llvm-project/lld
Fangrui Song 92b5b980d2 [ELF] Postpone evaluation of ORIGIN/LENGTH in a MEMORY command
```
createFiles(args)
 readDefsym
 readerLinkerScript(*mb)
  ...
   readMemory
    readMemoryAssignment("ORIGIN", "org", "o") // eagerly evaluated
target = getTarget();
link(args)
 writeResult<ELFT>()
  ...
   finalizeSections()
    script->processSymbolAssignments()
     addSymbol(cmd) // with this patch, evaluated here
```

readMemoryAssignment eagerly evaluates ORIGIN/LENGTH and returns an uint64_t.
This patch postpones the evaluation to make

* --defsym and symbol assignments
* `CONSTANT(COMMONPAGESIZE)` (requires a non-null `lld:🧝:target`)

work. If the expression somehow requires interaction with memory
regions, the circular dependency may cause the expression to evaluate to
a strange value. See the new test added to memory-err.s

Reviewed By: grimar

Differential Revision: https://reviews.llvm.org/D75763
2020-03-09 08:31:41 -07:00
..
COFF [lld][ELF][COFF] Fix archived bitcode files naming 2020-03-04 12:46:31 +03:00
Common Make llvm::StringRef to std::string conversions explicit. 2020-01-28 23:25:25 +01:00
ELF [ELF] Postpone evaluation of ORIGIN/LENGTH in a MEMORY command 2020-03-09 08:31:41 -07:00
MinGW [lld] Replace SmallStr.str().str() with std::string conversion operator. 2020-01-29 21:30:21 -08:00
cmake/modules
docs fix typo 2020-03-02 21:01:50 -05:00
include/lld LLD already has a mechanism for caching creation of DWARCContext: 2020-03-06 21:17:07 +03:00
lib Make llvm::StringRef to std::string conversions explicit. 2020-01-28 23:25:25 +01:00
test [ELF] Postpone evaluation of ORIGIN/LENGTH in a MEMORY command 2020-03-09 08:31:41 -07:00
tools/lld Make it possible to redirect not only errs() but also outs() 2019-11-18 11:18:06 +09:00
unittests Make llvm::StringRef to std::string conversions explicit. 2020-01-28 23:25:25 +01:00
utils Python 2/3 compatibility 2019-03-20 07:42:13 +00:00
wasm [lld][WebAssembly] Add support for --rsp-quoting 2020-03-04 11:41:33 -08:00
.clang-format
.clang-tidy [lld] Add .clang-tidy to customize readability-identifier-naming.{Member,Parameter,Variable}Case => camelBack 2020-03-09 08:26:41 -07:00
.gitignore
CMakeLists.txt try to unbreak build after 4b6d9ac392 2020-01-16 10:12:35 -05:00
CODE_OWNERS.TXT
LICENSE.TXT Fix typos throughout the license files that somehow I and my reviewers 2019-01-21 09:52:34 +00:00
README.md

README.md

LLVM Linker (lld)

This directory and its subdirectories contain source code for the LLVM Linker, a modular cross platform linker which is built as part of the LLVM compiler infrastructure project.

lld is open source software. You may freely distribute it under the terms of the license agreement found in LICENSE.txt.

Benchmarking

In order to make sure various developers can evaluate patches over the same tests, we create a collection of self contained programs.

It is hosted at https://s3-us-west-2.amazonaws.com/linker-tests/lld-speed-test.tar.xz

The current sha256 is 10eec685463d5a8bbf08d77f4ca96282161d396c65bd97dc99dbde644a31610f.