Auto merge of #28866 - nikomatsakis:remove-hair-trait, r=nrc

As the subject says. This PR also removes the `Hair` trait, which was impeding the ability to build such a map, as described in this thread on internals:

https://internals.rust-lang.org/t/removing-the-hair-trait-from-mir-construction/2732

r? @nrc

Author: bors

mk/main.mk

@@ -175,18 +175,6 @@ ifdef CFG_DISABLE_STAGE0_LANDING_PADS
   RUSTFLAGS_STAGE0 += -Z no-landing-pads
 endif
 
-# Enable MIR to "always build" for crates where this works. This is
-# just temporary while MIR is being actively built up -- it's just a
-# poor man's unit testing infrastructure. Anyway we only want this for
-# stage1/stage2.
-define ADD_MIR_FLAG
-RUSTFLAGS1_$(1) += -Z always-build-mir
-RUSTFLAGS2_$(1) += -Z always-build-mir
-endef
-$(foreach crate,$(TARGET_CRATES),$(eval $(call ADD_MIR_FLAG,$(crate))))
-$(foreach crate,$(RUSTC_CRATES),$(eval $(call ADD_MIR_FLAG,$(crate))))
-$(foreach crate,$(HOST_CRATES),$(eval $(call ADD_MIR_FLAG,$(crate))))
-
 # platform-specific auto-configuration
 include $(CFG_SRC_DIR)mk/platform.mk
 

src/librustc/session/config.rs

@@ -101,7 +101,6 @@ pub struct Options {
     pub parse_only: bool,
     pub no_trans: bool,
     pub treat_err_as_bug: bool,
-    pub always_build_mir: bool,
     pub no_analysis: bool,
     pub debugging_opts: DebuggingOptions,
     pub prints: Vec<PrintRequest>,
@@ -211,7 +210,6 @@ pub fn basic_options() -> Options {
         parse_only: false,
         no_trans: false,
         treat_err_as_bug: false,
-        always_build_mir: false,
         no_analysis: false,
         debugging_opts: basic_debugging_options(),
         prints: Vec::new(),
@@ -578,8 +576,6 @@ options! {DebuggingOptions, DebuggingSetter, basic_debugging_options,
           "Run all passes except translation; no output"),
     treat_err_as_bug: bool = (false, parse_bool,
           "Treat all errors that occur as bugs"),
-    always_build_mir: bool = (false, parse_bool,
-          "Always build MIR for all fns, even without a #[rustc_mir] annotation"),
     no_analysis: bool = (false, parse_bool,
           "Parse and expand the source, but run no analysis"),
     extra_plugins: Vec<String> = (Vec::new(), parse_list,
@@ -895,7 +891,6 @@ pub fn build_session_options(matches: &getopts::Matches) -> Options {
     let parse_only = debugging_opts.parse_only;
     let no_trans = debugging_opts.no_trans;
     let treat_err_as_bug = debugging_opts.treat_err_as_bug;
-    let always_build_mir = debugging_opts.always_build_mir;
     let no_analysis = debugging_opts.no_analysis;
 
     if debugging_opts.debug_llvm {
@@ -1049,7 +1044,6 @@ pub fn build_session_options(matches: &getopts::Matches) -> Options {
         parse_only: parse_only,
         no_trans: no_trans,
         treat_err_as_bug: treat_err_as_bug,
-        always_build_mir: always_build_mir,
         no_analysis: no_analysis,
         debugging_opts: debugging_opts,
         prints: prints,

src/librustc_driver/driver.rs

@@ -738,8 +738,9 @@ pub fn phase_3_run_analysis_passes<'tcx, F, R>(sess: Session,
         time(time_passes, "match checking", ||
             middle::check_match::check_crate(tcx));
 
-        time(time_passes, "MIR dump", ||
-             mir::dump::dump_crate(tcx));
+        let _mir_map =
+            time(time_passes, "MIR dump", ||
+                 mir::mir_map::build_mir_for_crate(tcx));
 
         time(time_passes, "liveness checking", ||
             middle::liveness::check_crate(tcx));

src/librustc_mir/build/block.rs

@@ -8,15 +8,16 @@
 // option. This file may not be copied, modified, or distributed
 // except according to those terms.
 
