From 09d2db4e963c6696f7c22386b6791e419ad75cfb Mon Sep 17 00:00:00 2001 From: Simonas Kazlauskas Date: Tue, 6 Mar 2018 20:27:19 +0200 Subject: [PATCH] Rework force-frame-pointer This reworks the force-frame-pointer PR to explicitly only consider the value of the flag if it is provided, and use a target default otherwise. Something that was tried but not kept was renaming the flag to `frame-pointer`, because for flag `frame-pointer=no`, there is no guarante, that LLVM will elide *all* the frame pointers; oposite of what the literal reading of the flag would suggest. --- src/librustc/session/config.rs | 6 +++--- src/librustc/session/mod.rs | 7 +++++-- src/test/codegen/force-frame-pointers.rs | 2 +- 3 files changed, 9 insertions(+), 6 deletions(-) diff --git a/src/librustc/session/config.rs b/src/librustc/session/config.rs index 023be789222..59b40e9e2dc 100644 --- a/src/librustc/session/config.rs +++ b/src/librustc/session/config.rs @@ -1053,8 +1053,8 @@ options! {CodegenOptions, CodegenSetter, basic_codegen_options, 2 = full debug info with variable and type information"), opt_level: Option = (None, parse_opt_string, [TRACKED], "optimize with possible levels 0-3, s, or z"), - force_frame_pointers: bool = (false, parse_bool, [TRACKED], - "force frame pointers to be used"), + force_frame_pointers: Option = (None, parse_opt_bool, [TRACKED], + "force use of the frame pointers"), debug_assertions: Option = (None, parse_opt_bool, [TRACKED], "explicitly enable the cfg(debug_assertions) directive"), inline_threshold: Option = (None, parse_opt_uint, [TRACKED], @@ -2968,7 +2968,7 @@ mod tests { assert!(reference.dep_tracking_hash() != opts.dep_tracking_hash()); opts = reference.clone(); - opts.cg.force_frame_pointers = true; + opts.cg.force_frame_pointers = Some(false); assert!(reference.dep_tracking_hash() != opts.dep_tracking_hash()); opts = reference.clone(); diff --git a/src/librustc/session/mod.rs b/src/librustc/session/mod.rs index 45b7e2d1740..2ab72ba20bf 100644 --- a/src/librustc/session/mod.rs +++ b/src/librustc/session/mod.rs @@ -658,8 +658,11 @@ impl Session { } pub fn must_not_eliminate_frame_pointers(&self) -> bool { - self.opts.debuginfo != DebugInfoLevel::NoDebugInfo - || !self.target.target.options.eliminate_frame_pointer + if let Some(x) = self.opts.cg.force_frame_pointers { + x + } else { + !self.target.target.options.eliminate_frame_pointer + } } /// Returns the symbol name for the registrar function, diff --git a/src/test/codegen/force-frame-pointers.rs b/src/test/codegen/force-frame-pointers.rs index d40406a0476..f70e3667198 100644 --- a/src/test/codegen/force-frame-pointers.rs +++ b/src/test/codegen/force-frame-pointers.rs @@ -8,7 +8,7 @@ // option. This file may not be copied, modified, or distributed // except according to those terms. // -// compile-flags: -C no-prepopulate-passes -C force-frame-pointers +// compile-flags: -C no-prepopulate-passes -C force-frame-pointers=y #![crate_type="lib"]