diff --git a/dub.sdl b/dub.sdl
index 98c9cff15a..50634f40c2 100644
--- a/dub.sdl
+++ b/dub.sdl
@@ -10,7 +10,7 @@ dependency ":frontend" version="*"
 subPackage {
   name "root"
   targetType "library"
-  sourcePaths "src/dmd/root"
+  sourcePaths "src/dmd/common" "src/dmd/root"
 }
 
 subPackage {
@@ -86,6 +86,7 @@ subPackage {
 
   excludedSourceFiles "src/dmd/backend/*"
   excludedSourceFiles "src/dmd/root/*"
+  excludedSourceFiles "src/dmd/common/*"
   excludedSourceFiles "src/dmd/{\
     astbase,\
     console,\
diff --git a/src/build.d b/src/build.d
index b9841642b0..cac19e8a30 100755
--- a/src/build.d
+++ b/src/build.d
@@ -1367,9 +1367,9 @@ auto sourceFiles()
             statement.h staticassert.h target.h template.h tokens.h version.h visitor.h
         "),
         lexer: fileArray(env["D"], "
-            console.d entity.d errors.d filecache.d globals.d id.d identifier.d lexer.d tokens.d utf.d
+            console.d entity.d errors.d filecache.d globals.d id.d identifier.d lexer.d tokens.d utf.d common/outbuffer.d
         ") ~ fileArray(env["ROOT"], "
-            array.d bitarray.d ctfloat.d file.d filename.d hash.d outbuffer.d port.d region.d rmem.d
+            array.d bitarray.d ctfloat.d file.d filename.d hash.d port.d region.d rmem.d
             rootobject.d stringtable.d
         "),
         root: fileArray(env["ROOT"], "
@@ -1377,7 +1377,7 @@ auto sourceFiles()
         "),
         rootHeaders: fileArray(env["ROOT"], "
             array.h bitarray.h ctfloat.h dcompat.h dsystem.h file.h filename.h longdouble.h
-            object.h outbuffer.h port.h rmem.h
+            object.h ../common/outbuffer.h port.h rmem.h root.h
         "),
         backend: fileArray(env["C"], "
             backend.d bcomplex.d evalu8.d divcoeff.d dvec.d go.d gsroa.d glocal.d gdag.d gother.d gflow.d
diff --git a/src/dmd/arrayop.d b/src/dmd/arrayop.d
index 66be73ea21..e2b33194f0 100644
--- a/src/dmd/arrayop.d
+++ b/src/dmd/arrayop.d
@@ -26,7 +26,7 @@ import dmd.globals;
 import dmd.id;
 import dmd.identifier;
 import dmd.mtype;
-import dmd.root.outbuffer;
+import dmd.common.outbuffer;
 import dmd.statement;
 import dmd.tokens;
 import dmd.visitor;
diff --git a/src/dmd/astbase.d b/src/dmd/astbase.d
index 333b731617..368296ae46 100644
--- a/src/dmd/astbase.d
+++ b/src/dmd/astbase.d
@@ -25,7 +25,7 @@ struct ASTBase
     import dmd.root.filename;
     import dmd.root.array;
     import dmd.root.rootobject;
-    import dmd.root.outbuffer;
+    import dmd.common.outbuffer;
     import dmd.root.ctfloat;
     import dmd.root.rmem;
     import dmd.root.string : toDString;
diff --git a/src/dmd/attrib.d b/src/dmd/attrib.d
index af45ed358d..bafa2fd5d5 100644
--- a/src/dmd/attrib.d
+++ b/src/dmd/attrib.d
@@ -42,7 +42,7 @@ import dmd.id;
 import dmd.identifier;
 import dmd.mtype;
 import dmd.objc; // for objc.addSymbols
-import dmd.root.outbuffer;
+import dmd.common.outbuffer;
 import dmd.target; // for target.systemLinkage
 import dmd.tokens;
 import dmd.visitor;
diff --git a/src/dmd/root/outbuffer.d b/src/dmd/common/outbuffer.d
similarity index 97%
rename from src/dmd/root/outbuffer.d
rename to src/dmd/common/outbuffer.d
index e756917b88..641d3b431d 100644
--- a/src/dmd/root/outbuffer.d
+++ b/src/dmd/common/outbuffer.d
@@ -9,7 +9,7 @@
  * Coverage:    https://codecov.io/gh/dlang/dmd/src/master/src/dmd/root/outbuffer.d
  */
 
-module dmd.root.outbuffer;
+module dmd.common.outbuffer;
 
 import core.stdc.stdarg;
 import core.stdc.stdio;
@@ -63,7 +63,7 @@ struct OutBuffer
     /**
     Frees resources associated automatically.
     */
-    extern (C++) ~this() pure nothrow
+    extern (C++) ~this() pure nothrow @trusted
     {
         if (fileMapping)
         {
@@ -199,6 +199,32 @@ struct OutBuffer
         offset += buf.length;
     }
 