+use build::{BlockAnd, Builder};
 use hair::*;
 use repr::*;
-use build::{BlockAnd, Builder};
+use rustc_front::hir;
 
-impl<H:Hair> Builder<H> {
+impl<'a,'tcx> Builder<'a,'tcx> {
     pub fn ast_block(&mut self,
-                     destination: &Lvalue<H>,
+                     destination: &Lvalue<'tcx>,
                      mut block: BasicBlock,
-                     ast_block: H::Block)
+                     ast_block: &'tcx hir::Block)
                      -> BlockAnd<()> {
         let this = self;
         let Block { extent, span: _, stmts, expr } = this.hir.mirror(ast_block);

src/librustc_mir/build/cfg.rs

@@ -14,15 +14,15 @@
 //! Routines for manipulating the control-flow graph.
 
 use build::CFG;
-use hair::*;
 use repr::*;
+use syntax::codemap::Span;
 
-impl<H:Hair> CFG<H> {
-    pub fn block_data(&self, blk: BasicBlock) -> &BasicBlockData<H> {
+impl<'tcx> CFG<'tcx> {
+    pub fn block_data(&self, blk: BasicBlock) -> &BasicBlockData<'tcx> {
         &self.basic_blocks[blk.index()]
     }
 
-    pub fn block_data_mut(&mut self, blk: BasicBlock) -> &mut BasicBlockData<H> {
+    pub fn block_data_mut(&mut self, blk: BasicBlock) -> &mut BasicBlockData<'tcx> {
         &mut self.basic_blocks[blk.index()]
     }
 
@@ -39,21 +39,21 @@ impl<H:Hair> CFG<H> {
         BasicBlock::new(node_index)
     }
 
-    pub fn push(&mut self, block: BasicBlock, statement: Statement<H>) {
+    pub fn push(&mut self, block: BasicBlock, statement: Statement<'tcx>) {
         debug!("push({:?}, {:?})", block, statement);
         self.block_data_mut(block).statements.push(statement);
     }
 
     pub fn push_assign_constant(&mut self,
                                 block: BasicBlock,
-                                span: H::Span,
-                                temp: &Lvalue<H>,
-                                constant: Constant<H>) {
+                                span: Span,
+                                temp: &Lvalue<'tcx>,
+                                constant: Constant<'tcx>) {
         self.push_assign(block, span, temp, Rvalue::Use(Operand::Constant(constant)));
     }
 
-    pub fn push_drop(&mut self, block: BasicBlock, span: H::Span,
-                     kind: DropKind, lvalue: &Lvalue<H>) {
+    pub fn push_drop(&mut self, block: BasicBlock, span: Span,
+                     kind: DropKind, lvalue: &Lvalue<'tcx>) {
         self.push(block, Statement {
             span: span,
             kind: StatementKind::Drop(kind, lvalue.clone())
@@ -62,9 +62,9 @@ impl<H:Hair> CFG<H> {
 
     pub fn push_assign(&mut self,
                        block: BasicBlock,
-                       span: H::Span,
-                       lvalue: &Lvalue<H>,
-                       rvalue: Rvalue<H>) {
+                       span: Span,
+                       lvalue: &Lvalue<'tcx>,
+                       rvalue: Rvalue<'tcx>) {
         self.push(block, Statement {
             span: span,
             kind: StatementKind::Assign(lvalue.clone(), rvalue)
@@ -73,7 +73,7 @@ impl<H:Hair> CFG<H> {
 
     pub fn terminate(&mut self,
                      block: BasicBlock,
-                     terminator: Terminator<H>) {
+                     terminator: Terminator<'tcx>) {
         // Check whether this block has already been terminated. For
         // this, we rely on the fact that the initial state is to have
         // a Diverge terminator and an empty list of targets (which

src/librustc_mir/build/expr/as_constant.rs

@@ -14,17 +14,17 @@ use build::{Builder};
 use hair::*;
 use repr::*;
 
-impl<H:Hair> Builder<H> {
+impl<'a,'tcx> Builder<'a,'tcx> {
     /// Compile `expr`, yielding a compile-time constant. Assumes that
     /// `expr` is a valid compile-time constant!
-    pub fn as_constant<M>(&mut self, expr: M) -> Constant<H>
-        where M: Mirror<H, Output=Expr<H>>
+    pub fn as_constant<M>(&mut self, expr: M) -> Constant<'tcx>
+        where M: Mirror<'tcx, Output=Expr<'tcx>>
     {
         let expr = self.hir.mirror(expr);
         self.expr_as_constant(expr)
     }
 
-    fn expr_as_constant(&mut self, expr: Expr<H>) -> Constant<H> {
+    fn expr_as_constant(&mut self, expr: Expr<'tcx>) -> Constant<'tcx> {
         let this = self;
         let Expr { ty, temp_lifetime: _, span, kind } = expr;
         match kind {

src/librustc_mir/build/expr/as_lvalue.rs

@@ -15,22 +15,22 @@ use build::expr::category::Category;
 use hair::*;
 use repr::*;
 
