From 1ca7bfe481a18909e4769a9f6aee58f8cec17b44 Mon Sep 17 00:00:00 2001 From: Andrew Paverd Date: Mon, 6 Jul 2020 16:10:42 +0100 Subject: [PATCH] Only add cfguard module flag on windows-msvc --- src/librustc_codegen_llvm/context.rs | 19 ++++++++++++------- src/librustc_codegen_ssa/back/linker.rs | 16 ++++------------ .../{cfguard_checks.rs => cfguard-checks.rs} | 1 + ...fguard_disabled.rs => cfguard-disabled.rs} | 1 + ...fguard_nochecks.rs => cfguard-nochecks.rs} | 1 + src/test/codegen/cfguard-non-msvc.rs | 11 +++++++++++ src/test/ui/cfguard-run.rs | 6 ++++++ 7 files changed, 36 insertions(+), 19 deletions(-) rename src/test/codegen/{cfguard_checks.rs => cfguard-checks.rs} (93%) rename src/test/codegen/{cfguard_disabled.rs => cfguard-disabled.rs} (93%) rename src/test/codegen/{cfguard_nochecks.rs => cfguard-nochecks.rs} (93%) create mode 100644 src/test/codegen/cfguard-non-msvc.rs create mode 100644 src/test/ui/cfguard-run.rs diff --git a/src/librustc_codegen_llvm/context.rs b/src/librustc_codegen_llvm/context.rs index d484e15eb2f..21ba97d15a4 100644 --- a/src/librustc_codegen_llvm/context.rs +++ b/src/librustc_codegen_llvm/context.rs @@ -188,14 +188,19 @@ pub unsafe fn create_module( llvm::LLVMRustAddModuleFlag(llmod, avoid_plt, 1); } - // Set module flags to enable Windows Control Flow Guard (/guard:cf) metadata - // only (`cfguard=1`) or metadata and checks (`cfguard=2`). - match sess.opts.debugging_opts.control_flow_guard { - CFGuard::Disabled => {} - CFGuard::NoChecks => { - llvm::LLVMRustAddModuleFlag(llmod, "cfguard\0".as_ptr() as *const _, 1) + // Control Flow Guard is currently only supported by the MSVC linker on Windows. + if sess.target.target.options.is_like_msvc { + match sess.opts.debugging_opts.control_flow_guard { + CFGuard::Disabled => {} + CFGuard::NoChecks => { + // Set `cfguard=1` module flag to emit metadata only. + llvm::LLVMRustAddModuleFlag(llmod, "cfguard\0".as_ptr() as *const _, 1) + } + CFGuard::Checks => { + // Set `cfguard=2` module flag to emit metadata and checks. + llvm::LLVMRustAddModuleFlag(llmod, "cfguard\0".as_ptr() as *const _, 2) + } } - CFGuard::Checks => llvm::LLVMRustAddModuleFlag(llmod, "cfguard\0".as_ptr() as *const _, 2), } llmod diff --git a/src/librustc_codegen_ssa/back/linker.rs b/src/librustc_codegen_ssa/back/linker.rs index 54f55c806d0..550de75c709 100644 --- a/src/librustc_codegen_ssa/back/linker.rs +++ b/src/librustc_codegen_ssa/back/linker.rs @@ -475,9 +475,7 @@ impl<'a> Linker for GccLinker<'a> { self.cmd.arg("__llvm_profile_runtime"); } - fn control_flow_guard(&mut self) { - self.sess.warn("Windows Control Flow Guard is not supported by this linker."); - } + fn control_flow_guard(&mut self) {} fn debuginfo(&mut self, strip: Strip) { match strip { @@ -959,9 +957,7 @@ impl<'a> Linker for EmLinker<'a> { // noop, but maybe we need something like the gnu linker? } - fn control_flow_guard(&mut self) { - self.sess.warn("Windows Control Flow Guard is not supported by this linker."); - } + fn control_flow_guard(&mut self) {} fn debuginfo(&mut self, _strip: Strip) { // Preserve names or generate source maps depending on debug info @@ -1163,9 +1159,7 @@ impl<'a> Linker for WasmLd<'a> { } } - fn control_flow_guard(&mut self) { - self.sess.warn("Windows Control Flow Guard is not supported by this linker."); - } + fn control_flow_guard(&mut self) {} fn no_crt_objects(&mut self) {} @@ -1330,9 +1324,7 @@ impl<'a> Linker for PtxLinker<'a> { fn no_default_libraries(&mut self) {} - fn control_flow_guard(&mut self) { - self.sess.warn("Windows Control Flow Guard is not supported by this linker."); - } + fn control_flow_guard(&mut self) {} fn export_symbols(&mut self, _tmpdir: &Path, _crate_type: CrateType) {} diff --git a/src/test/codegen/cfguard_checks.rs b/src/test/codegen/cfguard-checks.rs similarity index 93% rename from src/test/codegen/cfguard_checks.rs rename to src/test/codegen/cfguard-checks.rs index 96f9158f9d3..96a0a321199 100644 --- a/src/test/codegen/cfguard_checks.rs +++ b/src/test/codegen/cfguard-checks.rs @@ -1,4 +1,5 @@ // compile-flags: -Z control-flow-guard=checks +// only-msvc #![crate_type = "lib"] diff --git a/src/test/codegen/cfguard_disabled.rs b/src/test/codegen/cfguard-disabled.rs similarity index 93% rename from src/test/codegen/cfguard_disabled.rs rename to src/test/codegen/cfguard-disabled.rs index 1325ffc0f25..925e4e8e2d1 100644 --- a/src/test/codegen/cfguard_disabled.rs +++ b/src/test/codegen/cfguard-disabled.rs @@ -1,4 +1,5 @@ // compile-flags: -Z control-flow-guard=no +// only-msvc #![crate_type = "lib"] diff --git a/src/test/codegen/cfguard_nochecks.rs b/src/test/codegen/cfguard-nochecks.rs similarity index 93% rename from src/test/codegen/cfguard_nochecks.rs rename to src/test/codegen/cfguard-nochecks.rs index ae1de4c4d26..d7dc3d7e89e 100644 --- a/src/test/codegen/cfguard_nochecks.rs +++ b/src/test/codegen/cfguard-nochecks.rs @@ -1,4 +1,5 @@ // compile-flags: -Z control-flow-guard=nochecks +// only-msvc #![crate_type = "lib"] diff --git a/src/test/codegen/cfguard-non-msvc.rs b/src/test/codegen/cfguard-non-msvc.rs new file mode 100644 index 00000000000..4008f0187a0 --- /dev/null +++ b/src/test/codegen/cfguard-non-msvc.rs @@ -0,0 +1,11 @@ +// compile-flags: -Z control-flow-guard +// ignore-msvc + +#![crate_type = "lib"] + +// A basic test function. +pub fn test() { +} + +// Ensure the cfguard module flag is not added for non-MSVC targets. +// CHECK-NOT: !"cfguard" diff --git a/src/test/ui/cfguard-run.rs b/src/test/ui/cfguard-run.rs new file mode 100644 index 00000000000..21368fad3b0 --- /dev/null +++ b/src/test/ui/cfguard-run.rs @@ -0,0 +1,6 @@ +// run-pass +// compile-flags: -Z control-flow-guard + +pub fn main() { + println!("hello, world"); +}