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-rw-r--r--lib/std/build/emit_raw.zig8
-rw-r--r--lib/std/elf.zig263
2 files changed, 140 insertions, 131 deletions
diff --git a/lib/std/build/emit_raw.zig b/lib/std/build/emit_raw.zig
index 058a4a64ff..688a50e8fa 100644
--- a/lib/std/build/emit_raw.zig
+++ b/lib/std/build/emit_raw.zig
@@ -46,9 +46,10 @@ const BinaryElfOutput = struct {
.segments = ArrayList(*BinaryElfSegment).init(allocator),
.sections = ArrayList(*BinaryElfSection).init(allocator),
};
- const elf_hdrs = try std.elf.readAllHeaders(allocator, elf_file);
+ const elf_hdr = try std.elf.readHeader(elf_file);
- for (elf_hdrs.section_headers) |section, i| {
+ var section_headers = elf_hdr.section_header_iterator(elf_file);
+ while (try section_headers.next()) |section| {
if (sectionValidForOutput(section)) {
const newSection = try allocator.create(BinaryElfSection);
@@ -61,7 +62,8 @@ const BinaryElfOutput = struct {
}
}
- for (elf_hdrs.program_headers) |phdr, i| {
+ var program_headers = elf_hdr.program_header_iterator(elf_file);
+ while (try program_headers.next()) |phdr| {
if (phdr.p_type == elf.PT_LOAD) {
const newSegment = try allocator.create(BinaryElfSegment);
diff --git a/lib/std/elf.zig b/lib/std/elf.zig
index 469ab693c7..9765bedc29 100644
--- a/lib/std/elf.zig
+++ b/lib/std/elf.zig
@@ -341,6 +341,20 @@ const Header = struct {
shentsize: u16,
shnum: u16,
shstrndx: u16,
+
+ pub fn program_header_iterator(self: Header, file: File) ProgramHeaderIterator {
+ return .{
+ .elf_header = self,
+ .file = file,
+ };
+ }
+
+ pub fn section_header_iterator(self: Header, file: File) SectionHeaderIterator {
+ return .{
+ .elf_header = self,
+ .file = file,
+ };
+ }
};
pub fn readHeader(file: File) !Header {
@@ -378,144 +392,137 @@ pub fn readHeader(file: File) !Header {
});
}
-/// All integers are native endian.
-pub const AllHeaders = struct {
- header: Header,
- section_headers: []Elf64_Shdr,
- program_headers: []Elf64_Phdr,
- allocator: *mem.Allocator,
-};
-
-pub fn readAllHeaders(allocator: *mem.Allocator, file: File) !AllHeaders {
- var hdrs: AllHeaders = .{
- .allocator = allocator,
- .header = try readHeader(file),
- .section_headers = undefined,
- .program_headers = undefined,
- };
- const is_64 = hdrs.header.is_64;
- const need_bswap = hdrs.header.endian != std.builtin.endian;
-
- hdrs.section_headers = try allocator.alloc(Elf64_Shdr, hdrs.header.shnum);
- errdefer allocator.free(hdrs.section_headers);
-
- hdrs.program_headers = try allocator.alloc(Elf64_Phdr, hdrs.header.phnum);
- errdefer allocator.free(hdrs.program_headers);
-
- // If the ELF file is 64-bit and same-endianness, then all we have to do is
- // yeet the bytes into memory.
- // If only the endianness is different, they can be simply byte swapped.
- if (is_64) {
- const shdr_buf = std.mem.sliceAsBytes(hdrs.section_headers);
- const phdr_buf = std.mem.sliceAsBytes(hdrs.program_headers);
- try preadNoEof(file, shdr_buf, hdrs.header.shoff);
- try preadNoEof(file, phdr_buf, hdrs.header.phoff);
+pub const ProgramHeaderIterator = struct {
+ elf_header: Header,
+ file: File,
+ index: usize = 0,
+
+ pub fn next(self: *ProgramHeaderIterator) !?Elf64_Phdr {
+ if (self.index >= self.elf_header.phnum) return null;
+ defer self.index += 1;
+
+ if (self.elf_header.is_64) {
+ var phdr: Elf64_Phdr = undefined;
+ const offset = self.elf_header.phoff + @sizeOf(@TypeOf(phdr)) * self.index;
+ try preadNoEof(self.file, mem.asBytes(&phdr), offset);
+
+ // ELF endianness matches native endianness.
