| 1 |
From 4b95b1a4fd035a73998dc21b265ce4594e35f8ae Mon Sep 17 00:00:00 2001 |
| 2 |
From: Alex Crichton <alex@alexcrichton.com> |
| 3 |
Date: Thu, 16 Aug 2018 13:19:04 -0700 |
| 4 |
Subject: [PATCH] Set more llvm function attributes for __rust_try |
| 5 |
|
| 6 |
This shim is generated elsewhere in the compiler so this commit adds support to |
| 7 |
ensure it goes through similar paths as the rest of the compiler to set llvm |
| 8 |
function attributes like target features. |
| 9 |
|
| 10 |
cc #53372 |
| 11 |
--- |
| 12 |
src/librustc_codegen_llvm/attributes.rs | 52 +++++++++++++++++++------ |
| 13 |
src/librustc_codegen_llvm/base.rs | 21 ---------- |
| 14 |
src/librustc_codegen_llvm/callee.rs | 2 +- |
| 15 |
src/librustc_codegen_llvm/intrinsic.rs | 2 + |
| 16 |
src/librustc_codegen_llvm/mono_item.rs | 2 +- |
| 17 |
5 files changed, 44 insertions(+), 35 deletions(-) |
| 18 |
|
| 19 |
diff --git a/src/librustc_codegen_llvm/attributes.rs b/src/librustc_codegen_llvm/attributes.rs |
| 20 |
index 3b5f927d52f0..2a79ce2f2285 100644 |
| 21 |
--- a/src/librustc_codegen_llvm/attributes.rs |
| 22 |
+++ b/src/librustc_codegen_llvm/attributes.rs |
| 23 |
@@ -11,7 +11,7 @@ |
| 24 |
|
| 25 |
use std::ffi::{CStr, CString}; |
| 26 |
|
| 27 |
-use rustc::hir::CodegenFnAttrFlags; |
| 28 |
+use rustc::hir::{CodegenFnAttrFlags, CodegenFnAttrs}; |
| 29 |
use rustc::hir::def_id::{DefId, LOCAL_CRATE}; |
| 30 |
use rustc::session::Session; |
| 31 |
use rustc::session::config::Sanitizer; |
| 32 |
@@ -123,11 +123,37 @@ pub fn llvm_target_features(sess: &Session) -> impl Iterator<Item = &str> { |
| 33 |
|
| 34 |
/// Composite function which sets LLVM attributes for function depending on its AST (#[attribute]) |
| 35 |
/// attributes. |
| 36 |
-pub fn from_fn_attrs(cx: &CodegenCx, llfn: ValueRef, id: DefId) { |
| 37 |
- let codegen_fn_attrs = cx.tcx.codegen_fn_attrs(id); |
| 38 |
+pub fn from_fn_attrs( |
| 39 |
+ cx: &CodegenCx, |
| 40 |
+ llfn: ValueRef, |
| 41 |
+ id: Option<DefId>, |
| 42 |
+) { |
| 43 |
+ let codegen_fn_attrs = id.map(|id| cx.tcx.codegen_fn_attrs(id)) |
| 44 |
+ .unwrap_or(CodegenFnAttrs::new()); |
| 45 |
|
| 46 |
inline(llfn, codegen_fn_attrs.inline); |
| 47 |
|
| 48 |
+ // The `uwtable` attribute according to LLVM is: |
| 49 |
+ // |
| 50 |
+ // This attribute indicates that the ABI being targeted requires that an |
| 51 |
+ // unwind table entry be produced for this function even if we can show |
| 52 |
+ // that no exceptions passes by it. This is normally the case for the |
| 53 |
+ // ELF x86-64 abi, but it can be disabled for some compilation units. |
| 54 |
+ // |
| 55 |
+ // Typically when we're compiling with `-C panic=abort` (which implies this |
| 56 |
+ // `no_landing_pads` check) we don't need `uwtable` because we can't |
| 57 |
+ // generate any exceptions! On Windows, however, exceptions include other |
| 58 |
+ // events such as illegal instructions, segfaults, etc. This means that on |
| 59 |
+ // Windows we end up still needing the `uwtable` attribute even if the `-C |
