Commit Graph

282 Commits

Author SHA1 Message Date
Eugene Leviant f9bc3bd2cf [ELF] Ignore .interp section in case linker script specifies PHDRS without PT_INTERP
llvm-svn: 278781
2016-08-16 06:40:58 +00:00
George Rimar 06ae683620 [ELF] - Linkerscript: reimplemented output sections constrains matching functionality.
Previously filtering that was used worked incorrectly. 
For example for next script it would just remove both sections completely:

SECTIONS { 
. = 0x1000;
.aaa : ONLY_IF_RW { *(.aaa.*) } 
. = 0x2000;
.aaa : ONLY_IF_RO { *(.aaa.*) } 
}

Patch fixes above issues and adds testcase showing the issue. Testcase is a subset of
FreeBSD script which has:

.eh_frame       : ONLY_IF_RO { KEEP (*(.eh_frame)) }
...
.eh_frame       : ONLY_IF_RW { KEEP (*(.eh_frame)) }

Differential revision: https://reviews.llvm.org/D23326

llvm-svn: 278486
2016-08-12 09:07:57 +00:00
Rui Ueyama 4f7500bfc2 Rename getSizeOfHeaders -> getHeaderSize.
We have getSectionSize for SIZEOF command. So, I think
getHeaderSize is a better name for SIZEOF_HEADERS.

llvm-svn: 278470
2016-08-12 04:00:22 +00:00
Rui Ueyama 0b9ce6a48a Create only one section for a name in LinkerScript.
Previously, we created two or more output sections if there are
input sections with the same name but with different attributes.
That is a wrong behavior. This patch fixes the issue.

One thing we need to do is to merge output section attributes.
Currently, we create an output section based on the first input
section's attributes. This may make a wrong output section
attributes. What we need to do is to bitwise-OR attributes.
We'll do it in a follow-up patch.

llvm-svn: 278461
2016-08-12 03:16:56 +00:00
Rui Ueyama f34d0e0875 Allocate LayoutInputSections using SpecificBumpPtrAllocator.
llvm-svn: 278453
2016-08-12 01:24:53 +00:00
Rui Ueyama 48c3f1cebc Split LinkerScript<ELFT>::createSections.
Also avoid to use a lambda that is called only once.

llvm-svn: 278445
2016-08-12 00:27:23 +00:00
Eugene Leviant ceabe80e97 [ELF] Symbol assignment within output section description
llvm-svn: 278322
2016-08-11 07:56:43 +00:00
George Rimar e32a3598bc [ELF] - Linkerscript: implement SIZEOF_HEADERS.
SIZEOF_HEADERS - Return the size in bytes of the output file’s headers.

It is is a feature used in FreeBsd script, for example.
There is a discussion on PR28688 page about it.

Differential revision: https://reviews.llvm.org/D23165

llvm-svn: 278204
2016-08-10 07:59:34 +00:00
Rui Ueyama 742c38361b Split InputSectionDescription::Sort into SortInner and SortOuter.
Summary:
The comparator function to compare input sections as instructed by
SORT command was a bit too complicated because it needed to handle
four different cases. This patch split it into two function calls.

This patch also simplifies the parser.

Reviewers: grimar

Subscribers: llvm-commits

Differential Revision: https://reviews.llvm.org/D23140

llvm-svn: 277780
2016-08-04 22:27:00 +00:00
Rafael Espindola a4b41dca31 Remove redundant argument.
But always set Script<ELFT>::X->OutputSections.

llvm-svn: 277720
2016-08-04 12:13:05 +00:00
George Rimar eefa758ee2 [ELF] - Linkerscript: implemented ASSERT() keyword.
ASSERT(exp, message)
Ensure that exp is non-zero. If it is zero, then exit the linker with an error
code, and print message.

ASSERT is useful and was seen in few projects in the wild.

Differential revision: https://reviews.llvm.org/D22912

llvm-svn: 277710
2016-08-04 09:29:31 +00:00
Nico Weber 2e36772caf Revert 277594, it caused PR28827
llvm-svn: 277599
2016-08-03 14:37:57 +00:00
Rafael Espindola a348532ec3 Remove redundant argument.
llvm-svn: 277594
2016-08-03 13:21:16 +00:00
George Rimar 350ece4efb [ELF] - Linkerscript: support all kinds of sorting (including nested).
Previously we supported only sorting by name.

When there are nested section sorting commands in linker script, there can be at most 1
level of nesting for section sorting commands.

