#33006: enhancement: gcc46 variant for R-framework --------------------------------------+------------------------------------- Reporter: adfernandes@… | Owner: kjell.konis@… Type: enhancement | Status: new Priority: Normal | Milestone: Component: ports | Version: 2.0.3 Keywords: haspatch | Port: R-framework --------------------------------------+------------------------------------- Comment(by adfernandes@…): I understand completely. I have been bitten by the "different pieces compiled by different compilers" bug before, and it was a nightmare to sort out. I believe that some of the old problems were caused by an ABI change in gcc back in the early 4-something days. That was horrible. Plus, now I believe that for shared objects as long as you link to the correct `libgcc_s` initialization library, you should never have a problem combining shared objects with an executable no matter the compiler version. Objective-C is a tricky beast, though. Here we're talking about compiling one object via apple's gcc then linking with the gcc runtime... I did a `DYLD_PRINT_LIBRARIES=1` for R and used the quartz plotting system as a test just now. The first few entries are {{{ dyld: loaded: /opt/local/Library/Frameworks/R.framework/Versions/2.14/Resources/library/grDevices/libs/x86_64/grDevices.so dyld: loaded: /System/Library/Frameworks/AppKit.framework/Versions/C/AppKit dyld: loaded: /System/Library/Frameworks/ApplicationServices.framework/Versions/A/ApplicationServices dyld: loaded: /System/Library/Frameworks/Foundation.framework/Versions/C/Foundation ... }}} Now all of these, including `R`'s `grDevices.so' link to the system `/usr/lib/libobjc.A.dylib`. I've checked ALL the libraries in ALL of the executable and shared objects in the `R` port, and NONE of them link to any of the `/opt/local/lib/gcc46 /libobjc-gnu.*` files. So what I think is happening is that using Apple's objective-c compiler is always legal in this case because it always links to Apple's objective-c runtime, and not the GNU objective-c runtime by mistake. I '''do''' know, from hacking with gcc and clang on mac and linux, that the compiler is tightly coupled to the runtime; gcc-objc assumes the gnu-objc runtime, apple's compilers assume apple's runtime. It appears that, since `grDevices.so` automagically links the apple runtime, the apple objective-c gets used to resolve all objective-c link references. (And it appears that this graphics device is the only part of the R code base that uses any objective-c!) So... my conclusion is that this appears safe for `gcc46` and the current `R-framework` port since the correct libraries and compilers and runtimes always seem to link up together. Plus... I've been using `R`, `Rcpp`, `Rmpi`, and `rgl` a '''lot''' in the past couple of weeks, along with many of my own compiled objects (fortran with openmpi), and have never had a crash yet... :-) -- Ticket URL: <https://trac.macports.org/ticket/33006#comment:2> MacPorts <http://www.macports.org/> Ports system for Mac OS

#33006: enhancement: gcc46 variant for R-framework --------------------------------------+------------------------------------- Reporter: adfernandes@… | Owner: kjell.konis@… Type: enhancement | Status: new Priority: Normal | Milestone: Component: ports | Version: 2.0.3 Keywords: haspatch | Port: R-framework --------------------------------------+------------------------------------- Comment(by adfernandes@…): Note to maintainer - I've been swamped the past few days - will get to testing this shortly - thanks for your patience! -- Ticket URL: <https://trac.macports.org/ticket/33006#comment:4> MacPorts <http://www.macports.org/> Ports system for Mac OS