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Merged
youknowone merged 1 commit into from
Jan 13, 2026
+234 −36
Merged

Fix wasm build #13

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4 changes: 4 additions & 0 deletions Cargo.toml
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Original file line number Diff line number Diff line change
Expand Up @@ -22,6 +22,10 @@ _bigint = ["dep:num-traits", "dep:num-integer"] # Internal feature. User must u
# See also: https://github.com/python/cpython/issues/132763
mul_add = []

# For WASM and other targets without native libm
[target.'cfg(not(any(unix, windows)))'.dependencies]
libm = "0.2"

[dependencies]
libc = "0.2"
num-complex = { version = "0.4", optional = true }
Expand Down
10 changes: 8 additions & 2 deletions src/err.rs
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Original file line number Diff line number Diff line change
Expand Up @@ -44,7 +44,10 @@ pub(crate) fn set_errno(value: i32) {
unsafe {
*_errno() = value;
}
#[cfg(all(unix, not(any(target_os = "linux", target_os = "android", target_os = "macos"))))]
#[cfg(all(
unix,
not(any(target_os = "linux", target_os = "android", target_os = "macos"))
))]
unsafe {
// FreeBSD, NetBSD, OpenBSD, etc. use __error()
*libc::__error() = value;
Expand Down Expand Up @@ -73,7 +76,10 @@ pub(crate) fn get_errno() -> i32 {
unsafe {
*_errno()
}
#[cfg(all(unix, not(any(target_os = "linux", target_os = "android", target_os = "macos"))))]
#[cfg(all(
unix,
not(any(target_os = "linux", target_os = "android", target_os = "macos"))
))]
unsafe {
// FreeBSD, NetBSD, OpenBSD, etc. use __error()
*libc::__error()
Expand Down
7 changes: 7 additions & 0 deletions src/lib.rs
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Original file line number Diff line number Diff line change
Expand Up @@ -5,7 +5,14 @@ pub mod math;

// Internal modules
mod err;
// Native libm via FFI (unix/windows)
#[cfg(any(unix, windows))]
pub(crate) mod m;
// Pure Rust libm for WASM and other targets
#[cfg(not(any(unix, windows)))]
#[path = "m_rust.rs"]
pub(crate) mod m;
#[cfg(any(unix, windows))]
mod m_sys;
#[cfg(test)]
mod test;
Expand Down
211 changes: 211 additions & 0 deletions src/m_rust.rs
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Original file line number Diff line number Diff line change
@@ -0,0 +1,211 @@
//! Pure Rust implementations of libm functions using the libm crate.
//! Used on targets without native libm (e.g., WASM).