SORT_BY_NAME (SORT_BY_ALIGNMENT (wildcard section pattern)). It will sort the input
sections by name first, then by alignment if 2 sections have the same name.

SORT_BY_ALIGNMENT (SORT_BY_NAME (wildcard section pattern)). It will sort the input
sections by alignment first, then by name if 2 sections have the same alignment.

SORT_BY_NAME (SORT_BY_NAME (wildcard section pattern)) is treated the same as SORT_
BY_NAME (wildcard section pattern).

SORT_BY_ALIGNMENT (SORT_BY_ALIGNMENT (wildcard section pattern)) is treated the
same as SORT_BY_ALIGNMENT (wildcard section pattern).

All other nested section sorting commands are invalid.

Patch implements that all above.

Differential revision: https://reviews.llvm.org/D23019

llvm-svn: 277583
2016-08-03 08:35:59 +00:00
George Rimar 9e69450ec7 [ELF] - Linkerscript: implemented SIZEOF(section)
SIZEOF(section)
Return the size in bytes of the named section, if that section has been allocated.

SIZEOF(section) often used in scripts. Few examples from the wild:
https://github.com/chipKIT32/pic32-Arduino-USB-Bootloader-original/blob/master/boot-linkerscript.ld
https://github.com/devkitPro/buildscripts/blob/master/dkarm-eabi/crtls/gba_cart.ld

Patch implements it.

Differential revision: https://reviews.llvm.org/D22915

llvm-svn: 277165
2016-07-29 16:18:47 +00:00
Rui Ueyama 1acefcd11e Remove dead declaration.
llvm-svn: 277159
2016-07-29 16:08:04 +00:00
George Rimar 0702c4e86e [ELF] - Linkerscript: Implemented SORT command.
When the SORT keyword is used, the linker will sort the files or sections into ascending order by name before placing them in the output file.
It is used in FreeBSD script:
https://svnweb.freebsd.org/base/head/sys/conf/ldscript.amd64?revision=284870&view=markup#l139

This is PR28689.

Differential revision: https://reviews.llvm.org/D22749

llvm-svn: 277153
2016-07-29 15:32:46 +00:00
Rui Ueyama 202042439c Add comments.
llvm-svn: 277116
2016-07-29 05:52:33 +00:00
Rui Ueyama 8d083e6a0a Remove `Ignore` flag from SymbolAssignment class.
Previously, Ignore flag is set if we don't want to assign
a value to symbols. It happens if a symbol assingment is in
PROVIDE() and there's already a symbol with the same name.

The previous code had a subtle but that we assume that the
existing symbol is an absolute symbol even if it is not.
This patch fixes the issue by always overwriting an absolute
symbol.

llvm-svn: 277115
2016-07-29 05:48:39 +00:00
Rui Ueyama 3de0a3308b Rename DoLayout -> HasContents. NFC.
llvm-svn: 277102
2016-07-29 03:31:09 +00:00
George Rimar 0659800ef0 [ELF] - Linkerscript: implemented filename specification.
Scripts can contain something like:
KEEP (*crtbegin.o(.ctors))

What means that "*crtbegin.o" is a wildcard of file to take the sections from.
This is some kind of opposite to EXCLUDE_FILE and used in FreeBSD script:
https://svnweb.freebsd.org/base/head/sys/conf/ldscript.amd64?revision=284870&view=markup#l122

Patch implements this.

Differential revision: https://reviews.llvm.org/D22852

llvm-svn: 277042
2016-07-28 21:51:30 +00:00
Rui Ueyama ad10c3d8d4 Make CommonInputSection singleton class.
All other singleton instances are accessible globally.
CommonInputSection shouldn't be an exception.

Differential Revision: https://reviews.llvm.org/D22935

llvm-svn: 277034
2016-07-28 21:05:04 +00:00
Eugene Leviant 3e6b027705 [ELF] Allows setting section for common symbols in linker script
llvm-svn: 277023
2016-07-28 19:24:13 +00:00
Davide Italiano e7282797aa [ELF/LinkerScript] Support EXCLUDE_FILE inside KEEP.
Differential Revision:	https://reviews.llvm.org/D22795

llvm-svn: 276825
2016-07-27 01:44:01 +00:00
George Rimar 630c617912 [ELF] - Linkerscript: implemented ALIGN modificatior of output sections.
Output section description can contain ALIGN modificator:
https://sourceware.org/binutils/docs/ld/Output-Section-Description.html#Output-Section-Description

Patch implements it.

