[project @ 2004-10-07 15:54:03 by wolfgang]
Position Independent Code and Dynamic Linking Support, Part 1 This commit allows generation of position independent code (PIC) that fully supports dynamic linking on Mac OS X and PowerPC Linux. Other platforms are not yet supported, and there is no support for actually linking or using dynamic libraries - so if you use the -fPIC or -dynamic code generation flags, you have to type your (platform-specific) linker command lines yourself. nativeGen/PositionIndependentCode.hs: New file. Look here for some more comments on how this works. cmm/CLabel.hs: Add support for DynamicLinkerLabels and PIC base labels - for use inside the NCG. needsCDecl: Case alternative labels now need C decls, see the codeGen/CgInfoTbls.hs below for details cmm/Cmm.hs: Add CmmPicBaseReg (used in NCG), and CmmLabelDiffOff (used in NCG and for offsets in info tables) cmm/CmmParse.y: support offsets in info tables cmm/PprC.hs: support CmmLabelDiffOff Case alternative labels now need C decls (see the codeGen/CgInfoTbls.hs for details), so we need to pprDataExterns for info tables. cmm/PprCmm.hs: support CmmLabelDiffOff codeGen/CgInfoTbls.hs: no longer store absolute addresses in info tables, instead, we store offsets. Also, for vectored return points, emit the alternatives _after_ the vector table. This is to work around a limitation in Apple's as, which refuses to handle label differences where one label is at the end of a section. Emitting alternatives after vector info tables makes sure this never happens in GHC generated code. Case alternatives now require prototypes in hc code, though (see changes in PprC.hs, CLabel.hs). main/CmdLineOpts.lhs: Add a new option, -fPIC. main/DriverFlags.hs: Pass the correct options for PIC to gcc, depending on the platform. Only for powerpc for now. nativeGen/AsmCodeGen.hs: Many changes... Mac OS X-specific management of import stubs is no longer, it's now part of a general mechanism to handle such things for all platforms that need it (Darwin [both ppc and x86], Linux on ppc, and some platforms we don't support). Move cmmToCmm into its own monad which can accumulate a list of imported symbols. Make it call cmmMakeDynamicReference at the right places. nativeGen/MachCodeGen.hs: nativeGen/MachInstrs.hs: nativeGen/MachRegs.lhs: nativeGen/PprMach.hs: nativeGen/RegAllocInfo.hs: Too many changes to enumerate here, PowerPC specific. nativeGen/NCGMonad.hs: NatM still tracks imported symbols, as more labels can be created during code generation (float literals, jump tables; on some platforms all data access has to go through the dynamic linking mechanism). driver/mangler/ghc-asm.lprl: Mangle absolute addresses in info tables to offsets. Correctly pass through GCC-generated PIC for Mac OS X and powerpc linux. includes/Cmm.h: includes/InfoTables.h: includes/Storage.h: includes/mkDerivedConstants.c: rts/GC.c: rts/GCCompact.c: rts/HeapStackCheck.cmm: rts/Printer.c: rts/RetainerProfile.c: rts/Sanity.c: Adapt to the fact that info tables now contain offsets. rts/Linker.c: Mac-specific: change machoInitSymbolsWithoutUnderscore to support PIC.