wrap ccalls that return Cstring in unsafe_string

Author: visr

gen/wrap_geos.jl

@@ -12,18 +12,77 @@ like `GEOS_VERSION`, which are just strings, are correct.
 =#
 
 using Clang
+using MacroTools
 
 includedir = normpath(joinpath(@__DIR__, "..", "deps", "usr", "include"))
 headerfiles = [joinpath(includedir, "geos_c.h")]
 
+"""
+Custom rewriter for Clang.jl's C wrapper
+
+Gets called with all expressions in a header file, or all expressions in a common file.
+The expressions get sent to `rewriter(::Expr)`` for
+further treatment.
+"""
+function rewriter(xs::Vector)
+    rewritten = Any[]
+    for x in xs
+        # Clang.jl inserts strings like "# Skipping MacroDefinition: X"
+        # keep these to get a sense of what we are missing
+        if x isa String
+            push!(rewritten, x)
+            continue
+        end
+        @assert x isa Expr
+
+        x2 = rewriter(x)
+        push!(rewritten, x2)
+    end
+    rewritten
+end
+
+"Functions that return a Cstring are wrapped in unsafe_string to return a String"
+function rewriter(x::Expr)
+    if @capture(x,
+        function f_(fargs__)
+            ccall(fname_, rettype_, argtypes_, argvalues__)
+        end
+    )
+        # it is a function wrapper around a ccall
+
+        # bind the ccall such that we can easily wrap it
+        cc = :(ccall($fname, $rettype, $argtypes, $(argvalues...)))
+
+        cc2 = if rettype == :Cstring
+            :(unsafe_string($cc))
+        else
+            cc
+        end
+
+        # stitch the modified function expression back together
+        x2 = :(function $f($(fargs...))
+            $cc2
+        end) |> prettify
+        x2
+    else
+        # do not modify expressions that are no ccall function wrappers
+        x
+    end
+end
+
 wc = init(; headers = headerfiles,
-            output_file = joinpath(@__DIR__, "geos_c.jl"),
-            common_file = joinpath(@__DIR__, "geos_common.jl"),
+            output_file = joinpath(@__DIR__, "..", "src", "geos_c.jl"),
+            common_file = joinpath(@__DIR__, "..", "src", "geos_common.jl"),
             clang_includes = [includedir, CLANG_INCLUDE],
             clang_args = ["-I", includedir],
             header_wrapped = (root, current) -> root == current,
             header_library = x -> "libgeos",
             clang_diagnostics = true,
+            rewriter = rewriter,
             )
 
 run(wc)
+
+# delete Clang.jl helper files
+rm(joinpath(@__DIR__, "..", "src", "LibTemplate.jl"))
+rm(joinpath(@__DIR__, "..", "src", "ctypes.jl"))

src/geos_c.jl

@@ -47,15 +47,15 @@ function GEOSContext_setErrorMessageHandler_r(extHandle, ef, userData)
 end
 
 function GEOSversion()
-    ccall((:GEOSversion, libgeos), Cstring, ())
+    unsafe_string(ccall((:GEOSversion, libgeos), Cstring, ()))
 end
 
 function GEOSGeomFromWKT_r(handle, wkt)
     ccall((:GEOSGeomFromWKT_r, libgeos), Ptr{GEOSGeometry}, (GEOSContextHandle_t, Cstring), handle, wkt)
 end
 
 function GEOSGeomToWKT_r(handle, g)
-    ccall((:GEOSGeomToWKT_r, libgeos), Cstring, (GEOSContextHandle_t, Ptr{GEOSGeometry}), handle, g)
+    unsafe_string(ccall((:GEOSGeomToWKT_r, libgeos), Cstring, (GEOSContextHandle_t, Ptr{GEOSGeometry}), handle, g))
 end
 
 function GEOS_getWKBOutputDims_r(handle)
@@ -523,31 +523,31 @@ function GEOSRelatePattern_r(handle, g1, g2, pat)
 end
 
 function GEOSRelate_r(handle, g1, g2)
-    ccall((:GEOSRelate_r, libgeos), Cstring, (GEOSContextHandle_t, Ptr{GEOSGeometry}, Ptr{GEOSGeometry}), handle, g1, g2)
+    unsafe_string(ccall((:GEOSRelate_r, libgeos), Cstring, (GEOSContextHandle_t, Ptr{GEOSGeometry}, Ptr{GEOSGeometry}), handle, g1, g2))
 end
 
 function GEOSRelatePatternMatch_r(handle, mat, pat)
     ccall((:GEOSRelatePatternMatch_r, libgeos), UInt8, (GEOSContextHandle_t, Cstring, Cstring), handle, mat, pat)
 end
 
 function GEOSRelateBoundaryNodeRule_r(handle, g1, g2, bnr)
-    ccall((:GEOSRelateBoundaryNodeRule_r, libgeos), Cstring, (GEOSContextHandle_t, Ptr{GEOSGeometry}, Ptr{GEOSGeometry}, Cint), handle, g1, g2, bnr)
+    unsafe_string(ccall((:GEOSRelateBoundaryNodeRule_r, libgeos), Cstring, (GEOSContextHandle_t, Ptr{GEOSGeometry}, Ptr{GEOSGeometry}, Cint), handle, g1, g2, bnr))
 end
 
 function GEOSisValid_r(handle, g)
     ccall((:GEOSisValid_r, libgeos), UInt8, (GEOSContextHandle_t, Ptr{GEOSGeometry}), handle, g)
 end
 
 function GEOSisValidReason_r(handle, g)
-    ccall((:GEOSisValidReason_r, libgeos), Cstring, (GEOSContextHandle_t, Ptr{GEOSGeometry}), handle, g)
+    unsafe_string(ccall((:GEOSisValidReason_r, libgeos), Cstring, (GEOSContextHandle_t, Ptr{GEOSGeometry}), handle, g))
 end
 
