llvm-svn: 202288

llvm-svn: 202287

If all input files are compatible with Structured Exception Handling, linker
is supposed to create an exectuable with a table for SEH handlers. The table
consists of exception handlers entry point addresses.

The basic idea of SEH in x86 Microsoft ABI is to list all valid entry points
of exception handlers in an read-only memory, so that an attacker cannot
override the addresses in it. In x86 ABI, data for exception handling is mostly
on stack, so it's volnerable to stack overflow attack. In order to protect
against it, Windows runtime uses the table to check a return address, to
ensure that the address is really an valid entry point for an exception handler.

Compiler emits a list of exception handler functions to .sxdata section. It
also emits a marker symbol "@feat.00" to indicate that the object is compatible
with SEH. SEH is a relatively new feature for COFF, and mixing SEH-compatible
and SEH-incompatible objects will result in an invalid executable, so is the
marker.

If all input files are compatible with SEH, LLD emits a SEH table. SEH table
needs to be pointed by Load Configuration strucutre, so when emitting a SEH
table LLD emits it too. The address of a Load Configuration will be stored to
the file header.

llvm-svn: 202248

[CMake] Use target_link_libraries(INTERFACE|PRIVATE) on CMake-2.8.12 to increase opportunity for parallel build.

target_link_libraries(INTERFACE) doesn't bring inter-target dependencies in add_library,
although final targets have dependencies to whole dependent libraries.
It makes most libraries can be built in parallel.

target_link_libraries(PRIVATE) is used to shaared library.
Each dependent library is linked to the target.so, and its user will not see its grandchildren.
For example,

  - libclang.so has sufficient libclang*.a(s).
  - c-index-test requires just only libclang.so.

FIXME: lld is tweaked minimally. Adding INTERFACE in each library would be better thing.
llvm-svn: 202241

For now, use both keywords, INTERFACE and PRIVATE via the variable,
  - ${cmake_2_8_12_INTERFACE}
  - ${cmake_2_8_12_PRIVATE}

They could be cleaned up when we introduce 2.8.12.

llvm-svn: 202239

Please give LLVMObject explicitly in each subdirectory if any of subdirectories required it.

llvm-svn: 202236

llvm-svn: 202235

llvm-svn: 202217

IMAGE_DLL_CHARACTERISTICS_NO_SEH flag should be set only when SEH is disabled.

llvm-svn: 202215

llvm-svn: 202166

llvm-svn: 202113

llvm-svn: 202111

llvm-svn: 202101

llvm-svn: 202100

This restores the debug output to how it was before r197727 broke it. This
went undetected because the corresponding test was never run due to broken
feature detection.

llvm-svn: 202079

llvm-svn: 202078

llvm-svn: 202054

llvm-svn: 202039

llvm-svn: 201970

[CMake] add_lld_library: link_system_libs is not needed any more. LLVMSupport may provide dependencies to system libs.

llvm-svn: 201967

LLD now prints an error message if /SAFESEH option is specified and one or
more input files are not compatible with SEH.

llvm-svn: 201900

Syntactically /SAFESEH is a boolean flag -- you can pass /SAFESEH or /SAFESEH:no.

The meaning of /SAFESEH is as follows.

 - If /SAFESEH is specified, the linker will produce an executable with SEH table.
   If any input files are not compatible with SEH, it's an error.
 - If /SAFESEH:no is specified, the linker will not emit SEH table even if all
   input files are compatible with SEH.
 - If no option is specified, the linker emits SEH table if all input files are
   compatible with SEH.

llvm-svn: 201895

llvm-svn: 201741

The sections .rela/.rel.(*) have a alignment of 2 in the final image created by
the linker. This needs to be properly set to the right alignment depending on
the architecture(32/64bits).

llvm-svn: 201740

line by line.

llvm-svn: 201133

llvm-svn: 201131

llvm-svn: 201129

llvm-svn: 201128

llvm-svn: 201109

llvm-svn: 200956

llvm-svn: 200911

undefined symbols to '.dynsym' if these symbols have corresponding entries
in a global part of GOT.

llvm-svn: 200716

llvm-svn: 200715

llvm-svn: 200712

This makes it a lot easier for Section Group design.

llvm-svn: 200675

llvm-svn: 200649

The patch reviewed by Shankar Easwaran and Rui Ueyama.

llvm-svn: 200630

llvm-svn: 200629

llvm-svn: 200599

The target machine type affects the meaning of other options, in particular
how to mangle symbols. So we want to handle the option first and then parse
all the other options.

llvm-svn: 200589