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Canonical handling of overflow to remove compiler warning / avoid UB #362

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Merged
MichaelChirico merged 9 commits into from
Aug 16, 2026
Merged

Canonical handling of overflow to remove compiler warning / avoid UB #362

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342d2cc
Gemini: canonical handling of overflow to remove compiler warning / a…
MichaelChirico Aug 16, 2026
33e7c19
shared warning message to reduce noise
MichaelChirico Aug 16, 2026
e93508f
Gemini: more tests around NA_INTEGER64 sentinel value
MichaelChirico Aug 16, 2026
a83b8e2
touch-up esp. comments
MichaelChirico Aug 16, 2026
4b4ea7f
Gemini: more tests for coverage
MichaelChirico Aug 16, 2026
fadfacb
Gemini: include results in expect_warning test
MichaelChirico Aug 16, 2026
0e31f4c
delint
MichaelChirico Aug 16, 2026
86b1b65
Gemini: nocov rather than a fake test
MichaelChirico Aug 16, 2026
160df8d
clarifying comment
MichaelChirico Aug 16, 2026
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137 changes: 60 additions & 77 deletions src/integer64.c
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Original file line number Diff line number Diff line change
Expand Up @@ -2,7 +2,7 @@
# C-Code
# S3 atomic 64bit integers for R
# (c) 2011-2024 Jens Oehlschägel
# (c) 2025 Michael Chirico
# (c) 2025-2026 Michael Chirico
# Licence: GPL2
# Provided 'as is', use at your own risk
# Created: 2011-12-11
Expand Down Expand Up @@ -227,11 +227,13 @@ SEXP as_integer64_bitstring(SEXP x_, SEXP ret_){
for(i=0; i<n; i++){
str = CHAR(STRING_ELT(x_, i));
l = strlen(str);
if (l>BITS_INTEGER64){
// # nocov start: only reachable with invalid bitstring input
if (l > BITS_INTEGER64){
ret[i] = NA_INTEGER64;
naflag = TRUE;
break;
}
// # nocov end
mask = 1;
v = 0;
for (k=l-1; k>=0; k--){
Expand All @@ -243,13 +245,13 @@ SEXP as_integer64_bitstring(SEXP x_, SEXP ret_){
ret[i] = v;
R_CheckUserInterrupt();
}
if (naflag)warning(BITSTRING_OVERFLOW_WARNING);
if (naflag)warning(BITSTRING_OVERFLOW_WARNING); // # nocov
return ret_;
}



__attribute__((no_sanitize("signed-integer-overflow"))) SEXP plus_integer64(SEXP e1_, SEXP e2_, SEXP ret_){
SEXP plus_integer64(SEXP e1_, SEXP e2_, SEXP ret_){
long long i, n = LENGTH(ret_);
long long i1, n1 = LENGTH(e1_);
long long i2, n2 = LENGTH(e2_);
Expand All @@ -264,7 +266,7 @@ __attribute__((no_sanitize("signed-integer-overflow"))) SEXP plus_integer64(SEXP
return ret_;
}

__attribute__((no_sanitize("signed-integer-overflow"))) SEXP minus_integer64(SEXP e1_, SEXP e2_, SEXP ret_){
SEXP minus_integer64(SEXP e1_, SEXP e2_, SEXP ret_){
long long i, n = LENGTH(ret_);
long long i1, n1 = LENGTH(e1_);
long long i2, n2 = LENGTH(e2_);
Expand All @@ -279,7 +281,7 @@ __attribute__((no_sanitize("signed-integer-overflow"))) SEXP minus_integer64(SEX
return ret_;
}

__attribute__((no_sanitize("signed-integer-overflow"))) SEXP diff_integer64(SEXP x_, SEXP lag_, SEXP n_, SEXP ret_){
SEXP diff_integer64(SEXP x_, SEXP lag_, SEXP n_, SEXP ret_){
long long i, n = *((long long *) REAL(n_));
long long * x = (long long *) REAL(x_);
long long * lag = (long long *) REAL(lag_);
Expand Down Expand Up @@ -326,7 +328,7 @@ SEXP mod_integer64(SEXP e1_, SEXP e2_, SEXP ret_){
}


