| <!DOCTYPE html><html lang="en"><head><meta charset="utf-8"><meta name="viewport" content="width=device-width, initial-scale=1.0"><meta name="generator" content="rustdoc"><meta name="description" content="Source of the Rust file `crates/hir-ty/src/utils.rs`."><title>utils.rs - source</title><script>if(window.location.protocol!=="file:")document.head.insertAdjacentHTML("beforeend","SourceSerif4-Regular-6b053e98.ttf.woff2,FiraSans-Italic-81dc35de.woff2,FiraSans-Regular-0fe48ade.woff2,FiraSans-MediumItalic-ccf7e434.woff2,FiraSans-Medium-e1aa3f0a.woff2,SourceCodePro-Regular-8badfe75.ttf.woff2,SourceCodePro-Semibold-aa29a496.ttf.woff2".split(",").map(f=>`<link rel="preload" as="font" type="font/woff2"href="../../static.files/${f}">`).join(""))</script><link rel="stylesheet" href="../../static.files/normalize-9960930a.css"><link rel="stylesheet" href="../../static.files/rustdoc-77263533.css"><meta name="rustdoc-vars" data-root-path="../../" data-static-root-path="../../static.files/" data-current-crate="hir_ty" data-themes="" data-resource-suffix="" data-rustdoc-version="1.94.0 (4a4ef493e 2026-03-02)" data-channel="1.94.0" data-search-js="search-9e2438ea.js" data-stringdex-js="stringdex-b897f86f.js" data-settings-js="settings-c38705f0.js" ><script src="../../static.files/storage-e2aeef58.js"></script><script defer src="../../static.files/src-script-813739b1.js"></script><script defer src="../../src-files.js"></script><script defer src="../../static.files/main-7bab91a1.js"></script><noscript><link rel="stylesheet" href="../../static.files/noscript-ffcac47a.css"></noscript><link rel="alternate icon" type="image/png" href="../../static.files/favicon-32x32-eab170b8.png"><link rel="icon" type="image/svg+xml" href="../../static.files/favicon-044be391.svg"></head><body class="rustdoc src"><!--[if lte IE 11]><div class="warning">This old browser is unsupported and will most likely display funky things.</div><![endif]--><nav class="sidebar"><div class="src-sidebar-title"><h2>Files</h2></div></nav><div class="sidebar-resizer" title="Drag to resize sidebar"></div><main><section id="main-content" class="content"><div class="main-heading"><h1><div class="sub-heading">hir_ty/</div>utils.rs</h1><rustdoc-toolbar></rustdoc-toolbar></div><div class="example-wrap digits-3"><pre class="rust"><code><a href=#1 id=1 data-nosnippet>1</a><span class="doccomment">//! Helper functions for working with def, which don't need to be a separate |
| <a href=#2 id=2 data-nosnippet>2</a>//! query, but can't be computed directly from `*Data` (ie, which need a `db`). |
| <a href=#3 id=3 data-nosnippet>3</a> |
| <a href=#4 id=4 data-nosnippet>4</a></span><span class="kw">use </span>base_db::target::{<span class="self">self</span>, TargetData}; |
| <a href=#5 id=5 data-nosnippet>5</a><span class="kw">use </span>hir_def::{ |
| <a href=#6 id=6 data-nosnippet>6</a> EnumId, EnumVariantId, FunctionId, Lookup, TraitId, attrs::AttrFlags, lang_item::LangItems, |
| <a href=#7 id=7 data-nosnippet>7</a>}; |
| <a href=#8 id=8 data-nosnippet>8</a><span class="kw">use </span>intern::sym; |
| <a href=#9 id=9 data-nosnippet>9</a><span class="kw">use </span>rustc_abi::TargetDataLayout; |
| <a href=#10 id=10 data-nosnippet>10</a><span class="kw">use </span>span::Edition; |
| <a href=#11 id=11 data-nosnippet>11</a> |
| <a href=#12 id=12 data-nosnippet>12</a><span class="kw">use </span>crate::{ |
| <a href=#13 id=13 data-nosnippet>13</a> TargetFeatures, |
| <a href=#14 id=14 data-nosnippet>14</a> db::HirDatabase, |
| <a href=#15 id=15 data-nosnippet>15</a> layout::{Layout, TagEncoding}, |