 function GEOSisValidDetail_r(handle, g, flags, reason, location)
     ccall((:GEOSisValidDetail_r, libgeos), UInt8, (GEOSContextHandle_t, Ptr{GEOSGeometry}, Cint, Ptr{Cstring}, Ptr{Ptr{GEOSGeometry}}), handle, g, flags, reason, location)
 end
 
 function GEOSGeomType_r(handle, g)
-    ccall((:GEOSGeomType_r, libgeos), Cstring, (GEOSContextHandle_t, Ptr{GEOSGeometry}), handle, g)
+    unsafe_string(ccall((:GEOSGeomType_r, libgeos), Cstring, (GEOSContextHandle_t, Ptr{GEOSGeometry}), handle, g))
 end
 
 function GEOSGeomTypeId_r(handle, g)
@@ -727,7 +727,7 @@ function GEOSWKTWriter_destroy_r(handle, writer)
 end
 
 function GEOSWKTWriter_write_r(handle, writer, g)
-    ccall((:GEOSWKTWriter_write_r, libgeos), Cstring, (GEOSContextHandle_t, Ptr{GEOSWKTWriter}, Ptr{GEOSGeometry}), handle, writer, g)
+    unsafe_string(ccall((:GEOSWKTWriter_write_r, libgeos), Cstring, (GEOSContextHandle_t, Ptr{GEOSWKTWriter}, Ptr{GEOSGeometry}), handle, writer, g))
 end
 
 function GEOSWKTWriter_setTrim_r(handle, writer, trim)
@@ -823,7 +823,7 @@ function GEOSGeomFromWKT(wkt)
 end
 
 function GEOSGeomToWKT(g)
-    ccall((:GEOSGeomToWKT, libgeos), Cstring, (Ptr{GEOSGeometry},), g)
+    unsafe_string(ccall((:GEOSGeomToWKT, libgeos), Cstring, (Ptr{GEOSGeometry},), g))
 end
 
 function GEOS_getWKBOutputDims()
@@ -1291,31 +1291,31 @@ function GEOSRelatePattern(g1, g2, pat)
 end
 
 function GEOSRelate(g1, g2)
-    ccall((:GEOSRelate, libgeos), Cstring, (Ptr{GEOSGeometry}, Ptr{GEOSGeometry}), g1, g2)
+    unsafe_string(ccall((:GEOSRelate, libgeos), Cstring, (Ptr{GEOSGeometry}, Ptr{GEOSGeometry}), g1, g2))
 end
 
 function GEOSRelatePatternMatch(mat, pat)
     ccall((:GEOSRelatePatternMatch, libgeos), UInt8, (Cstring, Cstring), mat, pat)
 end
 
 function GEOSRelateBoundaryNodeRule(g1, g2, bnr)
-    ccall((:GEOSRelateBoundaryNodeRule, libgeos), Cstring, (Ptr{GEOSGeometry}, Ptr{GEOSGeometry}, Cint), g1, g2, bnr)
+    unsafe_string(ccall((:GEOSRelateBoundaryNodeRule, libgeos), Cstring, (Ptr{GEOSGeometry}, Ptr{GEOSGeometry}, Cint), g1, g2, bnr))
 end
 
 function GEOSisValid(g)
     ccall((:GEOSisValid, libgeos), UInt8, (Ptr{GEOSGeometry},), g)
 end
 
 function GEOSisValidReason(g)
-    ccall((:GEOSisValidReason, libgeos), Cstring, (Ptr{GEOSGeometry},), g)
+    unsafe_string(ccall((:GEOSisValidReason, libgeos), Cstring, (Ptr{GEOSGeometry},), g))
 end
 
 function GEOSisValidDetail(g, flags, reason, location)
     ccall((:GEOSisValidDetail, libgeos), UInt8, (Ptr{GEOSGeometry}, Cint, Ptr{Cstring}, Ptr{Ptr{GEOSGeometry}}), g, flags, reason, location)
 end
 
 function GEOSGeomType(g)
-    ccall((:GEOSGeomType, libgeos), Cstring, (Ptr{GEOSGeometry},), g)
+    unsafe_string(ccall((:GEOSGeomType, libgeos), Cstring, (Ptr{GEOSGeometry},), g))
 end
 
 function GEOSGeomTypeId(g)
@@ -1495,7 +1495,7 @@ function GEOSWKTWriter_destroy(writer)
 end
 
 function GEOSWKTWriter_write(writer, g)
-    ccall((:GEOSWKTWriter_write, libgeos), Cstring, (Ptr{GEOSWKTWriter}, Ptr{GEOSGeometry}), writer, g)
+    unsafe_string(ccall((:GEOSWKTWriter_write, libgeos), Cstring, (Ptr{GEOSWKTWriter}, Ptr{GEOSGeometry}), writer, g))
 end
 
 function GEOSWKTWriter_setTrim(writer, trim)

src/geos_functions.jl

@@ -19,7 +19,7 @@ _readgeom(wkbbuffer::Vector{Cuchar}, context::GEOSContext = _context) =
     _readgeom(wkbbuffer, WKBReader(context), context)
 
 function _writegeom(geom::GEOSGeom, wktwriter::WKTWriter, context::GEOSContext = _context)
-    unsafe_string(GEOSWKTWriter_write_r(context.ptr, wktwriter.ptr, geom))
+    GEOSWKTWriter_write_r(context.ptr, wktwriter.ptr, geom)
 end
 
 function _writegeom(geom::GEOSGeom, wkbwriter::WKBWriter, context::GEOSContext = _context)