diff options
Diffstat (limited to 'gold/incremental.cc')
| -rw-r--r-- | gold/incremental.cc | 192 |
1 files changed, 192 insertions, 0 deletions
diff --git a/gold/incremental.cc b/gold/incremental.cc index 4a3ecb1..9f7c4c2 100644 --- a/gold/incremental.cc +++ b/gold/incremental.cc @@ -21,11 +21,15 @@ // MA 02110-1301, USA. #include "gold.h" + +#include <cstdarg> + #include "elfcpp.h" #include "output.h" #include "incremental.h" #include "archive.h" #include "output.h" +#include "target-select.h" using elfcpp::Convert; @@ -150,6 +154,162 @@ class Incremental_inputs_entry_write internal::Incremental_inputs_entry_data* p_; }; +// Inform the user why we don't do an incremental link. Not called in +// the obvious case of missing output file. TODO: Is this helpful? + +void +vexplain_no_incremental(const char* format, va_list args) +{ + char* buf = NULL; + if (vasprintf(&buf, format, args) < 0) + gold_nomem(); + gold_info(_("the link might take longer: " + "cannot perform incremental link: %s"), buf); + free(buf); +} + +void +explain_no_incremental(const char* format, ...) +{ + va_list args; + va_start(args, format); + vexplain_no_incremental(format, args); + va_end(args); +} + +// Report an error. + +void +Incremental_binary::error(const char* format, ...) const +{ + va_list args; + va_start(args, format); + // Current code only checks if the file can be used for incremental linking, + // so errors shouldn't fail the build, but only result in a fallback to a + // full build. + // TODO: when we implement incremental editing of the file, we may need a + // flag that will cause errors to be treated seriously. + vexplain_no_incremental(format, args); + va_end(args); +} + +template<int size, bool big_endian> +bool +Sized_incremental_binary<size, big_endian>::do_find_incremental_inputs_section( + Location* location) +{ + unsigned int shndx = this->elf_file_.find_section_by_type( + elfcpp::SHT_GNU_INCREMENTAL_INPUTS); + if (shndx == elfcpp::SHN_UNDEF) // Not found. + return false; + *location = this->elf_file_.section_contents(shndx); + return true; +} + +namespace +{ + +// Create a Sized_incremental_binary object of the specified size and +// endianness. Fails if the target architecture is not supported. + +template<int size, bool big_endian> +Incremental_binary* +make_sized_incremental_binary(Output_file* file, + const elfcpp::Ehdr<size, big_endian>& ehdr) +{ + Target* target = select_target(ehdr.get_e_machine(), size, big_endian, + ehdr.get_e_ident()[elfcpp::EI_OSABI], + ehdr.get_e_ident()[elfcpp::EI_ABIVERSION]); + if (target == NULL) + { + explain_no_incremental(_("unsupported ELF machine number %d"), + ehdr.get_e_machine()); + return NULL; + } + + return new Sized_incremental_binary<size, big_endian>(file, ehdr, target); +} + +} // End of anonymous namespace. + +// Create an Incremental_binary object for FILE. Returns NULL is this is not +// possible, e.g. FILE is not an ELF file or has an unsupported target. FILE +// should be opened. + +Incremental_binary* +open_incremental_binary(Output_file* file) +{ + off_t filesize = file->filesize(); + int want = elfcpp::Elf_recognizer::max_header_size; + if (filesize < want) + want = filesize; + + const unsigned char* p = file->get_input_view(0, want); + if (!elfcpp::Elf_recognizer::is_elf_file(p, want)) + { + explain_no_incremental(_("output is not an ELF file.")); + return NULL; + } + + int size; + bool big_endian; + std::string error; + if (!elfcpp::Elf_recognizer::is_valid_header(p, want, &size, &big_endian, + &error)) + { + explain_no_incremental(error.c_str()); + return NULL; + } + + Incremental_binary* result = NULL; + if (size == 32) + { + if (big_endian) + { +#ifdef HAVE_TARGET_32_BIG + result = make_sized_incremental_binary<32, true>( + file, elfcpp::Ehdr<32, true>(p)); +#else + explain_no_incremental(_("unsupported file: 32-bit, big-endian")); +#endif + } + else + { +#ifdef HAVE_TARGET_32_LITTLE + result = make_sized_incremental_binary<32, false>( + file, elfcpp::Ehdr<32, false>(p)); +#else + explain_no_incremental(_("unsupported file: 32-bit, little-endian")); +#endif + } + } + else if (size == 64) + { + if (big_endian) + { +#ifdef HAVE_TARGET_64_BIG + result = make_sized_incremental_binary<64, true>( + file, elfcpp::Ehdr<64, true>(p)); +#else + explain_no_incremental(_("unsupported file: 64-bit, big-endian")); +#endif + } + else + { +#ifdef HAVE_TARGET_64_LITTLE + result = make_sized_incremental_binary<64, false>( + file, elfcpp::Ehdr<64, false>(p)); +#else + explain_no_incremental(_("unsupported file: 64-bit, little-endian")); +#endif + } + } + else + gold_unreachable(); + + return result; +} + // Analyzes the output file to check if incremental linking is possible and // (to be done) what files need to be relinked. @@ -159,6 +319,16 @@ Incremental_checker::can_incrementally_link_output_file() Output_file output(this->output_name_); if (!output.open_for_modification()) return false; + Incremental_binary* binary = open_incremental_binary(&output); + if (binary == NULL) + return false; + Incremental_binary::Location inputs_location; + if (!binary->find_incremental_inputs_section(&inputs_location)) + { + explain_no_incremental("no incremental data from previous build"); + delete binary; + return false; + } return true; } @@ -392,4 +562,26 @@ Incremental_inputs::sized_create_inputs_section_data() "** incremental link inputs list"); } +// Instantiate the templates we need. + +#ifdef HAVE_TARGET_32_LITTLE +template +class Sized_incremental_binary<32, false>; +#endif + +#ifdef HAVE_TARGET_32_BIG +template +class Sized_incremental_binary<32, true>; +#endif + +#ifdef HAVE_TARGET_64_LITTLE +template +class Sized_incremental_binary<64, false>; +#endif + +#ifdef HAVE_TARGET_64_BIG +template +class Sized_incremental_binary<64, true>; +#endif + } // End namespace gold. |