Differential revision: https://reviews.llvm.org/D22674

llvm-svn: 276780
2016-07-26 18:06:29 +00:00
Rui Ueyama 29c5a2a9b7 Split getPhdrsIndices. NFC.
llvm-svn: 276717
2016-07-26 00:27:36 +00:00
Rui Ueyama 6b2748104b Split LinkerScript::createSections into small functions.
createSections function is getting longer, so it is time to split it
into small functions. The reason why the function is long is because
it has deeply nested for-loops. This patch constructs temporary data
to reduce nesting level.

Differential Revision: https://reviews.llvm.org/D22786

llvm-svn: 276706
2016-07-25 22:51:07 +00:00
Rui Ueyama efc4066b47 Make ConstraintKind an enum class.
llvm-svn: 276697
2016-07-25 22:00:10 +00:00
Rui Ueyama 3c291e1aa2 Re-commit "Split LinkerScript::createSections".
Re-commit r276543 with a fix for buildbots.

llvm-svn: 276693
2016-07-25 21:30:00 +00:00
George Rimar 58e5c4dcfe [ELF] - Linkerscript: implemented output section [address] attribute.
Output section description in SECTIONS looks like that:

section [address] [(type)] :
...
{
...
}

Patch implements support of address atribute.

Differential revision: https://reviews.llvm.org/D22689

llvm-svn: 276619
2016-07-25 08:29:46 +00:00
Rui Ueyama edebbdf12a Simplify. NFC.
llvm-svn: 276586
2016-07-24 23:47:31 +00:00
Rui Ueyama 708019c41b Make readExpr return an Expr object instead of a vector of tokens.
Previously, we handled an expression as a vector of tokens. In other
words, an expression was a vector of uncooked raw StringRefs.
When we need a value of an expression, we used ExprParser to run
the expression.

The separation was needed essentially because parse time is too
early to evaluate an expression. In order to evaluate an expression,
we need to finalize section sizes. Because linker script parsing
is done at very early stage of the linking process, we can't
evaluate expressions while parsing.

The above mechanism worked fairly well, but there were a few
drawbacks.

One thing is that we sometimes have to parse the same expression
more than once in order to find the end of the expression.
In some contexts, linker script expressions have no clear end marker.
So, we needed to recognize balanced expressions and ternary operators.

The other is poor error reporting. Since expressions are parsed
basically twice, and some information that is available at the first
stage is lost in the second stage, it was hard to print out
apprpriate error messages.

This patch fixes the issues with a new approach.

Now the expression parsing is integrated into ScriptParser.
ExprParser class is removed. Expressions are represented as lambdas
instead of vectors of tokens. Lambdas captures information they
need to run themselves when they are created.

In this way, ends of expressions are naturally detected, and
errors are handled in the usual way. This patch also reduces
the amount of code.

Differential Revision: https://reviews.llvm.org/D22728

llvm-svn: 276574
2016-07-24 18:19:40 +00:00
Rui Ueyama 8a9bb7baeb Rollback r276538 and r276540 to unbreak asan bot.
llvm-svn: 276543
2016-07-24 02:05:09 +00:00
Rui Ueyama 01151e9c24 Split LinkerScript::createSections.
createSections is getting longer, so it is probably time to split.

Differential Revision: https://reviews.llvm.org/D22730

llvm-svn: 276538
2016-07-24 01:06:18 +00:00
Rui Ueyama adca245f79 Remove Phdr typedef.
I don't think this typedef contributes to readability.

llvm-svn: 276525
2016-07-23 14:18:48 +00:00
Rui Ueyama 36a153cd83 Make a pure function a non-member file-scoped function.
llvm-svn: 276524
2016-07-23 14:09:58 +00:00
Eugene Leviant a31c91b150 [ELF] Support PROVIDE and PROVIDE_HIDDEN inside SECTIONS
llvm-svn: 276398
2016-07-22 07:38:40 +00:00
Davide Italiano 246f681e0b [ELF/LinkerScript] Support ONLY_IF_{RO, RW} directive.
Differential Revision:   https://reviews.llvm.org/D22660

llvm-svn: 276384
2016-07-22 03:36:24 +00:00
George Rimar 10e576e109 [ELF] - Cleanup of LinkerScript<ELFT>::assignAddresses()
LinkerScript<ELFT>::assignAddresses is becoming larger and looks 
it can be good time for splitting. I expect to can more SectionsCommand's there, 
and dispatching some of them separatelly can help to keep method smaller either.

