env! syntax extension changes

env! aborts compilation of the specified environment variable is not
defined and takes an optional second argument containing a custom
error message. option_env! creates an Option<&'static str> containing
the value of the environment variable.

There are no run-pass tests that check the behavior when the environment
variable is defined since the test framework doesn't support setting
environment variables at compile time as opposed to runtime. However,
both env! and option_env! are used inside of rustc itself, which should
act as a sufficient test.

Close #2248

Author: sfackler

src/librustc/back/rpath.rs

@@ -168,6 +168,7 @@ pub fn get_absolute_rpath(lib: &Path) -> Path {
     os::make_absolute(lib).dir_path()
 }
 
+#[cfg(stage0)]
 pub fn get_install_prefix_rpath(target_triple: &str) -> Path {
     let install_prefix = env!("CFG_PREFIX");
 
@@ -179,6 +180,14 @@ pub fn get_install_prefix_rpath(target_triple: &str) -> Path {
     os::make_absolute(&Path(install_prefix).push_rel(&tlib))
 }
 
+#[cfg(not(stage0))]
+pub fn get_install_prefix_rpath(target_triple: &str) -> Path {
+    let install_prefix = env!("CFG_PREFIX");
+
+    let tlib = filesearch::relative_target_lib_path(target_triple);
+    os::make_absolute(&Path(install_prefix).push_rel(&tlib))
+}
+
 pub fn minimize_rpaths(rpaths: &[Path]) -> ~[Path] {
     let mut set = HashSet::new();
     let mut minimized = ~[];

src/librustc/driver/driver.rs

@@ -1,4 +1,4 @@
-// Copyright 2012 The Rust Project Developers. See the COPYRIGHT
+// Copyright 2012-2013 The Rust Project Developers. See the COPYRIGHT
 // file at the top-level directory of this distribution and at
 // http://rust-lang.org/COPYRIGHT.
 //
@@ -578,6 +578,7 @@ pub fn build_target_config(sopts: @session::options,
     return target_cfg;
 }
 
+#[cfg(stage0)]
 pub fn host_triple() -> ~str {
     // Get the host triple out of the build environment. This ensures that our
     // idea of the host triple is the same as for the set of libraries we've
@@ -595,6 +596,19 @@ pub fn host_triple() -> ~str {
         };
 }
 
+#[cfg(not(stage0))]
+pub fn host_triple() -> ~str {
+    // Get the host triple out of the build environment. This ensures that our
+    // idea of the host triple is the same as for the set of libraries we've
+    // actually built.  We can't just take LLVM's host triple because they
+    // normalize all ix86 architectures to i386.
+    //
+    // Instead of grabbing the host triple (for the current host), we grab (at
+    // compile time) the target triple that this rustc is built with and
+    // calling that (at runtime) the host triple.
+    (env!("CFG_COMPILER_TRIPLE")).to_owned()
+}
+
 pub fn build_session_options(binary: @str,
                              matches: &getopts::Matches,
                              demitter: diagnostic::Emitter)

src/librustc/metadata/filesearch.rs

@@ -1,4 +1,4 @@
-// Copyright 2012 The Rust Project Developers. See the COPYRIGHT
+// Copyright 2012-2013 The Rust Project Developers. See the COPYRIGHT
 // file at the top-level directory of this distribution and at
 // http://rust-lang.org/COPYRIGHT.
 //
@@ -186,10 +186,16 @@ fn get_rustpkg_lib_path_nearest() -> Result<Path, ~str> {
 
 // The name of the directory rustc expects libraries to be located.
 // On Unix should be "lib", on windows "bin"
+#[cfg(stage0)]
 pub fn libdir() -> ~str {
    let libdir = env!("CFG_LIBDIR");
    if libdir.is_empty() {
       fail!("rustc compiled without CFG_LIBDIR environment variable");
    }
    libdir.to_owned()
 }
+
+#[cfg(not(stage0))]
+pub fn libdir() -> ~str {
+    (env!("CFG_LIBDIR")).to_owned()
+}

src/librustc/middle/resolve.rs

@@ -1,4 +1,4 @@
-// Copyright 2012 The Rust Project Developers. See the COPYRIGHT
+// Copyright 2012-2013 The Rust Project Developers. See the COPYRIGHT
 // file at the top-level directory of this distribution and at
 // http://rust-lang.org/COPYRIGHT.
 //
@@ -4991,7 +4991,9 @@ impl Resolver {
                             if self.structs.contains(&class_id) => {
                         self.record_def(expr.id, definition);
                     }
-                    _ => {
+                    result => {
+                        debug!("(resolving expression) didn't find struct \
+                                def: %?", result);
                         self.session.span_err(
                             path.span,
                             fmt!("`%s` does not name a structure",

src/librustc/rustc.rs

@@ -117,6 +117,7 @@ mod std {
 }
 */
 
+#[cfg(stage0)]
 pub fn version(argv0: &str) {
     let mut vers = ~"unknown version";
     let env_vers = env!("CFG_VERSION");
@@ -125,6 +126,16 @@ pub fn version(argv0: &str) {
     printfln!("host: %s", host_triple());
 }
 
