Support -Cforce-frame-pointers=non-leaf

compiler/rustc_codegen_cranelift/src/lib.rs

@@ -271,9 +271,9 @@ fn build_isa(sess: &Session, backend_config: &BackendConfig) -> Arc<dyn TargetIs
     flags_builder.set("enable_verifier", enable_verifier).unwrap();
     flags_builder.set("regalloc_checker", enable_verifier).unwrap();
 
-    let preserve_frame_pointer = sess.target.options.frame_pointer
-        != rustc_target::spec::FramePointer::MayOmit
-        || matches!(sess.opts.cg.force_frame_pointers, Some(true));
+    let mut frame_ptr = sess.target.options.frame_pointer.clone();
+    frame_ptr.ratchet(sess.opts.cg.force_frame_pointers);
+    let preserve_frame_pointer = frame_ptr != rustc_target::spec::FramePointer::MayOmit;
     flags_builder
         .set("preserve_frame_pointers", if preserve_frame_pointer { "true" } else { "false" })
         .unwrap();

compiler/rustc_codegen_llvm/src/attributes.rs

@@ -108,9 +108,10 @@ pub fn frame_pointer_type_attr<'ll>(cx: &CodegenCx<'ll, '_>) -> Option<&'ll Attr
     let opts = &cx.sess().opts;
     // "mcount" function relies on stack pointer.
     // See <https://sourceware.org/binutils/docs/gprof/Implementation.html>.
-    if opts.unstable_opts.instrument_mcount || matches!(opts.cg.force_frame_pointers, Some(true)) {
-        fp = FramePointer::Always;
+    if opts.unstable_opts.instrument_mcount {
+        fp.ratchet(FramePointer::Always);
     }
+    fp.ratchet(opts.cg.force_frame_pointers);
     let attr_value = match fp {
         FramePointer::Always => "all",
         FramePointer::NonLeaf => "non-leaf",

compiler/rustc_interface/src/tests.rs

@@ -20,9 +20,9 @@ use rustc_span::source_map::{RealFileLoader, SourceMapInputs};
 use rustc_span::symbol::sym;
 use rustc_span::{FileName, SourceFileHashAlgorithm};
 use rustc_target::spec::{
-    CodeModel, LinkerFlavorCli, MergeFunctions, OnBrokenPipe, PanicStrategy, RelocModel, WasmCAbi,
+    CodeModel, FramePointer, LinkerFlavorCli, MergeFunctions, OnBrokenPipe, PanicStrategy,
+    RelocModel, RelroLevel, SanitizerSet, SplitDebuginfo, StackProtector, TlsModel, WasmCAbi,
 };
-use rustc_target::spec::{RelroLevel, SanitizerSet, SplitDebuginfo, StackProtector, TlsModel};
 use std::collections::{BTreeMap, BTreeSet};
 use std::num::NonZero;
 use std::path::{Path, PathBuf};
@@ -605,7 +605,7 @@ fn test_codegen_options_tracking_hash() {
     tracked!(debug_assertions, Some(true));
     tracked!(debuginfo, DebugInfo::Limited);
     tracked!(embed_bitcode, false);
-    tracked!(force_frame_pointers, Some(false));
+    tracked!(force_frame_pointers, FramePointer::Always);
     tracked!(force_unwind_tables, Some(true));
     tracked!(inline_threshold, Some(0xf007ba11));
     tracked!(instrument_coverage, InstrumentCoverage::Yes);

compiler/rustc_session/src/config.rs

@@ -19,7 +19,7 @@ use rustc_macros::{Decodable, Encodable, HashStable_Generic};
 use rustc_span::edition::{Edition, DEFAULT_EDITION, EDITION_NAME_LIST, LATEST_STABLE_EDITION};
 use rustc_span::source_map::FilePathMapping;
 use rustc_span::{FileName, FileNameDisplayPreference, RealFileName, SourceFileHashAlgorithm};
-use rustc_target::spec::{LinkSelfContainedComponents, LinkerFeatures};
+use rustc_target::spec::{FramePointer, LinkSelfContainedComponents, LinkerFeatures};
 use rustc_target::spec::{SplitDebuginfo, Target, TargetTriple};
 use std::collections::btree_map::{
     Iter as BTreeMapIter, Keys as BTreeMapKeysIter, Values as BTreeMapValuesIter,
@@ -2524,6 +2524,15 @@ pub fn build_session_options(early_dcx: &mut EarlyDiagCtxt, matches: &getopts::M
         }
     }
 
