6 files changed, 74 insertions, 24 deletions

diff --git a/crates/ra_parser/src/grammar/expressions/atom.rs b/crates/ra_parser/src/grammar/expressions/atom.rs
index bc942ae01..ab8fb9f6e 100644
--- a/crates/ra_parser/src/grammar/expressions/atom.rs
+++ b/crates/ra_parser/src/grammar/expressions/atom.rs
@@ -414,6 +414,8 @@ pub(crate) fn match_arm_list(p: &mut Parser) {
 //         X | Y if Z => (),
 //         | X | Y if Z => (),
 //         | X => (),
+//         box X => (),
+//         Some(box X) => (),
 //     };
 // }
 fn match_arm(p: &mut Parser) -> BlockLike {
diff --git a/crates/ra_parser/src/grammar/patterns.rs b/crates/ra_parser/src/grammar/patterns.rs
index df6000707..1f6a6fd48 100644
--- a/crates/ra_parser/src/grammar/patterns.rs
+++ b/crates/ra_parser/src/grammar/patterns.rs
@@ -2,7 +2,7 @@ use super::*;
 
 pub(super) const PATTERN_FIRST: TokenSet = expressions::LITERAL_FIRST
     .union(paths::PATH_FIRST)
-    .union(token_set![REF_KW, MUT_KW, L_PAREN, L_BRACK, AMP, UNDERSCORE, MINUS]);
+    .union(token_set![BOX_KW, REF_KW, MUT_KW, L_PAREN, L_BRACK, AMP, UNDERSCORE, MINUS]);
 
 pub(super) fn pattern(p: &mut Parser) {
     pattern_r(p, PAT_RECOVERY_SET);
diff --git a/crates/ra_project_model/src/sysroot.rs b/crates/ra_project_model/src/sysroot.rs
index 2a7927f7e..0c27d4f4b 100644
--- a/crates/ra_project_model/src/sysroot.rs
+++ b/crates/ra_project_model/src/sysroot.rs
@@ -1,4 +1,5 @@
 use std::{
+    env,
     path::{Path, PathBuf},
     process::Command,
 };
@@ -33,21 +34,13 @@ impl Sysroot {
     }
 
     pub fn discover(cargo_toml: &Path) -> Result<Sysroot> {
-        let rustc_output = Command::new("rustc")
-            .current_dir(cargo_toml.parent().unwrap())
-            .args(&["--print", "sysroot"])
-            .output()?;
-        if !rustc_output.status.success() {
-            Err("failed to locate sysroot")?
-        }
-        let stdout = String::from_utf8(rustc_output.stdout)?;
-        let sysroot_path = Path::new(stdout.trim());
-        let src = sysroot_path.join("lib/rustlib/src/rust/src");
+        let src = try_find_src_path(cargo_toml)?;
+
         if !src.exists() {
             Err(format!(
                 "can't load standard library from sysroot\n\
                  {:?}\n\
-                 try running `rustup component add rust-src`",
+                 try running `rustup component add rust-src` or set `RUST_SRC_PATH`",
                 src,
             ))?;
         }
@@ -83,6 +76,23 @@ impl Sysroot {
     }
 }
 