Differential revision: https://reviews.llvm.org/D22506

llvm-svn: 276300
2016-07-21 16:07:40 +00:00
George Rimar eea3114ff9 [ELF] - Linkerscript: add InputSectionDescription command to LS parser.
This adds InputSectionDescription command to represent
the input section declaration.

This leads to next cleanup:
SectionRule removed.
ScriptConfiguration::Sections mamber removed.
LinkerScript<ELFT>::getOutputSection() removed.

Differential revision: https://reviews.llvm.org/D22617

llvm-svn: 276283
2016-07-21 14:26:59 +00:00
Eugene Leviant 865bf8637b [ELF] Support FLAGS attribute in program header definition
llvm-svn: 276260
2016-07-21 10:43:25 +00:00
George Rimar f6c3ccef5e [ELF] - Linkerscript: remove excessive ScriptConfiguration::Filler field
Previously OutputSectionCommand::Filler was introduced, but unused.
Patch fixes that.

Differential revision: https://reviews.llvm.org/D22615

llvm-svn: 276253
2016-07-21 07:48:54 +00:00
George Rimar 076fe15757 [ELF] - Initial support of tree-style linker script implemented.
Approach uses LLVM-style RTTI for representing the linker script
commands in a form of tree for future simplification of parsing.

Core idea and code sample belongs to Rui Ueyama.

Differential revision: https://reviews.llvm.org/D22604

llvm-svn: 276243
2016-07-21 06:43:01 +00:00
Rui Ueyama a7f7884df8 Simplify output section ownership.
This patch simplifies output section management by making
Factory class have ownership of sections that creates.

Differential Revision: https://reviews.llvm.org/D22575

llvm-svn: 276141
2016-07-20 17:19:03 +00:00
George Rimar 70ce0a9f74 Removed trailing whitespaces. NFC.
llvm-svn: 276126
2016-07-20 15:09:10 +00:00
Eugene Leviant e63d81bd05 [ELF] Create output sections in LinkerScript class
llvm-svn: 276121
2016-07-20 14:43:20 +00:00
Rafael Espindola 74df5c7eeb Fix build with gcc 6.
llvm-svn: 275972
2016-07-19 12:33:46 +00:00
Eugene Leviant bbe3860244 [ELF] Minimal PHDRS parser and section to segment assignment support
llvm-svn: 275965
2016-07-19 09:25:43 +00:00
Rui Ueyama 05ef4cff44 Merge SymbolAssignmentKind and ExprKind.
In a linker script, `.` is a special symbol indicating a counter.
Previously, we had two expression types, ExprKind and SymbolAssignmentKind
for `.` and all the other symbol names, respectively. But we could merge
them because the former is a special case of the latter.

llvm-svn: 275527
2016-07-15 04:19:37 +00:00
Eugene Leviant eda81a1b86 [ELF] Support for symbol assignment in linker scripts within SECTIONS {} block
llvm-svn: 275158
2016-07-12 06:39:48 +00:00
Rui Ueyama 93c9af425e Create Strings.cpp and move string manipulation functions to that file.
llvm-svn: 274109
2016-06-29 08:01:32 +00:00
Rui Ueyama 722830a51b Rename matchStr -> globMatch.
llvm-svn: 274103
2016-06-29 05:32:09 +00:00
Davide Italiano 8e1131dc46 [ELF] Support for wildcard in version scripts.
Example:

VERSION_1.0 {
  global: foo*;
  local: *; }

now correctly matches all the symbols which name starts with
`foo`.

Differential Revision:  http://reviews.llvm.org/D21732

llvm-svn: 274091
2016-06-29 02:46:51 +00:00
George Rimar 5ed31e2f58 Removed another dead code. NFC.
llvm-svn: 268505
2016-05-04 15:04:08 +00:00
George Rimar 1a4f89ab0a [ELF] - Removed dead declarations. NFC.
llvm-svn: 267381
2016-04-25 08:08:54 +00:00
Rui Ueyama 0b3868ec6b Move uintX_t typedef to the class definition. NFC.
Now it is doable because LinkerScript is a template class.

llvm-svn: 267212
2016-04-22 20:41:07 +00:00
George Rimar fba45c41df Recommitted r267132 "[ELF] - implemented ternary operator for linkerscript expressions"
With fix: removed redundant Dot parameter.