| 60 |
+ // panic=abort` flag is passed. |
| 61 |
+ // |
| 62 |
+ // You can also find more info on why Windows is whitelisted here in: |
| 63 |
+ // https://bugzilla.mozilla.org/show_bug.cgi?id=1302078 |
| 64 |
+ if !cx.sess().no_landing_pads() || |
| 65 |
+ cx.sess().target.target.options.requires_uwtable { |
| 66 |
+ attributes::emit_uwtable(llfn, true); |
| 67 |
+ } |
| 68 |
+ |
| 69 |
set_frame_pointer_elimination(cx, llfn); |
| 70 |
set_probestack(cx, llfn); |
| 71 |
|
| 72 |
@@ -151,7 +177,7 @@ pub fn from_fn_attrs(cx: &CodegenCx, llfn: ValueRef, id: DefId) { |
| 73 |
// *in Rust code* may unwind. Foreign items like `extern "C" { |
| 74 |
// fn foo(); }` are assumed not to unwind **unless** they have |
| 75 |
// a `#[unwind]` attribute. |
| 76 |
- } else if !cx.tcx.is_foreign_item(id) { |
| 77 |
+ } else if id.map(|id| !cx.tcx.is_foreign_item(id)).unwrap_or(false) { |
| 78 |
Some(true) |
| 79 |
} else { |
| 80 |
None |
| 81 |
@@ -188,14 +214,16 @@ pub fn from_fn_attrs(cx: &CodegenCx, llfn: ValueRef, id: DefId) { |
| 82 |
// Note that currently the `wasm-import-module` doesn't do anything, but |
| 83 |
// eventually LLVM 7 should read this and ferry the appropriate import |
| 84 |
// module to the output file. |
| 85 |
- if cx.tcx.sess.target.target.arch == "wasm32" { |
| 86 |
- if let Some(module) = wasm_import_module(cx.tcx, id) { |
| 87 |
- llvm::AddFunctionAttrStringValue( |
| 88 |
- llfn, |
| 89 |
- llvm::AttributePlace::Function, |
| 90 |
- cstr("wasm-import-module\0"), |
| 91 |
- &module, |
| 92 |
- ); |
| 93 |
+ if let Some(id) = id { |
| 94 |
+ if cx.tcx.sess.target.target.arch == "wasm32" { |
| 95 |
+ if let Some(module) = wasm_import_module(cx.tcx, id) { |
| 96 |
+ llvm::AddFunctionAttrStringValue( |
| 97 |
+ llfn, |
| 98 |
+ llvm::AttributePlace::Function, |
| 99 |
+ cstr("wasm-import-module\0"), |
| 100 |
+ &module, |
| 101 |
+ ); |
| 102 |
+ } |
| 103 |
} |
| 104 |
} |
| 105 |
} |
| 106 |
diff --git a/src/librustc_codegen_llvm/base.rs b/src/librustc_codegen_llvm/base.rs |
| 107 |
index 223c04f420f3..b0461582ddcb 100644 |
| 108 |
--- a/src/librustc_codegen_llvm/base.rs |
| 109 |
+++ b/src/librustc_codegen_llvm/base.rs |
| 110 |
@@ -486,27 +486,6 @@ pub fn codegen_instance<'a, 'tcx>(cx: &CodegenCx<'a, 'tcx>, instance: Instance<' |
| 111 |
|
| 112 |
cx.stats.borrow_mut().n_closures += 1; |
| 113 |
|
| 114 |
- // The `uwtable` attribute according to LLVM is: |
| 115 |
- // |
| 116 |
- // This attribute indicates that the ABI being targeted requires that an |
| 117 |
- // unwind table entry be produced for this function even if we can show |
| 118 |
- // that no exceptions passes by it. This is normally the case for the |
| 119 |
- // ELF x86-64 abi, but it can be disabled for some compilation units. |
| 120 |
- // |
| 121 |
- // Typically when we're compiling with `-C panic=abort` (which implies this |
| 122 |
- // `no_landing_pads` check) we don't need `uwtable` because we can't |
| 123 |