| <a href=#16 id=16 data-nosnippet>16</a> lower::SupertraitsInfo, |
| <a href=#17 id=17 data-nosnippet>17</a> mir::pad16, |
| <a href=#18 id=18 data-nosnippet>18</a>}; |
| <a href=#19 id=19 data-nosnippet>19</a> |
| <a href=#20 id=20 data-nosnippet>20</a><span class="doccomment">/// SAFETY: `old_pointer` must be valid for unique writes |
| <a href=#21 id=21 data-nosnippet>21</a></span><span class="kw">pub</span>(<span class="kw">crate</span>) <span class="kw">unsafe fn </span>unsafe_update_eq<T>(old_pointer: <span class="kw-2">*mut </span>T, new_value: T) -> bool |
| <a href=#22 id=22 data-nosnippet>22</a><span class="kw">where |
| <a href=#23 id=23 data-nosnippet>23</a> </span>T: PartialEq, |
| <a href=#24 id=24 data-nosnippet>24</a>{ |
| <a href=#25 id=25 data-nosnippet>25</a> <span class="comment">// SAFETY: Caller obligation |
| <a href=#26 id=26 data-nosnippet>26</a> </span><span class="kw">let </span>old_ref: <span class="kw-2">&mut </span>T = <span class="kw">unsafe </span>{ <span class="kw-2">&mut *</span>old_pointer }; |
| <a href=#27 id=27 data-nosnippet>27</a> |
| <a href=#28 id=28 data-nosnippet>28</a> <span class="kw">if </span><span class="kw-2">*</span><span class="macro">old_ref !</span>= new_value { |
| <a href=#29 id=29 data-nosnippet>29</a> <span class="kw-2">*</span>old_ref = new_value; |
| <a href=#30 id=30 data-nosnippet>30</a> <span class="bool-val">true |
| <a href=#31 id=31 data-nosnippet>31</a> </span>} <span class="kw">else </span>{ |
| <a href=#32 id=32 data-nosnippet>32</a> <span class="comment">// Subtle but important: Eq impls can be buggy or define equality |
| <a href=#33 id=33 data-nosnippet>33</a> // in surprising ways. If it says that the value has not changed, |
| <a href=#34 id=34 data-nosnippet>34</a> // we do not modify the existing value, and thus do not have to |
| <a href=#35 id=35 data-nosnippet>35</a> // update the revision, as downstream code will not see the new value. |
| <a href=#36 id=36 data-nosnippet>36</a> </span><span class="bool-val">false |
| <a href=#37 id=37 data-nosnippet>37</a> </span>} |
| <a href=#38 id=38 data-nosnippet>38</a>} |
| <a href=#39 id=39 data-nosnippet>39</a> |
| <a href=#40 id=40 data-nosnippet>40</a><span class="kw">pub</span>(<span class="kw">crate</span>) <span class="kw">fn </span>fn_traits(lang_items: <span class="kw-2">&</span>LangItems) -> <span class="kw">impl </span>Iterator<Item = TraitId> + <span class="lifetime">'_ </span>{ |
| <a href=#41 id=41 data-nosnippet>41</a> [lang_items.Fn, lang_items.FnMut, lang_items.FnOnce].into_iter().flatten() |
| <a href=#42 id=42 data-nosnippet>42</a>} |
| <a href=#43 id=43 data-nosnippet>43</a> |
| <a href=#44 id=44 data-nosnippet>44</a><span class="doccomment">/// Returns an iterator over the direct super traits (including the trait itself). |
| <a href=#45 id=45 data-nosnippet>45</a></span><span class="kw">pub fn </span>direct_super_traits(db: <span class="kw-2">&</span><span class="kw">dyn </span>HirDatabase, trait_: TraitId) -> <span class="kw-2">&</span>[TraitId] { |
| <a href=#46 id=46 data-nosnippet>46</a> <span class="kw-2">&</span>SupertraitsInfo::query(db, trait_).direct_supertraits |
| <a href=#47 id=47 data-nosnippet>47</a>} |
| <a href=#48 id=48 data-nosnippet>48</a> |
| <a href=#49 id=49 data-nosnippet>49</a><span class="doccomment">/// Returns the whole super trait hierarchy (including the trait itself). |
| <a href=#50 id=50 data-nosnippet>50</a></span><span class="kw">pub fn </span>all_super_traits(db: <span class="kw-2">&</span><span class="kw">dyn </span>HirDatabase, trait_: TraitId) -> <span class="kw-2">&</span>[TraitId] { |
