clover/llvm: Clean up ELF parsing.
This function was doing three separate things: - Initializing and releasing the ELF parsing state (the latter can be better done using RAII). - Searching for the symbol table in the ELF file. - Extraction of kernel symbol offsets from the symbol table. Split each one into a separate function for clarity and clean up the result slightly. Reviewed-by: Serge Martin <edb+mesa@sigluy.net> Tested-by: Jan Vesely <jan.vesely@rutgers.edu>
This commit is contained in:
Francisco Jerez
parent
574477e599
commit
7bcefa5903
|
|
@ -618,67 +618,64 @@ namespace {
|
|||
return code;
|
||||
}
|
||||
|
||||
namespace elf {
|
||||
std::unique_ptr<Elf, int (*)(Elf *)>
|
||||
get(const std::vector<char> &code) {
|
||||
// One of the libelf implementations
|
||||
// (http://www.mr511.de/software/english.htm) requires calling
|
||||
// elf_version() before elf_memory().
|
||||
elf_version(EV_CURRENT);
|
||||
return { elf_memory(const_cast<char *>(code.data()), code.size()),
|
||||
elf_end };
|
||||
}
|
||||
|
||||
Elf_Scn *
|
||||
get_symbol_table(Elf *elf) {
|
||||
size_t section_str_index;
|
||||
elf_getshdrstrndx(elf, §ion_str_index);
|
||||
|
||||
for (Elf_Scn *s = elf_nextscn(elf, NULL); s; s = elf_nextscn(elf, s)) {
|
||||
GElf_Shdr header;
|
||||
if (gelf_getshdr(s, &header) != &header)
|
||||
return nullptr;
|
||||
|
||||
if (!std::strcmp(elf_strptr(elf, section_str_index, header.sh_name),
|
||||
".symtab"))
|
||||
return s;
|
||||
}
|
||||
|
||||
return nullptr;
|
||||
}
|
||||
|
||||
std::map<std::string, unsigned>
|
||||
get_symbol_offsets(Elf *elf, Elf_Scn *symtab) {
|
||||
Elf_Data *const symtab_data = elf_getdata(symtab, NULL);
|
||||
GElf_Shdr header;
|
||||
if (gelf_getshdr(symtab, &header) != &header)
|
||||
return {};
|
||||
|
||||
std::map<std::string, unsigned> symbol_offsets;
|
||||
GElf_Sym symbol;
|
||||
unsigned i = 0;
|
||||
|
||||
while (GElf_Sym *s = gelf_getsym(symtab_data, i++, &symbol)) {
|
||||
const char *name = elf_strptr(elf, header.sh_link, s->st_name);
|
||||
symbol_offsets[name] = s->st_value;
|
||||
}
|
||||
|
||||
return symbol_offsets;
|
||||
}
|
||||
}
|
||||
|
||||
std::map<std::string, unsigned>
|
||||
get_kernel_offsets(std::vector<char> &code,
|
||||
const std::vector<llvm::Function *> &kernels,
|
||||
get_symbol_offsets(const std::vector<char> &code,
|
||||
std::string &r_log) {
|
||||
const auto elf = elf::get(code);
|
||||
const auto symtab = elf::get_symbol_table(elf.get());
|
||||
if (!symtab)
|
||||
fail(r_log, compile_error(), "Unable to find symbol table.");
|
||||
|
||||
// One of the libelf implementations
|
||||
// (http://www.mr511.de/software/english.htm) requires calling
|
||||
// elf_version() before elf_memory().
|
||||
//
|
||||
elf_version(EV_CURRENT);
|
||||
|
||||
Elf *elf = elf_memory(&code[0], code.size());
|
||||
size_t section_str_index;
|
||||
elf_getshdrstrndx(elf, §ion_str_index);
|
||||
Elf_Scn *section = NULL;
|
||||
Elf_Scn *symtab = NULL;
|
||||
GElf_Shdr symtab_header;
|
||||
|
||||
// Find the symbol table
|
||||
try {
|
||||
while ((section = elf_nextscn(elf, section))) {
|
||||
const char *name;
|
||||
if (gelf_getshdr(section, &symtab_header) != &symtab_header)
|
||||
fail(r_log, compile_error(),
|
||||
"Failed to read ELF section header.");
|
||||
|
||||
name = elf_strptr(elf, section_str_index, symtab_header.sh_name);
|
||||
if (!strcmp(name, ".symtab")) {
|
||||
symtab = section;
|
||||
break;
|
||||
}
|
||||
}
|
||||
if (!symtab)
|
||||
fail(r_log, compile_error(), "Unable to find symbol table.");
|
||||
|
||||
} catch (compile_error &e) {
|
||||
elf_end(elf);
|
||||
throw e;
|
||||
}
|
||||
|
||||
|
||||
// Extract symbol information from the table
|
||||
Elf_Data *symtab_data = NULL;
|
||||
GElf_Sym *symbol;
|
||||
GElf_Sym s;
|
||||
|
||||
std::map<std::string, unsigned> kernel_offsets;
|
||||
symtab_data = elf_getdata(symtab, symtab_data);
|
||||
|
||||
// Determine the offsets for each kernel
|
||||
for (int i = 0; (symbol = gelf_getsym(symtab_data, i, &s)); i++) {
|
||||
char *name = elf_strptr(elf, symtab_header.sh_link, symbol->st_name);
|
||||
for (std::vector<llvm::Function*>::const_iterator it = kernels.begin(),
|
||||
e = kernels.end(); it != e; ++it) {
|
||||
llvm::Function *f = *it;
|
||||
if (f->getName() == std::string(name))
|
||||
kernel_offsets[f->getName()] = symbol->st_value;
|
||||
}
|
||||
}
|
||||
elf_end(elf);
|
||||
return kernel_offsets;
|
||||
return elf::get_symbol_offsets(elf.get(), symtab);
|
||||
}
|
||||
|
||||
module
|
||||
|
|
@ -688,9 +685,7 @@ namespace {
|
|||
std::string &r_log) {
|
||||
|
||||
const std::vector<llvm::Function *> kernels = find_kernels(mod);
|
||||
|
||||
std::map<std::string, unsigned> kernel_offsets =
|
||||
get_kernel_offsets(code, kernels, r_log);
|
||||
auto kernel_offsets = get_symbol_offsets(code, r_log);
|
||||
|
||||
// Begin building the clover module
|
||||
module m;
|
||||
|
|
@ -707,8 +702,10 @@ namespace {
|
|||
|
||||
for (std::map<std::string, unsigned>::iterator i = kernel_offsets.begin(),
|
||||
e = kernel_offsets.end(); i != e; ++i) {
|
||||
std::vector<module::argument> args = get_kernel_args(mod, i->first, c);
|
||||
m.syms.push_back(module::symbol(i->first, 0, i->second, args ));
|
||||
if (count(i->first, map(std::mem_fn(&llvm::Function::getName), kernels))) {
|
||||
std::vector<module::argument> args = get_kernel_args(mod, i->first, c);
|
||||
m.syms.push_back(module::symbol(i->first, 0, i->second, args));
|
||||
}
|
||||
}
|
||||
|
||||
return m;
|
||||
|
|
|
|||
Loading…
Reference in New Issue