- // generate any exceptions! On Windows, however, exceptions include other |
| 124 |
- // events such as illegal instructions, segfaults, etc. This means that on |
| 125 |
- // Windows we end up still needing the `uwtable` attribute even if the `-C |
| 126 |
- // panic=abort` flag is passed. |
| 127 |
- // |
| 128 |
- // You can also find more info on why Windows is whitelisted here in: |
| 129 |
- // https://bugzilla.mozilla.org/show_bug.cgi?id=1302078 |
| 130 |
- if !cx.sess().no_landing_pads() || |
| 131 |
- cx.sess().target.target.options.requires_uwtable { |
| 132 |
- attributes::emit_uwtable(lldecl, true); |
| 133 |
- } |
| 134 |
- |
| 135 |
let mir = cx.tcx.instance_mir(instance.def); |
| 136 |
mir::codegen_mir(cx, lldecl, &mir, instance, sig); |
| 137 |
} |
| 138 |
diff --git a/src/librustc_codegen_llvm/callee.rs b/src/librustc_codegen_llvm/callee.rs |
| 139 |
index 2c01bd42cc77..97f07792ede8 100644 |
| 140 |
--- a/src/librustc_codegen_llvm/callee.rs |
| 141 |
+++ b/src/librustc_codegen_llvm/callee.rs |
| 142 |
@@ -97,7 +97,7 @@ pub fn get_fn<'a, 'tcx>(cx: &CodegenCx<'a, 'tcx>, |
| 143 |
if instance.def.is_inline(tcx) { |
| 144 |
attributes::inline(llfn, attributes::InlineAttr::Hint); |
| 145 |
} |
| 146 |
- attributes::from_fn_attrs(cx, llfn, instance.def.def_id()); |
| 147 |
+ attributes::from_fn_attrs(cx, llfn, Some(instance.def.def_id())); |
| 148 |
|
| 149 |
let instance_def_id = instance.def_id(); |
| 150 |
|
| 151 |
diff --git a/src/librustc_codegen_llvm/intrinsic.rs b/src/librustc_codegen_llvm/intrinsic.rs |
| 152 |
index 9c5c0f730c16..f69fce15dc55 100644 |
| 153 |
--- a/src/librustc_codegen_llvm/intrinsic.rs |
| 154 |
+++ b/src/librustc_codegen_llvm/intrinsic.rs |
| 155 |
@@ -10,6 +10,7 @@ |
| 156 |
|
| 157 |
#![allow(non_upper_case_globals)] |
| 158 |
|
| 159 |
+use attributes; |
| 160 |
use intrinsics::{self, Intrinsic}; |
| 161 |
use llvm; |
| 162 |
use llvm::{ValueRef}; |
| 163 |
@@ -936,6 +937,7 @@ fn gen_fn<'a, 'tcx>(cx: &CodegenCx<'a, 'tcx>, |
| 164 |
Abi::Rust |
| 165 |
))); |
| 166 |
let llfn = declare::define_internal_fn(cx, name, rust_fn_ty); |
| 167 |
+ attributes::from_fn_attrs(cx, llfn, None); |
| 168 |
let bx = Builder::new_block(cx, llfn, "entry-block"); |
| 169 |
codegen(bx); |
| 170 |
llfn |
| 171 |
diff --git a/src/librustc_codegen_llvm/mono_item.rs b/src/librustc_codegen_llvm/mono_item.rs |
| 172 |
index a528008e3b4b..32d8b24e3c15 100644 |
| 173 |
--- a/src/librustc_codegen_llvm/mono_item.rs |
| 174 |
+++ b/src/librustc_codegen_llvm/mono_item.rs |
| 175 |
@@ -183,7 +183,7 @@ fn predefine_fn<'a, 'tcx>(cx: &CodegenCx<'a, 'tcx>, |
| 176 |
if instance.def.is_inline(cx.tcx) { |
| 177 |
attributes::inline(lldecl, attributes::InlineAttr::Hint); |
| 178 |
} |
| 179 |
- attributes::from_fn_attrs(cx, lldecl, instance.def.def_id()); |
| 180 |
+ attributes::from_fn_attrs(cx, lldecl, Some(instance.def.def_id())); |
| 181 |
|
| 182 |
cx.instances.borrow_mut().insert(instance, lldecl); |
| 183 |
} |
| 184 |
-- |
| 185 |
2.17.1 |
| 186 |
|
Parent Directory
| 
Revision Log