+ if (self.elf_header.endian == std.builtin.endian) return phdr;
+
+ // Convert fields to native endianness.
+ return Elf64_Phdr{
+ .p_type = @byteSwap(@TypeOf(phdr.p_type), phdr.p_type),
+ .p_offset = @byteSwap(@TypeOf(phdr.p_offset), phdr.p_offset),
+ .p_vaddr = @byteSwap(@TypeOf(phdr.p_vaddr), phdr.p_vaddr),
+ .p_paddr = @byteSwap(@TypeOf(phdr.p_paddr), phdr.p_paddr),
+ .p_filesz = @byteSwap(@TypeOf(phdr.p_filesz), phdr.p_filesz),
+ .p_memsz = @byteSwap(@TypeOf(phdr.p_memsz), phdr.p_memsz),
+ .p_flags = @byteSwap(@TypeOf(phdr.p_flags), phdr.p_flags),
+ .p_align = @byteSwap(@TypeOf(phdr.p_align), phdr.p_align),
+ };
+ }
- if (need_bswap) {
- for (hdrs.section_headers) |*shdr| {
- shdr.* = .{
- .sh_name = @byteSwap(@TypeOf(shdr.sh_name), shdr.sh_name),
- .sh_type = @byteSwap(@TypeOf(shdr.sh_type), shdr.sh_type),
- .sh_flags = @byteSwap(@TypeOf(shdr.sh_flags), shdr.sh_flags),
- .sh_addr = @byteSwap(@TypeOf(shdr.sh_addr), shdr.sh_addr),
- .sh_offset = @byteSwap(@TypeOf(shdr.sh_offset), shdr.sh_offset),
- .sh_size = @byteSwap(@TypeOf(shdr.sh_size), shdr.sh_size),
- .sh_link = @byteSwap(@TypeOf(shdr.sh_link), shdr.sh_link),
- .sh_info = @byteSwap(@TypeOf(shdr.sh_info), shdr.sh_info),
- .sh_addralign = @byteSwap(@TypeOf(shdr.sh_addralign), shdr.sh_addralign),
- .sh_entsize = @byteSwap(@TypeOf(shdr.sh_entsize), shdr.sh_entsize),
- };
- }
- for (hdrs.program_headers) |*phdr| {
- phdr.* = .{
- .p_type = @byteSwap(@TypeOf(phdr.p_type), phdr.p_type),
- .p_offset = @byteSwap(@TypeOf(phdr.p_offset), phdr.p_offset),
- .p_vaddr = @byteSwap(@TypeOf(phdr.p_vaddr), phdr.p_vaddr),
- .p_paddr = @byteSwap(@TypeOf(phdr.p_paddr), phdr.p_paddr),
- .p_filesz = @byteSwap(@TypeOf(phdr.p_filesz), phdr.p_filesz),
- .p_memsz = @byteSwap(@TypeOf(phdr.p_memsz), phdr.p_memsz),
- .p_flags = @byteSwap(@TypeOf(phdr.p_flags), phdr.p_flags),
- .p_align = @byteSwap(@TypeOf(phdr.p_align), phdr.p_align),
- };
- }
+ var phdr: Elf32_Phdr = undefined;
+ const offset = self.elf_header.phoff + @sizeOf(@TypeOf(phdr)) * self.index;
+ try preadNoEof(self.file, mem.asBytes(&phdr), offset);
+
+ // ELF endianness does NOT match native endianness.
+ if (self.elf_header.endian != std.builtin.endian) {
+ // Convert fields to native endianness.
+ phdr = .{
+ .p_type = @byteSwap(@TypeOf(phdr.p_type), phdr.p_type),
+ .p_offset = @byteSwap(@TypeOf(phdr.p_offset), phdr.p_offset),
+ .p_vaddr = @byteSwap(@TypeOf(phdr.p_vaddr), phdr.p_vaddr),
+ .p_paddr = @byteSwap(@TypeOf(phdr.p_paddr), phdr.p_paddr),
+ .p_filesz = @byteSwap(@TypeOf(phdr.p_filesz), phdr.p_filesz),
+ .p_memsz = @byteSwap(@TypeOf(phdr.p_memsz), phdr.p_memsz),
+ .p_flags = @byteSwap(@TypeOf(phdr.p_flags), phdr.p_flags),
+ .p_align = @byteSwap(@TypeOf(phdr.p_align), phdr.p_align),
+ };
}
- return hdrs;
+ // Convert 32-bit header to 64-bit.