+    /**
+     * Writes a 16 bit value, no reserve check.
+     */
+    // @trusted
+    // void write16n(int v)
+    // {
+    //     assert(0);
+    // }
+
+    /**
+     * Writes a 16 bit value.
+     */
+    void write16(int v) nothrow
+    {
+        auto u = cast(ushort) v;
+        write(&u, u.sizeof);
+    }
+
+    /**
+     * Writes a 32 bit int.
+     */
+    @trusted void write32(int v) nothrow
+    {
+        write(&v, v.sizeof);
+    }
+
     extern (C++) void writestring(const(char)* string) pure nothrow
     {
         write(string.toDString);
diff --git a/src/dmd/root/outbuffer.h b/src/dmd/common/outbuffer.h
similarity index 93%
rename from src/dmd/root/outbuffer.h
rename to src/dmd/common/outbuffer.h
index 0ad0c8d7ab..0d1f48c95b 100644
--- a/src/dmd/root/outbuffer.h
+++ b/src/dmd/common/outbuffer.h
@@ -4,14 +4,14 @@
  * http://www.digitalmars.com
  * Distributed under the Boost Software License, Version 1.0.
  * http://www.boost.org/LICENSE_1_0.txt
- * https://github.com/dlang/dmd/blob/master/src/dmd/root/outbuffer.h
+ * https://github.com/dlang/dmd/blob/master/src/dmd/common/outbuffer.h
  */
 
 #pragma once
 
-#include "dsystem.h"
-#include "dcompat.h"
-#include "rmem.h"
+#include "root/dsystem.h"
+#include "root/dcompat.h"
+#include "root/rmem.h"
 
 class RootObject;
 
diff --git a/src/dmd/cond.d b/src/dmd/cond.d
index d4a8b136d4..fac0efb482 100644
--- a/src/dmd/cond.d
+++ b/src/dmd/cond.d
@@ -28,7 +28,7 @@ import dmd.globals;
 import dmd.identifier;
 import dmd.mtype;
 import dmd.typesem;
-import dmd.root.outbuffer;
+import dmd.common.outbuffer;
 import dmd.root.rootobject;
 import dmd.root.string;
 import dmd.tokens;
diff --git a/src/dmd/cparse.d b/src/dmd/cparse.d
index 354c271c5a..a1c3325c9e 100644
--- a/src/dmd/cparse.d
+++ b/src/dmd/cparse.d
@@ -23,7 +23,7 @@ import dmd.lexer;
 import dmd.parse;
 import dmd.errors;
 import dmd.root.filename;
-import dmd.root.outbuffer;
+import dmd.common.outbuffer;
 import dmd.root.rmem;
 import dmd.root.rootobject;
 import dmd.root.string;
diff --git a/src/dmd/cppmangle.d b/src/dmd/cppmangle.d
index 28150b2daf..df742c0bd8 100644
--- a/src/dmd/cppmangle.d
+++ b/src/dmd/cppmangle.d
@@ -41,7 +41,7 @@ import dmd.identifier;
 import dmd.mtype;
 import dmd.nspace;
 import dmd.root.array;
-import dmd.root.outbuffer;
+import dmd.common.outbuffer;
 import dmd.root.rootobject;
 import dmd.root.string;
 import dmd.target;
diff --git a/src/dmd/cppmanglewin.d b/src/dmd/cppmanglewin.d
index 7c2809478c..b73cf249bf 100644
--- a/src/dmd/cppmanglewin.d
+++ b/src/dmd/cppmanglewin.d
@@ -30,7 +30,7 @@ import dmd.globals;
 import dmd.id;
 import dmd.identifier;
 import dmd.mtype;
-import dmd.root.outbuffer;
+import dmd.common.outbuffer;
 import dmd.root.rootobject;
 import dmd.target;
 import dmd.tokens;
diff --git a/src/dmd/dcast.d b/src/dmd/dcast.d
index 6f7f537bac..7c504fced3 100644
--- a/src/dmd/dcast.d
+++ b/src/dmd/dcast.d
@@ -37,7 +37,7 @@ import dmd.intrange;
 import dmd.mtype;
 import dmd.opover;
 import dmd.root.ctfloat;
-import dmd.root.outbuffer;
+import dmd.common.outbuffer;
 import dmd.root.rmem;
 import dmd.tokens;
 import dmd.typesem;
diff --git a/src/dmd/declaration.d b/src/dmd/declaration.d
index 66536cc23e..2faeba6ddd 100644
--- a/src/dmd/declaration.d
+++ b/src/dmd/declaration.d
@@ -35,7 +35,7 @@ import dmd.init;
 import dmd.initsem;
 import dmd.intrange;
 import dmd.mtype;
-import dmd.root.outbuffer;
+import dmd.common.outbuffer;
 import dmd.root.rootobject;
 import dmd.target;
 import dmd.tokens;
diff --git a/src/dmd/dinifile.d b/src/dmd/dinifile.d
index f94874a6b9..a4e2cd15ae 100644
--- a/src/dmd/dinifile.d
+++ b/src/dmd/dinifile.d
@@ -23,7 +23,7 @@ import dmd.errors;
 import dmd.globals;
 import dmd.root.rmem;
 import dmd.root.filename;
-import dmd.root.outbuffer;
+import dmd.common.outbuffer;
 import dmd.root.port;
 import dmd.root.string;
 import dmd.root.stringtable;
diff --git a/src/dmd/dmacro.d b/src/dmd/dmacro.d
index ddfee2ccab..357f7bdcd9 100644
--- a/src/dmd/dmacro.d
+++ b/src/dmd/dmacro.d
@@ -16,7 +16,7 @@ import core.stdc.string;
 import dmd.doc;
 import dmd.errors;
 import dmd.globals;
-import dmd.root.outbuffer;
+import dmd.common.outbuffer;
 import dmd.root.rmem;
 
