Dependent libraries support for the legacy api was committed in a
broken state (see: https://reviews.llvm.org/D60274). This was missed
due to the painful nature of having to integrate the changes into a
linker in order to test. This change implements support for dependent
libraries in the legacy LTO api:
- I have removed the current api function, which returns a single
string, and added functions to access each dependent library
specifier individually.
- To reduce the testing pain, I have made the api functions as thin as
possible to maximize coverage from llvm-lto.
- When doing ThinLTO the system linker will load the modules lazily
when scanning the input files. Unfortunately, when modules are
lazily loaded there is no access to module level named metadata. To
fix this I have added api functions that allow querying the IRSymtab
for the dependent libraries. I hope to expand the api in the future
so that, eventually, all the information needed by a client linker
during scan can be retrieved from the IRSymtab.
Differential Revision: https://reviews.llvm.org/D62935
llvm-svn: 363140
This patch implements a limited form of autolinking primarily designed to allow
either the --dependent-library compiler option, or "comment lib" pragmas (
https://docs.microsoft.com/en-us/cpp/preprocessor/comment-c-cpp?view=vs-2017) in
C/C++ e.g. #pragma comment(lib, "foo"), to cause an ELF linker to automatically
add the specified library to the link when processing the input file generated
by the compiler.
Currently this extension is unique to LLVM and LLD. However, care has been taken
to design this feature so that it could be supported by other ELF linkers.
The design goals were to provide:
- A simple linking model for developers to reason about.
- The ability to to override autolinking from the linker command line.
- Source code compatibility, where possible, with "comment lib" pragmas in other
environments (MSVC in particular).
Dependent library support is implemented differently for ELF platforms than on
the other platforms. Primarily this difference is that on ELF we pass the
dependent library specifiers directly to the linker without manipulating them.
This is in contrast to other platforms where they are mapped to a specific
linker option by the compiler. This difference is a result of the greater
variety of ELF linkers and the fact that ELF linkers tend to handle libraries in
a more complicated fashion than on other platforms. This forces us to defer
handling the specifiers to the linker.
In order to achieve a level of source code compatibility with other platforms
we have restricted this feature to work with libraries that meet the following
"reasonable" requirements:
1. There are no competing defined symbols in a given set of libraries, or
if they exist, the program owner doesn't care which is linked to their
program.
2. There may be circular dependencies between libraries.
The binary representation is a mergeable string section (SHF_MERGE,
SHF_STRINGS), called .deplibs, with custom type SHT_LLVM_DEPENDENT_LIBRARIES
(0x6fff4c04). The compiler forms this section by concatenating the arguments of
the "comment lib" pragmas and --dependent-library options in the order they are
encountered. Partial (-r, -Ur) links are handled by concatenating .deplibs
sections with the normal mergeable string section rules. As an example, #pragma
comment(lib, "foo") would result in:
.section ".deplibs","MS",@llvm_dependent_libraries,1
.asciz "foo"
For LTO, equivalent information to the contents of a the .deplibs section can be
retrieved by the LLD for bitcode input files.
LLD processes the dependent library specifiers in the following way:
1. Dependent libraries which are found from the specifiers in .deplibs sections
of relocatable object files are added when the linker decides to include that
file (which could itself be in a library) in the link. Dependent libraries
behave as if they were appended to the command line after all other options. As
a consequence the set of dependent libraries are searched last to resolve
symbols.
2. It is an error if a file cannot be found for a given specifier.
3. Any command line options in effect at the end of the command line parsing apply
to the dependent libraries, e.g. --whole-archive.
4. The linker tries to add a library or relocatable object file from each of the
strings in a .deplibs section by; first, handling the string as if it was
specified on the command line; second, by looking for the string in each of the
library search paths in turn; third, by looking for a lib<string>.a or
lib<string>.so (depending on the current mode of the linker) in each of the
library search paths.
5. A new command line option --no-dependent-libraries tells LLD to ignore the
dependent libraries.
Rationale for the above points:
1. Adding the dependent libraries last makes the process simple to understand
from a developers perspective. All linkers are able to implement this scheme.
2. Error-ing for libraries that are not found seems like better behavior than
failing the link during symbol resolution.
