Implement __hscore_ftruncate

asterius/rts/browser/default.mjs

@@ -22,6 +22,9 @@ class Posix {
   close() {
     throw WebAssembly.RuntimeError("Unsupported rts interface: close");
   }
+  ftruncate() {
+    throw WebAssembly.RuntimeError("Unsupported rts interface: ftruncate");
+  }
   stat() {
     throw WebAssembly.RuntimeError("Unsupported rts interface: stat");
   }

asterius/rts/node/default.mjs

@@ -20,7 +20,7 @@ class Posix {
       argv_total_size =
         argv_header_size +
         // All strings are \0-terminated, hence the +1
-        arg_bufs.reduce((acc, buf) => acc + buf.byteLength + 1, 0); 
+        arg_bufs.reduce((acc, buf) => acc + buf.byteLength + 1, 0);
     // The total size (in bytes) of the runtime arguments cannot exceed the 1KB
     // size of the data segment we have reserved. If you wish to change this
     // number, you should also update envArgvBuf in Asterius.Builtins.Env.
@@ -64,6 +64,15 @@ class Posix {
       return -1;
     }
   }
+  ftruncate(fd, len) {
+    try {
+      fs.ftruncateSync(fd, len);
+      return 0;
+    } catch (err) {
+      this.set_errno(-err.errno);
+      return -1;
+    }
+  }
   stat(f, b) {
     try {
       const r = fs.statSync(this.memory.strLoad(f));

asterius/src/Asterius/Builtins/Posix.hs

@@ -58,6 +58,16 @@ posixImports =
         externalBaseName = "close",
         functionType = FunctionType {paramTypes = [F64], returnTypes = [F64]}
       },
+    FunctionImport
+      { internalName = "__asterius_posix_ftruncate",
+        externalModuleName = "posix",
+        externalBaseName = "ftruncate",
+        functionType =
+          FunctionType
+            { paramTypes = [F64, F64],
+              returnTypes = [F64]
+            }
+      },
     FunctionImport
       { internalName = "__asterius_posix_stat",
         externalModuleName = "posix",
@@ -136,6 +146,7 @@ posixCBits :: AsteriusModule
 posixCBits =
   posixOpen
     <> posixClose
+    <> posixFtruncate
     <> posixStat
     <> posixFstat
     <> posixFstatGetters
@@ -175,6 +186,17 @@ posixClose = runEDSL "close" $ do
     <$> callImport' "__asterius_posix_close" [convertSInt64ToFloat64 fd] F64
     >>= emit
 
+posixFtruncate :: AsteriusModule
+posixFtruncate = runEDSL "__hscore_ftruncate" $ do
+  setReturnTypes [I64]
+  args <- params [I64, I64]
+  truncSFloat64ToInt64
+    <$> callImport'
+      "__asterius_posix_ftruncate"
+      (map convertSInt64ToFloat64 args)
+      F64
+    >>= emit
+
 posixStat :: AsteriusModule
 posixStat = runEDSL "__hscore_stat" $ do
   setReturnTypes [I64]