Recursively remove unused functions (#199)

Fixes #12

src/rewriter.fs

@@ -466,17 +466,19 @@ let private computeAllDependencies code =
     nodes
 
 
-let removeUnused code =
+let rec 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)
+    let mutable edited = false
+    let code = code |> List.filter (function
+        | Function _ as t -> if Set.contains t unused then edited <- true; false else true
         | _ -> true)
+    if edited then removeUnused code else code
 
 // reorder functions if there were forward declarations
 let reorder code =

tests/commands.txt

@@ -37,7 +37,7 @@
 --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
+--no-renaming-list rotatey,main --format c-variables -o tests/real/sult.expected tests/real/sult.frag
 --no-remove-unused --preserve-externals -o tests/unit/externals.preserved.expected tests/unit/externals.frag
 
 # Multifile tests

tests/real/sult.expected

@@ -3,35 +3,54 @@
  */
 #ifndef SULT_EXPECTED_
 # define SULT_EXPECTED_
-# define VAR_resolution "m"
-# define VAR_time "l"
+# define VAR_resolution "r"
+# define VAR_time "m"
 
 const char *sult_frag =
- "float v=5.,y=.9,a=0.,f=90.,e=0.;"
- "vec3 r=vec3(1),c=vec3(0,0,1),t=vec3(0,0,1.5);"
- "uniform vec2 m;"
- "uniform float l;"
- "vec3 rotatey(vec3 v,float m)"
+ "float y=5.,z=.9,x=0.,a=90.,s=0.;"
+ "vec3 v=vec3(1),n=vec3(0,0,1),f=vec3(0,0,1.5);"
+ "uniform vec2 r;"
+ "uniform float m;"
+ "vec3 rotatey(vec3 v,float y)"
  "{"
-   "return vec3(v.x*cos(m)+v.z*sin(m),v.y,v.z*cos(m)-v.x*sin(m));"
+   "return vec3(v.x*cos(y)+v.z*sin(y),v.y,v.z*cos(y)-v.x*sin(y));"
  "}"
- "float u=0.,n=10.;"
- "float s(vec3 m)"
+ "float c=0.,w=10.;"
+ "float e(vec3 v)"
  "{"
-   "float z=l,y,a=0.,f,e,c;"
+   "float z=m,w,a=0.,g,o,f;"
    "vec3 r;"
-   "m+=(sin(m.zxy*1.7+z)+sin(m.yzx+z*3.))*.2;"
-   "if(v<6.)"
-     "a=length(m.xyz*vec3(1,1,.1)-vec3(0,-.1,z*.15-.3))-.34;"
+   "v+=(sin(v.zxy*1.7+z)+sin(v.yzx+z*3.))*.2;"
+   "if(y<6.)"
+     "a=length(v.xyz*vec3(1,1,.1)-vec3(0,-.1,z*.15-.3))-.34;"
    "else"
-     " 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);"
+     " a=length(v.xy+vec2(0,.7))-.3+(sin(v.z*17.+z*.6)+sin(v.z*2.)*6.)*.01;"
+   "v.xy=vec2(atan(v.x,v.y)*1.113,1.6-length(v.xy)-sin(z*2.)*.3);"
+   "r=fract(v.xzz+.5).xyz-.5;"
+   "r.y=(v.y-.35)*1.3;"
+   "w=max(abs(v.y-.3)-.05,abs(length(fract(v.xz)-.5)-.4)-.03);"
+   "c=step(a,w);"
+   "return min(min(w,a),v.y-.2);"
  "}"
- "vec3 x=vec3(.19,.2,.24),i=vec3(1),z=vec3(.45,.01,0),o=vec3(.17,0,0);";
+ "vec3 d=vec3(.19,.2,.24),o=vec3(1),l=vec3(.45,.01,0),g=vec3(.17,0,0);"
+ "void main()"
+ "{"
+   "vec2 t=-1.+2.*gl_FragCoord.xy/r.xy;"
+   "vec3 i=normalize(rotatey(rotatey(vec3(t.y*z,t.x*z*1.33,1),-x*.035).yxz,(a+s*m)*.035)),p=n+f*m,u,h,F;"
+   "float C=1.,b=0.,Z,Y,X=0.,W,V,U,T;"
+   "u=vec3(.01,0,0);"
+   "h=u.yyy;"
+   "while(C>.1)"
+     "{"
+       "for(Z=X,Y=1.;Z<w&&Y>.005;Z+=Y)"
+         "Y=e(p+i*Z);"
+       "if(Z<w)"
+         "p+=i*Z,W=e(p),U=c,F=normalize(-vec3(W-e(p+u.xyy),W-e(p+u.yxy),W-e(p+u.yyx))),V=clamp(e(p+F*.05)*4.+e(p+F*.1)*2.+.5,.1,1.),b=U*.3,F=normalize(F+step(4.,y)*c*sin(p.yzx*40.)*.05),i=reflect(i,F),T=clamp(dot(normalize(v),F),0.,1.),F=mix(mix(d,o,T),l*(T+.2),U)+vec3(.7*pow(clamp(dot(normalize(v),i),0.,1.),12.)),h+=C*mix(F*V,g,Z/w),C*=b*(1.-Z/w),X=.1;"
+       "else"
+         " h+=C*g,C=0.;"
+     "}"
+   "gl_FragColor.xyz=h;"
+   "gl_FragColor.w=1.;"
+ "}";
 
 #endif // SULT_EXPECTED_

tests/unit/unused_removal.frag

@@ -1,9 +1,11 @@
 float f();
 
+float actually_unreachable() { return 1.5; }
+
 float f(){
   float r = 1.;
 
-  return r;
+  return actually_unreachable();
 }
 
 vec3 g() { return vec3(0.); }