From b66df46f33d8c8d0e12ffb50c7dd18688173b85d Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Florian=20Mei=C3=9Fner?= <florian.meissner@mailbox.org>
Date: Mon, 5 Jun 2023 23:04:25 +0000
Subject: [PATCH] strtof(), strtod(): handle NaN and Infinity
---
src/macros.rs | 129 ++++++++++--------
tests/expected/bins_static/stdlib/atof.stdout | 1 +
.../expected/bins_static/stdlib/strtod.stdout | 25 ++++
tests/stdlib/atof.c | 3 +
tests/stdlib/strtod.c | 11 ++
5 files changed, 111 insertions(+), 58 deletions(-)
diff --git a/src/macros.rs b/src/macros.rs
index 88383d659..01f7f3461 100644
--- a/src/macros.rs
+++ b/src/macros.rs
@@ -227,19 +227,19 @@ macro_rules! strto_impl {
num
}};
}
+
#[macro_export]
macro_rules! strto_float_impl {
($type:ident, $s:expr, $endptr:expr) => {{
let mut s = $s;
let endptr = $endptr;
- // TODO: Handle named floats: NaN, Inf...
-
while ctype::isspace(*s as c_int) != 0 {
s = s.offset(1);
}
let mut result: $type = 0.0;
+ let mut exponent: Option<$type> = None;
let mut radix = 10;
let result_sign = match *s as u8 {
@@ -254,75 +254,88 @@ macro_rules! strto_float_impl {
_ => 1.0,
};
- if *s as u8 == b'0' && *s.offset(1) as u8 == b'x' {
- s = s.offset(2);
- radix = 16;
- }
-
- while let Some(digit) = (*s as u8 as char).to_digit(radix) {
- result *= radix as $type;
- result += digit as $type;
- s = s.offset(1);
- }
-
- if *s as u8 == b'.' {
- s = s.offset(1);
+ let rust_s = CStr::from_ptr(s).to_string_lossy();
+
+ // detect NaN, Inf
+ if rust_s.to_lowercase().starts_with("inf") {
+ result = $type::INFINITY;
+ s = s.offset(3);
+ } else if rust_s.to_lowercase().starts_with("nan") {
+ // we cannot signal negative NaN in LLVM backed languages
+ // https://github.com/rust-lang/rust/issues/73328 , https://github.com/rust-lang/rust/issues/81261
+ result = $type::NAN;
+ s = s.offset(3);
+ } else {
+ if *s as u8 == b'0' && *s.offset(1) as u8 == b'x' {
+ s = s.offset(2);
+ radix = 16;
+ }
- let mut i = 1.0;
while let Some(digit) = (*s as u8 as char).to_digit(radix) {
- i *= radix as $type;
- result += digit as $type / i;
+ result *= radix as $type;
+ result += digit as $type;
s = s.offset(1);
}
- }
-
- let s_before_exponent = s;
- let exponent = match (*s as u8, radix) {
- (b'e' | b'E', 10) | (b'p' | b'P', 16) => {
+ if *s as u8 == b'.' {
s = s.offset(1);
- let is_exponent_positive = match *s as u8 {
- b'-' => {
- s = s.offset(1);
- false
- }
- b'+' => {
- s = s.offset(1);
- true
- }
- _ => true,
- };
-
- // Exponent digits are always in base 10.
- if (*s as u8 as char).is_digit(10) {
- let mut exponent_value = 0;
-
- while let Some(digit) = (*s as u8 as char).to_digit(10) {
- exponent_value *= 10;
- exponent_value += digit;
- s = s.offset(1);
- }
+ let mut i = 1.0;
+ while let Some(digit) = (*s as u8 as char).to_digit(radix) {
+ i *= radix as $type;
+ result += digit as $type / i;
+ s = s.offset(1);
+ }
+ }
- let exponent_base = match radix {
- 10 => 10u128,
- 16 => 2u128,
- _ => unreachable!(),
+ let s_before_exponent = s;
+
+ exponent = match (*s as u8, radix) {
+ (b'e' | b'E', 10) | (b'p' | b'P', 16) => {
+ s = s.offset(1);
+
+ let is_exponent_positive = match *s as u8 {
+ b'-' => {
+ s = s.offset(1);
+ false
+ }
+ b'+' => {
+ s = s.offset(1);
+ true
+ }
+ _ => true,
};
- if is_exponent_positive {
- Some(exponent_base.pow(exponent_value) as $type)
+ // Exponent digits are always in base 10.