Original commit message:
[ELF] - implemented ternary operator for linkerscript expressions

Patch implements ternary operator for linkerscript expressions.
Like:

SECTIONS {
 . = 0x1 ? 0x2 : 0x3;
...
}

Differential revision: http://reviews.llvm.org/D19332

llvm-svn: 267140
2016-04-22 11:28:54 +00:00
George Rimar f8e230b277 Revert r267132 as it broke buildbot.
llvm-svn: 267134
2016-04-22 10:51:34 +00:00
George Rimar 8c4acddebc [ELF] - implemented ternary operator for linkerscript expressions
Patch implements ternary operator for linkerscript expressions.
Like:

SECTIONS {
 . = 0x1 ? 0x2 : 0x3;
...
}

Differential revision: http://reviews.llvm.org/D19332

llvm-svn: 267132
2016-04-22 10:35:34 +00:00
Rui Ueyama c9f402eadc Inline SectionRule::match.
This short function was used only once and didn't provide much value.

llvm-svn: 267086
2016-04-22 00:23:52 +00:00
Rui Ueyama c998a8c044 ELF: Make the special variable "." as a LinkerScript class member.
I will eventually make `evaluate` function a usual parse function
rather than a function that works on a separate token list.
This is the first step toward that.

llvm-svn: 267083
2016-04-22 00:03:13 +00:00
Rui Ueyama 8ec77e64fc ELF: Change how to handle KEEP linker script command.
You can instruct the linker to not discard sections even if they
are unused and --gc-sections option is given. The linker script
command for doing that is KEEP. The syntax is KEEP(foo) where foo
is a section name. KEEP commands are written in SECTIONS command,
so you can specify the order of sections *and* which sections
will be kept.

Each sub-command in SECTIONS command are translated into SectionRule
object. Previously, each SectionRule has `Keep` bit. However,
if you think about it, this hid information in too deep in elements
of a list. Semantically, KEEP commands aren't really related to
SECTIONS subcommands. We can keep the section list for KEEP in a
separate list. This patch does that.

llvm-svn: 267065
2016-04-21 22:00:51 +00:00
Rui Ueyama c3e2a4b006 ELF: Change the return type of getSectionOrder.
Also changed the function name and added comments.

llvm-svn: 267044
2016-04-21 20:30:00 +00:00
George Rimar 72ab8481fa [ELF] - Make LinkerScript::getSectionOrder private. NFC.
llvm-svn: 266979
2016-04-21 11:28:11 +00:00
George Rimar dbbd8b15bf [ELF] - Use ArrayRef instead of std::vector& for LinkerScript module. NFC.
llvm-svn: 266978
2016-04-21 11:21:48 +00:00
George Rimar 71b26e94fd [ELF] - Get rid of SectionOrder array.
SectionOrder vector was a part of LinkerScript class.

It can be removed because Commands vector contains the 
same information and SectiorOrder is just a subset.

Differential revision: http://reviews.llvm.org/D19171

llvm-svn: 266974
2016-04-21 10:22:02 +00:00
Rui Ueyama 07320e4030 ELF: Template LinkerScript class.
Originally, linker scripts were basically an alternative way to specify
options to the command line options. But as we add more features to hanlde
symbols and sections, many member functions needed to be templated.
Now most the members are templated. It is probably time to template the
entire class.

Previously, LinkerScript is an executor of the linker script as well as
a storage of linker script configurations. This is not suitable to template
the class because when we are reading linker script files, we don't know
the ELF type yet, so we can't instantiate ELF-templated classes.

In this patch, I defined a new class, ScriptConfiguration, to store
linker script configurations. ScriptParser writes parse results to it,
and LinkerScript uses them.

Differential Revision: http://reviews.llvm.org/D19302

llvm-svn: 266908
2016-04-20 20:13:41 +00:00
Rui Ueyama 960504b91d ELF: Add +, -, *, / and & to SECTIONS linker script command.
This patch is based heavily on George Rimor's patch
http://reviews.llvm.org/D19221.

In the linker script, you can write expressions to compute addresses.
Currently we only support "+" operator. This adds a few more operators.

Since this patch adds * and /, we need to handle operator precedences
properly. I implemented that using the operator-precedence grammar.

Differential Revision: http://reviews.llvm.org/D19237

llvm-svn: 266798
2016-04-19 18:58:11 +00:00
George Rimar a3ab1091d1 Updated comment. NFC.
llvm-svn: 266727
2016-04-19 12:09:25 +00:00
Rui Ueyama 9e957a0ac6 Rename LocationNode -> SectionsCommand.
They are called sections-command in the doc, so it is nice to keep
it consistent with it.
https://sourceware.org/binutils/docs/ld/SECTIONS.html#SECTIONS

llvm-svn: 266668
2016-04-18 21:00:45 +00:00
Rui Ueyama 7c18c28c97 Refactor LinkerScript::assignAddresses. NFC.
llvm-svn: 266666
2016-04-18 21:00:40 +00:00
George Rimar 652852c5c0 Recommitted 266457 with fix:
* Do script driven layout only if SECTIONS section exist.