3. It seems useful for the user to be able to apply command line options which
will affect all of the dependent libraries. There is a potential problem of
surprise for developers, who might not realize that these options would apply
to these "invisible" input files; however, despite the potential for surprise,
this is easy for developers to reason about and gives developers the control
that they may require.
4. This algorithm takes into account all of the different ways that ELF linkers
find input files. The different search methods are tried by the linker in most
obvious to least obvious order.
5. I considered adding finer grained control over which dependent libraries were
ignored (e.g. MSVC has /nodefaultlib:<library>); however, I concluded that this
is not necessary: if finer control is required developers can fall back to using
the command line directly.
RFC thread: http://lists.llvm.org/pipermail/llvm-dev/2019-March/131004.html.
Differential Revision: https://reviews.llvm.org/D60274
llvm-svn: 360984
In C a function declaration with an empty argument list isn't a real
prototype, it will allow calling the function with any number of
arguments. It will also cause warnings when used in C code compiled with
'-Wstrict-prototypes'
Reviewed By: whitequark
Differential Revision: https://reviews.llvm.org/D61568
llvm-svn: 360012
Summary: There is still some value in using these functions while the remaining LLVMValueRef-based accessors are still around, but LLVMMDNodeInContext in particular has some wonky semantics that make it worth replacing outright.
Reviewers: whitequark, deadalnix
Reviewed By: whitequark
Subscribers: hiraditya, llvm-commits
Tags: #llvm
Differential Revision: https://reviews.llvm.org/D60524
llvm-svn: 359114
Summary:
Add accessors for the file, directory, source file name (curiously, an `Optional` value?), of a DIFile.
This is intended to replace the LLVMValueRef-based accessors used in D52239
Reviewers: whitequark, jberdine, deadalnix
Reviewed By: whitequark, jberdine
Subscribers: hiraditya, llvm-commits
Tags: #llvm
Differential Revision: https://reviews.llvm.org/D60489
llvm-svn: 358577
Summary: Metadata for a global variable is really a (GlobalVariable, Expression) tuple. Allow access to these, then allow retrieving the file, scope, and line for a DIVariable, whether global or local. This should be the last of the accessors required for uniform access to location and file information metadata.
Reviewers: jberdine, whitequark, deadalnix
Reviewed By: jberdine, whitequark
Subscribers: hiraditya, llvm-commits
Tags: #llvm
Differential Revision: https://reviews.llvm.org/D60725
llvm-svn: 358532
Summary: Deprecate the existing accessors for the "current debug location" of an IRBuilder. The setter could not handle being reset to NULL, and the getter would create bogus metadata if the NULL location was returned. Provide direct metadata-based accessors instead.
Reviewers: whitequark, deadalnix
Reviewed By: whitequark
Subscribers: hiraditya, llvm-commits
Tags: #llvm
Differential Revision: https://reviews.llvm.org/D60484
llvm-svn: 358039
Summary: Provide direct accessors to supplement LLVMSetInstDebugLocation. In addition, properly accept and return the NULL location. The old accessors provided no way to do this, so the current debug location cannot currently be cleared.
Reviewers: whitequark, deadalnix
Reviewed By: whitequark
Subscribers: hiraditya, llvm-commits
Tags: #llvm
Differential Revision: https://reviews.llvm.org/D60481
llvm-svn: 358038
Summary: This brings us to full feature parity with the old API, so I've deprecated it and updated the tests. I'll do a follow-up patch to do some more cleanup and documentation work in this header.
Reviewers: whitequark, deadalnix
Reviewed By: whitequark
Subscribers: hiraditya, llvm-commits
Tags: #llvm
Differential Revision: https://reviews.llvm.org/D60407
llvm-svn: 358037
COMMON blocks are a feature of Fortran that has no direct analog in C languages, but they are similar to data sections in assembly language programming. A COMMON block is a named area of memory that holds a collection of variables. Fortran subprograms may map the COMMON block memory area to their own, possibly distinct, non-empty list of variables. A Fortran COMMON block might look like the following example.
COMMON /ALPHA/ I, J
For this construct, the compiler generates a new scope-like DI construct (!DICommonBlock) into which variables (see I, J above) can be placed. As the common block implies a range of storage with global lifetime, the !DICommonBlock refers to a !DIGlobalVariable. The Fortran variable that comprise the COMMON block are also linked via metadata to offsets within the global variable that stands for the entire common block.
