This implements execute-only support for ARM code generation, which
prevents the compiler from generating data accesses to code sections.
The following changes are involved:
* Add the CodeGen option "-arm-execute-only" to the ARM code generator.
* Add the clang flag "-mexecute-only" as well as the GCC-compatible
alias "-mpure-code" to enable this option.
* When enabled, literal pools are replaced with MOVW/MOVT instructions,
with VMOV used in addition for floating-point literals. As the MOVT
instruction is required, execute-only support is only available in
Thumb mode for targets supporting ARMv8-M baseline or Thumb2.
* Jump tables are placed in data sections when in execute-only mode.
* The execute-only text section is assigned section ID 0, and is
marked as unreadable with the SHF_ARM_PURECODE flag with symbol 'y'.
This also overrides selection of ELF sections for globals.
llvm-svn: 289784
Since DWARF formatting is agnostic to the object file it is stored in, it doesn't make sense for this to be in the MachOYAML implementation. Pulling it into its own namespace means we could modify the ELF and COFF YAML tools to emit DWARF as well.
In a follow-up patch I will better abstract this in obj2yaml and yaml2obj so that the DWARF bits in the tools can be re-used too.
llvm-svn: 288984
This patch adds the starting support for encoding data from the MachO __DWARF segment. The first section supported is the __debug_str section because it is the simplest.
llvm-svn: 288774
Add the necessary definitions for RISC-V ELF files, including relocs. Also
make necessary trivial change to ELFYaml, llvm-objdump, and llvm-readobj in
order to work with RISC-V ELFs.
Differential Revision: https://reviews.llvm.org/D23557
llvm-svn: 285708
Since I stopped writing empty export tries it causes LinkEdit to potentially be completely empty which results in invalid yaml being generated.
To prevent this we skip linkedit data if it is empty.
llvm-svn: 278985
The YAML representation was always outputting the root node of an export trie even if the trie was empty. While this doesn't really have any functional impact, it does add visual clutter to the yaml file.
llvm-svn: 278307
The same value for EM_BPF is being propagated to glibc,
elfutils, and binutils.
Signed-off-by: Richard Henderson <rth@twiddle.net>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
llvm-svn: 275633
Our existing yaml::Output code writes tags immediately when mapTag is called, without any state handling. This results in tags on sequence elements being written before the element itself. For example, we see this:
SomeArray: !elem_type
- key1: 1
key2: 2 !elem_type2
- key3: 3
key4: 4
We should instead see:
SomeArray:
- !elem_type
key1: 1
key2: 2
- !elem_type2
key3: 3
key4: 4
Our reader handles reading properly, so this bug only impacts writing yaml sequences with tagged elements.
As a test for this I've modified the Mach-O yaml encoding to allways apply the !mach-o tag when encoding MachOYAML::Object entries. This results in the !mach-o tag appearing as expected in dumped fat files.
llvm-svn: 274067
Summary:
Our YAML library's handling of tags isn't perfect, but it is good enough to get rid of the need for the --format argument to yaml2obj. This patch does exactly that.
Instead of requiring --format, it infers the format based on the tags found in the object file. The supported tags are:
!ELF
!COFF
!mach-o
!fat-mach-o
I have a corresponding patch that is quite large that fixes up all the in-tree test cases.
Reviewers: rafael, Bigcheese, compnerd, silvas
Subscribers: compnerd, llvm-commits
Differential Revision: http://reviews.llvm.org/D21711
llvm-svn: 273915
This patch adds round-trip support for MachO Universal binaries to obj2yaml and yaml2obj. Universal binaries have a header and list of architecture structures, followed by a the individual object files at specified offsets.
llvm-svn: 273719
32-bit Mach headers don't have reserved fields. When generating the
mapping for 32-bit headers leaving off the reserved field will result in
parse errors if the field is present in the yaml.
