when we are calling an implemented function, call it using the signature it is implemented as, to avoid issues with LLVM casting for no reason

3 files changed, 38 insertions, 1 deletions

diff --git a/src/jsifier.js b/src/jsifier.js
index 38581ce4..e86a345d 100644
--- a/src/jsifier.js
+++ b/src/jsifier.js
@@ -1498,7 +1498,12 @@ function JSify(data, functionsOnly, givenFunctions) {
 
     var returnType = 'void';
     if ((byPointer || ASM_JS) && hasReturn) {
-      returnType = getReturnType(type);
+      if (callIdent in Functions.implementedFunctions) {
+        // LLVM sometimes bitcasts for no reason. We must call using the exact same type as the actual function is generated as
+        returnType = Functions.getSignatureReturnType(Functions.implementedFunctions[callIdent]);
+      } else {
+        returnType = getReturnType(type);
+      }
     }
 
     if (byPointer) {
diff --git a/src/modules.js b/src/modules.js
index 53d97817..8cfc38de 100644
--- a/src/modules.js
+++ b/src/modules.js
@@ -258,6 +258,15 @@ var Functions = {
     return sig;
   },
 
+  getSignatureReturnType: function(sig) {
+    switch(sig[0]) {
+      case 'v': return 'void';
+      case 'i': return 'i32';
+      case 'f': return 'double';
+      default: throw 'what is this sig? ' + sig;
+    }
+  },
+
   // Mark a function as needing indexing. Python will coordinate them all
   getIndex: function(ident, doNotCreate, sig) {
     if (doNotCreate && !(ident in this.indexedFunctions)) {
diff --git a/tests/cases/sillyfuncast.ll b/tests/cases/sillyfuncast.ll
new file mode 100644
index 00000000..36c26720
--- /dev/null
+++ b/tests/cases/sillyfuncast.ll
@@ -0,0 +1,23 @@
+; ModuleID = 'tests/hello_world.bc'
+target datalayout = "e-p:32:32:32-i1:8:8-i8:8:8-i16:16:16-i32:32:32-i64:32:64-f32:32:32-f64:32:64-v64:64:64-v128:128:128-a0:0:64-f80:32:32-n8:16:32-S128"
+target triple = "i386-pc-linux-gnu"
+
+@.str = private unnamed_addr constant [15 x i8] c"hello, world!\0A\00", align 1 ; [#uses=1 type=[15 x i8]*]
+
+define void @doit() {
+  %call = call i32 (i8*, ...)* @printf(i8* getelementptr inbounds ([15 x i8]* @.str, i32 0, i32 0)) ; [#uses=0 type=i32]
+  ret void
+}
+
+define i32 @main() {
+entry:
+  %retval = alloca i32, align 4                   ; [#uses=1 type=i32*]
+  store i32 0, i32* %retval
+  %58 = tail call i32 bitcast (void ()* @doit to i32 ()*)() nounwind
+  ret i32 1
+}
+
+declare i32 @printf(i8*, ...)
+
+
+