From 62c9fa939d95fcc009afb7ab80483081c3d1f068 Mon Sep 17 00:00:00 2001 From: Vadim Petrochenkov Date: Wed, 22 Jul 2020 21:08:01 +0300 Subject: [PATCH] proc_macro: Add API for tracked access to environment variables --- src/libproc_macro/bridge/client.rs | 1 + src/libproc_macro/bridge/mod.rs | 4 ++++ src/libproc_macro/bridge/server.rs | 2 ++ src/libproc_macro/lib.rs | 21 +++++++++++++++++++++ src/librustc_expand/proc_macro_server.rs | 9 +++++++++ src/test/run-make/env-dep-info/Makefile | 11 +++++++++++ src/test/run-make/env-dep-info/macro_def.rs | 12 ++++++++++++ src/test/run-make/env-dep-info/macro_use.rs | 6 ++++++ 8 files changed, 66 insertions(+) create mode 100644 src/test/run-make/env-dep-info/macro_def.rs create mode 100644 src/test/run-make/env-dep-info/macro_use.rs diff --git a/src/libproc_macro/bridge/client.rs b/src/libproc_macro/bridge/client.rs index 283aa25b0ea13..c00e07388b882 100644 --- a/src/libproc_macro/bridge/client.rs +++ b/src/libproc_macro/bridge/client.rs @@ -157,6 +157,7 @@ macro_rules! define_handles { } define_handles! { 'owned: + FreeFunctions, TokenStream, TokenStreamBuilder, TokenStreamIter, diff --git a/src/libproc_macro/bridge/mod.rs b/src/libproc_macro/bridge/mod.rs index bf0d8fcee5b8f..324be9f470108 100644 --- a/src/libproc_macro/bridge/mod.rs +++ b/src/libproc_macro/bridge/mod.rs @@ -52,6 +52,10 @@ use std::thread; macro_rules! with_api { ($S:ident, $self:ident, $m:ident) => { $m! { + FreeFunctions { + fn drop($self: $S::FreeFunctions); + fn track_env_var(var: &str, value: Option<&str>); + }, TokenStream { fn drop($self: $S::TokenStream); fn clone($self: &$S::TokenStream) -> $S::TokenStream; diff --git a/src/libproc_macro/bridge/server.rs b/src/libproc_macro/bridge/server.rs index ca18d4459aa89..eb39025e4c228 100644 --- a/src/libproc_macro/bridge/server.rs +++ b/src/libproc_macro/bridge/server.rs @@ -8,6 +8,8 @@ use super::client::HandleStore; /// Declare an associated item of one of the traits below, optionally /// adjusting it (i.e., adding bounds to types and default bodies to methods). macro_rules! associated_item { + (type FreeFunctions) => + (type FreeFunctions: 'static;); (type TokenStream) => (type TokenStream: 'static + Clone;); (type TokenStreamBuilder) => diff --git a/src/libproc_macro/lib.rs b/src/libproc_macro/lib.rs index f960bdecc579f..c050a3c591cee 100644 --- a/src/libproc_macro/lib.rs +++ b/src/libproc_macro/lib.rs @@ -24,6 +24,7 @@ #![feature(decl_macro)] #![feature(extern_types)] #![feature(in_band_lifetimes)] +#![feature(inner_deref)] #![feature(negative_impls)] #![feature(optin_builtin_traits)] #![feature(restricted_std)] @@ -1160,3 +1161,23 @@ impl fmt::Debug for Literal { self.0.fmt(f) } } + +/// Tracked access to environment variables. +#[unstable(feature = "proc_macro_tracked_env", issue = "74690")] +pub mod tracked_env { + use std::env::{self, VarError}; + use std::ffi::OsStr; + + /// Retrieve an environment variable and add it to build dependency info. + /// Build system executing the compiler will know that the variable was accessed during + /// compilation, and will be able to rerun the build when the value of that variable changes. + /// Besides the dependency tracking this function should be equivalent to `env::var` from the + /// standard library, except