Initial support for #56

2 files changed, 46 insertions, 1 deletions

diff --git a/nimterop/cimport.nim b/nimterop/cimport.nim
index beaaeb2..ad9a4de 100644
--- a/nimterop/cimport.nim
+++ b/nimterop/cimport.nim
@@ -99,6 +99,9 @@ proc getToast(fullpath: string, recurse: bool = false): string =
   for i in gStateCT.includeDirs:
     cmd.add &"--includeDirs+={i.quoteShell} "
 
+  for i in gStateCT.symOverride:
+    cmd.add &"--symOverride+={i} "
+
   cmd.add &"{fullpath.quoteShell}"
   echo cmd
   (result, ret) = gorgeEx(cmd, cache=getCacheValue(fullpath))
@@ -112,6 +115,48 @@ proc getGccPaths(mode = "c"): string =
 
   (result, ret) = gorgeEx("gcc -Wp,-v -x" & mmode & " " & nul)
 
+macro cOverride*(body): untyped =
+  ## When the wrapper code generated by nimterop is missing certain symbols or not
+  ## accurate, it may be required to hand wrap them. Define them in a ``cOverride()``
+  ## macro block so that Nimterop no longer defines these symbols.
+  ##
+  ## For example:
+  ##
+  ## .. code-block:: c
+  ##
+  ##    int svGetCallerInfo(const char** fileName, int *lineNumber);
+  ##
+  ## This could get mapped to:
+  ##
+  ## .. code-block:: nim
+  ##
+  ##    proc svGetCallerInfo(fileName: ptr cstring; lineNumber: var cint)
+  ##
+  ## Whereas it might mean:
+  ##
+  ## .. code-block:: nim
+  ##
+  ##    cOverride:
+  ##      proc svGetCallerInfo(fileName: var cstring; lineNumber: var cint)
+  ##
+  ## Using the ``cOverride()`` block, nimterop can be instructed to skip over
+  ## ``svGetCallerInfo()``. This works for procs, consts and types.
+
+  for sym in body:
+    case sym.kind:
+      of nnkProcDef:
+        gStateCT.symOverride.add $sym[0]
+      of nnkConstSection, nnkTypeSection:
+        for ssym in sym:
+          gStateCT.symOverride.add $ssym[0]
+      else:
+        discard
+
+  result = body
+
+  if gStateCT.debug:
+    echo "Overriding " & gStateCT.symOverride.join(" ")
+
 proc cSearchPath*(path: string): string {.compileTime.}=
   ## Return a file or directory found in search path configured using
   ## ``cSearchPath()``
diff --git a/nimterop/globals.nim b/nimterop/globals.nim
index 1a96aa3..42abf8f 100644
--- a/nimterop/globals.nim
+++ b/nimterop/globals.nim
@@ -46,7 +46,7 @@ type
     regex*: Regex
 
   State = object
-    compile*, defines*, headers*, includeDirs*, searchDirs*: seq[string]
+    compile*, defines*, headers*, includeDirs*, searchDirs*, symOverride*: seq[string]
 
     nocache*, debug*, past*, preprocess*, pnim*, pretty*, recurse*: bool