| <a href=#51 id=51 data-nosnippet>51</a> <span class="kw-2">&</span>SupertraitsInfo::query(db, trait_).all_supertraits |
| <a href=#52 id=52 data-nosnippet>52</a>} |
| <a href=#53 id=53 data-nosnippet>53</a> |
| <a href=#54 id=54 data-nosnippet>54</a><span class="attr">#[derive(Debug, Clone, Copy, PartialEq, Eq)] |
| <a href=#55 id=55 data-nosnippet>55</a></span><span class="kw">pub enum </span>Unsafety { |
| <a href=#56 id=56 data-nosnippet>56</a> Safe, |
| <a href=#57 id=57 data-nosnippet>57</a> Unsafe, |
| <a href=#58 id=58 data-nosnippet>58</a> <span class="doccomment">/// A lint. |
| <a href=#59 id=59 data-nosnippet>59</a> </span>DeprecatedSafe2024, |
| <a href=#60 id=60 data-nosnippet>60</a>} |
| <a href=#61 id=61 data-nosnippet>61</a> |
| <a href=#62 id=62 data-nosnippet>62</a><span class="attr">#[derive(Debug, Clone, Copy, PartialEq, Eq)] |
| <a href=#63 id=63 data-nosnippet>63</a></span><span class="kw">pub enum </span>TargetFeatureIsSafeInTarget { |
| <a href=#64 id=64 data-nosnippet>64</a> No, |
| <a href=#65 id=65 data-nosnippet>65</a> Yes, |
| <a href=#66 id=66 data-nosnippet>66</a>} |
| <a href=#67 id=67 data-nosnippet>67</a> |
| <a href=#68 id=68 data-nosnippet>68</a><span class="kw">pub fn </span>target_feature_is_safe_in_target(target: <span class="kw-2">&</span>TargetData) -> TargetFeatureIsSafeInTarget { |
| <a href=#69 id=69 data-nosnippet>69</a> <span class="kw">match </span>target.arch { |
| <a href=#70 id=70 data-nosnippet>70</a> target::Arch::Wasm32 | target::Arch::Wasm64 => TargetFeatureIsSafeInTarget::Yes, |
| <a href=#71 id=71 data-nosnippet>71</a> <span class="kw">_ </span>=> TargetFeatureIsSafeInTarget::No, |
| <a href=#72 id=72 data-nosnippet>72</a> } |
| <a href=#73 id=73 data-nosnippet>73</a>} |
| <a href=#74 id=74 data-nosnippet>74</a> |
| <a href=#75 id=75 data-nosnippet>75</a><span class="kw">pub fn </span>is_fn_unsafe_to_call( |
| <a href=#76 id=76 data-nosnippet>76</a> db: <span class="kw-2">&</span><span class="kw">dyn </span>HirDatabase, |
| <a href=#77 id=77 data-nosnippet>77</a> func: FunctionId, |
| <a href=#78 id=78 data-nosnippet>78</a> caller_target_features: <span class="kw-2">&</span>TargetFeatures<<span class="lifetime">'_</span>>, |
| <a href=#79 id=79 data-nosnippet>79</a> call_edition: Edition, |
| <a href=#80 id=80 data-nosnippet>80</a> target_feature_is_safe: TargetFeatureIsSafeInTarget, |
| <a href=#81 id=81 data-nosnippet>81</a>) -> Unsafety { |
| <a href=#82 id=82 data-nosnippet>82</a> <span class="kw">let </span>data = db.function_signature(func); |
| <a href=#83 id=83 data-nosnippet>83</a> <span class="kw">if </span>data.is_unsafe() { |
| <a href=#84 id=84 data-nosnippet>84</a> <span class="kw">return </span>Unsafety::Unsafe; |
| <a href=#85 id=85 data-nosnippet>85</a> } |
| <a href=#86 id=86 data-nosnippet>86</a> |
| <a href=#87 id=87 data-nosnippet>87</a> <span class="kw">if </span>data.has_target_feature() && target_feature_is_safe == TargetFeatureIsSafeInTarget::No { |
| <a href=#88 id=88 data-nosnippet>88</a> <span class="comment">// RFC 2396 <https://rust-lang.github.io/rfcs/2396-target-feature-1.1.html>. |
| <a href=#89 id=89 data-nosnippet>89</a> </span><span class="kw">let </span>callee_target_features = TargetFeatures::from_fn_no_implications(db, func); |
| <a href=#90 id=90 data-nosnippet>90</a> <span class="kw">if </span>!caller_target_features.enabled.is_superset(<span class="kw-2">&</span>callee_target_features.enabled) { |
| <a href=#91 id=91 data-nosnippet>91</a> <span class="kw">return </span>Unsafety::Unsafe; |
| <a href=#92 id=92 data-nosnippet>92</a> } |