 extern (C++) struct MacroTable
diff --git a/src/dmd/dmangle.d b/src/dmd/dmangle.d
index 71b8c7a609..8aa6f5de2d 100644
--- a/src/dmd/dmangle.d
+++ b/src/dmd/dmangle.d
@@ -139,7 +139,7 @@ import dmd.id;
 import dmd.identifier;
 import dmd.mtype;
 import dmd.root.ctfloat;
-import dmd.root.outbuffer;
+import dmd.common.outbuffer;
 import dmd.root.aav;
 import dmd.root.string;
 import dmd.root.stringtable;
diff --git a/src/dmd/dmodule.d b/src/dmd/dmodule.d
index 93ea2b683d..e2e4e9b08c 100644
--- a/src/dmd/dmodule.d
+++ b/src/dmd/dmodule.d
@@ -39,7 +39,7 @@ import dmd.cparse;
 import dmd.root.array;
 import dmd.root.file;
 import dmd.root.filename;
-import dmd.root.outbuffer;
+import dmd.common.outbuffer;
 import dmd.root.port;
 import dmd.root.rmem;
 import dmd.root.rootobject;
diff --git a/src/dmd/doc.d b/src/dmd/doc.d
index 50f696b81f..f9b765c521 100644
--- a/src/dmd/doc.d
+++ b/src/dmd/doc.d
@@ -45,7 +45,7 @@ import dmd.mtype;
 import dmd.root.array;
 import dmd.root.file;
 import dmd.root.filename;
-import dmd.root.outbuffer;
+import dmd.common.outbuffer;
 import dmd.root.port;
 import dmd.root.rmem;
 import dmd.root.string;
diff --git a/src/dmd/dscope.d b/src/dmd/dscope.d
index 6aa184bd24..ccbf5ecbdd 100644
--- a/src/dmd/dscope.d
+++ b/src/dmd/dscope.d
@@ -33,7 +33,7 @@ import dmd.func;
 import dmd.globals;
 import dmd.id;
 import dmd.identifier;
-import dmd.root.outbuffer;
+import dmd.common.outbuffer;
 import dmd.root.rmem;
 import dmd.root.speller;
 import dmd.statement;
diff --git a/src/dmd/dsymbolsem.d b/src/dmd/dsymbolsem.d
index c144843557..67c53f12fd 100644
--- a/src/dmd/dsymbolsem.d
+++ b/src/dmd/dsymbolsem.d
@@ -56,7 +56,7 @@ import dmd.objc;
 import dmd.opover;
 import dmd.parse;
 import dmd.root.filename;
-import dmd.root.outbuffer;
+import dmd.common.outbuffer;
 import dmd.root.rmem;
 import dmd.root.rootobject;
 import dmd.semantic2;
diff --git a/src/dmd/dtemplate.d b/src/dmd/dtemplate.d
index 90e2e33658..b46a578a02 100644
--- a/src/dmd/dtemplate.d
+++ b/src/dmd/dtemplate.d
@@ -67,7 +67,7 @@ import dmd.initsem;
 import dmd.mtype;
 import dmd.opover;
 import dmd.root.array;
-import dmd.root.outbuffer;
+import dmd.common.outbuffer;
 import dmd.root.rootobject;
 import dmd.semantic2;
 import dmd.semantic3;
diff --git a/src/dmd/dtoh.d b/src/dmd/dtoh.d
index b31b675f09..8d0d789dec 100644
--- a/src/dmd/dtoh.d
+++ b/src/dmd/dtoh.d
@@ -26,7 +26,7 @@ import dmd.root.filename;
 import dmd.visitor;
 import dmd.tokens;
 
-import dmd.root.outbuffer;
+import dmd.common.outbuffer;
 import dmd.utils;
 
 //debug = Debug_DtoH;
diff --git a/src/dmd/dversion.d b/src/dmd/dversion.d
index 0dff754bee..49ee4b3b3e 100644
--- a/src/dmd/dversion.d
+++ b/src/dmd/dversion.d
@@ -22,7 +22,7 @@ import dmd.dsymbol;
 import dmd.dsymbolsem;
 import dmd.globals;
 import dmd.identifier;
-import dmd.root.outbuffer;
+import dmd.common.outbuffer;
 import dmd.visitor;
 
 /***********************************************************
diff --git a/src/dmd/e2ir.d b/src/dmd/e2ir.d
index abb284365e..2c409b5b27 100644
--- a/src/dmd/e2ir.d
+++ b/src/dmd/e2ir.d
@@ -226,7 +226,7 @@ Symbol *toStringSymbol(const(char)* str, size_t len, size_t sz)
              * But the checksum algorithm is unknown. Just invent our own.
              */
 