__attribute__((no_sanitize("signed-integer-overflow"))) SEXP times_integer64_integer64(SEXP e1_, SEXP e2_, SEXP ret_){
SEXP times_integer64_integer64(SEXP e1_, SEXP e2_, SEXP ret_){
long long i, n = LENGTH(ret_);
long long i1, n1 = LENGTH(e1_);
long long i2, n2 = LENGTH(e2_);
Expand Down Expand Up @@ -612,36 +614,31 @@ SEXP sum_integer64(SEXP e1_, SEXP na_rm_, SEXP ret_){
long long i, n = LENGTH(e1_);
long long * e1 = (long long *) REAL(e1_);
long long * ret = (long long *) REAL(ret_);
long long cumsum, tempsum;
cumsum = 0;
if (asLogical(na_rm_)){
for(i=0; i<n; i++){
if (e1[i]!=NA_INTEGER64){
tempsum = cumsum + e1[i];
if (!GOODISUM64(cumsum, e1[i], tempsum)){
warning(INTEGER64_OVERFLOW_WARNING);
ret[0] = NA_INTEGER64;
return ret_;
}
cumsum = tempsum;
}
long long cumsum = 0;
if (asLogical(na_rm_)){
for(i=0; i<n; i++){
if (e1[i]!=NA_INTEGER64){
if (add64_overflow(cumsum, e1[i], &cumsum)){
warning(INTEGER64_OVERFLOW_WARNING);
ret[0] = NA_INTEGER64;
return ret_;
}
}else{
for(i=0; i<n; i++){
if (e1[i]==NA_INTEGER64){
ret[0] = NA_INTEGER64;
return ret_;
}else{
tempsum = cumsum + e1[i];
if (!GOODISUM64(cumsum, e1[i], tempsum)){
warning(INTEGER64_OVERFLOW_WARNING);
ret[0] = NA_INTEGER64;
return ret_;
}
cumsum = tempsum;
}
}
}
}else{
for(i=0; i<n; i++){
if (e1[i]==NA_INTEGER64){
ret[0] = NA_INTEGER64;
return ret_;
}else{
if (add64_overflow(cumsum, e1[i], &cumsum)){
warning(INTEGER64_OVERFLOW_WARNING);
ret[0] = NA_INTEGER64;
return ret_;
}
}
}
}
ret[0] = cumsum;
return ret_;
}
Expand Down Expand Up @@ -678,36 +675,31 @@ SEXP prod_integer64(SEXP e1_, SEXP na_rm_, SEXP ret_){
long long i, n = LENGTH(e1_);
long long * e1 = (long long *) REAL(e1_);
long long * ret = (long long *) REAL(ret_);
long long cumprod, tempprod;
cumprod = 1;
if (asLogical(na_rm_)){
for(i=0; i<n; i++){
if (e1[i]!=NA_INTEGER64){
tempprod = cumprod * e1[i];
if (!GOODIPROD64(cumprod, e1[i], tempprod)){
warning(INTEGER64_OVERFLOW_WARNING);
ret[0] = NA_INTEGER64;
return ret_;
}
cumprod = tempprod;
}
long long cumprod = 1;
if (asLogical(na_rm_)){
for(i=0; i<n; i++){
if (e1[i]!=NA_INTEGER64){
if (mul64_overflow(cumprod, e1[i], &cumprod)){
warning(INTEGER64_OVERFLOW_WARNING);
ret[0] = NA_INTEGER64;
return ret_;
}
}else{
for(i=0; i<n; i++){
if (e1[i]==NA_INTEGER64){
ret[0] = NA_INTEGER64;
return ret_;
}else{
tempprod = cumprod * e1[i];
if (!GOODIPROD64(cumprod, e1[i], tempprod)){
warning(INTEGER64_OVERFLOW_WARNING);
ret[0] = NA_INTEGER64;
return ret_;
}
cumprod = tempprod;
}
}
}
}else{
for(i=0; i<n; i++){
if (e1[i]==NA_INTEGER64){
ret[0] = NA_INTEGER64;
return ret_;
}else{
if (mul64_overflow(cumprod, e1[i], &cumprod)){
warning(INTEGER64_OVERFLOW_WARNING);
ret[0] = NA_INTEGER64;
return ret_;
}
}
}
}
ret[0] = cumprod;
return ret_;
}
Expand Down Expand Up @@ -1065,7 +1057,7 @@ SEXP as_list_integer64(SEXP x_){
return x_;
}