@alpha_ = common global %alphabytes_ zeroinitializer, align 64, !dbg !27, !dbg !30, !dbg !33!14 = distinct !DISubprogram(…)
!20 = distinct !DICommonBlock(scope: !14, declaration: !25, name: "alpha")
!25 = distinct !DIGlobalVariable(scope: !20, name: "common alpha", type: !24)
!27 = !DIGlobalVariableExpression(var: !25, expr: !DIExpression())
!29 = distinct !DIGlobalVariable(scope: !20, name: "i", file: !3, type: !28)
!30 = !DIGlobalVariableExpression(var: !29, expr: !DIExpression())
!31 = distinct !DIGlobalVariable(scope: !20, name: "j", file: !3, type: !28)
!32 = !DIExpression(DW_OP_plus_uconst, 4)
!33 = !DIGlobalVariableExpression(var: !31, expr: !32)
The DWARF generated for this is as follows.
DW_TAG_common_block:
DW_AT_name: alpha
DW_AT_location: @alpha_+0
DW_TAG_variable:
DW_AT_name: common alpha
DW_AT_type: array of 8 bytes
DW_AT_location: @alpha_+0
DW_TAG_variable:
DW_AT_name: i
DW_AT_type: integer*4
DW_AT_location: @Alpha+0
DW_TAG_variable:
DW_AT_name: j
DW_AT_type: integer*4
DW_AT_location: @Alpha+4
Patch by Eric Schweitz!
Differential Revision: https://reviews.llvm.org/D54327
llvm-svn: 357934
Summary: Add an accessor for the type of a binary file.
Reviewers: whitequark, deadalnix
Reviewed By: whitequark
Subscribers: hiraditya, aheejin, llvm-commits
Tags: #llvm
Differential Revision: https://reviews.llvm.org/D60366
llvm-svn: 357872
Summary:
Provides a new type, `LLVMBinaryRef`, and a binding to `llvm::object::createBinary` for more general interoperation with binary files than `LLVMObjectFileRef`. It also provides the proper non-consuming API for input buffers and populates an out parameter for error handling if necessary - two things the previous API did not do.
In a follow-up, I'll define section and symbol iterators and begin to build upon the existing test infrastructure.
This patch is a first step towards deprecating that API and replacing it with something more robust.
Reviewers: deadalnix, whitequark
Reviewed By: whitequark
Subscribers: hiraditya, llvm-commits
Tags: #llvm
Differential Revision: https://reviews.llvm.org/D60322
llvm-svn: 357822
Summary:
Now that we can create standalone basic blocks, it's useful to be able to append them. Add bindings to
- Insert a basic block after the current insertion block
- Append a basic block to the end of a function's list of basic blocks
Reviewers: whitequark, deadalnix, harlanhaskins
Reviewed By: whitequark, harlanhaskins
Subscribers: hiraditya, llvm-commits
Tags: #llvm
Differential Revision: https://reviews.llvm.org/D59658
llvm-svn: 357812
Summary: Add a binding to Function::lookupIntrinsicID so clients don't have to go searching the ID table themselves.
Reviewers: whitequark, deadalnix
Reviewed By: whitequark
Subscribers: hiraditya, llvm-commits
Tags: #llvm
Differential Revision: https://reviews.llvm.org/D59697
llvm-svn: 356948
Our minimum MSVC toolchain requirement is greater than 2015, so we don't
need this conditional macro anymore. New versions of MSVC apparently
have a header, xkeycheck.h, to check that keywords haven't been
redefined.
Fixes PR41144
llvm-svn: 356524
This adds a Remark class that allows us to share code when working with
remarks.
The C API has been updated to reflect this. Instead of the parser
generating C structs, it's now using a C++ object that is used through
opaque pointers in C. This gives us much more flexibility on what
changes we can make to the internal state of the object and interacts
much better with scenarios where the library is used through dlopen.
* C API updates:
* move from C structs to opaque pointers and functions
* the remark type is now an enum instead of a string
* unit tests updates:
* use mostly the C++ API
* keep one test for the C API
* rename to YAMLRemarksParsingTest
* a typo was fixed: AnalysisFPCompute -> AnalysisFPCommute.
* a new error message was added: "expected a remark tag."