-            import dmd.root.outbuffer : OutBuffer;
+            import dmd.common.outbuffer : OutBuffer;
             OutBuffer buf;
             buf.writestring("__");
 
diff --git a/src/dmd/errors.d b/src/dmd/errors.d
index 5e1758ba65..f8f258dd90 100644
--- a/src/dmd/errors.d
+++ b/src/dmd/errors.d
@@ -16,7 +16,7 @@ import core.stdc.stdio;
 import core.stdc.stdlib;
 import core.stdc.string;
 import dmd.globals;
-import dmd.root.outbuffer;
+import dmd.common.outbuffer;
 import dmd.root.rmem;
 import dmd.root.string;
 import dmd.console;
diff --git a/src/dmd/expression.d b/src/dmd/expression.d
index da0adb9081..2a07437770 100644
--- a/src/dmd/expression.d
+++ b/src/dmd/expression.d
@@ -59,7 +59,7 @@ import dmd.opover;
 import dmd.optimize;
 import dmd.root.ctfloat;
 import dmd.root.filename;
-import dmd.root.outbuffer;
+import dmd.common.outbuffer;
 import dmd.root.rmem;
 import dmd.root.rootobject;
 import dmd.root.string;
diff --git a/src/dmd/expressionsem.d b/src/dmd/expressionsem.d
index f2840bcb1d..24759b624c 100644
--- a/src/dmd/expressionsem.d
+++ b/src/dmd/expressionsem.d
@@ -63,7 +63,7 @@ import dmd.printast;
 import dmd.root.ctfloat;
 import dmd.root.file;
 import dmd.root.filename;
-import dmd.root.outbuffer;
+import dmd.common.outbuffer;
 import dmd.root.rootobject;
 import dmd.root.string;
 import dmd.semantic2;
diff --git a/src/dmd/frontend.d b/src/dmd/frontend.d
index 198fb4eeda..4a98b0c017 100644
--- a/src/dmd/frontend.d
+++ b/src/dmd/frontend.d
@@ -445,7 +445,7 @@ Returns:
 */
 string prettyPrint(Module m)
 {
-    import dmd.root.outbuffer: OutBuffer;
+    import dmd.common.outbuffer: OutBuffer;
     import dmd.hdrgen : HdrGenState, moduleToBuffer2;
 
     auto buf = OutBuffer();
diff --git a/src/dmd/func.d b/src/dmd/func.d
index 0d8f50d7bf..15365c3d70 100644
--- a/src/dmd/func.d
+++ b/src/dmd/func.d
@@ -46,7 +46,7 @@ import dmd.init;
 import dmd.mtype;
 import dmd.objc;
 import dmd.root.aav;
-import dmd.root.outbuffer;
+import dmd.common.outbuffer;
 import dmd.root.rootobject;
 import dmd.root.string;
 import dmd.root.stringtable;
diff --git a/src/dmd/globals.d b/src/dmd/globals.d
index 691ec181ba..56ff261724 100644
--- a/src/dmd/globals.d
+++ b/src/dmd/globals.d
@@ -14,7 +14,7 @@ module dmd.globals;
 import core.stdc.stdint;
 import dmd.root.array;
 import dmd.root.filename;
-import dmd.root.outbuffer;
+import dmd.common.outbuffer;
 import dmd.identifier;
 
 /// Defines a setting for how compiler warnings and deprecations are handled
diff --git a/src/dmd/globals.h b/src/dmd/globals.h
index db68508047..186fd985c8 100644
--- a/src/dmd/globals.h
+++ b/src/dmd/globals.h
@@ -12,7 +12,7 @@
 
 #include "root/dcompat.h"
 #include "root/ctfloat.h"
-#include "root/outbuffer.h"
+#include "common/outbuffer.h"
 #include "root/filename.h"
 #include "compiler.h"
 
diff --git a/src/dmd/glue.d b/src/dmd/glue.d
index 46e9a8be98..2e9ff85e2a 100644
--- a/src/dmd/glue.d
+++ b/src/dmd/glue.d
@@ -18,7 +18,7 @@ import core.stdc.stdlib;
 import dmd.root.array;
 import dmd.root.file;
 import dmd.root.filename;
-import dmd.root.outbuffer;
+import dmd.common.outbuffer;
 import dmd.root.rmem;
 import dmd.root.string;
 
diff --git a/src/dmd/hdrgen.d b/src/dmd/hdrgen.d
index 781cf74c65..4ff07b5de3 100644
--- a/src/dmd/hdrgen.d
+++ b/src/dmd/hdrgen.d
@@ -44,7 +44,7 @@ import dmd.mtype;
 import dmd.nspace;
 import dmd.parse;
 import dmd.root.ctfloat;
-import dmd.root.outbuffer;
+import dmd.common.outbuffer;
 import dmd.root.rootobject;
 import dmd.root.string;
 import dmd.statement;
diff --git a/src/dmd/iasmdmd.d b/src/dmd/iasmdmd.d
index 96a0df21d9..9538da6cb0 100644
--- a/src/dmd/iasmdmd.d
+++ b/src/dmd/iasmdmd.d
@@ -37,7 +37,7 @@ import dmd.target;
 import dmd.tokens;
 