__attribute__((no_sanitize("signed-integer-overflow"))) SEXP matmult_integer64_integer64(SEXP x_, SEXP y_, SEXP ret_){
SEXP matmult_integer64_integer64(SEXP x_, SEXP y_, SEXP ret_){
long long i, j, k;
// get dimension of x
SEXP dim1 = getAttrib(x_, R_DimSymbol);
Expand All @@ -1080,7 +1072,7 @@ __attribute__((no_sanitize("signed-integer-overflow"))) SEXP matmult_integer64_i
long long * y = (long long *) REAL(y_);
long long * ret = (long long *) REAL(ret_);
Rboolean naflag = FALSE;
long long cumsum, tempsum, addValue;
long long cumsum, addValue;

for(i=0; i<nrow1; i++){
for(j=0; j<ncol2; j++){
Expand All @@ -1091,16 +1083,11 @@ __attribute__((no_sanitize("signed-integer-overflow"))) SEXP matmult_integer64_i
cumsum = NA_INTEGER64;
break;
}
tempsum = cumsum + addValue;
// for some reason GOODISUM64(cumsum, addValue, tempsum) does not work properly on macos-latest, compared to the others
// therefore a workaround is tried here by adding the GOODISUM64 logic with long double casting
if(!GOODISUM64(cumsum, addValue, tempsum) ||
!((cumsum > 0) ? (((long double) addValue) < ((long double) tempsum)) : ! (((long double) addValue) < ((long double) tempsum)))){
if(add64_overflow(cumsum, addValue, &cumsum)){
naflag = TRUE;
cumsum = NA_INTEGER64;
break;
}
cumsum = tempsum;
}
ret[i + j*nrow1] = cumsum;
}
Expand All @@ -1125,7 +1112,7 @@ SEXP matmult_double_integer64(SEXP x_, SEXP y_, SEXP ret_){
long long * y = (long long *) REAL(y_);
long long * ret = (long long *) REAL(ret_);
Rboolean naflag = FALSE;
long long cumsum, tempsum, addValue;
long long cumsum, addValue;
long double longret;

for(i=0; i<nrow1; i++){
Expand All @@ -1137,13 +1124,11 @@ SEXP matmult_double_integer64(SEXP x_, SEXP y_, SEXP ret_){
cumsum = NA_INTEGER64;
break;
}
tempsum = cumsum + addValue;
if(!GOODISUM64(cumsum, addValue, tempsum)){
if(add64_overflow(cumsum, addValue, &cumsum)){
naflag = TRUE;
cumsum = NA_INTEGER64;
break;
}
cumsum = tempsum;
}
ret[i + j*nrow1] = cumsum;
}
Expand All @@ -1167,7 +1152,7 @@ SEXP matmult_integer64_double(SEXP x_, SEXP y_, SEXP ret_){
double * y = REAL(y_);
long long * ret = (long long *) REAL(ret_);
Rboolean naflag = FALSE;
long long cumsum, tempsum, addValue;
long long cumsum, addValue;
long double longret;

for(i=0; i<nrow1; i++){
Expand All @@ -1179,13 +1164,11 @@ SEXP matmult_integer64_double(SEXP x_, SEXP y_, SEXP ret_){
cumsum = NA_INTEGER64;
break;
}
tempsum = cumsum + addValue;
if(!GOODISUM64(cumsum, addValue, tempsum)){
if(add64_overflow(cumsum, addValue, &cumsum)){
naflag = TRUE;
cumsum = NA_INTEGER64;
break;
}
cumsum = tempsum;
}
ret[i + j*nrow1] = cumsum;
}
Expand Down
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