+fn try_find_src_path(cargo_toml: &Path) -> Result<PathBuf> {
+    if let Ok(path) = env::var("RUST_SRC_PATH") {
+        return Ok(path.into());
+    }
+
+    let rustc_output = Command::new("rustc")
+        .current_dir(cargo_toml.parent().unwrap())
+        .args(&["--print", "sysroot"])
+        .output()?;
+    if !rustc_output.status.success() {
+        Err("failed to locate sysroot")?;
+    }
+    let stdout = String::from_utf8(rustc_output.stdout)?;
+    let sysroot_path = Path::new(stdout.trim());
+    Ok(sysroot_path.join("lib/rustlib/src/rust/src"))
+}
+
 impl SysrootCrate {
     pub fn name(self, sysroot: &Sysroot) -> &str {
         &sysroot.crates[self].name
diff --git a/crates/ra_syntax/test_data/parser/inline/ok/0066_match_arm.rs b/crates/ra_syntax/test_data/parser/inline/ok/0066_match_arm.rs
index 9e009e24f..2d476278d 100644
--- a/crates/ra_syntax/test_data/parser/inline/ok/0066_match_arm.rs
+++ b/crates/ra_syntax/test_data/parser/inline/ok/0066_match_arm.rs
@@ -5,5 +5,7 @@ fn foo() {
         X | Y if Z => (),
         | X | Y if Z => (),
         | X => (),
+        box X => (),
+        Some(box X) => (),
     };
 }
diff --git a/crates/ra_syntax/test_data/parser/inline/ok/0066_match_arm.txt b/crates/ra_syntax/test_data/parser/inline/ok/0066_match_arm.txt
index 041e7179e..28d501459 100644
--- a/crates/ra_syntax/test_data/parser/inline/ok/0066_match_arm.txt
+++ b/crates/ra_syntax/test_data/parser/inline/ok/0066_match_arm.txt
@@ -1,5 +1,5 @@
-SOURCE_FILE@[0; 167)
-  FN_DEF@[0; 166)
+SOURCE_FILE@[0; 215)
+  FN_DEF@[0; 214)
     FN_KW@[0; 2) "fn"
     WHITESPACE@[2; 3) " "
     NAME@[3; 6)
@@ -8,18 +8,18 @@ SOURCE_FILE@[0; 167)
       L_PAREN@[6; 7) "("
       R_PAREN@[7; 8) ")"
     WHITESPACE@[8; 9) " "
-    BLOCK@[9; 166)
+    BLOCK@[9; 214)
       L_CURLY@[9; 10) "{"
       WHITESPACE@[10; 15) "\n    "
-      EXPR_STMT@[15; 164)
-        MATCH_EXPR@[15; 163)
+      EXPR_STMT@[15; 212)
+        MATCH_EXPR@[15; 211)
           MATCH_KW@[15; 20) "match"
           WHITESPACE@[20; 21) " "
           TUPLE_EXPR@[21; 23)
             L_PAREN@[21; 22) "("
             R_PAREN@[22; 23) ")"
           WHITESPACE@[23; 24) " "
-          MATCH_ARM_LIST@[24; 163)
+          MATCH_ARM_LIST@[24; 211)
             L_CURLY@[24; 25) "{"
             WHITESPACE@[25; 34) "\n        "
             MATCH_ARM@[34; 41)
@@ -141,9 +141,44 @@ SOURCE_FILE@[0; 167)
                 L_PAREN@[154; 155) "("
                 R_PAREN@[155; 156) ")"
             COMMA@[156; 157) ","
-            WHITESPACE@[157; 162) "\n    "
-            R_CURLY@[162; 163) "}"
-        SEMI@[163; 164) ";"
-      WHITESPACE@[164; 165) "\n"
-      R_CURLY@[165; 166) "}"
-  WHITESPACE@[166; 167) "\n"
+            WHITESPACE@[157; 166) "\n        "
+            MATCH_ARM@[166; 177)
+              BIND_PAT@[166; 171)
+                BOX_KW@[166; 169) "box"
+                WHITESPACE@[169; 170) " "
+                NAME@[170; 171)
+                  IDENT@[170; 171) "X"
+              WHITESPACE@[171; 172) " "
+              FAT_ARROW@[172; 174) "=>"
+              WHITESPACE@[174; 175) " "
+              TUPLE_EXPR@[175; 177)
+                L_PAREN@[175; 176) "("
+                R_PAREN@[176; 177) ")"
+            COMMA@[177; 178) ","
+            WHITESPACE@[178; 187) "\n        "
+            MATCH_ARM@[187; 204)
+              TUPLE_STRUCT_PAT@[187; 198)
+                PATH@[187; 191)
+                  PATH_SEGMENT@[187; 191)
+                    NAME_REF@[187; 191)
+                      IDENT@[187; 191) "Some"
+                L_PAREN@[191; 192) "("
+                BIND_PAT@[192; 197)
+                  BOX_KW@[192; 195) "box"
+                  WHITESPACE@[195; 196) " "
+                  NAME@[196; 197)
+                    IDENT@[196; 197) "X"
+                R_PAREN@[197; 198) ")"
+              WHITESPACE@[198; 199) " "
+              FAT_ARROW@[199; 201) "=>"
+              WHITESPACE@[201; 202) " "
+              TUPLE_EXPR@[202; 204)
+                L_PAREN@[202; 203) "("
+                R_PAREN@[203; 204) ")"
+            COMMA@[204; 205) ","
+            WHITESPACE@[205; 210) "\n    "
+            R_CURLY@[210; 211) "}"
+        SEMI@[211; 212) ";"
+      WHITESPACE@[212; 213) "\n"
+      R_CURLY@[213; 214) "}"
+  WHITESPACE@[214; 215) "\n"
diff --git a/docs/user/README.md b/docs/user/README.md
index 7990d1d31..453e8e273 100644
--- a/docs/user/README.md
+++ b/docs/user/README.md
@@ -78,6 +78,7 @@ See https://github.com/microsoft/vscode/issues/72308[microsoft/vscode#72308] for
   (e.g: `--features="shumway,pdf"` will run as `cargo watch -x "check --features="shumway,pdf""` )
 * `rust-analyzer.trace.server`: enables internal logging
 * `rust-analyzer.trace.cargo-watch`: enables cargo-watch logging
+* `RUST_SRC_PATH`: environment variable that overwrites the sysroot
 
 
 ## Emacs