 import dmd.root.ctfloat;
-import dmd.root.outbuffer;
+import dmd.common.outbuffer;
 import dmd.root.rmem;
 import dmd.root.rootobject;
 
diff --git a/src/dmd/identifier.d b/src/dmd/identifier.d
index 43a1435cd1..8add74a142 100644
--- a/src/dmd/identifier.d
+++ b/src/dmd/identifier.d
@@ -16,7 +16,7 @@ import core.stdc.stdio;
 import core.stdc.string;
 import dmd.globals;
 import dmd.id;
-import dmd.root.outbuffer;
+import dmd.common.outbuffer;
 import dmd.root.rootobject;
 import dmd.root.string;
 import dmd.root.stringtable;
diff --git a/src/dmd/init.d b/src/dmd/init.d
index 45e101b903..d036ee1635 100644
--- a/src/dmd/init.d
+++ b/src/dmd/init.d
@@ -23,7 +23,7 @@ import dmd.globals;
 import dmd.hdrgen;
 import dmd.identifier;
 import dmd.mtype;
-import dmd.root.outbuffer;
+import dmd.common.outbuffer;
 import dmd.root.rootobject;
 import dmd.tokens;
 import dmd.visitor;
diff --git a/src/dmd/json.d b/src/dmd/json.d
index bfd31bc1d1..f4865998a5 100644
--- a/src/dmd/json.d
+++ b/src/dmd/json.d
@@ -33,7 +33,7 @@ import dmd.hdrgen;
 import dmd.id;
 import dmd.identifier;
 import dmd.mtype;
-import dmd.root.outbuffer;
+import dmd.common.outbuffer;
 import dmd.root.rootobject;
 import dmd.root.string;
 import dmd.target;
diff --git a/src/dmd/lambdacomp.d b/src/dmd/lambdacomp.d
index d29bdc1380..44a6c06650 100644
--- a/src/dmd/lambdacomp.d
+++ b/src/dmd/lambdacomp.d
@@ -27,7 +27,7 @@ import dmd.expression;
 import dmd.func;
 import dmd.dmangle;
 import dmd.mtype;
-import dmd.root.outbuffer;
+import dmd.common.outbuffer;
 import dmd.root.rmem;
 import dmd.root.stringtable;
 import dmd.dscope;
diff --git a/src/dmd/lexer.d b/src/dmd/lexer.d
index d38ff286e5..df4cfb56ab 100644
--- a/src/dmd/lexer.d
+++ b/src/dmd/lexer.d
@@ -28,7 +28,7 @@ import dmd.id;
 import dmd.identifier;
 import dmd.root.array;
 import dmd.root.ctfloat;
-import dmd.root.outbuffer;
+import dmd.common.outbuffer;
 import dmd.root.port;
 import dmd.root.rmem;
 import dmd.root.string;
diff --git a/src/dmd/lib.d b/src/dmd/lib.d
index 8c5c80d0c1..f72a79e62b 100644
--- a/src/dmd/lib.d
+++ b/src/dmd/lib.d
@@ -20,7 +20,7 @@ import dmd.errors;
 import dmd.target;
 import dmd.utils;
 
-import dmd.root.outbuffer;
+import dmd.common.outbuffer;
 import dmd.root.file;
 import dmd.root.filename;
 import dmd.root.string;
diff --git a/src/dmd/libelf.d b/src/dmd/libelf.d
index 900b0be770..6e06c9e3fa 100644
--- a/src/dmd/libelf.d
+++ b/src/dmd/libelf.d
@@ -32,7 +32,7 @@ import dmd.utils;
 import dmd.root.array;
 import dmd.root.file;
 import dmd.root.filename;
-import dmd.root.outbuffer;
+import dmd.common.outbuffer;
 import dmd.root.port;
 import dmd.root.rmem;
 import dmd.root.string;
diff --git a/src/dmd/libmach.d b/src/dmd/libmach.d
index 7909c15eda..5f3a8da8a7 100644
--- a/src/dmd/libmach.d
+++ b/src/dmd/libmach.d
@@ -34,7 +34,7 @@ import dmd.utils;
 import dmd.root.array;
 import dmd.root.file;
 import dmd.root.filename;
-import dmd.root.outbuffer;
+import dmd.common.outbuffer;
 import dmd.root.port;
 import dmd.root.rmem;
 import dmd.root.string;
diff --git a/src/dmd/libmscoff.d b/src/dmd/libmscoff.d
index 798f84caee..d499144071 100644
--- a/src/dmd/libmscoff.d
+++ b/src/dmd/libmscoff.d
@@ -34,7 +34,7 @@ import dmd.utils;
 import dmd.root.array;
 import dmd.root.file;
 import dmd.root.filename;
-import dmd.root.outbuffer;
+import dmd.common.outbuffer;
 import dmd.root.port;
 import dmd.root.rmem;
 import dmd.root.string;
diff --git a/src/dmd/libomf.d b/src/dmd/libomf.d
index ada06df80d..5696c8a50a 100644
--- a/src/dmd/libomf.d
+++ b/src/dmd/libomf.d
@@ -24,7 +24,7 @@ import dmd.root.array;
 import dmd.root.file;
 import dmd.root.filename;
 import dmd.root.rmem;
-import dmd.root.outbuffer;
+import dmd.common.outbuffer;
 import dmd.root.string;
 import dmd.root.stringtable;
 