+ return Elf64_Phdr{
+ .p_type = phdr.p_type,
+ .p_offset = phdr.p_offset,
+ .p_vaddr = phdr.p_vaddr,
+ .p_paddr = phdr.p_paddr,
+ .p_filesz = phdr.p_filesz,
+ .p_memsz = phdr.p_memsz,
+ .p_flags = phdr.p_flags,
+ .p_align = phdr.p_align,
+ };
}
+};
- const shdrs_32 = try allocator.alloc(Elf32_Shdr, hdrs.header.shnum);
- defer allocator.free(shdrs_32);
-
- const phdrs_32 = try allocator.alloc(Elf32_Phdr, hdrs.header.phnum);
- defer allocator.free(phdrs_32);
-
- const shdr_buf = std.mem.sliceAsBytes(shdrs_32);
- const phdr_buf = std.mem.sliceAsBytes(phdrs_32);
- try preadNoEof(file, shdr_buf, hdrs.header.shoff);
- try preadNoEof(file, phdr_buf, hdrs.header.phoff);
-
- if (need_bswap) {
- for (hdrs.section_headers) |*shdr, i| {
- const o = shdrs_32[i];
- shdr.* = .{
- .sh_name = @byteSwap(@TypeOf(o.sh_name), o.sh_name),
- .sh_type = @byteSwap(@TypeOf(o.sh_type), o.sh_type),
- .sh_flags = @byteSwap(@TypeOf(o.sh_flags), o.sh_flags),
- .sh_addr = @byteSwap(@TypeOf(o.sh_addr), o.sh_addr),
- .sh_offset = @byteSwap(@TypeOf(o.sh_offset), o.sh_offset),
- .sh_size = @byteSwap(@TypeOf(o.sh_size), o.sh_size),
- .sh_link = @byteSwap(@TypeOf(o.sh_link), o.sh_link),
- .sh_info = @byteSwap(@TypeOf(o.sh_info), o.sh_info),
- .sh_addralign = @byteSwap(@TypeOf(o.sh_addralign), o.sh_addralign),
- .sh_entsize = @byteSwap(@TypeOf(o.sh_entsize), o.sh_entsize),
- };
- }
- for (hdrs.program_headers) |*phdr, i| {
- const o = phdrs_32[i];
- phdr.* = .{
- .p_type = @byteSwap(@TypeOf(o.p_type), o.p_type),
- .p_offset = @byteSwap(@TypeOf(o.p_offset), o.p_offset),
- .p_vaddr = @byteSwap(@TypeOf(o.p_vaddr), o.p_vaddr),
- .p_paddr = @byteSwap(@TypeOf(o.p_paddr), o.p_paddr),
- .p_filesz = @byteSwap(@TypeOf(o.p_filesz), o.p_filesz),
- .p_memsz = @byteSwap(@TypeOf(o.p_memsz), o.p_memsz),
- .p_flags = @byteSwap(@TypeOf(o.p_flags), o.p_flags),
- .p_align = @byteSwap(@TypeOf(o.p_align), o.p_align),
+pub const SectionHeaderIterator = struct {
+ elf_header: Header,
+ file: File,
+ index: usize = 0,
+
+ pub fn next(self: *SectionHeaderIterator) !?Elf64_Shdr {
+ if (self.index >= self.elf_header.shnum) return null;
+ defer self.index += 1;
+
+ if (self.elf_header.is_64) {
+ var shdr: Elf64_Shdr = undefined;
+ const offset = self.elf_header.phoff + @sizeOf(@TypeOf(shdr)) * self.index;
+ try preadNoEof(self.file, mem.asBytes(&shdr), offset);
+
+ // ELF endianness matches native endianness.
+ if (self.elf_header.endian == std.builtin.endian) return shdr;
+
+ // Convert fields to native endianness.