| <a href=#93 id=93 data-nosnippet>93</a> } |
| <a href=#94 id=94 data-nosnippet>94</a> |
| <a href=#95 id=95 data-nosnippet>95</a> <span class="kw">if </span>data.is_deprecated_safe_2024() { |
| <a href=#96 id=96 data-nosnippet>96</a> <span class="kw">if </span>call_edition.at_least_2024() { |
| <a href=#97 id=97 data-nosnippet>97</a> <span class="kw">return </span>Unsafety::Unsafe; |
| <a href=#98 id=98 data-nosnippet>98</a> } <span class="kw">else </span>{ |
| <a href=#99 id=99 data-nosnippet>99</a> <span class="kw">return </span>Unsafety::DeprecatedSafe2024; |
| <a href=#100 id=100 data-nosnippet>100</a> } |
| <a href=#101 id=101 data-nosnippet>101</a> } |
| <a href=#102 id=102 data-nosnippet>102</a> |
| <a href=#103 id=103 data-nosnippet>103</a> <span class="kw">let </span>loc = func.lookup(db); |
| <a href=#104 id=104 data-nosnippet>104</a> <span class="kw">match </span>loc.container { |
| <a href=#105 id=105 data-nosnippet>105</a> hir_def::ItemContainerId::ExternBlockId(block) => { |
| <a href=#106 id=106 data-nosnippet>106</a> <span class="kw">let </span>is_intrinsic_block = block.abi(db) == <span class="prelude-val">Some</span>(sym::rust_dash_intrinsic); |
| <a href=#107 id=107 data-nosnippet>107</a> <span class="kw">if </span>is_intrinsic_block { |
| <a href=#108 id=108 data-nosnippet>108</a> <span class="comment">// legacy intrinsics |
| <a href=#109 id=109 data-nosnippet>109</a> // extern "rust-intrinsic" intrinsics are unsafe unless they have the rustc_safe_intrinsic attribute |
| <a href=#110 id=110 data-nosnippet>110</a> </span><span class="kw">if </span>AttrFlags::query(db, func.into()).contains(AttrFlags::RUSTC_SAFE_INTRINSIC) { |
| <a href=#111 id=111 data-nosnippet>111</a> Unsafety::Safe |
| <a href=#112 id=112 data-nosnippet>112</a> } <span class="kw">else </span>{ |
| <a href=#113 id=113 data-nosnippet>113</a> Unsafety::Unsafe |
| <a href=#114 id=114 data-nosnippet>114</a> } |
| <a href=#115 id=115 data-nosnippet>115</a> } <span class="kw">else </span>{ |
| <a href=#116 id=116 data-nosnippet>116</a> <span class="comment">// Function in an `extern` block are always unsafe to call, except when |
| <a href=#117 id=117 data-nosnippet>117</a> // it is marked as `safe`. |
| <a href=#118 id=118 data-nosnippet>118</a> </span><span class="kw">if </span>data.is_safe() { Unsafety::Safe } <span class="kw">else </span>{ Unsafety::Unsafe } |
| <a href=#119 id=119 data-nosnippet>119</a> } |
| <a href=#120 id=120 data-nosnippet>120</a> } |
| <a href=#121 id=121 data-nosnippet>121</a> <span class="kw">_ </span>=> Unsafety::Safe, |
| <a href=#122 id=122 data-nosnippet>122</a> } |
| <a href=#123 id=123 data-nosnippet>123</a>} |
| <a href=#124 id=124 data-nosnippet>124</a> |
| <a href=#125 id=125 data-nosnippet>125</a><span class="kw">pub</span>(<span class="kw">crate</span>) <span class="kw">fn </span>detect_variant_from_bytes<<span class="lifetime">'a</span>>( |
| <a href=#126 id=126 data-nosnippet>126</a> layout: <span class="kw-2">&</span><span class="lifetime">'a </span>Layout, |
| <a href=#127 id=127 data-nosnippet>127</a> db: <span class="kw-2">&</span><span class="kw">dyn </span>HirDatabase, |
| <a href=#128 id=128 data-nosnippet>128</a> target_data_layout: <span class="kw-2">&</span>TargetDataLayout, |
| <a href=#129 id=129 data-nosnippet>129</a> b: <span class="kw-2">&</span>[u8], |
| <a href=#130 id=130 data-nosnippet>130</a> e: EnumId, |
| <a href=#131 id=131 data-nosnippet>131</a>) -> <span class="prelude-ty">Option</span><(EnumVariantId, <span class="kw-2">&</span><span class="lifetime">'a </span>Layout)> { |