diff --git a/src/dmd/link.d b/src/dmd/link.d
index e57ee40bcf..f33dc65f26 100644
--- a/src/dmd/link.d
+++ b/src/dmd/link.d
@@ -25,7 +25,7 @@ import dmd.globals;
 import dmd.mars;
 import dmd.root.file;
 import dmd.root.filename;
-import dmd.root.outbuffer;
+import dmd.common.outbuffer;
 import dmd.root.rmem;
 import dmd.root.string;
 import dmd.utils;
diff --git a/src/dmd/mars.d b/src/dmd/mars.d
index 908cb5fef6..fbf8a96647 100644
--- a/src/dmd/mars.d
+++ b/src/dmd/mars.d
@@ -57,7 +57,7 @@ import dmd.root.array;
 import dmd.root.file;
 import dmd.root.filename;
 import dmd.root.man;
-import dmd.root.outbuffer;
+import dmd.common.outbuffer;
 import dmd.root.response;
 import dmd.root.rmem;
 import dmd.root.string;
diff --git a/src/dmd/mtype.d b/src/dmd/mtype.d
index 39b3ed93c9..14f67aa618 100644
--- a/src/dmd/mtype.d
+++ b/src/dmd/mtype.d
@@ -43,7 +43,7 @@ import dmd.identifier;
 import dmd.init;
 import dmd.opover;
 import dmd.root.ctfloat;
-import dmd.root.outbuffer;
+import dmd.common.outbuffer;
 import dmd.root.rmem;
 import dmd.root.rootobject;
 import dmd.root.stringtable;
diff --git a/src/dmd/ob.d b/src/dmd/ob.d
index 7719ccfe29..605e9f3bfd 100644
--- a/src/dmd/ob.d
+++ b/src/dmd/ob.d
@@ -43,7 +43,7 @@ import dmd.tokens;
 import dmd.visitor;
 
 import dmd.root.bitarray;
-import dmd.root.outbuffer;
+import dmd.common.outbuffer;
 
 /**********************************
  * Perform ownership/borrowing checks for funcdecl.
diff --git a/src/dmd/objc.d b/src/dmd/objc.d
index 85e371e6e6..eb4ba1db20 100644
--- a/src/dmd/objc.d
+++ b/src/dmd/objc.d
@@ -38,7 +38,7 @@ import dmd.id;
 import dmd.identifier;
 import dmd.mtype;
 import dmd.root.array;
-import dmd.root.outbuffer;
+import dmd.common.outbuffer;
 import dmd.root.stringtable;
 import dmd.target;
 import dmd.tokens;
diff --git a/src/dmd/parse.d b/src/dmd/parse.d
index f199c6ca6d..c5754eaf11 100644
--- a/src/dmd/parse.d
+++ b/src/dmd/parse.d
@@ -22,7 +22,7 @@ import dmd.identifier;
 import dmd.lexer;
 import dmd.errors;
 import dmd.root.filename;
-import dmd.root.outbuffer;
+import dmd.common.outbuffer;
 import dmd.root.rmem;
 import dmd.root.rootobject;
 import dmd.root.string;
diff --git a/src/dmd/printast.d b/src/dmd/printast.d
index 3f12b17335..414d6f665f 100644
--- a/src/dmd/printast.d
+++ b/src/dmd/printast.d
@@ -59,7 +59,7 @@ extern (C++) final class PrintASTVisitor : Visitor
         printIndent(indent);
 
         import dmd.hdrgen : floatToBuffer;
-        import dmd.root.outbuffer : OutBuffer;
+        import dmd.common.outbuffer : OutBuffer;
         OutBuffer buf;
         floatToBuffer(e.type, e.value, &buf, false);
         printf("Real %s %s\n", buf.peekChars(), e.type ? e.type.toChars() : "");
diff --git a/src/dmd/root/filename.d b/src/dmd/root/filename.d
index 1e4ccb5d34..c3c1131bd5 100644
--- a/src/dmd/root/filename.d
+++ b/src/dmd/root/filename.d
@@ -16,7 +16,7 @@ import core.stdc.errno;
 import core.stdc.string;
 import dmd.root.array;
 import dmd.root.file;
-import dmd.root.outbuffer;
+import dmd.common.outbuffer;
 import dmd.root.port;
 import dmd.root.rmem;
 import dmd.root.rootobject;
diff --git a/src/dmd/root/rootobject.d b/src/dmd/root/rootobject.d
index 854ec1a65b..64104b823d 100644
--- a/src/dmd/root/rootobject.d
+++ b/src/dmd/root/rootobject.d
@@ -13,7 +13,7 @@ module dmd.root.rootobject;
 
 import core.stdc.stdio;
 