+#[cfg(not(stage0))]
+pub fn version(argv0: &str) {
+    let vers = match option_env!("CFG_VERSION") {
+        Some(vers) => vers,
+        None => "unknown version"
+    };
+    printfln!("%s %s", argv0, vers);
+    printfln!("host: %s", host_triple());
+}
+
 pub fn usage(argv0: &str) {
     let message = fmt!("Usage: %s [OPTIONS] INPUT", argv0);
     printfln!("%s\

src/libsyntax/ext/asm.rs

@@ -1,4 +1,4 @@
-// Copyright 2012 The Rust Project Developers. See the COPYRIGHT
+// Copyright 2012-2013 The Rust Project Developers. See the COPYRIGHT
 // file at the top-level directory of this distribution and at
 // http://rust-lang.org/COPYRIGHT.
 //
@@ -59,7 +59,7 @@ pub fn expand_asm(cx: @ExtCtxt, sp: span, tts: &[ast::token_tree])
         match state {
             Asm => {
                 asm = expr_to_str(cx, p.parse_expr(),
-                                  ~"inline assembly must be a string literal.");
+                                  "inline assembly must be a string literal.");
             }
             Outputs => {
                 while *p.token != token::EOF &&

src/libsyntax/ext/base.rs

@@ -146,7 +146,9 @@ pub fn syntax_expander_table() -> SyntaxEnv {
         intern(&"auto_decode"),
         @SE(ItemDecorator(ext::auto_encode::expand_auto_decode)));
     syntax_expanders.insert(intern(&"env"),
-                            builtin_normal_tt(ext::env::expand_syntax_ext));
+                            builtin_normal_tt(ext::env::expand_env));
+    syntax_expanders.insert(intern(&"option_env"),
+                            builtin_normal_tt(ext::env::expand_option_env));
     syntax_expanders.insert(intern("bytes"),
                             builtin_normal_tt(ext::bytes::expand_syntax_ext));
     syntax_expanders.insert(intern("concat_idents"),
@@ -311,7 +313,7 @@ impl ExtCtxt {
     }
 }
 
-pub fn expr_to_str(cx: @ExtCtxt, expr: @ast::expr, err_msg: ~str) -> @str {
+pub fn expr_to_str(cx: @ExtCtxt, expr: @ast::expr, err_msg: &str) -> @str {
     match expr.node {
       ast::expr_lit(l) => match l.node {
         ast::lit_str(s) => s,
@@ -536,8 +538,8 @@ mod test {
         a.insert (@"abc",@15);
         let m = MapChain::new(~a);
         m.insert (@"def",@16);
-        // FIXME: #4492 (ICE)  assert_eq!(m.find(&@"abc"),Some(@15));
-        //  ....               assert_eq!(m.find(&@"def"),Some(@16));
+        assert_eq!(m.find(&@"abc"),Some(@15));
+        assert_eq!(m.find(&@"def"),Some(@16));
         assert_eq!(*(m.find(&@"abc").unwrap()),15);
         assert_eq!(*(m.find(&@"def").unwrap()),16);
         let n = m.push_frame();
@@ -549,8 +551,8 @@ mod test {
         assert_eq!(*(n.find(&@"abc").unwrap()),15);
         assert_eq!(*(n.find(&@"def").unwrap()),17);
         // ... but m still has the old ones
-        // FIXME: #4492: assert_eq!(m.find(&@"abc"),Some(@15));
-        // FIXME: #4492: assert_eq!(m.find(&@"def"),Some(@16));
+        assert_eq!(m.find(&@"abc"),Some(@15));
+        assert_eq!(m.find(&@"def"),Some(@16));
         assert_eq!(*(m.find(&@"abc").unwrap()),15);
         assert_eq!(*(m.find(&@"def").unwrap()),16);
     }

src/libsyntax/ext/env.rs

@@ -1,4 +1,4 @@
-// Copyright 2012 The Rust Project Developers. See the COPYRIGHT
+// Copyright 2012-2013 The Rust Project Developers. See the COPYRIGHT
 // file at the top-level directory of this distribution and at
 // http://rust-lang.org/COPYRIGHT.
 //
@@ -22,17 +22,35 @@ use ext::build::AstBuilder;
 
 use std::os;
 