// Trigonometric functions

#[inline(always)]
pub fn acos(n: f64) -> f64 {
libm::acos(n)
}

#[inline(always)]
pub fn asin(n: f64) -> f64 {
libm::asin(n)
}

#[inline(always)]
pub fn atan(n: f64) -> f64 {
libm::atan(n)
}

#[inline(always)]
pub fn atan2(y: f64, x: f64) -> f64 {
libm::atan2(y, x)
}

#[inline(always)]
pub fn cos(n: f64) -> f64 {
libm::cos(n)
}

#[inline(always)]
pub fn sin(n: f64) -> f64 {
libm::sin(n)
}

#[inline(always)]
pub fn tan(n: f64) -> f64 {
libm::tan(n)
}

// Hyperbolic functions

#[inline(always)]
pub fn acosh(n: f64) -> f64 {
libm::acosh(n)
}

#[inline(always)]
pub fn asinh(n: f64) -> f64 {
libm::asinh(n)
}

#[inline(always)]
pub fn atanh(n: f64) -> f64 {
libm::atanh(n)
}

#[inline(always)]
pub fn cosh(n: f64) -> f64 {
libm::cosh(n)
}

#[inline(always)]
pub fn sinh(n: f64) -> f64 {
libm::sinh(n)
}

#[inline(always)]
pub fn tanh(n: f64) -> f64 {
libm::tanh(n)
}

// Exponential and logarithmic functions

#[inline(always)]
pub fn exp(n: f64) -> f64 {
libm::exp(n)
}

#[inline(always)]
pub fn exp2(n: f64) -> f64 {
libm::exp2(n)
}

#[inline(always)]
pub fn expm1(n: f64) -> f64 {
libm::expm1(n)
}

#[inline(always)]
pub fn log(n: f64) -> f64 {
libm::log(n)
}

#[inline(always)]
pub fn log10(n: f64) -> f64 {
libm::log10(n)
}

#[inline(always)]
pub fn log1p(n: f64) -> f64 {
libm::log1p(n)
}

#[inline(always)]
pub fn log2(n: f64) -> f64 {
libm::log2(n)
}

// Power functions

#[inline(always)]
pub fn cbrt(n: f64) -> f64 {
libm::cbrt(n)
}

#[inline(always)]
pub fn hypot(x: f64, y: f64) -> f64 {
libm::hypot(x, y)
}

#[inline(always)]
pub fn pow(x: f64, y: f64) -> f64 {
libm::pow(x, y)
}

#[inline(always)]
pub fn sqrt(n: f64) -> f64 {
libm::sqrt(n)
}

// Floating-point manipulation functions

#[inline(always)]
pub fn ceil(n: f64) -> f64 {
libm::ceil(n)
}

#[inline(always)]
pub fn copysign(x: f64, y: f64) -> f64 {
libm::copysign(x, y)
}

#[inline(always)]
pub fn fabs(n: f64) -> f64 {
libm::fabs(n)
}

#[inline(always)]
pub fn floor(n: f64) -> f64 {
libm::floor(n)
}

#[inline(always)]
pub fn fmod(x: f64, y: f64) -> f64 {
libm::fmod(x, y)
}

#[inline(always)]
pub fn frexp(n: f64, exp: &mut i32) -> f64 {
let (mantissa, exponent) = libm::frexp(n);
*exp = exponent;
mantissa
}

#[inline(always)]
pub fn ldexp(x: f64, n: i32) -> f64 {
libm::ldexp(x, n)
}

#[inline(always)]
pub fn modf(n: f64, iptr: &mut f64) -> f64 {
let (frac, int) = libm::modf(n);
*iptr = int;
frac
}
Comment on lines +159 to +176
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@coderabbitai coderabbitai bot Jan 13, 2026

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⚠️ Potential issue | 🟠 Major

Signature mismatch: frexp and modf use references vs raw pointers.

The m_sys.rs FFI declarations use raw pointers (*mut i32, *mut f64), while these pure Rust wrappers use safe references (&mut i32, &mut f64). If callers use raw pointers (common in FFI-adjacent code), this will cause compilation errors on WASM.

Verify if existing call sites use references or raw pointers:

#!/bin/bash
# Check how frexp and modf are called in the codebase
rg -n '\bm::(frexp|modf)\s*\(' src/ -A2
🤖 Prompt for AI Agents 
In @src/m_rust.rs around lines 159 - 176, The wrappers frexp and modf currently
take safe references (&mut i32, &mut f64) but the FFI declarations in m_sys.rs
expect raw pointers (*mut i32, *mut f64); change frexp to pub fn frexp(n: f64,
exp: *mut i32) -> f64 and modf to pub fn modf(n: f64, iptr: *mut f64) -> f64,
dereference the pointers inside an unsafe block to assign the returned
exponent/int (e.g., let (mantissa, exponent) = libm::frexp(n); unsafe { if
!exp.is_null() { *exp = exponent } } ), and similarly for modf, preserving
return values; ensure ldexp remains unchanged, and run the suggested rg search
to verify/update all call sites that pass raw pointers.


#[inline(always)]
pub fn nextafter(x: f64, y: f64) -> f64 {
libm::nextafter(x, y)
}

#[inline(always)]
pub fn remainder(x: f64, y: f64) -> f64 {
libm::remainder(x, y)
}

#[inline(always)]
pub fn trunc(n: f64) -> f64 {
libm::trunc(n)
}

// Special functions

#[inline(always)]
pub fn erf(n: f64) -> f64 {
libm::erf(n)
}

#[inline(always)]
pub fn erfc(n: f64) -> f64 {
libm::erfc(n)
}

// Platform-specific sincos (fallback: call sin and cos separately)

#[cfg(feature = "complex")]
#[inline(always)]
pub fn sincos(x: f64) -> (f64, f64) {
(libm::sin(x), libm::cos(x))
}
Comment on lines +207 to +211
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⚠️ Potential issue | 🔴 Critical

🧩 Analysis chain

🏁 Script executed:

# Check for sincos declaration in m_sys.rs
grep -n "sincos" src/m_sys.rs

Repository: RustPython/pymath

Length of output: 178

🏁 Script executed:

# Check for m::sincos usage in cmath module
rg -n 'm::sincos' src/cmath/

Repository: RustPython/pymath

Length of output: 349

🏁 Script executed:

# Check the module structure to understand how m:: is resolved
cat -n src/lib.rs | head -80

Repository: RustPython/pymath

Length of output: 3360

🏁 Script executed:

# Look for any sincos declarations across the codebase
rg -n "fn sincos" src/ --type rs

Repository: RustPython/pymath

Length of output: 87

🏁 Script executed:

# Check if there's feature gating around sincos in m_rust.rs
rg -B 5 -A 5 "sincos" src/m_rust.rs

Repository: RustPython/pymath

Length of output: 316

🏁 Script executed:

# Get line count of m_sys.rs
wc -l src/m_sys.rs

Repository: RustPython/pymath

Length of output: 76

🏁 Script executed:

# Read m_sys.rs to see if sincos is missing or if there's feature gating
cat -n src/m_sys.rs

Repository: RustPython/pymath

Length of output: 2731

🏁 Script executed:

# Verify compilation by checking Cargo.toml features
cat src/../Cargo.toml | grep -A 20 "\[features\]"

Repository: RustPython/pymath

Length of output: 992

Add sincos FFI declaration to m_sys.rs.

