attempt to fix #7632 for generics

compiler/astalgo.nim

@@ -502,7 +502,7 @@ proc strTableContains*(t: TStrTable, n: PSym): bool =
 
 proc strTableRawInsert(data: var TSymSeq, n: PSym) =
   var h: Hash = n.name.h and high(data)
-  if sfImmediate notin n.flags:
+  if {sfImmediate, sfAllUntyped} * n.flags == {}:
     # fast path:
     while data[h] != nil:
       if data[h] == n:

compiler/semcall.nim

@@ -459,7 +459,7 @@ proc semOverloadedCall(c: PContext, n, nOrig: PNode,
   var r = resolveOverloads(c, n, nOrig, filter, flags, errors, efExplain in flags)
   if r.state == csMatch:
     # this may be triggered, when the explain pragma is used
-    if errors.len > 0:
+    if errors.len > 0 and efExplain in flags:
       let (_, candidates) = presentFailedCandidates(c, n, errors)
       message(c.config, n.info, hintUserRaw,
               "Non-matching candidates for " & renderTree(n) & "\n" &

compiler/semgnrc.nim

@@ -229,7 +229,9 @@ proc semGenericStmt(c: PContext, n: PNode,
       let sc = symChoice(c, fn, s, if s.isMixedIn: scForceOpen else: scOpen)
       case s.kind
       of skMacro:
-        if macroToExpand(s) and sc.safeLen <= 1:
+        # new feature: overloading by arity only in an 'immediate' expand
+        # context. XXX This needs to be documented.
+        if macroToExpand(s) and (sc.safeLen <= 1 or s.typ.len == n.len):
           styleCheckUse(fn.info, s)
           result = semMacroExpr(c, n, n, s, {efNoSemCheck})
           result = semGenericStmt(c, result, flags, ctx)
@@ -238,7 +240,7 @@ proc semGenericStmt(c: PContext, n: PNode,
           result = n
         mixinContext = true
       of skTemplate:
-        if macroToExpand(s) and sc.safeLen <= 1:
+        if macroToExpand(s) and (sc.safeLen <= 1 or s.typ.len == n.len):
           styleCheckUse(fn.info, s)
           result = semTemplateExpr(c, n, s, {efNoSemCheck})
           result = semGenericStmt(c, result, flags, ctx)

lib/pure/strformat.nim

@@ -277,7 +277,7 @@ template callFormatOption(res, arg, option) {.dirty.} =
   else:
     format($arg, option, res)
 
-macro `&`*(pattern: string): untyped =
+macro `&`*(pattern: untyped{lit}): untyped =
   ## For a specification of the ``&`` macro, see the module level documentation.
   if pattern.kind notin {nnkStrLit..nnkTripleStrLit}:
     error "string formatting (fmt(), &) only works with string literals", pattern
@@ -333,7 +333,7 @@ macro `&`*(pattern: string): untyped =
   when defined(debugFmtDsl):
     echo repr result
 
-template fmt*(pattern: string): untyped =
+template fmt*(pattern: untyped{lit}): untyped =
   ## An alias for ``&``.
   bind `&`
   &pattern

tests/stdlib/mformat2.nim

@@ -0,0 +1,14 @@
+
+import strformat
+
+proc fails*(a: static[int]) =
+  echo &"formatted {a:2}"
+
+proc fails2*[N: static[int]](a: int) =
+  echo &"formatted {a:2}"
+
+proc works*(a: int) =
+  echo &"formatted {a:2}"
+
+proc fails0*(a: int or uint) =
+  echo &"formatted {a:2}"

tests/stdlib/tformat2.nim

@@ -0,0 +1,17 @@
+discard """
+  output: '''formatted  5
+formatted  6
+formatted  7
+formatted  8'''
+"""
+
+# bug #7632
+import mformat2
+
+works(5)
+
+fails0(6)
+
+fails(7)
+
+fails2[0](8)