* llvm-opt-report has been updated to use the C++ parser instead of the
C API
Differential Revision: https://reviews.llvm.org/D59049
Original llvm-svn: 356491
llvm-svn: 356519
This adds a Remark class that allows us to share code when working with
remarks.
The C API has been updated to reflect this. Instead of the parser
generating C structs, it's now using a C++ object that is used through
opaque pointers in C. This gives us much more flexibility on what
changes we can make to the internal state of the object and interacts
much better with scenarios where the library is used through dlopen.
* C API updates:
* move from C structs to opaque pointers and functions
* the remark type is now an enum instead of a string
* unit tests updates:
* use mostly the C++ API
* keep one test for the C API
* rename to YAMLRemarksParsingTest
* a typo was fixed: AnalysisFPCompute -> AnalysisFPCommute.
* a new error message was added: "expected a remark tag."
* llvm-opt-report has been updated to use the C++ parser instead of the
C API
Differential Revision: https://reviews.llvm.org/D59049
llvm-svn: 356491
Moving subprogram specific flags into DISPFlags makes IR code more readable.
In addition, we provide free space in DIFlags for other
'non-subprogram-specific' debug info flags.
Patch by Djordje Todorovic.
Differential Revision: https://reviews.llvm.org/D59288
llvm-svn: 356454
Summary: Add bindings to create a wrapped "Add Discriminators" pass. Now that we have debug info support, this is a handy transform to have.
Reviewers: whitequark, deadalnix
Reviewed By: whitequark
Subscribers: dblaikie, aprantl, hiraditya, llvm-commits
Tags: #llvm
Differential Revision: https://reviews.llvm.org/D58624
llvm-svn: 356272
Getting rid of the name "optimization remarks" for anything that
involves handling remarks on the client side.
It's safer to do this now, before we get stuck with that name in all the
APIs and public interfaces we decide to export to users in the future.
This renames llvm/tools/opt-remarks to llvm/tools/remarks-shlib, and now
generates `libRemarks.dylib` instead of `libOptRemarks.dylib`.
Differential Revision: https://reviews.llvm.org/D58535
llvm-svn: 355439
Summary: The C API don't have the bindings to create enumerators, needed to create an enumeration.
Reviewers: whitequark, CodaFi, harlanhaskins, deadalnix
Reviewed By: whitequark, CodaFi, harlanhaskins
Subscribers: hiraditya, llvm-commits
Tags: #llvm
Differential Revision: https://reviews.llvm.org/D58323
llvm-svn: 354237
This patch accompanies the RFC posted here:
http://lists.llvm.org/pipermail/llvm-dev/2018-October/127239.html
This patch adds a new CallBr IR instruction to support asm-goto
inline assembly like gcc as used by the linux kernel. This
instruction is both a call instruction and a terminator
instruction with multiple successors. Only inline assembly
usage is supported today.
This also adds a new INLINEASM_BR opcode to SelectionDAG and
MachineIR to represent an INLINEASM block that is also
considered a terminator instruction.
There will likely be more bug fixes and optimizations to follow
this, but we felt it had reached a point where we would like to
switch to an incremental development model.
Patch by Craig Topper, Alexander Ivchenko, Mikhail Dvoretckii
Differential Revision: https://reviews.llvm.org/D53765
llvm-svn: 353563
Summary:
Adds the standard gauntlet of accessors for global indirect functions and updates the echo test.
Now it would be nice to have a target abstraction so one could know if they have access to a suitable ELF linker and runtime.
Reviewers: whitequark, deadalnix
Reviewed By: whitequark
Subscribers: llvm-commits
Differential Revision: https://reviews.llvm.org/D56177
llvm-svn: 353193
to reflect the new license.
We understand that people may be surprised that we're moving the header
entirely to discuss the new license. We checked this carefully with the
Foundation's lawyer and we believe this is the correct approach.
Essentially, all code in the project is now made available by the LLVM
project under our new license, so you will see that the license headers
include that license only. Some of our contributors have contributed
code under our old license, and accordingly, we have retained a copy of
our old license notice in the top-level files in each project and
repository.
llvm-svn: 351636
consistently accept a pointee-type argument.
Note: this also adds a new C API and soft-deprecates the old C API.
Differential Revision: https://reviews.llvm.org/D56559
llvm-svn: 351124
accept a return-type argument.
Note: this also adds a new C API and soft-deprecates the old C API.