The sincos function is defined in m_rust.rs (lines 207-211) with the complex feature gate, but m_sys.rs lacks the corresponding FFI binding. On unix/windows targets with the complex feature enabled (default), the cmath module calls m::sincos at 4 locations (trigonometric.rs:121, 167; misc.rs:72; exponential.rs:115), which would fail to compile because sincos is not declared in the system libm FFI. Add the FFI declaration: pub fn sincos(x: f64) -> (f64, f64); to match the fallback implementation in m_rust.rs and enable CPython-compatible behavior on unix/windows.

🤖 Prompt for AI Agents 
In @src/m_rust.rs around lines 207 - 211, m_sys.rs is missing the FFI binding
for the sincos function defined under the complex feature in m_rust.rs, causing
unresolved calls to m::sincos from the cmath module; add the FFI declaration
matching the Rust fallback: declare pub fn sincos(x: f64) -> (f64, f64); inside
m_sys.rs (under the same cfg(feature = "complex")/platform-appropriate block) so
calls from trigonometric.rs, misc.rs and exponential.rs link correctly on
unix/windows when the complex feature is enabled.

38 changes: 4 additions & 34 deletions src/m_sys.rs
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Original file line number Diff line number Diff line change
@@ -1,5 +1,7 @@
// These symbols are all defined by `libm`,
// or by `compiler-builtins` on unsupported platforms.
// Raw FFI declarations for system libm.
// Only available on unix/windows where native libm exists.

#[cfg(any(unix, windows))]
#[cfg_attr(unix, link(name = "m"))]
#[allow(dead_code)]
unsafe extern "C" {
Expand Down Expand Up @@ -45,7 +47,6 @@ unsafe extern "C" {
pub fn ceil(n: f64) -> f64;
pub fn copysign(x: f64, y: f64) -> f64;
pub fn fabs(n: f64) -> f64;
// pub fn fdim(a: f64, b: f64) -> f64;
pub fn fdimf(a: f32, b: f32) -> f32;
pub fn floor(n: f64) -> f64;
pub fn fmod(x: f64, y: f64) -> f64;
Expand All @@ -61,38 +62,7 @@ unsafe extern "C" {
pub fn erfc(n: f64) -> f64;
pub fn erff(n: f32) -> f32;
pub fn erfcf(n: f32) -> f32;
// pub fn lgamma_r(n: f64, s: &mut i32) -> f64;
#[cfg(not(target_os = "aix"))]
pub fn lgammaf_r(n: f32, s: &mut i32) -> f32;
// pub fn tgamma(n: f64) -> f64;
pub fn tgammaf(n: f32) -> f32;

// pub fn acosf128(n: f128) -> f128;
// pub fn asinf128(n: f128) -> f128;
// pub fn atanf128(n: f128) -> f128;
// pub fn atan2f128(a: f128, b: f128) -> f128;
// pub fn cbrtf128(n: f128) -> f128;
// pub fn coshf128(n: f128) -> f128;
// pub fn expm1f128(n: f128) -> f128;
// pub fn hypotf128(x: f128, y: f128) -> f128;
// pub fn log1pf128(n: f128) -> f128;
// pub fn sinhf128(n: f128) -> f128;
// pub fn tanf128(n: f128) -> f128;
// pub fn tanhf128(n: f128) -> f128;
// pub fn tgammaf128(n: f128) -> f128;
// pub fn lgammaf128_r(n: f128, s: &mut i32) -> f128;
// pub fn erff128(n: f128) -> f128;
// pub fn erfcf128(n: f128) -> f128;

// cfg_if::cfg_if! {
// if #[cfg(not(all(target_os = "windows", target_env = "msvc", target_arch = "x86")))] {
// pub fn acosf(n: f32) -> f32;
// pub fn asinf(n: f32) -> f32;
// pub fn atan2f(a: f32, b: f32) -> f32;
// pub fn atanf(n: f32) -> f32;
// pub fn coshf(n: f32) -> f32;
// pub fn sinhf(n: f32) -> f32;
// pub fn tanf(n: f32) -> f32;
// pub fn tanhf(n: f32) -> f32;
// }}
}