| <a href=#132 id=132 data-nosnippet>132</a> <span class="kw">let </span>(var_id, var_layout) = <span class="kw">match </span><span class="kw-2">&</span>layout.variants { |
| <a href=#133 id=133 data-nosnippet>133</a> hir_def::layout::Variants::Empty => <span class="macro">unreachable!</span>(), |
| <a href=#134 id=134 data-nosnippet>134</a> hir_def::layout::Variants::Single { index } => { |
| <a href=#135 id=135 data-nosnippet>135</a> (e.enum_variants(db).variants[index.<span class="number">0</span>].<span class="number">0</span>, layout) |
| <a href=#136 id=136 data-nosnippet>136</a> } |
| <a href=#137 id=137 data-nosnippet>137</a> hir_def::layout::Variants::Multiple { tag, tag_encoding, variants, .. } => { |
| <a href=#138 id=138 data-nosnippet>138</a> <span class="kw">let </span>size = tag.size(target_data_layout).bytes_usize(); |
| <a href=#139 id=139 data-nosnippet>139</a> <span class="kw">let </span>offset = layout.fields.offset(<span class="number">0</span>).bytes_usize(); <span class="comment">// The only field on enum variants is the tag field |
| <a href=#140 id=140 data-nosnippet>140</a> </span><span class="kw">let </span>tag = i128::from_le_bytes(pad16(<span class="kw-2">&</span>b[offset..offset + size], <span class="bool-val">false</span>)); |
| <a href=#141 id=141 data-nosnippet>141</a> <span class="kw">match </span>tag_encoding { |
| <a href=#142 id=142 data-nosnippet>142</a> TagEncoding::Direct => { |
| <a href=#143 id=143 data-nosnippet>143</a> <span class="kw">let </span>(var_idx, layout) = |
| <a href=#144 id=144 data-nosnippet>144</a> variants.iter_enumerated().find_map(|(var_idx, v)| { |
| <a href=#145 id=145 data-nosnippet>145</a> <span class="kw">let </span>def = e.enum_variants(db).variants[var_idx.<span class="number">0</span>].<span class="number">0</span>; |
| <a href=#146 id=146 data-nosnippet>146</a> (db.const_eval_discriminant(def) == <span class="prelude-val">Ok</span>(tag)).then_some((def, v)) |
| <a href=#147 id=147 data-nosnippet>147</a> })<span class="question-mark">?</span>; |
| <a href=#148 id=148 data-nosnippet>148</a> (var_idx, layout) |
| <a href=#149 id=149 data-nosnippet>149</a> } |
| <a href=#150 id=150 data-nosnippet>150</a> TagEncoding::Niche { untagged_variant, niche_start, .. } => { |
| <a href=#151 id=151 data-nosnippet>151</a> <span class="kw">let </span>candidate_tag = tag.wrapping_sub(<span class="kw-2">*</span>niche_start <span class="kw">as </span>i128) <span class="kw">as </span>usize; |
| <a href=#152 id=152 data-nosnippet>152</a> <span class="kw">let </span>variant = variants |
| <a href=#153 id=153 data-nosnippet>153</a> .iter_enumerated() |
| <a href=#154 id=154 data-nosnippet>154</a> .map(|(x, <span class="kw">_</span>)| x) |
| <a href=#155 id=155 data-nosnippet>155</a> .filter(|x| <span class="macro">x !</span>= untagged_variant) |
| <a href=#156 id=156 data-nosnippet>156</a> .nth(candidate_tag) |
| <a href=#157 id=157 data-nosnippet>157</a> .unwrap_or(<span class="kw-2">*</span>untagged_variant); |
| <a href=#158 id=158 data-nosnippet>158</a> (e.enum_variants(db).variants[variant.<span class="number">0</span>].<span class="number">0</span>, <span class="kw-2">&</span>variants[variant]) |
| <a href=#159 id=159 data-nosnippet>159</a> } |
| <a href=#160 id=160 data-nosnippet>160</a> } |
| <a href=#161 id=161 data-nosnippet>161</a> } |
| <a href=#162 id=162 data-nosnippet>162</a> }; |
| <a href=#163 id=163 data-nosnippet>163</a> <span class="prelude-val">Some</span>((var_id, var_layout)) |
| <a href=#164 id=164 data-nosnippet>164</a>} |
| </code></pre></div></section></main></body></html> |