-import dmd.root.outbuffer;
+import dmd.common.outbuffer;
 
 /***********************************************************
  */
diff --git a/src/dmd/scanomf.d b/src/dmd/scanomf.d
index eef2eff104..5d7ca1e0e3 100644
--- a/src/dmd/scanomf.d
+++ b/src/dmd/scanomf.d
@@ -15,7 +15,7 @@ import core.stdc.string;
 import core.stdc.stdlib;
 import dmd.globals;
 import dmd.root.rmem;
-import dmd.root.outbuffer;
+import dmd.common.outbuffer;
 import dmd.root.string;
 import dmd.arraytypes;
 import dmd.errors;
diff --git a/src/dmd/semantic2.d b/src/dmd/semantic2.d
index 612a2e5117..993db90552 100644
--- a/src/dmd/semantic2.d
+++ b/src/dmd/semantic2.d
@@ -53,7 +53,7 @@ import dmd.objc;
 import dmd.opover;
 import dmd.parse;
 import dmd.root.filename;
-import dmd.root.outbuffer;
+import dmd.common.outbuffer;
 import dmd.root.rmem;
 import dmd.root.rootobject;
 import dmd.sideeffect;
diff --git a/src/dmd/semantic3.d b/src/dmd/semantic3.d
index b593e86913..a9e9a5339e 100644
--- a/src/dmd/semantic3.d
+++ b/src/dmd/semantic3.d
@@ -55,7 +55,7 @@ import dmd.objc;
 import dmd.opover;
 import dmd.parse;
 import dmd.root.filename;
-import dmd.root.outbuffer;
+import dmd.common.outbuffer;
 import dmd.root.rmem;
 import dmd.root.rootobject;
 import dmd.sideeffect;
diff --git a/src/dmd/statement.d b/src/dmd/statement.d
index 175ed870b2..8bb407d4d9 100644
--- a/src/dmd/statement.d
+++ b/src/dmd/statement.d
@@ -39,7 +39,8 @@ import dmd.id;
 import dmd.identifier;
 import dmd.dinterpret;
 import dmd.mtype;
-import dmd.root.outbuffer;
+import dmd.parse;
+import dmd.common.outbuffer;
 import dmd.root.rootobject;
 import dmd.sapply;
 import dmd.sideeffect;
diff --git a/src/dmd/statementsem.d b/src/dmd/statementsem.d
index 56be90cc7a..07290c2259 100644
--- a/src/dmd/statementsem.d
+++ b/src/dmd/statementsem.d
@@ -54,7 +54,7 @@ import dmd.nogc;
 import dmd.opover;
 import dmd.parse;
 import dmd.printast;
-import dmd.root.outbuffer;
+import dmd.common.outbuffer;
 import dmd.root.string;
 import dmd.semantic2;
 import dmd.sideeffect;
diff --git a/src/dmd/staticcond.d b/src/dmd/staticcond.d
index 2f27414a56..d1578ec3a1 100644
--- a/src/dmd/staticcond.d
+++ b/src/dmd/staticcond.d
@@ -22,7 +22,7 @@ import dmd.globals;
 import dmd.identifier;
 import dmd.mtype;
 import dmd.root.array;
-import dmd.root.outbuffer;
+import dmd.common.outbuffer;
 import dmd.tokens;
 
 
diff --git a/src/dmd/tocsym.d b/src/dmd/tocsym.d
index 2747770f2b..af7c05265d 100644
--- a/src/dmd/tocsym.d
+++ b/src/dmd/tocsym.d
@@ -69,7 +69,7 @@ Symbol *toSymbolX(Dsymbol ds, const(char)* prefix, int sclass, type *t, const(ch
 {
     //printf("Dsymbol::toSymbolX('%s')\n", prefix);
     import core.stdc.stdlib : malloc, free;
-    import dmd.root.outbuffer : OutBuffer;
+    import dmd.common.outbuffer : OutBuffer;
 
     OutBuffer buf;
     mangleToBuffer(ds, &buf);
@@ -139,7 +139,7 @@ Symbol *toSymbol(Dsymbol s)
             assert(!vd.needThis());
 
             const(char)[] id;
-            import dmd.root.outbuffer : OutBuffer;
+            import dmd.common.outbuffer : OutBuffer;
             OutBuffer buf;
             bool isNRVO = false;
             if (vd.isDataseg())
diff --git a/src/dmd/toir.d b/src/dmd/toir.d
index af145f67a5..8c4b871f05 100644
--- a/src/dmd/toir.d
+++ b/src/dmd/toir.d
@@ -17,7 +17,7 @@ import core.stdc.string;
 import core.stdc.stdlib;
 
 import dmd.root.array;
-import dmd.root.outbuffer;
+import dmd.common.outbuffer;
 import dmd.root.rmem;
 