+ return Elf64_Shdr{
+ .sh_name = @byteSwap(@TypeOf(shdr.sh_name), shdr.sh_name),
+ .sh_type = @byteSwap(@TypeOf(shdr.sh_type), shdr.sh_type),
+ .sh_flags = @byteSwap(@TypeOf(shdr.sh_flags), shdr.sh_flags),
+ .sh_addr = @byteSwap(@TypeOf(shdr.sh_addr), shdr.sh_addr),
+ .sh_offset = @byteSwap(@TypeOf(shdr.sh_offset), shdr.sh_offset),
+ .sh_size = @byteSwap(@TypeOf(shdr.sh_size), shdr.sh_size),
+ .sh_link = @byteSwap(@TypeOf(shdr.sh_link), shdr.sh_link),
+ .sh_info = @byteSwap(@TypeOf(shdr.sh_info), shdr.sh_info),
+ .sh_addralign = @byteSwap(@TypeOf(shdr.sh_addralign), shdr.sh_addralign),
+ .sh_entsize = @byteSwap(@TypeOf(shdr.sh_entsize), shdr.sh_entsize),
};
}
- } else {
- for (hdrs.section_headers) |*shdr, i| {
- const o = shdrs_32[i];
- shdr.* = .{
- .sh_name = o.sh_name,
- .sh_type = o.sh_type,
- .sh_flags = o.sh_flags,
- .sh_addr = o.sh_addr,
- .sh_offset = o.sh_offset,
- .sh_size = o.sh_size,
- .sh_link = o.sh_link,
- .sh_info = o.sh_info,
- .sh_addralign = o.sh_addralign,
- .sh_entsize = o.sh_entsize,
- };
- }
- for (hdrs.program_headers) |*phdr, i| {
- const o = phdrs_32[i];
- phdr.* = .{
- .p_type = o.p_type,
- .p_offset = o.p_offset,
- .p_vaddr = o.p_vaddr,
- .p_paddr = o.p_paddr,
- .p_filesz = o.p_filesz,
- .p_memsz = o.p_memsz,
- .p_flags = o.p_flags,
- .p_align = o.p_align,
+
+ var shdr: Elf32_Shdr = undefined;
+ const offset = self.elf_header.shoff + @sizeOf(@TypeOf(shdr)) * self.index;
+ try preadNoEof(self.file, mem.asBytes(&shdr), offset);
+
+ // ELF endianness does NOT match native endianness.
+ if (self.elf_header.endian != std.builtin.endian) {
+ // Convert fields to native endianness.
+ shdr = .{
+ .sh_name = @byteSwap(@TypeOf(shdr.sh_name), shdr.sh_name),
+ .sh_type = @byteSwap(@TypeOf(shdr.sh_type), shdr.sh_type),
+ .sh_flags = @byteSwap(@TypeOf(shdr.sh_flags), shdr.sh_flags),
+ .sh_addr = @byteSwap(@TypeOf(shdr.sh_addr), shdr.sh_addr),
+ .sh_offset = @byteSwap(@TypeOf(shdr.sh_offset), shdr.sh_offset),
+ .sh_size = @byteSwap(@TypeOf(shdr.sh_size), shdr.sh_size),
+ .sh_link = @byteSwap(@TypeOf(shdr.sh_link), shdr.sh_link),
+ .sh_info = @byteSwap(@TypeOf(shdr.sh_info), shdr.sh_info),
+ .sh_addralign = @byteSwap(@TypeOf(shdr.sh_addralign), shdr.sh_addralign),
+ .sh_entsize = @byteSwap(@TypeOf(shdr.sh_entsize), shdr.sh_entsize),
};
}
- }
- return hdrs;
-}
+ // Convert 32-bit header to 64-bit.
+ return Elf64_Shdr{
+ .sh_name = shdr.sh_name,
+ .sh_type = shdr.sh_type,
+ .sh_flags = shdr.sh_flags,
+ .sh_addr = shdr.sh_addr,
+ .sh_offset = shdr.sh_offset,
+ .sh_size = shdr.sh_size,
+ .sh_link = shdr.sh_link,
+ .sh_info = shdr.sh_info,
+ .sh_addralign = shdr.sh_addralign,
+ .sh_entsize = shdr.sh_entsize,
+ };
+ }
+};
pub fn int(is_64: bool, need_bswap: bool, int_32: anytype, int_64: anytype) @TypeOf(int_64) {
if (is_64) {
generated by cgit v1.2.3 (git 2.39.1) at 2025-12-27 22:32:08 +0000