Unused functions are removed by default (#182)

.gitignore

@@ -33,6 +33,8 @@ local.properties
 ## Visual Studio
 #################
 
+.vs/
+
 ## Ignore Visual Studio temporary files, build results, and
 ## files generated by popular Visual Studio add-ons.
 

src/api.fs

@@ -23,6 +23,8 @@ let minify (files: (string*string)[]) =
     vprintf "File parsed. "; printSize shaders
 
     for shader in shaders do
+        if not options.noRemoveUnused then
+            shader.code <- Rewriter.removeUnused shader.code
         if shader.reorderFunctions then
             shader.code <- Rewriter.reorder shader.code
         shader.code <- Rewriter.simplify shader.code

src/options.fs

@@ -35,6 +35,7 @@ type CliArguments =
     | [<CustomCommandLine("--no-renaming-list")>] NoRenamingList of string
     | [<CustomCommandLine("--no-sequence")>] NoSequence
     | [<CustomCommandLine("--smoothstep")>] Smoothstep
+    | [<CustomCommandLine("--no-remove-unused")>] NoRemoveUnused
     | [<MainCommand>] Filenames of filename:string list
 
     interface IArgParserTemplate with
@@ -53,6 +54,7 @@ type CliArguments =
             | NoRenamingList _ -> "Comma-separated list of functions to preserve"
             | NoSequence -> "Do not use the comma operator trick"
             | Smoothstep -> "Use IQ's smoothstep trick"
+            | NoRemoveUnused -> "Do not remove unused code"
             | Filenames _ -> "List of files to minify" 
 
 type Options() =
@@ -69,6 +71,7 @@ type Options() =
     member val noSequence = false with get, set
     member val noRenaming = false with get, set
     member val noRenamingList = ["main"] with get, set
+    member val noRemoveUnused = false with get, set
     member val filenames = [||]: string[] with get, set
 
 module Globals =
@@ -109,6 +112,7 @@ let private initPrivate argv needFiles =
         options.aggroInlining <- args.Contains(AggroInlining) && not (args.Contains(NoInlining))
         options.noSequence <- args.Contains(NoSequence)
         options.noRenaming <- args.Contains(NoRenaming)
+        options.noRemoveUnused <- args.Contains(NoRemoveUnused)
         options.noRenamingList <- noRenamingList
         options.filenames <- filenames
         true

src/rewriter.fs

@@ -289,25 +289,32 @@ let simplify li =
           (* Reorder functions because of forward declarations *)
 
 
+type CallGraphNode = {
+    func: TopLevel
+    funcType: FunctionType
+    name: string
+    callees: string list
+}
+
 let rec private findRemove callback = function
-    | (name, [], content) :: l ->
+    | node :: l when node.callees.IsEmpty ->
         //printfn "=> %s" name
-        callback name content
+        callback node
         l
     | [] -> failwith "Cannot reorder functions (probably because of a recursion)."
     | x :: l -> x :: findRemove callback l
 
 // slow, but who cares?
-let private graphReorder deps =
+let private graphReorder nodes =
     let mutable list = []
     let mutable lastName = ""
 
-    let rec loop deps =
-        let deps = findRemove (fun (s: Ident) x -> lastName <- s.Name; list <- x :: list) deps
-        let deps = deps |> List.map (fun (n, d, c) -> n, List.filter ((<>) lastName) d, c)
-        if deps <> [] then loop deps
+    let rec loop nodes =
+        let nodes = findRemove (fun node -> lastName <- node.name; list <- node.func :: list) nodes
+        let nodes = nodes |> List.map (fun n -> { n with callees = List.filter ((<>) lastName) n.callees })
+        if nodes <> [] then loop nodes
 
-    if deps <> [] then loop deps
+    if nodes <> [] then loop nodes
     list |> List.rev
 