 import dmd.backend.cdef;
diff --git a/src/dmd/tokens.d b/src/dmd/tokens.d
index 7680fb8500..1ea51a89bf 100644
--- a/src/dmd/tokens.d
+++ b/src/dmd/tokens.d
@@ -19,7 +19,7 @@ import core.stdc.string;
 import dmd.globals;
 import dmd.identifier;
 import dmd.root.ctfloat;
-import dmd.root.outbuffer;
+import dmd.common.outbuffer;
 import dmd.root.rmem;
 import dmd.utf;
 
diff --git a/src/dmd/toobj.d b/src/dmd/toobj.d
index f1e75d6276..bdbfc40a1b 100644
--- a/src/dmd/toobj.d
+++ b/src/dmd/toobj.d
@@ -17,7 +17,7 @@ import core.stdc.string;
 import core.stdc.time;
 
 import dmd.root.array;
-import dmd.root.outbuffer;
+import dmd.common.outbuffer;
 import dmd.root.rmem;
 import dmd.root.rootobject;
 
diff --git a/src/dmd/traits.d b/src/dmd/traits.d
index 207f12bd31..cc1d2e351e 100644
--- a/src/dmd/traits.d
+++ b/src/dmd/traits.d
@@ -49,7 +49,7 @@ import dmd.tokens;
 import dmd.typesem;
 import dmd.visitor;
 import dmd.root.rootobject;
-import dmd.root.outbuffer;
+import dmd.common.outbuffer;
 import dmd.root.string;
 
 enum LOGSEMANTIC = false;
diff --git a/src/dmd/typesem.d b/src/dmd/typesem.d
index c58cf88243..3067baf5c6 100644
--- a/src/dmd/typesem.d
+++ b/src/dmd/typesem.d
@@ -54,7 +54,7 @@ import dmd.opover;
 import dmd.parse;
 import dmd.root.ctfloat;
 import dmd.root.rmem;
-import dmd.root.outbuffer;
+import dmd.common.outbuffer;
 import dmd.root.rootobject;
 import dmd.root.string;
 import dmd.root.stringtable;
diff --git a/src/dmd/utils.d b/src/dmd/utils.d
index 600521fbd4..6cd5d20f6f 100644
--- a/src/dmd/utils.d
+++ b/src/dmd/utils.d
@@ -16,7 +16,7 @@ import dmd.errors;
 import dmd.globals;
 import dmd.root.file;
 import dmd.root.filename;
-import dmd.root.outbuffer;
+import dmd.common.outbuffer;
 import dmd.root.string;
 
 
diff --git a/src/dmd/vsoptions.d b/src/dmd/vsoptions.d
index 3f130572cf..25eeca7608 100644
--- a/src/dmd/vsoptions.d
+++ b/src/dmd/vsoptions.d
@@ -23,7 +23,7 @@ import core.sys.windows.winreg;
 import dmd.env;
 import dmd.root.file;
 import dmd.root.filename;
-import dmd.root.outbuffer;
+import dmd.common.outbuffer;
 import dmd.root.rmem;
 import dmd.root.string : toDString;
 
diff --git a/src/tests/cxxfrontend.c b/src/tests/cxxfrontend.c
index 945f39fee0..5f5cf64329 100644
--- a/src/tests/cxxfrontend.c
+++ b/src/tests/cxxfrontend.c
@@ -17,7 +17,7 @@
 #include "root/filename.h"
 #include "root/longdouble.h"
 #include "root/object.h"
-#include "root/outbuffer.h"
+#include "common/outbuffer.h"
 #include "root/port.h"
 #include "root/rmem.h"
 
diff --git a/test/dub_package/impvisitor.d b/test/dub_package/impvisitor.d
index 93631ead60..85df47da22 100755
--- a/test/dub_package/impvisitor.d
+++ b/test/dub_package/impvisitor.d
@@ -7,7 +7,7 @@ import dmd.permissivevisitor;
 import dmd.transitivevisitor;
 
 import dmd.tokens;
-import dmd.root.outbuffer;
+import dmd.common.outbuffer;
 
 import core.stdc.stdio;
 
diff --git a/test/unit/frontend.d b/test/unit/frontend.d
index 938d07e523..289594624d 100644
--- a/test/unit/frontend.d
+++ b/test/unit/frontend.d
@@ -185,7 +185,7 @@ unittest
 
     import dmd.frontend;
     import dmd.globals : Loc;
-    import dmd.root.outbuffer;
+    import dmd.common.outbuffer;
     import dmd.console : Color;
 
     string[] diagnosticMessages;
diff --git a/test/unit/support.d b/test/unit/support.d
index d3013e88d2..6559bd2996 100644
--- a/test/unit/support.d
+++ b/test/unit/support.d
@@ -134,7 +134,7 @@ const struct Diagnostic
 
     string toString() nothrow
     {
-        import dmd.root.outbuffer : OutBuffer;
+        import dmd.common.outbuffer : OutBuffer;
 
         auto buffer = OutBuffer();
         buffer.printf("%s: %.*s", location.toChars(true),
@@ -168,7 +168,7 @@ struct DiagnosticCollector
     {
         import std.array : replace;
         import std.string : strip;
-        import dmd.root.outbuffer : OutBuffer;
+        import dmd.common.outbuffer : OutBuffer;
 
         auto buffer = OutBuffer();