Differential Revision: https://reviews.llvm.org/D56558
llvm-svn: 351123
accept a callee-type argument.
Note: this also adds a new C API and soft-deprecates the old C API.
Differential Revision: https://reviews.llvm.org/D56557
llvm-svn: 351122
accept a callee-type argument.
Note: this also adds a new C API and soft-deprecates the old C API.
Differential Revision: https://reviews.llvm.org/D56556
llvm-svn: 351121
Normally, changing the function signatures of C APIs is disallowed,
but as these two are brand new last week, and haven't been released
yet, it is okay in this instance.
As per discussion in D56556, we will not add NameLen arguments to IR
building APIs, for the following reasons:
1. We do not want to deprecate all of the IR building APIs, just to add a
NameLen argument to each one.
2. Consistency is important, so adding it just to new ones is unfortunate.
3. The IR names are completely optional, useful for readability of IR
only. There is no value in ever supporting nul bytes.
Differential Revision: https://reviews.llvm.org/D56669
llvm-svn: 351076
Summary: Add a utility function for creating a basic block without a parent function. A useful operation for compilers that need to synthesize and conditionally insert code without having to bother with appending and immediately unlinking a block.
Reviewers: whitequark, deadalnix
Reviewed By: whitequark
Subscribers: llvm-commits
Differential Revision: https://reviews.llvm.org/D56279
llvm-svn: 350608
Summary: Fix an old outstanding problem with the int cast builder binding always assuming the cast is signed by introducing a new LLVMBuildIntCast2 operation and deprecating the old prototype.
Reviewers: whitequark, deadalnix
Reviewed By: whitequark
Subscribers: llvm-commits
Differential Revision: https://reviews.llvm.org/D56280
llvm-svn: 350607
Summary: Add read[only|write] PIC relocation models to the C API and teach the TargetMachine API about it.
Reviewers: whitequark, deadalnix
Reviewed By: whitequark
Subscribers: llvm-commits
Differential Revision: https://reviews.llvm.org/D56187
llvm-svn: 350279
Summary: Add accessors so the performance improvement from this setting is accessible to third parties.
Reviewers: whitequark, deadalnix
Reviewed By: whitequark
Subscribers: llvm-commits
Differential Revision: https://reviews.llvm.org/D56179
llvm-svn: 350196
The IEEE-754 Standard makes it clear that fneg(x) and
fsub(-0.0, x) are two different operations. The former is a bitwise
operation, while the latter is an arithmetic operation. This patch
creates a dedicated FNeg IR Instruction to model that behavior.
Differential Revision: https://reviews.llvm.org/D53877
llvm-svn: 346774
Summary:
Improve the intrinsic bindings with operations for
- Retrieving and automatically inserting the declaration of an intrinsic by ID
- Retrieving the name of a non-overloaded intrinsic by ID
- Retrieving the name of an overloaded intrinsic by ID and overloaded parameter types
Improve the echo test to copy non-overloaded intrinsics by ID.
Reviewers: whitequark, deadalnix
Reviewed By: whitequark
Subscribers: llvm-commits
Differential Revision: https://reviews.llvm.org/D53626
llvm-svn: 346195
* Create an install target for it
* Add it under tools/opt-remarks
* Add an export file for the dylib
* Install the llvm-c/OptRemarks.h header
* Add an API to query its version
rdar://45458839
llvm-svn: 346127
Declaration and definition have slightly different names with a typo in the
declaration, which leads to a link error.
See the following bug report for more details: https://bugs.llvm.org/show_bug.cgi?id=39523
llvm-svn: 345960
This updates the C API for the removal of `TerminatorInst`. It converts
the type query to a predicate query and moves the generic methods to
work on `Instruction` instances that satisfy this predicate rather than
requiring a specific type. It also clarifies that the C API wrapping
`BasicBlock::getTerminator` just returns an `Instruction`. Because this
was always wrapped opaquely as a value and the functions consuming these
values will work on `Instruction` objects, this shouldn't break any
clients.
This is a completely compatible change to the C API.
Differential Revision: https://reviews.llvm.org/D52968
llvm-svn: 344764
Add thin shims to C interface to provide access to DebugLoc info for
Instructions, GlobalVariables and Functions. Patch by Josh Berdine!
llvm-svn: 344202
Ben Dunbobbin