+    if !nightly_options::is_unstable_enabled(matches)
+        && cg.force_frame_pointers == FramePointer::NonLeaf
+    {
+        early_dcx.early_fatal(
+            "`-Cforce-frame-pointers=non-leaf` or `always` also requires `-Zunstable-options` \
+                and a nightly compiler",
+        )
+    }
+
     // For testing purposes, until we have more feedback about these options: ensure `-Z
     // unstable-options` is required when using the unstable `-C link-self-contained` and `-C
     // linker-flavor` options.
@@ -2966,10 +2975,8 @@ pub(crate) mod dep_tracking {
     use rustc_span::edition::Edition;
     use rustc_span::RealFileName;
     use rustc_target::spec::{
-        CodeModel, MergeFunctions, OnBrokenPipe, PanicStrategy, RelocModel, WasmCAbi,
-    };
-    use rustc_target::spec::{
-        RelroLevel, SanitizerSet, SplitDebuginfo, StackProtector, TargetTriple, TlsModel,
+        CodeModel, FramePointer, MergeFunctions, OnBrokenPipe, PanicStrategy, RelocModel,
+        RelroLevel, SanitizerSet, SplitDebuginfo, StackProtector, TargetTriple, TlsModel, WasmCAbi,
     };
     use std::collections::BTreeMap;
     use std::hash::{DefaultHasher, Hash};
@@ -3023,6 +3030,7 @@ pub(crate) mod dep_tracking {
         lint::Level,
         WasiExecModel,
         u32,
+        FramePointer,
         RelocModel,
         CodeModel,
         TlsModel,

compiler/rustc_session/src/options.rs

@@ -12,10 +12,9 @@ use rustc_span::edition::Edition;
 use rustc_span::RealFileName;
 use rustc_span::SourceFileHashAlgorithm;
 use rustc_target::spec::{
-    CodeModel, LinkerFlavorCli, MergeFunctions, OnBrokenPipe, PanicStrategy, SanitizerSet, WasmCAbi,
-};
-use rustc_target::spec::{
-    RelocModel, RelroLevel, SplitDebuginfo, StackProtector, TargetTriple, TlsModel,
+    CodeModel, FramePointer, LinkerFlavorCli, MergeFunctions, OnBrokenPipe, PanicStrategy,
+    RelocModel, RelroLevel, SanitizerSet, SplitDebuginfo, StackProtector, TargetTriple, TlsModel,
+    WasmCAbi,
 };
 use std::collections::BTreeMap;
 use std::hash::{DefaultHasher, Hasher};
@@ -374,6 +373,7 @@ mod desc {
     pub const parse_opt_comma_list: &str = parse_comma_list;
     pub const parse_number: &str = "a number";
     pub const parse_opt_number: &str = parse_number;
+    pub const parse_frame_pointer: &str = "one of `true`/`yes`/`on`, `false`/`no`/`off`, or (with -Zunstable-options) `non-leaf` or `always`";
     pub const parse_threads: &str = parse_number;
     pub const parse_time_passes_format: &str = "`text` (default) or `json`";
     pub const parse_passes: &str = "a space-separated list of passes, or `all`";
@@ -672,6 +672,18 @@ mod parse {
         }
     }
 