-impl<H:Hair> Builder<H> {
+impl<'a,'tcx> Builder<'a,'tcx> {
     /// Compile `expr`, yielding an lvalue that we can move from etc.
     pub fn as_lvalue<M>(&mut self,
                         block: BasicBlock,
                         expr: M)
-                        -> BlockAnd<Lvalue<H>>
-        where M: Mirror<H, Output=Expr<H>>
+                        -> BlockAnd<Lvalue<'tcx>>
+        where M: Mirror<'tcx, Output=Expr<'tcx>>
     {
         let expr = self.hir.mirror(expr);
         self.expr_as_lvalue(block, expr)
     }
 
     fn expr_as_lvalue(&mut self,
                       mut block: BasicBlock,
-                      expr: Expr<H>)
-                      -> BlockAnd<Lvalue<H>>
+                      expr: Expr<'tcx>)
+                      -> BlockAnd<Lvalue<'tcx>>
     {
         debug!("expr_as_lvalue(block={:?}, expr={:?})",
                block, expr);

src/librustc_mir/build/expr/as_operand.rs

@@ -15,25 +15,25 @@ use build::expr::category::Category;
 use hair::*;
 use repr::*;
 
-impl<H:Hair> Builder<H> {
+impl<'a,'tcx> Builder<'a,'tcx> {
     /// Compile `expr` into a value that can be used as an operand.
     /// If `expr` is an lvalue like `x`, this will introduce a
     /// temporary `tmp = x`, so that we capture the value of `x` at
     /// this time.
     pub fn as_operand<M>(&mut self,
                          block: BasicBlock,
                          expr: M)
-                         -> BlockAnd<Operand<H>>
-        where M: Mirror<H, Output=Expr<H>>
+                         -> BlockAnd<Operand<'tcx>>
+        where M: Mirror<'tcx, Output=Expr<'tcx>>
     {
         let expr = self.hir.mirror(expr);
         self.expr_as_operand(block, expr)
     }
 
     fn expr_as_operand(&mut self,
                        mut block: BasicBlock,
-                       expr: Expr<H>)
-                       -> BlockAnd<Operand<H>>
+                       expr: Expr<'tcx>)
+                       -> BlockAnd<Operand<'tcx>>
     {
         debug!("expr_as_operand(block={:?}, expr={:?})",
                block, expr);

src/librustc_mir/build/expr/as_rvalue.rs

@@ -17,22 +17,22 @@ use build::expr::category::{Category, RvalueFunc};
 use hair::*;
 use repr::*;
 
-impl<H:Hair> Builder<H> {
+impl<'a,'tcx> Builder<'a,'tcx> {
     /// Compile `expr`, yielding an rvalue.
     pub fn as_rvalue<M>(&mut self,
                         block: BasicBlock,
                         expr: M)
-                        -> BlockAnd<Rvalue<H>>
-        where M: Mirror<H, Output=Expr<H>>
+                        -> BlockAnd<Rvalue<'tcx>>
+        where M: Mirror<'tcx, Output=Expr<'tcx>>
     {
         let expr = self.hir.mirror(expr);
         self.expr_as_rvalue(block, expr)
     }
 
     fn expr_as_rvalue(&mut self,
                       mut block: BasicBlock,
-                      expr: Expr<H>)
-                      -> BlockAnd<Rvalue<H>>
+                      expr: Expr<'tcx>)
+                      -> BlockAnd<Rvalue<'tcx>>
     {
         debug!("expr_as_rvalue(block={:?}, expr={:?})",
                block, expr);

src/librustc_mir/build/expr/as_temp.rs

@@ -15,23 +15,23 @@ use build::expr::category::Category;
 use hair::*;
 use repr::*;
 
-impl<H:Hair> Builder<H> {
+impl<'a,'tcx> Builder<'a,'tcx> {
     /// Compile `expr` into a fresh temporary. This is used when building
     /// up rvalues so as to freeze the value that will be consumed.
     pub fn as_temp<M>(&mut self,
                       block: BasicBlock,
                       expr: M)
-                      -> BlockAnd<Lvalue<H>>
-        where M: Mirror<H, Output=Expr<H>>
+                      -> BlockAnd<Lvalue<'tcx>>
+        where M: Mirror<'tcx, Output=Expr<'tcx>>
     {
         let expr = self.hir.mirror(expr);
         self.expr_as_temp(block, expr)
     }
 
     fn expr_as_temp(&mut self,
                     mut block: BasicBlock,
-                    expr: Expr<H>)
-                    -> BlockAnd<Lvalue<H>>
+                    expr: Expr<'tcx>)
+                    -> BlockAnd<Lvalue<'tcx>>
     {
         debug!("expr_as_temp(block={:?}, expr={:?})",
                block, expr);