1 files changed, 50 insertions, 20 deletions

diff --git a/BigInt.c b/BigInt.c
index 1e1a0db..fe0eedf 100644
--- a/BigInt.c
+++ b/BigInt.c
@@ -18,8 +18,8 @@ struct BigIntMeta {
 };
 
 static inline struct BigIntMeta*
-B_metadata(BigInt s) {
-return (struct BigIntMeta*)(s - sizeof(struct BigIntMeta));
+B_metadata(const BigInt s) {
+    return (struct BigIntMeta*)(s - sizeof(struct BigIntMeta));
 }
 
 /** Helpers **/
@@ -127,7 +127,7 @@ B_newbytes(MemoryManager *mm, usize bytes) {
 }
 
 BigInt
-B_dup(MemoryManager *mm, BigInt bigint) {
+B_dup(MemoryManager *mm, const BigInt bigint) {
     if (NULL == bigint)
         return NULL;
 
@@ -182,10 +182,13 @@ B_free(BigInt *bigint) {
 /* Modify */
 
 Result
-B_sum(BigInt *inta, BigInt intb) {
-    if (NULL == inta || NULL == intb || NULL == *inta)
+B_sum(BigInt *inta, const BigInt intb) {
+    if (NULL == inta || NULL == intb)
         return R_NullArgument;
 
+    if (NULL == *inta)
+        return R_InvalidArgument;
+
     struct BigIntMeta *am = B_metadata(*inta), *bm = B_metadata(intb);
 
     if (am->resizeable && am->words < bm->words) {
@@ -226,10 +229,13 @@ B_sum(BigInt *inta, BigInt intb) {
 }
 
 Result
-B_sub(BigInt *inta, BigInt intb) {
-    if (NULL == inta || NULL == intb || NULL == *inta)
+B_sub(BigInt *inta, const BigInt intb) {
+    if (NULL == inta || NULL == intb)
         return R_NullArgument;
 
+    if (NULL == *inta)
+        return R_InvalidArgument;
+
     struct BigIntMeta *am = B_metadata(*inta), *bm = B_metadata(intb);
 
     if (am->resizeable && am->words < bm->words) {
@@ -269,6 +275,8 @@ B_sub(BigInt *inta, BigInt intb) {
     return R_Ok;
 }
 
+
+
 Result
 B_compl(BigInt *intx) {
     if (NULL == intx)
@@ -284,11 +292,14 @@ B_compl(BigInt *intx) {
 }
 
 Result
-B_bitand(BigInt *intx, BigInt *inty) {
+B_bitand(BigInt *intx, const BigInt inty) {
     if (NULL == intx || NULL == inty)
         return R_NullArgument;
 
-    struct BigIntMeta *xm = B_metadata(intx), *ym = B_metadata(inty);
+    if (NULL == *intx)
+        return R_InvalidArgument;
+
+    struct BigIntMeta *xm = B_metadata(*intx), *ym = B_metadata(inty);
 
     if (xm->resizeable && xm->words < ym->words) {
         RETURN_NOTOK(B_resize(intx, ym->words));
@@ -306,11 +317,14 @@ B_bitand(BigInt *intx, BigInt *inty) {
 }
 
 Result
-B_bitor(BigInt *intx, BigInt *inty) {
+B_bitor(BigInt *intx, const BigInt inty) {
     if (NULL == intx || NULL == inty)
         return R_NullArgument;
 
-    struct BigIntMeta *xm = B_metadata(intx), *ym = B_metadata(inty);
+    if (NULL == *intx)
+        return R_InvalidArgument;
+
+    struct BigIntMeta *xm = B_metadata(*intx), *ym = B_metadata(inty);
 
     if (xm->resizeable && xm->words < ym->words) {
         RETURN_NOTOK(B_resize(intx, ym->words));
@@ -328,11 +342,14 @@ B_bitor(BigInt *intx, BigInt *inty) {
 }
 
 Result
-B_bitxor(BigInt *intx, BigInt *inty) {
+B_bitxor(BigInt *intx, const BigInt inty) {
     if (NULL == intx || NULL == inty)
         return R_NullArgument;
 
-    struct BigIntMeta *xm = B_metadata(intx), *ym = B_metadata(inty);
+    if (NULL == *intx)
+        return R_InvalidArgument;
+
+    struct BigIntMeta *xm = B_metadata(*intx), *ym = B_metadata(inty);
 
     if (xm->resizeable && xm->words < ym->words) {
         RETURN_NOTOK(B_resize(intx, ym->words));
@@ -351,13 +368,20 @@ B_bitxor(BigInt *intx, BigInt *inty) {
 
 Result
 B_rshift(BigInt *intx, usize shift) {
-    if (NULL == intx || NULL == *intx)
+    if (NULL == intx)
         return R_NullArgument;
 
-    if (shift == 0)
+    if (NULL == *intx)
+        return R_InvalidArgument;
+
+    if (0 == shift)
         return R_Ok;
 
     struct BigIntMeta *xm = B_metadata(*intx);
+
+    if (0 == xm->words)
+        return R_Uninitialized;
+
     UWord *x = *intx;
 
     usize word_moves = shift / UWORD_BIT;
@@ -392,14 +416,20 @@ B_rshift(BigInt *intx, usize shift) {
 
 Result
 B_lshift(BigInt *intx, usize shift) {
-    if (NULL == intx || NULL == *intx)
+    if (NULL == intx)
         return R_NullArgument;
 
-    if (shift == 0)
+    if (NULL == *intx)
+        return R_InvalidArgument;
+
+    if (0 == shift)
         return R_Ok;
 
     struct BigIntMeta *xm = B_metadata(*intx);
 
+    if (0 == xm->words)
+        return R_Uninitialized;
+
     if (xm->resizeable) {
         UWord width = B_bitwidth(*intx);
         if (width + shift > xm->words * UWORD_BIT) {
@@ -445,14 +475,14 @@ B_lshift(BigInt *intx, usize shift) {
 /* Get */
 
 usize
-B_bytes(BigInt x) {
+B_bytes(const BigInt x) {
     if (NULL == x)
         return 0;
     return B_metadata(x)->words * sizeof(UWord);
 }
 
 usize
-B_bitwidth(BigInt intx) {
+B_bitwidth(const BigInt intx) {
     if (NULL == intx)
         return 0;
 
@@ -474,7 +504,7 @@ B_bitwidth(BigInt intx) {
 }
 
 char*
-B_tostr(MemoryManager *mm, BigInt intx) {
+B_tostr(MemoryManager *mm, const BigInt intx) {
     if (NULL == intx)
         return NULL;