Use to_string() instead of write!(&mut text, "{}", ....

lib/filetests/src/test_compile.rs

@@ -7,7 +7,6 @@ use cretonne_codegen::print_errors::pretty_error;
 use cretonne_codegen::{binemit, ir};
 use cretonne_reader::TestCommand;
 use std::borrow::Cow;
-use std::fmt::Write;
 use subtest::{run_filecheck, Context, Result, SubTest};
 
 struct TestCompile;
@@ -64,8 +63,7 @@ impl SubTest for TestCompile {
         }
 
         // Run final code through filecheck.
-        let mut text = String::new();
+        let text = comp_ctx.func.display(Some(isa)).to_string();
-        write!(&mut text, "{}", &comp_ctx.func.display(Some(isa))).map_err(|e| e.to_string())?;
         run_filecheck(&text, context)
     }
 }

lib/filetests/src/test_dce.rs

@@ -10,7 +10,6 @@ use cretonne_codegen::ir::Function;
 use cretonne_codegen::print_errors::pretty_error;
 use cretonne_reader::TestCommand;
 use std::borrow::Cow;
-use std::fmt::Write;
 use subtest::{run_filecheck, Context, Result, SubTest};
 
 struct TestDCE;
@@ -42,8 +41,7 @@ impl SubTest for TestDCE {
             .dce(context.flags_or_isa())
             .map_err(|e| pretty_error(&comp_ctx.func, context.isa, Into::into(e)))?;
 
-        let mut text = String::new();
+        let text = comp_ctx.func.to_string();
-        write!(&mut text, "{}", &comp_ctx.func).map_err(|e| e.to_string())?;
         run_filecheck(&text, context)
     }
 }

lib/filetests/src/test_legalizer.rs

@@ -8,7 +8,6 @@ use cretonne_codegen::ir::Function;
 use cretonne_codegen::print_errors::pretty_error;
 use cretonne_reader::TestCommand;
 use std::borrow::Cow;
-use std::fmt::Write;
 use subtest::{run_filecheck, Context, Result, SubTest};
 
 struct TestLegalizer;
@@ -44,8 +43,7 @@ impl SubTest for TestLegalizer {
             .legalize(isa)
             .map_err(|e| pretty_error(&comp_ctx.func, context.isa, e))?;
 
-        let mut text = String::new();
+        let text = comp_ctx.func.display(Some(isa)).to_string();
-        write!(&mut text, "{}", &comp_ctx.func.display(Some(isa))).map_err(|e| e.to_string())?;
         run_filecheck(&text, context)
     }
 }

lib/filetests/src/test_licm.rs

@@ -10,7 +10,6 @@ use cretonne_codegen::ir::Function;
 use cretonne_codegen::print_errors::pretty_error;
 use cretonne_reader::TestCommand;
 use std::borrow::Cow;
-use std::fmt::Write;
 use subtest::{run_filecheck, Context, Result, SubTest};
 
 struct TestLICM;
@@ -42,8 +41,7 @@ impl SubTest for TestLICM {
             .licm(context.flags_or_isa())
             .map_err(|e| pretty_error(&comp_ctx.func, context.isa, Into::into(e)))?;
 
-        let mut text = String::new();
+        let text = comp_ctx.func.to_string();
-        write!(&mut text, "{}", &comp_ctx.func).map_err(|e| e.to_string())?;
         run_filecheck(&text, context)
     }
 }

lib/filetests/src/test_postopt.rs

@@ -7,7 +7,6 @@ use cretonne_codegen::ir::Function;
 use cretonne_codegen::print_errors::pretty_error;
 use cretonne_reader::TestCommand;
 use std::borrow::Cow;
-use std::fmt::Write;
 use subtest::{run_filecheck, Context, Result, SubTest};
 
 struct TestPostopt;
@@ -39,8 +38,7 @@ impl SubTest for TestPostopt {
             .postopt(isa)
             .map_err(|e| pretty_error(&comp_ctx.func, context.isa, Into::into(e)))?;
 
-        let mut text = String::new();
+        let text = comp_ctx.func.to_string();
-        write!(&mut text, "{}", &comp_ctx.func).map_err(|e| e.to_string())?;
         run_filecheck(&text, context)
     }
 }

lib/filetests/src/test_preopt.rs

@@ -7,7 +7,6 @@ use cretonne_codegen::ir::Function;
 use cretonne_codegen::print_errors::pretty_error;
 use cretonne_reader::TestCommand;
 use std::borrow::Cow;
-use std::fmt::Write;
 use subtest::{run_filecheck, Context, Result, SubTest};
 
 struct TestPreopt;
@@ -39,8 +38,7 @@ impl SubTest for TestPreopt {
             .preopt(isa)
             .map_err(|e| pretty_error(&comp_ctx.func, context.isa, Into::into(e)))?;
 
-        let mut text = String::new();
+        let text = &comp_ctx.func.to_string();
-        write!(&mut text, "{}", &comp_ctx.func).map_err(|e| e.to_string())?;
         run_filecheck(&text, context)
     }
 }

lib/filetests/src/test_regalloc.rs

@@ -10,7 +10,6 @@ use cretonne_codegen::ir::Function;
 use cretonne_codegen::print_errors::pretty_error;
 use cretonne_reader::TestCommand;
 use std::borrow::Cow;
-use std::fmt::Write;
 use subtest::{run_filecheck, Context, Result, SubTest};
 
 struct TestRegalloc;
@@ -51,8 +50,7 @@ impl SubTest for TestRegalloc {
             .regalloc(isa)
             .map_err(|e| pretty_error(&comp_ctx.func, context.isa, e))?;
 
-        let mut text = String::new();
+        let text = comp_ctx.func.display(Some(isa)).to_string();
-        write!(&mut text, "{}", &comp_ctx.func.display(Some(isa))).map_err(|e| e.to_string())?;
         run_filecheck(&text, context)
     }
 }

lib/filetests/src/test_simple_gvn.rs

@@ -10,7 +10,6 @@ use cretonne_codegen::ir::Function;
 use cretonne_codegen::print_errors::pretty_error;
 use cretonne_reader::TestCommand;
 use std::borrow::Cow;
-use std::fmt::Write;
 use subtest::{run_filecheck, Context, Result, SubTest};
 
 struct TestSimpleGVN;
@@ -41,8 +40,7 @@ impl SubTest for TestSimpleGVN {
             .simple_gvn(context.flags_or_isa())
             .map_err(|e| pretty_error(&comp_ctx.func, context.isa, Into::into(e)))?;
 
-        let mut text = String::new();
+        let text = comp_ctx.func.to_string();
-        write!(&mut text, "{}", &comp_ctx.func).map_err(|e| e.to_string())?;
         run_filecheck(&text, context)
     }
 }