Initial commit message:

[ELF] - Implemented basic location counter support.

This patch implements location counter support. 
It also separates assign addresses for sections to assignAddressesScript() if it scipt exists.

Main testcase is test/ELF/linkerscript-locationcounter.s, It contains some work with location counter. It is basic now.
Implemented location counter assignment and '+' operations.

Patch by myself with LOTS of comments and design suggestions from Rui Ueyama.

Differential revision: http://reviews.llvm.org/D18499

llvm-svn: 266526
2016-04-16 10:10:32 +00:00
Rui Ueyama faac567e68 Revert r266457: "[ELF] - Implemented basic location counter support."
This reverts commit r266457 as it breaks "hello world" both on
Linux and FreeBSD.

llvm-svn: 266485
2016-04-15 22:39:27 +00:00
George Rimar ea25877d4a [ELF] - Implemented basic location counter support.
This patch implements location counter support. 
It also separates assign addresses for sections to assignAddressesScript() if it scipt exists.

Main testcase is test/ELF/linkerscript-locationcounter.s, It contains some work with location counter. It is basic now.
Implemented location counter assignment and '+' operations.

Patch by myself with LOTS of comments and design suggestions from Rui Ueyama.

Differential revision: http://reviews.llvm.org/D18499

llvm-svn: 266457
2016-04-15 17:44:19 +00:00
Rui Ueyama 3e80897627 ELF: Remove OutSection class and use a map instead.
It is easier to handle section filler data separately rather than
merging with section names.

llvm-svn: 262175
2016-02-28 05:09:11 +00:00
Rafael Espindola e0df00b91f Rename elf2 to elf.
llvm-svn: 262159
2016-02-28 00:25:54 +00:00
George Rimar e2ee72b509 [ELF] - Implemented linkerscript sections padding.
BSD linker scripts contain special cases to add NOP
padding to code sections. Syntax is next:

.init:
 {
   KEEP (*(.init))
 } =0x90909090
(0x90 is NOP)

This patch implements that functionality.

llvm-svn: 262020
2016-02-26 14:48:31 +00:00
George Rimar 481c2ce64b [ELF] - Linkerscript KEEP command.
When link-time garbage collection is in use (-gc-sections), it is 
often useful to mark sections that should not be eliminated. 
This is accomplished by surrounding an input section's wildcard 
entry with KEEP(). Patch implements that command.

Differential revision: http://reviews.llvm.org/D17242

llvm-svn: 261616
2016-02-23 07:47:54 +00:00
Rui Ueyama 1ebc8ed78a ELF: Add wildcard pattern matching to SECTIONS linker script command.
Each rule in SECTIONS commands is something like ".foo *(.baz.*)",
which instructs the linker to collect all sections whose name matches
".baz.*" from all files and put them into .foo section.

Previously, we didn't recognize the wildcard character. This patch
adds that feature.

Performance impact is a bit concerning because a linker script can
contain hundreds of SECTIONS rules, and doing pattern matching against
each rule would be too expensive. We could merge all patterns into
single DFA so that it takes O(n) to the input size. However, it is
probably too much at this moment -- we don't know whether the
performance of pattern matching matters or not. So I chose to
implement the simplest algorithm in this patch. I hope this simple
pattern matcher is sufficient.

llvm-svn: 260745
2016-02-12 21:47:28 +00:00
Rui Ueyama e9c5806593 ELF: Remove use of MapVector from LinkerScript.
We don't have to use a MapVector here. Instead, just std::vector suffices.

llvm-svn: 260724
2016-02-12 20:41:43 +00:00
Rui Ueyama f9de0d6904 ELF: Remove readLinkerScript and define LinkerScript::read instead.
llvm-svn: 260598
2016-02-11 21:38:55 +00:00
Rui Ueyama 717677af35 ELF: Create LinkerScript class to move code out of Writer.
Previously, we had code for linker scripts in Writer. This patch
separates that as LinkerScript class. The class provides a few
functions to query linker scripts and is also a container of some
linker-script-specific information.

Hopefully, Writer will only implement the default behavior and let
the new class handle gotchas regarding linker scripts.

llvm-svn: 260591
2016-02-11 21:17:59 +00:00