Transition to quote + syn for code generation.

prost-build/Cargo.toml

@@ -17,7 +17,7 @@ rust-version = "1.70"
 
 [features]
 default = ["format"]
-format = ["dep:prettyplease", "dep:syn"]
+format = ["dep:prettyplease"]
 cleanup-markdown = ["dep:pulldown-cmark", "dep:pulldown-cmark-to-cmark"]
 
 [dependencies]
@@ -27,18 +27,21 @@ itertools = { version = ">=0.10, <=0.12", default-features = false, features = [
 log = "0.4.4"
 multimap = { version = ">=0.8, <=0.10", default-features = false }
 petgraph = { version = "0.6", default-features = false }
+proc-macro2 = "1"
 prost = { version = "0.12.4", path = "..", default-features = false }
 prost-types = { version = "0.12.4", path = "../prost-types", default-features = false }
+quote = "1"
+syn = { version = "2", features = ["full", "extra-traits"] }
 tempfile = "3"
 once_cell = "1.17.1"
 regex = { version = "1.8.1", default-features = false, features = ["std", "unicode-bool"] }
 
 prettyplease = { version = "0.2", optional = true }
-syn = { version = "2", features = ["full"], optional = true }
 
 # These two must be kept in sync, used for `cleanup-markdown` feature.
 pulldown-cmark = { version = "0.9.1", optional = true, default-features = false }
 pulldown-cmark-to-cmark = { version = "10.0.1", optional = true }
 
 [dev-dependencies]
 env_logger = { version = "0.10", default-features = false }
+pretty_assertions = "1"

prost-build/src/ast.rs

@@ -42,13 +42,10 @@ impl Comments {
     /// Appends the comments to a buffer with indentation.
     ///
     /// Each level of indentation corresponds to four space (' ') characters.
-    pub fn append_with_indent(&self, indent_level: u8, buf: &mut String) {
+    pub fn append_with_indent(&self, buf: &mut String) {
         // Append blocks of detached comments.
         for detached_block in &self.leading_detached {
             for line in detached_block {
-                for _ in 0..indent_level {
-                    buf.push_str("    ");
-                }
                 buf.push_str("//");
                 buf.push_str(&Self::sanitize_line(line));
                 buf.push('\n');
@@ -58,27 +55,18 @@ impl Comments {
 
         // Append leading comments.
         for line in &self.leading {
-            for _ in 0..indent_level {
-                buf.push_str("    ");
-            }
             buf.push_str("///");
             buf.push_str(&Self::sanitize_line(line));
             buf.push('\n');
         }
 
         // Append an empty comment line if there are leading and trailing comments.
         if !self.leading.is_empty() && !self.trailing.is_empty() {
-            for _ in 0..indent_level {
-                buf.push_str("    ");
-            }
             buf.push_str("///\n");
         }
 
         // Append trailing comments.
         for line in &self.trailing {
-            for _ in 0..indent_level {
-                buf.push_str("    ");
-            }
             buf.push_str("///");
             buf.push_str(&Self::sanitize_line(line));
             buf.push('\n');
@@ -262,7 +250,7 @@ mod tests {
             };
 
             let mut actual = "".to_string();
-            input.append_with_indent(0, &mut actual);
+            input.append_with_indent(&mut actual);
 
             assert_eq!(t.expected, actual, "failed {}", t.name);
         }
@@ -306,7 +294,7 @@ mod tests {
             };
 
             let mut actual = "".to_string();
-            input.append_with_indent(0, &mut actual);
+            input.append_with_indent(&mut actual);
 
             assert_eq!(t.expected, actual, "failed {}", t.name);
         }
@@ -400,7 +388,7 @@ mod tests {
             };
 
             let mut actual = "".to_string();
-            input.append_with_indent(0, &mut actual);
+            input.append_with_indent(&mut actual);
 
             assert_eq!(t.expected, actual, "failed {}", t.name);
         }