Added a CHECK-NOT line to ensure that mach_header.yaml isn't adding a
reserved field, and a test to ensure that the parser error gets hit with
32-bit headers.
llvm-svn: 273623
This commit adds round tripping for MachO symbol data. Symbols are entries in the name list, that contain offsets into the string table which is at the end of the __LINKEDIT segment.
llvm-svn: 271604
This directory is used to find if there is a PDB associated with an
executable. I plan to use this functionality to teach llvm-symbolizer
whether it should use DIA or DWARF to symbolize a given DLL.
Reviewers: majnemer
Differential Revision: http://reviews.llvm.org/D20885
llvm-svn: 271539
The MachO export trie is a serially encoded trie keyed by symbol name. This code parses the trie and preserves the structure so that it can be dumped again.
llvm-svn: 271300
This adds support for YAML round tripping dyld info lazy bindings. The storage and format of these is the same as regular bind opcodes, they are just interpreted differently by dyld, and can have DONE opcodes in the middle of the opcode lists.
llvm-svn: 270920
This adds support for YAML round tripping dyld info weak bindings. The storage and format of these is the same as regular bind opcodes, they are just interpreted differently by dyld.
llvm-svn: 270911
This adds support for YAML round tripping dyld info bind opcodes. Bind opcodes can have signed or unsigned LEB128 data, and they can have symbols associated with them.
llvm-svn: 270901
The uuid_command was duplicating the load_command.cmdsize field. This removes the duplicate from the YAML mapping and from the test cases.
llvm-svn: 270248
This re-applies r270115.
Many of the MachO load commands can have data appended after the command structure. This data is frequently strings, but can actually be anything. This patch adds support for three optional fields on load command yaml descriptions.
The new PayloadString YAML field is populated with the data after load commands known to have strings as extra data.
The new ZeroPadBytes YAML field is a count of zero'd bytes after the end of the load command structure before the next command. This can apply anywhere in the file. MachO2YAML verifies that bytes are zero before populating this field, and YAML2MachO will add zero'd bytes.
The new PayloadBytes YAML field stores all bytes after the end of the load command structure before the next command if they are non-zero. This is a catch all for all unhandled bytes. If MachO2Yaml populates PayloadBytes it will not populate ZeroPadBytes, instead zero'd bytes will be in the PayloadBytes structure.
llvm-svn: 270124
Many of the MachO load commands can have data appended after the command structure. This data is frequently strings, but can actually be anything. This patch adds support for three optional fields on load command yaml descriptions.
The new PayloadString YAML field is populated with the data after load commands known to have strings as extra data.
The new ZeroPadBytes YAML field is a count of zero'd bytes after the end of the load command structure before the next command. This can apply anywhere in the file. MachO2YAML verifies that bytes are zero before populating this field, and YAML2MachO will add zero'd bytes.
The new PayloadBytes YAML field stores all bytes after the end of the load command structure before the next command if they are non-zero. This is a catch all for all unhandled bytes. If MachO2Yaml populates PayloadBytes it will not populate ZeroPadBytes, instead zero'd bytes will be in the PayloadBytes structure.
llvm-svn: 270115
This adds support for all the MachO *_command structures. The load_command payloads still are not represented, but that will come next.
llvm-svn: 269808
This adds support for all the MachO *_command structures. The load_command payloads still are not represented, but that will come next.
llvm-svn: 269782
This patch adds basic support for MachO::load_command. Load command types and sizes are encoded in the YAML and expanded back into MachO.
The YAML doesn't yet support load command structs, that is coming next. In the meantime as a temporary measure when writing MachO files the load commands are padded with zeros so that the generated binary is valid.
llvm-svn: 269442
I've added the reserved field as an "optional" in YAML, but I've added asserts in the yaml2macho code to enforce that the field is present in mach_header_64, but not in mach_header.
llvm-svn: 269320
Since we want to be able to use yaml to describe degenerate object files as well as valid ones, we need to be explicit of some fields in your yaml definitions.
llvm-svn: 269313
Chris Bieneman