Add --disable-whole-symbol-regex option

When this option is enabled, bindgen won't parentesize and surround any
regex with ^ and $.

Fixes rust-lang#1783

CHANGELOG.md

@@ -152,6 +152,8 @@
    matching a regular expression.
  * new feature: allow using the `C-unwind` ABI in `--override-abi` on nightly
    rust.
+ * new feature: `--disable-whole-symbol-regex` flag to avoid parentesizing and
+   wrapping any regex argument with `^` and `$`.
 
 ## Changed
 

bindgen-cli/options.rs

@@ -574,6 +574,9 @@ where
                 .value_name("override")
                 .multiple_occurrences(true)
                 .number_of_values(1),
+            Arg::new("disable-whole-symbol-regex")
+                .long("disable-whole-symbol-regex")
+                .help("Avoids parentesizing and surrounding any regex arguments with ^ and $."),
             Arg::new("V")
                 .long("version")
                 .help("Prints the version, and exits"),
@@ -1106,5 +1109,9 @@ where
         }
     }
 
+    if matches.is_present("disable-whole-symbol-regex") {
+        builder = builder.whole_symbol_regex(false);
+    }
+
     Ok((builder, output, verbose))
 }

bindgen-tests/tests/headers/disable-whole-symbol-regex.h

@@ -0,0 +1,6 @@
+// bindgen-flags: --disable-whole-symbol-regex --allowlist-function="^foo"
+
+int foo();
+int foo_bar();
+int bar_foo();
+int bar_foo_baz();

bindgen/lib.rs

@@ -624,6 +624,10 @@ impl Builder {
             output_vector.push("--merge-extern-blocks".into());
         }
 
+        if !self.options.whole_symbol_regex {
+            output_vector.push("--disable-whole-symbol-regex".into());
+        }
+
         // Add clang arguments
 
         output_vector.push("--".into());
@@ -1792,6 +1796,14 @@ impl Builder {
             .insert(arg.into());
         self
     }
+
+    /// If true, parenthesize and surround any regex argument with `^` and `$`.
+    ///
+    /// This option is enabled by default.
+    pub fn whole_symbol_regex(mut self, doit: bool) -> Self {
+        self.options.whole_symbol_regex = doit;
+        self
+    }
 }
 
 /// Configuration options for generated bindings.
@@ -2129,6 +2141,8 @@ struct BindgenOptions {
     merge_extern_blocks: bool,
 
     abi_overrides: HashMap<Abi, RegexSet>,
+
+    whole_symbol_regex: bool,
 }
 
 impl BindgenOptions {
@@ -2163,8 +2177,9 @@ impl BindgenOptions {
             &mut self.must_use_types,
         ];
         let record_matches = self.record_matches;
+        let whole_symbol_regex = self.whole_symbol_regex;
         for regex_set in self.abi_overrides.values_mut().chain(regex_sets) {
-            regex_set.build(record_matches);
+            regex_set.build(record_matches, whole_symbol_regex);
         }
     }
 
@@ -2232,6 +2247,7 @@ impl Default for BindgenOptions {
             record_matches: true,
             rustfmt_bindings: true,
             size_t_is_usize: true,
+            whole_symbol_regex: true,
 
             --default-fields--
             blocklisted_types,

bindgen/regex_set.rs

@@ -27,9 +27,6 @@ impl RegexSet {
         S: AsRef<str>,
     {
         let string = string.as_ref().to_owned();
-        if string == "*" {
-            warn!("using wildcard patterns (`*`) is no longer considered valid. Use `.*` instead");
-        }
         self.items.push(string);
         self.matched.push(Cell::new(false));
         self.set = None;
@@ -56,8 +53,19 @@ impl RegexSet {
     ///
     /// Must be called before calling `matches()`, or it will always return
     /// false.
-    pub fn build(&mut self, record_matches: bool) {
-        let items = self.items.iter().map(|item| format!("^({})$", item));
+    pub fn build(&mut self, record_matches: bool, whole_symbol_regex: bool) {
+        let f = if whole_symbol_regex {
+            (|item| {
+                if item == "*" {
+                    warn!("using wildcard patterns (`*`) with the `--whole-symbol-regex` option enabled is not considered valid. Use `.*` instead");
+                }
+                format!("^({})$", item)
+            }) as fn(&String) -> String
+        } else {
+            (|item| item.clone()) as fn(&String) -> String
+        };
+        let items = self.items.iter().map(f);
+
         self.record_matches = record_matches;
         self.set = match RxSet::new(items) {
             Ok(x) => Some(x),