(INST) / sizeof(INST[0]);
 size_t inst_find(const char *mnemonic, size_t len) {
-  for (size_t ii = 0; ii < INST_CNT; ii += 1) {
-    const char *entry = INST[ii].mnemonic;
-    if (strncmp(entry, mnemonic, len) == 0 && entry[len] == '\0') {
-      return ii;
+    for (size_t ii = 0; ii < INST_CNT; ii += 1) {
+        const char *entry = INST[ii].mnemonic;
+        if (strncmp(entry, mnemonic, len) == 0 && entry[len] == '\0') {
+            return ii;
+        }
     }
-  }
-  return INVALID;
+    return INVALID;
 }
diff --git a/src/register.c b/src/register.c
index 15047d2..b393d8b 100644
--- a/src/register.c
+++ b/src/register.c
@@ -1,23 +1,23 @@
 int parse_register(char *name, size_t len) {
-  if (name[0] != 'r') {
-    return 256;  // Register name should start with 'r'
-  }
-  if (len > 4) {
-    return 256;  // Register name too long
-  }
-  uint16_t rv = 0;
-  if (len > 2 && name[1] == '0') {
-    return 256;  // Extra zero suffix
-  }
-  for (size_t ii = 1; ii < len; ii += 1) {
-    char chr = name[ii];
-    if (!(chr >= '0' && chr <= '9')) {
-      return 256;  // Register name must only contain numbers
+    if (name[0] != 'r') {
+        return 256;  // Register name should start with 'r'
     }
-    rv = rv * 10 + (chr - '0');
-  }
-  if (rv > 255) {
-    return 256;  // Register number too large
-  }
-  return (int)rv;
+    if (len > 4) {
+        return 256;  // Register name too long
+    }
+    uint16_t rv = 0;
+    if (len > 2 && name[1] == '0') {
+        return 256;  // Extra zero suffix
+    }
+    for (size_t ii = 1; ii < len; ii += 1) {
+        char chr = name[ii];
+        if (!(chr >= '0' && chr <= '9')) {
+            return 256;  // Register name must only contain numbers
+        }
+        rv = rv * 10 + (chr - '0');
+    }
+    if (rv > 255) {
+        return 256;  // Register number too large
+    }
+    return (int)rv;
 }
diff --git a/src/token.c b/src/token.c
index d8ee1a2..c8bf3ae 100644
--- a/src/token.c
+++ b/src/token.c
@@ -23,7 +23,8 @@ Token token_ident(char *input, size_t len, size_t pos) {
     while (pos < len) {
         char chr = input[pos];
         char chru = chr & ~0x20;
-        int good = chr == '_' || (chr >= '0' && chr <= '9') || (chru >= 'A' && chru <= 'Z');
+        int good = chr == '_' || (chr >= '0' && chr <= '9') ||
+                   (chru >= 'A' && chru <= 'Z');
         if (!good) {
             break;
         }