 
@@ -324,14 +331,27 @@ let private computeDependencies block =
 
 // This function assumes that functions are NOT overloaded
 let private computeAllDependencies code =
-    let fct = code |> List.choose (function
-        | Function(fct, block) as f -> Some (fct.fName, block, f)
+    let functions = code |> List.choose (function
+        | Function(funcType, block) as f -> Some (funcType, funcType.fName.Name, block, f)
         | _ -> None)
-    let deps = fct |> List.map (fun (name, block, f) ->
-        let dep = computeDependencies block
-                  |> List.filter (fun name -> fct |> List.exists (fun (x,_,_) -> name = x.Name))
-        name, dep, f)
-    deps
+    let nodes = functions |> List.map (fun (funcType, name, block, f) ->
+        let callees = computeDependencies block
+                      |> List.filter (fun name2 -> functions |> List.exists (fun (_,n,_,_) -> name2 = n))
+        { CallGraphNode.func = f; funcType = funcType; name = name; callees = callees })
+    nodes
+
+
+let removeUnused code =
+    let nodes = computeAllDependencies code
+    let isUnused node =
+        let canBeRenamed = not (options.noRenamingList |> List.contains node.name) // noRenamingList includes "main"
+        let isCalled = (nodes |> List.exists (fun n -> n.callees |> List.contains node.name))
+        let isExternal = options.hlsl && node.funcType.semantics <> []
+        canBeRenamed && not isCalled && not isExternal
+    let unused = set [for node in nodes do if isUnused node then yield node.func]
+    code |> List.filter (function
+        | Function _ as t -> not (unused |> Set.contains t)
+        | _ -> true)
 
 // reorder functions if there were forward declarations
 let reorder code =

tests/commands.txt

@@ -8,52 +8,52 @@
 
 # Unit tests
 
---no-renaming --format c-variables -o tests/unit/blocks.expected tests/unit/blocks.frag
---hlsl --no-inlining --no-renaming --format c-variables -o tests/unit/geometry.hlsl.expected tests/unit/geometry.hlsl
---no-renaming --no-inlining --format c-array -o tests/unit/operators.expected tests/unit/operators.frag
+--no-remove-unused --no-renaming --format c-variables -o tests/unit/blocks.expected tests/unit/blocks.frag
+--no-remove-unused --hlsl --no-inlining --no-renaming --format c-variables -o tests/unit/geometry.hlsl.expected tests/unit/geometry.hlsl
+--no-remove-unused --no-renaming --no-inlining --format c-array -o tests/unit/operators.expected tests/unit/operators.frag
 --no-renaming --no-inlining --format c-array -o tests/unit/minus-zero.expected tests/unit/minus-zero.frag
---no-renaming --format c-array --no-inlining -o tests/unit/float.frag.expected tests/unit/float.frag
---no-renaming --format indented --no-inlining -o tests/unit/nested_if.frag.expected tests/unit/nested_if.frag
+--no-remove-unused --no-renaming --format c-array --no-inlining -o tests/unit/float.frag.expected tests/unit/float.frag
+--no-remove-unused --no-renaming --format indented --no-inlining -o tests/unit/nested_if.frag.expected tests/unit/nested_if.frag
 --format indented -o tests/unit/precision.frag.expected tests/unit/precision.frag
---format c-array --no-inlining --no-renaming -o tests/unit/verbatim.frag.expected tests/unit/verbatim.frag
---format indented --no-renaming -o tests/unit/forward_declaration.frag.expected tests/unit/forward_declaration.frag
+--no-remove-unused --format c-array --no-inlining --no-renaming -o tests/unit/verbatim.frag.expected tests/unit/verbatim.frag
+--no-remove-unused --format indented --no-renaming -o tests/unit/forward_declaration.frag.expected tests/unit/forward_declaration.frag
 
 # Inlining unit tests
 
---no-renaming --format indented -o tests/unit/inline.expected tests/unit/inline.frag
---no-renaming --format indented --aggressive-inlining -o tests/unit/inline.aggro.expected tests/unit/inline.frag
---no-renaming --format indented --no-inlining -o tests/unit/inline.no.expected tests/unit/inline.frag
---no-renaming --format indented -o tests/unit/inline-aggro.expected tests/unit/inline-aggro.frag
---no-renaming --format indented --aggressive-inlining -o tests/unit/inline-aggro.aggro.expected tests/unit/inline-aggro.frag
---no-renaming --format indented -o tests/unit/inline-fn.expected tests/unit/inline-fn.frag
---no-renaming --format indented --aggressive-inlining -o tests/unit/inline-fn.aggro.expected tests/unit/inline-fn.frag
+--no-remove-unused --no-renaming --format indented -o tests/unit/inline.expected tests/unit/inline.frag
+--no-remove-unused --no-renaming --format indented --aggressive-inlining -o tests/unit/inline.aggro.expected tests/unit/inline.frag
+--no-remove-unused --no-renaming --format indented --no-inlining -o tests/unit/inline.no.expected tests/unit/inline.frag
+--no-remove-unused --no-renaming --format indented -o tests/unit/inline-aggro.expected tests/unit/inline-aggro.frag
+--no-remove-unused --no-renaming --format indented --aggressive-inlining -o tests/unit/inline-aggro.aggro.expected tests/unit/inline-aggro.frag
+--no-remove-unused --no-renaming --format indented -o tests/unit/inline-fn.expected tests/unit/inline-fn.frag
+--no-remove-unused --no-renaming --format indented --aggressive-inlining -o tests/unit/inline-fn.aggro.expected tests/unit/inline-fn.frag
 
