minor refactorings

compiler/ast.nim

@@ -1832,3 +1832,21 @@ proc addParam*(procType: PType; param: PSym) =
 template destructor*(t: PType): PSym = t.attachedOps[attachedDestructor]
 template assignment*(t: PType): PSym = t.attachedOps[attachedAsgn]
 template asink*(t: PType): PSym = t.attachedOps[attachedSink]
+
+const magicsThatCanRaise = {
+  mNone, mSlurp, mStaticExec, mParseExprToAst, mParseStmtToAst}
+
+proc canRaiseConservative*(fn: PNode): bool =
+  if fn.kind == nkSym and fn.sym.magic notin magicsThatCanRaise:
+    result = false
+  else:
+    result = true
+
+proc canRaise*(fn: PNode): bool =
+  if fn.kind == nkSym and (fn.sym.magic notin magicsThatCanRaise or
+      {sfImportc, sfInfixCall} * fn.sym.flags == {sfImportc}):
+    result = false
+  else:
+    result = fn.typ != nil and ((fn.typ.n[0].len < effectListLen) or
+      (fn.typ.n[0][exceptionEffects] != nil and
+      fn.typ.n[0][exceptionEffects].safeLen > 0))

compiler/cgen.nim

@@ -104,17 +104,17 @@ proc getModuleDllPath(m: BModule, s: PSym): Rope =
 
 import macros
 
-proc cgFormatValue(result: var string; value: Rope): void =
+proc cgFormatValue(result: var string; value: Rope) =
   for str in leaves(value):
     result.add str
 
-proc cgFormatValue(result: var string; value: string): void =
+proc cgFormatValue(result: var string; value: string) =
   result.add value
 
-proc cgFormatValue(result: var string; value: BiggestInt): void =
+proc cgFormatValue(result: var string; value: BiggestInt) =
   result.addInt value
 
-proc cgFormatValue(result: var string; value: Int128): void =
+proc cgFormatValue(result: var string; value: Int128) =
   result.addInt128 value
 
 # TODO: please document

compiler/dfa.nim

@@ -693,14 +693,6 @@ proc genDef(c: var Con; n: PNode) =
   elif isAnalysableFieldAccess(n, c.owner):
     c.code.add Instr(n: n, kind: def, sym: nil)
 
-proc canRaise(fn: PNode): bool =
-  const magicsThatCanRaise = {
-    mNone, mSlurp, mStaticExec, mParseExprToAst, mParseStmtToAst}
-  if fn.kind == nkSym and fn.sym.magic notin magicsThatCanRaise:
-    result = false
-  else:
-    result = true
-
 proc genCall(c: var Con; n: PNode) =
   gen(c, n[0])
   var t = n[0].typ
@@ -715,7 +707,7 @@ proc genCall(c: var Con; n: PNode) =
         # optimizer.
         genDef(c, n[i])
   # every call can potentially raise:
-  if c.inTryStmt > 0 and canRaise(n[0]):
+  if c.inTryStmt > 0 and canRaiseConservative(n[0]):
     # we generate the instruction sequence:
     # fork lab1
     # goto exceptionHandler (except or finally)

compiler/sempass2.nim

@@ -708,6 +708,8 @@ proc track(tracked: PEffects, n: PNode) =
   of nkCallKinds:
     # p's effects are ours too:
     var a = n[0]
+    #if canRaise(a):
+    #  echo "this can raise ", tracked.config $ n.info
     let op = a.typ
     if n.typ != nil:
       if tracked.owner.kind != skMacro and n.typ.skipTypes(abstractVar).kind != tyOpenArray:

lib/system/io.nim

@@ -522,7 +522,7 @@ proc open*(f: var File, filename: string,
   ##
   ## Default mode is readonly. Returns true iff the file could be opened.
   ## This throws no exception if the file could not be opened.
-  var p: pointer = fopen(filename, FormatOpen[mode])
+  var p = fopen(filename, FormatOpen[mode])
   if p != nil:
     when defined(posix) and not defined(nimscript):
       # How `fopen` handles opening a directory is not specified in ISO C and
@@ -547,15 +547,13 @@ proc reopen*(f: File, filename: string, mode: FileMode = fmRead): bool {.
   ## file variables.
   ##
   ## Default mode is readonly. Returns true iff the file could be reopened.
-  var p: pointer = freopen(filename, FormatOpen[mode], f)
-  result = p != nil
+  result = freopen(filename, FormatOpen[mode], f) != nil
 
 proc open*(f: var File, filehandle: FileHandle,
            mode: FileMode = fmRead): bool {.tags: [], raises: [], benign.} =
   ## Creates a ``File`` from a `filehandle` with given `mode`.
   ##
   ## Default mode is readonly. Returns true iff the file could be opened.
-
   f = c_fdopen(filehandle, FormatOpen[mode])
   result = f != nil
 
@@ -582,7 +580,7 @@ proc getFilePos*(f: File): int64 {.benign.} =
 
 proc getFileSize*(f: File): int64 {.tags: [ReadIOEffect], benign.} =
   ## retrieves the file size (in bytes) of `f`.
-  var oldPos = getFilePos(f)
+  let oldPos = getFilePos(f)
   discard c_fseek(f, 0, 2) # seek the end of the file
   result = getFilePos(f)
   setFilePos(f, oldPos)
@@ -639,7 +637,7 @@ when defined(windows) and not defined(nimscript):
     importc: when defined(bcc): "setmode" else: "_setmode",
     header: "<io.h>".}
   var
-    O_BINARY {.importc: "_O_BINARY", header:"<fcntl.h>".}: cint
+    O_BINARY {.importc: "_O_BINARY", header: "<fcntl.h>".}: cint
 
   # we use binary mode on Windows:
   c_setmode(c_fileno(stdin), O_BINARY)
@@ -731,9 +729,11 @@ iterator lines*(filename: string): TaintedString {.tags: [ReadIOEffect].} =
   ##       buffer.add(line.replace("a", "0") & '\x0A')
   ##     writeFile(filename, buffer)
   var f = open(filename, bufSize=8000)
-  defer: close(f)
-  var res = TaintedString(newStringOfCap(80))
-  while f.readLine(res): yield res
+  try:
+    var res = TaintedString(newStringOfCap(80))
+    while f.readLine(res): yield res
+  finally:
+    close(f)
 
 iterator lines*(f: File): TaintedString {.tags: [ReadIOEffect].} =
   ## Iterate over any line in the file `f`.