+    pub(crate) fn parse_frame_pointer(slot: &mut FramePointer, v: Option<&str>) -> bool {
+        let mut yes = false;
+        match v {
+            _ if parse_bool(&mut yes, v) && yes => slot.ratchet(FramePointer::Always),
+            _ if parse_bool(&mut yes, v) => slot.ratchet(FramePointer::MayOmit),
+            Some("always") => slot.ratchet(FramePointer::Always),
+            Some("non-leaf") => slot.ratchet(FramePointer::NonLeaf),
+            _ => return false,
+        };
+        true
+    }
+
     pub(crate) fn parse_passes(slot: &mut Passes, v: Option<&str>) -> bool {
         match v {
             Some("all") => {
@@ -1479,7 +1491,7 @@ options! {
         "emit bitcode in rlibs (default: yes)"),
     extra_filename: String = (String::new(), parse_string, [UNTRACKED],
         "extra data to put in each output filename"),
-    force_frame_pointers: Option<bool> = (None, parse_opt_bool, [TRACKED],
+    force_frame_pointers: FramePointer = (FramePointer::MayOmit, parse_frame_pointer, [TRACKED],
         "force use of the frame pointers"),
     #[rustc_lint_opt_deny_field_access("use `Session::must_emit_unwind_tables` instead of this field")]
     force_unwind_tables: Option<bool> = (None, parse_opt_bool, [TRACKED],

compiler/rustc_target/src/spec/mod.rs

@@ -1413,6 +1413,20 @@ pub enum FramePointer {
     MayOmit,
 }
 
+impl FramePointer {
+    /// It is intended that the "force frame pointer" transition is "one way"
+    /// so this convenience assures such if used
+    #[inline]
+    pub fn ratchet(&mut self, rhs: FramePointer) -> FramePointer {
+        *self = match (*self, rhs) {
+            (FramePointer::Always, _) | (_, FramePointer::Always) => FramePointer::Always,
+            (FramePointer::NonLeaf, _) | (_, FramePointer::NonLeaf) => FramePointer::NonLeaf,
+            _ => FramePointer::MayOmit,
+        };
+        *self
+    }
+}
+
 impl FromStr for FramePointer {
     type Err = ();
     fn from_str(s: &str) -> Result<Self, ()> {

src/tools/compiletest/src/header.rs

@@ -779,6 +779,7 @@ const KNOWN_DIRECTIVE_NAMES: &[&str] = &[
     "ignore-haiku",
     "ignore-horizon",
     "ignore-i686-pc-windows-msvc",
+    "ignore-illumos",
     "ignore-ios",
     "ignore-linux",
     "ignore-lldb",
@@ -843,6 +844,7 @@ const KNOWN_DIRECTIVE_NAMES: &[&str] = &[
     "ignore-x32",
     "ignore-x86",
     "ignore-x86_64",
+    "ignore-x86_64-apple-darwin",
     "ignore-x86_64-unknown-linux-gnu",
     "incremental",
     "known-bug",

tests/codegen/force-frame-pointers.rs

@@ -1,6 +1,18 @@
-//@ compile-flags: -C no-prepopulate-passes -C force-frame-pointers=y -Copt-level=0
+//@ revisions: Always NonLeaf
+//@ [Always] compile-flags: -Cforce-frame-pointers=yes
+//@ [NonLeaf] compile-flags: -Cforce-frame-pointers=non-leaf
+//@ compile-flags: -Zunstable-options
+//@ compile-flags: -C no-prepopulate-passes -Copt-level=0
+//@ [NonLeaf] ignore-illumos
+//@ [NonLeaf] ignore-openbsd
+//@ [NonLeaf] ignore-x86
+//@ [NonLeaf] ignore-x86_64-apple-darwin
+//@ [NonLeaf] ignore-windows-gnu
+//@ [NonLeaf] ignore-thumb
+// result is platform-dependent based on platform's frame pointer settings
 
 #![crate_type = "lib"]
 
-// CHECK: attributes #{{.*}} "frame-pointer"="all"
+// Always: attributes #{{.*}} "frame-pointer"="all"
+// NonLeaf: attributes #{{.*}} "frame-pointer"="non-leaf"
 pub fn foo() {}