 # Partial renaming tests
 
---no-renaming --format c-variables -o tests/unit/function_comma.expected tests/unit/function_comma.frag
+--no-remove-unused --no-renaming --format c-variables -o tests/unit/function_comma.expected tests/unit/function_comma.frag
 --preserve-externals --format c-variables -o tests/real/mandelbulb.expected tests/real/mandelbulb.frag
 --preserve-all-globals --format c-variables -o tests/real/to_the_road_of_ribbon.expected tests/real/to_the_road_of_ribbon.frag
 --no-renaming-list rotatey --format c-variables -o tests/real/sult.expected tests/real/sult.frag
---preserve-externals -o tests/unit/externals.preserved.expected tests/unit/externals.frag
+--no-remove-unused --preserve-externals -o tests/unit/externals.preserved.expected tests/unit/externals.frag
 
 # Multifile tests
 
---format c-array -o tests/unit/inout.expected tests/unit/inout.frag tests/unit/inout2.frag
+--no-remove-unused --format c-array -o tests/unit/inout.expected tests/unit/inout.frag tests/unit/inout2.frag
 
 # Tests with full renaming
 
---format c-array --no-inlining -o tests/unit/many_variables.expected tests/unit/many_variables.frag
+--no-remove-unused --format c-array --no-inlining -o tests/unit/many_variables.expected tests/unit/many_variables.frag
 --hlsl -o tests/real/elevated.hlsl.expected tests/real/elevated.hlsl
 -o tests/real/lunaquatic.frag.expected tests/real/lunaquatic.frag
 -o tests/real/yx_long_way_from_home.frag.expected tests/real/yx_long_way_from_home.frag
 -o tests/real/oscars_chair.frag.expected tests/real/oscars_chair.frag
 -o tests/real/the_real_party_is_in_your_pocket.frag.expected tests/real/the_real_party_is_in_your_pocket.frag
--o tests/unit/function_overload.expected tests/unit/function_overload.frag
--o tests/unit/externals.expected tests/unit/externals.frag
--o tests/unit/qualifiers.expected tests/unit/qualifiers.frag
--o tests/unit/macros.expected --no-inlining tests/unit/macros.frag
---format indented -o tests/unit/switch.expected tests/unit/switch.frag
---format indented -o tests/unit/forbidden.expected tests/unit/forbidden.frag
+--no-remove-unused -o tests/unit/function_overload.expected tests/unit/function_overload.frag
+--no-remove-unused -o tests/unit/externals.expected tests/unit/externals.frag
+--no-remove-unused -o tests/unit/qualifiers.expected tests/unit/qualifiers.frag
+--no-remove-unused -o tests/unit/macros.expected --no-inlining tests/unit/macros.frag
+--no-remove-unused --format indented -o tests/unit/switch.expected tests/unit/switch.frag
+--no-remove-unused --format indented -o tests/unit/forbidden.expected tests/unit/forbidden.frag
 --format c-variables -o tests/real/heart.frag.expected tests/real/heart.frag
 
 # Optimization tests

tests/real/sult.expected

@@ -4,56 +4,34 @@
 #ifndef SULT_EXPECTED_
 # define SULT_EXPECTED_
 # define VAR_resolution "m"
-# define VAR_time "c"
+# define VAR_time "l"
 