-pub fn expand_syntax_ext(cx: @ExtCtxt, sp: span, tts: &[ast::token_tree])
+pub fn expand_option_env(ext_cx: @ExtCtxt, sp: span, tts: &[ast::token_tree])
     -> base::MacResult {
+    let var = get_single_str_from_tts(ext_cx, sp, tts, "option_env!");
 
-    let var = get_single_str_from_tts(cx, sp, tts, "env!");
+    let e = match os::getenv(var) {
+      None => quote_expr!(::std::option::None),
+      Some(s) => quote_expr!(::std::option::Some($s))
+    };
+    MRExpr(e)
+}
 
-    // FIXME (#2248): if this was more thorough it would manufacture an
-    // Option<str> rather than just an maybe-empty string.
+pub fn expand_env(ext_cx: @ExtCtxt, sp: span, tts: &[ast::token_tree])
+    -> base::MacResult {
+    let exprs = get_exprs_from_tts(ext_cx, sp, tts);
+
+    if exprs.len() == 0 {
+        ext_cx.span_fatal(sp, "env! takes 1 or 2 arguments");
+    }
+
+    let var = expr_to_str(ext_cx, exprs[0], "expected string literal");
+    let msg = match exprs.len() {
+        1 => fmt!("Environment variable %s not defined", var).to_managed(),
+        2 => expr_to_str(ext_cx, exprs[1], "expected string literal"),
+        _ => ext_cx.span_fatal(sp, "env! takes 1 or 2 arguments")
+    };
 
     let e = match os::getenv(var) {
-      None => cx.expr_str(sp, @""),
-      Some(s) => cx.expr_str(sp, s.to_managed())
+        None => ext_cx.span_fatal(sp, msg),
+        Some(s) => ext_cx.expr_str(sp, s.to_managed())
     };
     MRExpr(e)
 }

src/libsyntax/ext/fmt.rs

@@ -1,4 +1,4 @@
-// Copyright 2012 The Rust Project Developers. See the COPYRIGHT
+// Copyright 2012-2013 The Rust Project Developers. See the COPYRIGHT
 // file at the top-level directory of this distribution and at
 // http://rust-lang.org/COPYRIGHT.
 //
@@ -32,7 +32,7 @@ pub fn expand_syntax_ext(cx: @ExtCtxt, sp: span, tts: &[ast::token_tree])
     }
     let fmt =
         expr_to_str(cx, args[0],
-                    ~"first argument to fmt! must be a string literal.");
+                    "first argument to fmt! must be a string literal.");
     let fmtspan = args[0].span;
     debug!("Format string: %s", fmt);
     fn parse_fmt_err_(cx: @ExtCtxt, sp: span, msg: &str) -> ! {

src/test/compile-fail/extenv-arg-2-not-string-literal.rs

@@ -0,0 +1,11 @@
+// Copyright 2013 The Rust Project Developers. See the COPYRIGHT
+// file at the top-level directory of this distribution and at
+// http://rust-lang.org/COPYRIGHT.
+//
+// Licensed under the Apache License, Version 2.0 <LICENSE-APACHE or
+// http://www.apache.org/licenses/LICENSE-2.0> or the MIT license
+// <LICENSE-MIT or http://opensource.org/licenses/MIT>, at your
+// option. This file may not be copied, modified, or distributed
+// except according to those terms.
+
+fn main() { env!("one", 10); } //~ ERROR: expected string literal

src/test/compile-fail/extenv-no-args.rs

@@ -1,4 +1,4 @@
-// Copyright 2012 The Rust Project Developers. See the COPYRIGHT
+// Copyright 2012-2013 The Rust Project Developers. See the COPYRIGHT
 // file at the top-level directory of this distribution and at
 // http://rust-lang.org/COPYRIGHT.
 //
@@ -8,6 +8,4 @@
 // option. This file may not be copied, modified, or distributed
 // except according to those terms.
 
-// error-pattern: env! takes 1 argument
-
-fn main() { env!(); }
+fn main() { env!(); } //~ ERROR: env! takes 1 or 2 arguments

src/test/compile-fail/extenv-not-defined-custom.rs

@@ -0,0 +1,11 @@
+// Copyright 2013 The Rust Project Developers. See the COPYRIGHT
+// file at the top-level directory of this distribution and at
+// http://rust-lang.org/COPYRIGHT.
+//
+// Licensed under the Apache License, Version 2.0 <LICENSE-APACHE or
+// http://www.apache.org/licenses/LICENSE-2.0> or the MIT license
+// <LICENSE-MIT or http://opensource.org/licenses/MIT>, at your
+// option. This file may not be copied, modified, or distributed
+// except according to those terms.
+
+fn main() { env!("__HOPEFULLY_NOT_DEFINED__", "my error message"); } //~ ERROR: my error message

