Format strings option https://github.com/nrc/rustfmt/issues/202

src/config.rs

@@ -80,6 +80,7 @@ create_config! {
     expr_indent_style: BlockIndentStyle,
     closure_indent_style: BlockIndentStyle,
     single_line_if_else: bool,
+    format_strings: bool,
 }
 
 impl Default for Config {
@@ -104,6 +105,7 @@ impl Default for Config {
             expr_indent_style: BlockIndentStyle::Tabbed,
             closure_indent_style: BlockIndentStyle::Visual,
             single_line_if_else: false,
+            format_strings: true,
         }
     }
 

src/expr.rs

@@ -828,6 +828,9 @@ fn rewrite_string_lit(context: &RewriteContext,
                       width: usize,
                       offset: usize)
                       -> Option<String> {
+    if context.config.format_strings == false {
+        return Some(context.snippet(span));
+    }
     // Check if there is anything to fix: we always try to fixup multi-line
     // strings, or if the string is too long for the line.
     let l_loc = context.codemap.lookup_char_pos(span.lo);

tests/config/small_tabs.toml

@@ -16,3 +16,4 @@ reorder_imports = false
 expr_indent_style = "Tabbed"
 closure_indent_style = "Visual"
 single_line_if_else = false
+format_strings = true

tests/target/string-lit-custom.rs

@@ -0,0 +1,22 @@
+// rustfmt-format_strings: false
+
+fn main() {
+    let expected = "; ModuleID = \'foo\'
+
+; Function Attrs: nounwind
+declare void @llvm.memset.p0i8.i32(i8* nocapture, i8, i32, i32, i1) #0
+
+declare i32 @write(i32, i8*, i32)
+
+declare i32 @putchar(i32)
+
+declare i32 @getchar()
+
+define i32 @main() {
+entry:
+  ret i32 0
+}
+
+attributes #0 = { nounwind }
+";
+}