that the argument must be UTF-8. + #[unstable(feature = "proc_macro_tracked_env", issue = "74690")] + pub fn var + AsRef>(key: K) -> Result { + let key: &str = key.as_ref(); + let value = env::var(key); + crate::bridge::client::FreeFunctions::track_env_var(key, value.as_deref().ok()); + value + } +} diff --git a/src/librustc_expand/proc_macro_server.rs b/src/librustc_expand/proc_macro_server.rs index 2805b4203f928..881d7b84b70b0 100644 --- a/src/librustc_expand/proc_macro_server.rs +++ b/src/librustc_expand/proc_macro_server.rs @@ -274,6 +274,8 @@ impl ToInternal for Level { } } +pub struct FreeFunctions; + #[derive(Clone)] pub struct TokenStreamIter { cursor: tokenstream::Cursor, @@ -379,6 +381,7 @@ impl<'a> Rustc<'a> { } impl server::Types for Rustc<'_> { + type FreeFunctions = FreeFunctions; type TokenStream = TokenStream; type TokenStreamBuilder = tokenstream::TokenStreamBuilder; type TokenStreamIter = TokenStreamIter; @@ -392,6 +395,12 @@ impl server::Types for Rustc<'_> { type Span = Span; } +impl server::FreeFunctions for Rustc<'_> { + fn track_env_var(&mut self, var: &str, value: Option<&str>) { + self.sess.env_depinfo.borrow_mut().insert((Symbol::intern(var), value.map(Symbol::intern))); + } +} + impl server::TokenStream for Rustc<'_> { fn new(&mut self) -> Self::TokenStream { TokenStream::default() diff --git a/src/test/run-make/env-dep-info/Makefile b/src/test/run-make/env-dep-info/Makefile index 2be0b4b324b08..25d9a31c2d6ff 100644 --- a/src/test/run-make/env-dep-info/Makefile +++ b/src/test/run-make/env-dep-info/Makefile @@ -1,8 +1,19 @@ -include ../../run-make-fulldeps/tools.mk +# FIXME(eddyb) provide `HOST_RUSTC` and `TARGET_RUSTC` +# instead of hardcoding them everywhere they're needed. +ifeq ($(IS_MUSL_HOST),1) +ADDITIONAL_ARGS := $(RUSTFLAGS) +endif + all: EXISTING_ENV=1 EXISTING_OPT_ENV=1 $(RUSTC) --emit dep-info main.rs $(CGREP) "# env-dep:EXISTING_ENV=1" < $(TMPDIR)/main.d $(CGREP) "# env-dep:EXISTING_OPT_ENV=1" < $(TMPDIR)/main.d $(CGREP) "# env-dep:NONEXISTENT_OPT_ENV" < $(TMPDIR)/main.d $(CGREP) "# env-dep:ESCAPE\nESCAPE\\" < $(TMPDIR)/main.d + # Proc macro + $(BARE_RUSTC) $(ADDITIONAL_ARGS) --out-dir $(TMPDIR) macro_def.rs + EXISTING_PROC_MACRO_ENV=1 $(RUSTC) --emit dep-info macro_use.rs + $(CGREP) "# env-dep:EXISTING_PROC_MACRO_ENV=1" < $(TMPDIR)/macro_use.d + $(CGREP) "# env-dep:NONEXISTENT_PROC_MACEO_ENV" < $(TMPDIR)/macro_use.d diff --git a/src/test/run-make/env-dep-info/macro_def.rs b/src/test/run-make/env-dep-info/macro_def.rs new file mode 100644 index 0000000000000..e328eae48326d --- /dev/null +++ b/src/test/run-make/env-dep-info/macro_def.rs @@ -0,0 +1,12 @@ +#![feature(proc_macro_tracked_env)] +#![crate_type = "proc-macro"] + +extern crate proc_macro; +use proc_macro::*; + +#[proc_macro] +pub fn access_env_vars(_: TokenStream) -> TokenStream { + let _ = tracked_env::var("EXISTING_PROC_MACRO_ENV"); + let _ = tracked_env::var("NONEXISTENT_PROC_MACEO_ENV"); + TokenStream::new() +} diff --git a/src/test/run-make/env-dep-info/macro_use.rs b/src/test/run-make/env-dep-info/macro_use.rs new file mode 100644 index 0000000000000..2f5267471fc82 --- /dev/null +++ b/src/test/run-make/env-dep-info/macro_use.rs @@ -0,0 +1,6 @@ +#[macro_use] +extern crate macro_def; + +access_env_vars!(); + +fn main() {}