src/test/compile-fail/extenv-not-defined-default.rs

@@ -0,0 +1,11 @@
+// Copyright 2012 The Rust Project Developers. See the COPYRIGHT
+// file at the top-level directory of this distribution and at
+// http://rust-lang.org/COPYRIGHT.
+//
+// Licensed under the Apache License, Version 2.0 <LICENSE-APACHE or
+// http://www.apache.org/licenses/LICENSE-2.0> or the MIT license
+// <LICENSE-MIT or http://opensource.org/licenses/MIT>, at your
+// option. This file may not be copied, modified, or distributed
+// except according to those terms.
+
+fn main() { env!("__HOPEFULLY_NOT_DEFINED__"); } //~ ERROR: Environment variable __HOPEFULLY_NOT_DEFINED__ not defined

src/test/compile-fail/extenv-not-string-literal.rs

@@ -1,4 +1,4 @@
-// Copyright 2012 The Rust Project Developers. See the COPYRIGHT
+// Copyright 2012-2013 The Rust Project Developers. See the COPYRIGHT
 // file at the top-level directory of this distribution and at
 // http://rust-lang.org/COPYRIGHT.
 //
@@ -8,6 +8,4 @@
 // option. This file may not be copied, modified, or distributed
 // except according to those terms.
 
-// error-pattern:requires a string
-
-fn main() { env!(10); }
+fn main() { env!(10, "two"); } //~ ERROR: expected string literal

src/test/compile-fail/extenv-too-many-args.rs

@@ -8,6 +8,4 @@
 // option. This file may not be copied, modified, or distributed
 // except according to those terms.
 
-// error-pattern: env! takes 1 argument
-
-fn main() { env!("one", "two"); }
+fn main() { env!("one", "two", "three"); } //~ ERROR: env! takes 1 or 2 arguments

src/test/compile-fail/extoption_env-no-args.rs

@@ -0,0 +1,11 @@
+// Copyright 2012 The Rust Project Developers. See the COPYRIGHT
+// file at the top-level directory of this distribution and at
+// http://rust-lang.org/COPYRIGHT.
+//
+// Licensed under the Apache License, Version 2.0 <LICENSE-APACHE or
+// http://www.apache.org/licenses/LICENSE-2.0> or the MIT license
+// <LICENSE-MIT or http://opensource.org/licenses/MIT>, at your
+// option. This file may not be copied, modified, or distributed
+// except according to those terms.
+
+fn main() { option_env!(); } //~ ERROR: option_env! takes 1 argument

src/test/compile-fail/extoption_env-not-string-literal.rs

@@ -0,0 +1,11 @@
+// Copyright 2012-2013 The Rust Project Developers. See the COPYRIGHT
+// file at the top-level directory of this distribution and at
+// http://rust-lang.org/COPYRIGHT.
+//
+// Licensed under the Apache License, Version 2.0 <LICENSE-APACHE or
+// http://www.apache.org/licenses/LICENSE-2.0> or the MIT license
+// <LICENSE-MIT or http://opensource.org/licenses/MIT>, at your
+// option. This file may not be copied, modified, or distributed
+// except according to those terms.
+
+fn main() { option_env!(10); } //~ ERROR: requires a string

src/test/compile-fail/extoption_env-too-many-args.rs

@@ -0,0 +1,11 @@
+// Copyright 2012-2013 The Rust Project Developers. See the COPYRIGHT
+// file at the top-level directory of this distribution and at
+// http://rust-lang.org/COPYRIGHT.
+//
+// Licensed under the Apache License, Version 2.0 <LICENSE-APACHE or
+// http://www.apache.org/licenses/LICENSE-2.0> or the MIT license
+// <LICENSE-MIT or http://opensource.org/licenses/MIT>, at your
+// option. This file may not be copied, modified, or distributed
+// except according to those terms.
+
+fn main() { option_env!("one", "two"); } //~ ERROR: option_env! takes 1 argument

src/test/run-pass/extoption_env-not-defined.rs

@@ -0,0 +1,14 @@
+// Copyright 2013 The Rust Project Developers. See the COPYRIGHT
+// file at the top-level directory of this distribution and at
+// http://rust-lang.org/COPYRIGHT.
+//
+// Licensed under the Apache License, Version 2.0 <LICENSE-APACHE or
+// http://www.apache.org/licenses/LICENSE-2.0> or the MIT license
+// <LICENSE-MIT or http://opensource.org/licenses/MIT>, at your
+// option. This file may not be copied, modified, or distributed
+// except according to those terms.
+
+fn main() {
+    let opt: Option<&'static str> = option_env!("__HOPEFULLY_DOESNT_EXIST__");
+    assert!(opt.is_none());
+}