 const char *sult_frag =
- "float v=5.,z=.9,y=0.,a=90.,x=0.;"
- "vec3 r=vec3(1,1,1),n=vec3(0,0,1),s=vec3(0,0,1.5);"
+ "float v=5.,y=.9,a=0.,f=90.,e=0.;"
+ "vec3 r=vec3(1,1,1),c=vec3(0,0,1),t=vec3(0,0,1.5);"
  "uniform vec2 m;"
- "uniform float c;"
- "vec3 rotatey(vec3 v,float r)"
+ "uniform float l;"
+ "vec3 rotatey(vec3 v,float m)"
  "{"
-   "return vec3(v.x*cos(r)+v.z*sin(r),v.y,v.z*cos(r)-v.x*sin(r));"
+   "return vec3(v.x*cos(m)+v.z*sin(m),v.y,v.z*cos(m)-v.x*sin(m));"
  "}"
- "vec3 e(vec3 v,float r)"
+ "float u=0.,n=10.;"
+ "float s(vec3 m)"
  "{"
-   "return vec3(v.y*cos(r)+v.z*sin(r),v.x,v.z*cos(r)-v.y*sin(r));"
- "}"
- "float f=0.,w=10.;"
- "float e(vec3 r)"
- "{"
-   "float y=c,w,z=0.,g,x,a;"
-   "vec3 m;"
-   "r+=(sin(r.zxy*1.7+y)+sin(r.yzx+y*3.))*.2;"
+   "float z=l,y,a=0.,f,e,c;"
+   "vec3 r;"
+   "m+=(sin(m.zxy*1.7+z)+sin(m.yzx+z*3.))*.2;"
    "if(v<6.)"
-     "z=length(r.xyz*vec3(1,1,.1)-vec3(0,-.1,y*.15-.3))-.34;"
+     "a=length(m.xyz*vec3(1,1,.1)-vec3(0,-.1,z*.15-.3))-.34;"
    "else"
-     " z=length(r.xy+vec2(0.,.7))-.3+(sin(r.z*17.+y*.6)+sin(r.z*2.)*6.)*.01;"
-   "r.xy=vec2(atan(r.x,r.y)*1.113,1.6-length(r.xy)-sin(y*2.)*.3);"
-   "m=fract(r.xzz+.5).xyz-.5;"
-   "m.y=(r.y-.35)*1.3;"
-   "w=max(abs(r.y-.3)-.05,abs(length(fract(r.xz)-.5)-.4)-.03);"
-   "f=step(z,w);"
-   "return min(min(w,z),r.y-.2);"
+     " a=length(m.xy+vec2(0.,.7))-.3+(sin(m.z*17.+z*.6)+sin(m.z*2.)*6.)*.01;"
+   "m.xy=vec2(atan(m.x,m.y)*1.113,1.6-length(m.xy)-sin(z*2.)*.3);"
+   "r=fract(m.xzz+.5).xyz-.5;"
+   "r.y=(m.y-.35)*1.3;"
+   "y=max(abs(m.y-.3)-.05,abs(length(fract(m.xz)-.5)-.4)-.03);"
+   "u=step(a,y);"
+   "return min(min(y,a),m.y-.2);"
  "}"
- "vec3 d=vec3(.19,.2,.24),o=vec3(1),t=vec3(.45,.01,0),g=vec3(.17,0,0);"
- "void e()"
- "{"
-   "vec2 l=-1.+2.*gl_FragCoord.xy/m.xy;"
-   "vec3 i=normalize(rotatey(rotatey(vec3(l.y*z,l.x*z*1.33,1),-y*.035).yxz,(a+x*c)*.035)),p=n+s*c;"
-   "float u=1.,h=0.,F,C,b=0.,Z,Y,X,W;"
-   "vec3 V=vec3(.01,0,0),U=V.yyy,T;"
-   "while(u>.1)"
-     "{"
-       "for(F=b,C=1.;F<w&&C>.005;F+=C)"
-         "C=e(p+i*F);"
-       "if(F<w)"
-         "p+=i*F,Z=e(p),X=f,T=normalize(-vec3(Z-e(p+V.xyy),Z-e(p+V.yxy),Z-e(p+V.yyx))),Y=clamp(e(p+T*.05)*4.+e(p+T*.1)*2.+.5,.1,1.),h=X*.3,T=normalize(T+step(4.,v)*f*sin(p.yzx*40.)*.05),i=reflect(i,T),W=clamp(dot(normalize(r),T),0.,1.),T=mix(mix(d,o,W),t*(W+.2),X)+vec3(.7*pow(clamp(dot(normalize(r),i),0.,1.),12.)),U+=u*mix(T*Y,g,F/w),u*=h*(1.-F/w),b=.1;"
-       "else"
-         " U+=u*g,u=0.;"
-     "}"
-   "gl_FragColor.xyz=U;"
-   "gl_FragColor.w=1.;"
- "}";
+ "vec3 x=vec3(.19,.2,.24),i=vec3(1),z=vec3(.45,.01,0),o=vec3(.17,0,0);";
 
 #endif // SULT_EXPECTED_