+ if (*s as u8 as char).is_digit(10) {
+ let mut exponent_value = 0;
+
+ while let Some(digit) = (*s as u8 as char).to_digit(10) {
+ exponent_value *= 10;
+ exponent_value += digit;
+ s = s.offset(1);
+ }
+
+ let exponent_base = match radix {
+ 10 => 10u128,
+ 16 => 2u128,
+ _ => unreachable!(),
+ };
+
+ if is_exponent_positive {
+ Some(exponent_base.pow(exponent_value) as $type)
+ } else {
+ Some(1.0 / (exponent_base.pow(exponent_value) as $type))
+ }
} else {
- Some(1.0 / (exponent_base.pow(exponent_value) as $type))
+ // Exponent had no valid digits after 'e'/'p' and '+'/'-', rollback
+ s = s_before_exponent;
+ None
}
- } else {
- // Exponent had no valid digits after 'e'/'p' and '+'/'-', rollback
- s = s_before_exponent;
- None
}
- }
- _ => None,
- };
+ _ => None,
+ };
+ }
if !endptr.is_null() {
// This is stupid, but apparently strto* functions want
diff --git a/tests/expected/bins_static/stdlib/atof.stdout b/tests/expected/bins_static/stdlib/atof.stdout
index dd1835a6f..3227d8538 100644
--- a/tests/expected/bins_static/stdlib/atof.stdout
+++ b/tests/expected/bins_static/stdlib/atof.stdout
@@ -1 +1,2 @@
-3.140000
+inf
diff --git a/tests/expected/bins_static/stdlib/strtod.stdout b/tests/expected/bins_static/stdlib/strtod.stdout
index 5ed8e2ec1..a92def04f 100644
--- a/tests/expected/bins_static/stdlib/strtod.stdout
+++ b/tests/expected/bins_static/stdlib/strtod.stdout
@@ -169,3 +169,28 @@ d: -49999999999999998431683053958987776.000000 Endptr: ""
d: -500000000000000021210318687008980992.000000 Endptr: ""
d: -4999999999999999769381329101060571136.000000 Endptr: ""
d: -49999999999999998874404911728017014784.000000 Endptr: ""
+d: -0.000000 Endptr: ""
+d: inf Endptr: ""
+d: inf Endptr: ""
+d: inf Endptr: ""
+d: inf Endptr: " foobarbaz"
+d: inf Endptr: ""
+d: inf Endptr: ""
+d: inf Endptr: ""
+d: inf Endptr: " foobarbaz"
+d: -inf Endptr: ""
+d: -inf Endptr: ""
+d: -inf Endptr: ""
+d: -inf Endptr: " foobarbaz"
+d: nan Endptr: "0.1e5"
+d: nan Endptr: "-37"
+d: nan Endptr: "1.05"
+d: nan Endptr: " foo bar baz"
+d: nan Endptr: "0.1e5"
+d: nan Endptr: "-37"
+d: nan Endptr: "1.05"
+d: nan Endptr: " foo bar baz"
+d: nan Endptr: "0.1e5"
+d: nan Endptr: "-37"
+d: nan Endptr: "1.05"
+d: nan Endptr: " foo bar baz"
diff --git a/tests/stdlib/atof.c b/tests/stdlib/atof.c
index ec945ef69..f9783467b 100644
--- a/tests/stdlib/atof.c
+++ b/tests/stdlib/atof.c
@@ -6,4 +6,7 @@
int main(void) {
double d = atof("-3.14");
printf("%f\n", d);
+
+ d = atof("INF");
+ printf("%f\n", d);
}
diff --git a/tests/stdlib/strtod.c b/tests/stdlib/strtod.c
index fa1013ed0..44fd371ec 100644
--- a/tests/stdlib/strtod.c
+++ b/tests/stdlib/strtod.c
@@ -61,6 +61,17 @@ int main(void) {
"-0.5e25", "-0.5e26", "-0.5e27", "-0.5e28", "-0.5e29",
"-0.5e30", "-0.5e31", "-0.5e32", "-0.5e33", "-0.5e34",
"-0.5e35", "-0.5e36", "-0.5e37", "-0.5e38",
+
+ "-0",
+
+ "INF", "inf", "iNf", "Inf foobarbaz",
+ "+INF", "+inf", "+iNf", "+Inf foobarbaz",
+ "-INF", "-inf", "-iNf", "-Inf foobarbaz",
+
+ "NaN0.1e5", "nan-37", "nAn1.05", "Nan foo bar baz",
+ "+NaN0.1e5", "+nan-37", "+nAn1.05", "+Nan foo bar baz",
+ "-NaN0.1e5", "-nan-37", "-nAn1.05", "-Nan foo bar baz",
+
};
for (int i = 0; i < sizeof(inputs) / sizeof(char*); i += 1) {
d = strtod(inputs[i], &endptr);
--
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