Author: ed Date: Tue Mar 7 12:15:52 2017 New Revision: 297174 URL: http://llvm.org/viewvc/llvm-project?rev=297174&view=rev Log: Improve readability and correctness of the OS specific libunwind bits.
All of the access to __exidx_*, dl_iterate_phdr(), etc. is specific to the findUnwindSections() function. Right now all of the includes and declarations related to them are scattered throughout the source file. For example, for <link.h>, we have a full list of operating systems guarding the #include, even though the code that uses dl_iterate_phdr() miraculously doesn't use the same list. Change the code so that findUnwindSections() is preceded by a block of #ifdefs that share the same structure as the function itself. First comes all of the macOS specific bits, followed by bare-metal ARM, followed by ELF EHABI + DWARF. This actually allows us to build a copy of libunwind without any specific ifdefs for NetBSD, CloudABI, etc. It likely also unbreaks the build of libunwind on FreeBSD/armv6, though I can't confirm. Reviewed by: compnerd Differential Revision: https://reviews.llvm.org/D30696 Modified: libunwind/trunk/src/AddressSpace.hpp Modified: libunwind/trunk/src/AddressSpace.hpp URL: http://llvm.org/viewvc/llvm-project/libunwind/trunk/src/AddressSpace.hpp?rev=297174&r1=297173&r2=297174&view=diff ============================================================================== --- libunwind/trunk/src/AddressSpace.hpp (original) +++ libunwind/trunk/src/AddressSpace.hpp Tue Mar 7 12:15:52 2017 @@ -34,32 +34,6 @@ namespace libunwind { #include "dwarf2.h" #include "Registers.hpp" -#if _LIBUNWIND_ARM_EHABI -#if defined(_LIBUNWIND_IS_BAREMETAL) -// When statically linked on bare-metal, the symbols for the EH table are looked -// up without going through the dynamic loader. -extern char __exidx_start; -extern char __exidx_end; -#else -#include <link.h> -#endif // !defined(_LIBUNWIND_IS_BAREMETAL) -#endif // _LIBUNWIND_ARM_EHABI - -#if defined(__CloudABI__) || defined(__FreeBSD__) || defined(__Fuchsia__) || \ - defined(__linux__) || defined(__NetBSD__) -#if _LIBUNWIND_SUPPORT_DWARF_UNWIND && _LIBUNWIND_SUPPORT_DWARF_INDEX -#include <link.h> -// Macro for machine-independent access to the ELF program headers. This -// macro is not available on some systems (e.g., FreeBSD). On these -// systems the data structures are just called Elf_XXX. Define ElfW() -// locally. -#if !defined(ElfW) -#define ElfW(type) Elf_##type -#endif -#include "EHHeaderParser.hpp" -#endif -#endif - namespace libunwind { /// Used by findUnwindSections() to return info about needed sections. @@ -291,6 +265,7 @@ LocalAddressSpace::getEncodedP(pint_t &a } #ifdef __APPLE__ + struct dyld_unwind_sections { const struct mach_header* mh; @@ -336,6 +311,30 @@ LocalAddressSpace::getEncodedP(pint_t &a return true; } #endif + +#elif _LIBUNWIND_ARM_EHABI && defined(_LIBUNWIND_IS_BAREMETAL) + +// When statically linked on bare-metal, the symbols for the EH table are looked +// up without going through the dynamic loader. +extern char __exidx_start; +extern char __exidx_end; + +#elif _LIBUNWIND_ARM_EHABI || _LIBUNWIND_SUPPORT_DWARF_UNWIND + +// ELF-based systems may use dl_iterate_phdr() to access sections +// containing unwinding information. The ElfW() macro for pointer-size +// independent ELF header traversal is not provided by <link.h> on some +// systems (e.g., FreeBSD). On these systems the data structures are +// just called Elf_XXX. Define ElfW() locally. +#include <link.h> +#if !defined(ElfW) +#define ElfW(type) Elf_##type +#endif + +#if _LIBUNWIND_SUPPORT_DWARF_UNWIND +#include "EHHeaderParser.hpp" +#endif + #endif inline bool LocalAddressSpace::findUnwindSections(pint_t targetAddr, _______________________________________________ cfe-commits mailing list cfe-commits@lists.llvm.org http://lists.llvm.org/cgi-bin/mailman/listinfo/cfe-commits
