Support custom search directories

src/driver.rs

@@ -249,6 +249,9 @@ struct BridgeState {
     /// The main filesystem backing for input files in the project.
     filesystem: FilesystemIo,
 
+    /// Extra paths we search through for files.
+    extra_search_paths: Vec<FilesystemIo>,
+
     /// Additional filesystem backing used if "shell escape" functionality is
     /// activated. If None, we take that to mean that shell-escape is
     /// disallowed. We have to use a persistent filesystem directory for this
@@ -447,6 +450,11 @@ macro_rules! bridgestate_ioprovider_cascade {
             if let Some(ref mut p) = $self.shell_escape_work {
                 bridgestate_ioprovider_try!(p, $($inner)+);
             }
+
+            // extra search paths
+            for fsio in $self.extra_search_paths.iter_mut() {
+                bridgestate_ioprovider_try!(fsio, $($inner)+);
+            }
         }
 
         bridgestate_ioprovider_try!($self.bundle.as_ioprovider_mut(), $($inner)+);
@@ -1068,6 +1076,12 @@ impl ProcessingSessionBuilder {
             primary_input: pio,
             mem,
             filesystem,
+            extra_search_paths: self
+                .unstables
+                .extra_search_paths
+                .iter()
+                .map(|p| FilesystemIo::new(p, false, false, HashSet::new()))
+                .collect(),
             shell_escape_work: None,
             format_cache,
             bundle,

src/unstable_opts.rs

@@ -8,8 +8,10 @@
 //! to be reliable or very polished. In particular, many of these prevent the build from being
 //! reproducible.
 
+use crate::errmsg;
 use crate::errors::{Error, Result};
 use std::default::Default;
+use std::path::PathBuf;
 use std::str::FromStr;
 
 const HELPMSG: &str = r#"Available unstable options:
@@ -19,6 +21,8 @@ const HELPMSG: &str = r#"Available unstable options:
     -Z min-crossrefs=<num>      Equivalent to bibtex's -min-crossrefs flag - "include after <num>
                                     crossrefs" [default: 2]
     -Z paper-size=<spec>        Change the default paper size [default: letter]
+    -Z search-path=<path>       Also look in <path> for files, like TEXINPUTS. Can be specified
+                                    multiple times.
     -Z shell-escape             Enable \write18
 "#;
 
@@ -29,6 +33,7 @@ pub enum UnstableArg {
     Help,
     MinCrossrefs(i32),
     PaperSize(String),
+    SearchPath(PathBuf),
     ShellEscapeEnabled,
 }
 
@@ -44,25 +49,30 @@ impl FromStr for UnstableArg {
         // For structopt/clap, if you pass a value to a flag which doesn't accept one, it's
         // silently ignored.
 
+        let require_value = |value_name| {
+            value.ok_or_else(|| {
+                errmsg!(
+                    "'-Z {}=<{}>' requires a value but none was supplied",
+                    arg,
+                    value_name
+                )
+            })
+        };
+
         match arg {
             "help" => Ok(UnstableArg::Help),
 
             "continue-on-errors" => Ok(UnstableArg::ContinueOnErrors),
 
-            "min-crossrefs" => value
-                .ok_or_else(|| {
-                    "'-Z min-crossrefs <spec>' requires a value but none was supplied".into()
-                })
+            "min-crossrefs" => require_value("num")
                 .and_then(|s| {
                     FromStr::from_str(s).map_err(|e| format!("-Z min-crossrefs: {}", e).into())
                 })
                 .map(UnstableArg::MinCrossrefs),
 
-            "paper-size" => value
-                .ok_or_else(|| {
-                    "'-Z paper-size <spec>' requires a value but none was supplied".into()
-                })
-                .map(|s| UnstableArg::PaperSize(s.to_string())),
+            "paper-size" => require_value("spec").map(|s| UnstableArg::PaperSize(s.to_string())),
+
+            "search-path" => require_value("path").map(|s| UnstableArg::SearchPath(s.into())),
 
             "shell-escape" => Ok(UnstableArg::ShellEscapeEnabled),
 
@@ -77,6 +87,7 @@ pub struct UnstableOptions {
     pub paper_size: Option<String>,
     pub shell_escape: bool,
     pub min_crossrefs: Option<i32>,
+    pub extra_search_paths: Vec<PathBuf>,
 }
 
 impl UnstableOptions {
@@ -97,6 +108,7 @@ impl UnstableOptions {
                 MinCrossrefs(num) => opts.min_crossrefs = Some(num),
                 PaperSize(size) => opts.paper_size = Some(size),
                 ShellEscapeEnabled => opts.shell_escape = true,
+                SearchPath(p) => opts.extra_search_paths.push(p),
             }
         }
 

tests/executable.rs

@@ -794,3 +794,17 @@ fn shell_escape_env_override() {
 
     error_or_panic(&output);
 }
+
+/// Test that include paths work
+#[test]
+fn extra_search_paths() {
+    let fmt_arg = get_plain_format_arg();
+    let tempdir = setup_and_copy_files(&["subdirectory/content/1.tex"]);
+
+    let output = run_tectonic_with_stdin(
+        tempdir.path(),
+        &[&fmt_arg, "-", "-Zsearch-path=subdirectory/content"],
+        "\\input 1.tex\n\\bye",
+    );
+    success_or_panic(&output);
+}