diff options
| -rw-r--r-- | src/librustc/session/config.rs | 2 | ||||
| -rw-r--r-- | src/librustc/session/mod.rs | 9 | ||||
| -rw-r--r-- | src/librustc_codegen_llvm/attributes.rs | 13 |
3 files changed, 23 insertions, 1 deletions
diff --git a/src/librustc/session/config.rs b/src/librustc/session/config.rs index e58c9d75a9d..33409f9b4a7 100644 --- a/src/librustc/session/config.rs +++ b/src/librustc/session/config.rs @@ -1227,6 +1227,8 @@ options! {DebuggingOptions, DebuggingSetter, basic_debugging_options, "verify incr. comp. hashes of green query instances"), incremental_ignore_spans: bool = (false, parse_bool, [UNTRACKED], "ignore spans during ICH computation -- used for testing"), + instrument_mcount: bool = (false, parse_bool, [TRACKED], + "insert function instrument code for mcount-based tracing"), dump_dep_graph: bool = (false, parse_bool, [UNTRACKED], "dump the dependency graph to $RUST_DEP_GRAPH (default: /tmp/dep_graph.gv)"), query_dep_graph: bool = (false, parse_bool, [UNTRACKED], diff --git a/src/librustc/session/mod.rs b/src/librustc/session/mod.rs index 4fc9b87ceef..5c977d5969e 100644 --- a/src/librustc/session/mod.rs +++ b/src/librustc/session/mod.rs @@ -503,6 +503,9 @@ impl Session { pub fn profile_queries_and_keys(&self) -> bool { self.opts.debugging_opts.profile_queries_and_keys } + pub fn instrument_mcount(&self) -> bool { + self.opts.debugging_opts.instrument_mcount + } pub fn count_llvm_insns(&self) -> bool { self.opts.debugging_opts.count_llvm_insns } @@ -667,7 +670,11 @@ impl Session { } pub fn must_not_eliminate_frame_pointers(&self) -> bool { - if let Some(x) = self.opts.cg.force_frame_pointers { + // "mcount" function relies on stack pointer. + // See https://sourceware.org/binutils/docs/gprof/Implementation.html + if self.instrument_mcount() { + true + } else if let Some(x) = self.opts.cg.force_frame_pointers { x } else { !self.target.target.options.eliminate_frame_pointer diff --git a/src/librustc_codegen_llvm/attributes.rs b/src/librustc_codegen_llvm/attributes.rs index acd1c4afd2e..226b03c99c0 100644 --- a/src/librustc_codegen_llvm/attributes.rs +++ b/src/librustc_codegen_llvm/attributes.rs @@ -78,6 +78,18 @@ pub fn set_frame_pointer_elimination(cx: &CodegenCx<'ll, '_>, llfn: &'ll Value) } } +/// Tell LLVM what instrument function to insert. +#[inline] +pub fn set_instrument_function(cx: &CodegenCx<'ll, '_>, llfn: &'ll Value) { + if cx.sess().instrument_mcount() { + // Similar to `clang -pg` behavior. Handled by the + // `post-inline-ee-instrument` LLVM pass. + llvm::AddFunctionAttrStringValue( + llfn, llvm::AttributePlace::Function, + const_cstr!("instrument-function-entry-inlined"), const_cstr!("mcount")); + } +} + pub fn set_probestack(cx: &CodegenCx<'ll, '_>, llfn: &'ll Value) { // Only use stack probes if the target specification indicates that we // should be using stack probes @@ -174,6 +186,7 @@ pub fn from_fn_attrs( } set_frame_pointer_elimination(cx, llfn); + set_instrument_function(cx, llfn); set_probestack(cx, llfn); if codegen_fn_attrs.flags.contains(CodegenFnAttrFlags::COLD) { |