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[LLD][ELF] - Linkerscript: fix FILL() expressions handling. 

D64130 introduced a bug described in the following message:
https://reviews.llvm.org/D64130#1571560

The problem can happen with the following script:

SECTIONS {
  .out : {
...
   FILL(0x10101010)
   *(.aaa)
...
}

The current code tries to read (0x10101010) as an expression and
does not break when meets *, what results in a script parsing error.

In this patch, I verify that FILL command's expression always wrapped in ().
And at the same time =<fillexp> expression can be both wrapped or unwrapped.
I checked it matches to bfd/gold.

Differential revision: https://reviews.llvm.org/D64476

llvm-svn: 365635
This commit is contained in:
George Rimar 2019-07-10 14:36:48 +00:00
parent d5214dfa7b
commit c44a23f8f4
3 changed files with 15 additions and 3 deletions
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2
lld/ELF/ScriptParser.cpp
View File

@ -828,7 +828,9 @@ OutputSection *ScriptParser::readOutputSectionDescription(StringRef outSec) {
// We handle the FILL command as an alias for =fillexp section attribute,
// which is different from what GNU linkers do.
// https://sourceware.org/binutils/docs/ld/Output-Section-Data.html
expect("(");
cmd->filler = readFill();
expect(")");
} else if (tok == "SORT") {
readSort();
} else if (tok == "INCLUDE") {

5
lld/test/ELF/linkerscript/fill.test
View File

@ -7,6 +7,7 @@ SECTIONS {
.out : {
FILL(0x11111111)
. += 2;
FILL(0x10101010)
*(.aaa)
. += 4;
*(.bbb)
@ -18,3 +19,7 @@ SECTIONS {
# CHECK: Contents of section .out:
# CHECK-NEXT: 2222aa22 222222bb 22222222 22222222
# RUN: echo 'SECTIONS { .out : { FILL 0x11111111 } }' > %t.script
# RUN: not ld.lld -o /dev/null --script %t.script 2>&1 | FileCheck %s --check-prefix=ERR
# ERR: ( expected, but got 0x11111111

11
lld/test/ELF/linkerscript/sections-padding.s
View File

@ -7,11 +7,16 @@
# RUN: llvm-objdump -s %t.out | FileCheck -check-prefix=YES %s
# YES: 66000011 22000011 22000011 22000011
# RUN: echo "SECTIONS { .mysec : { *(.mysec*) } =0x1100+0x22 }" > %t.script
# RUN: ld.lld -o %t.out --script %t.script %t
# RUN: llvm-objdump -s %t.out | FileCheck -check-prefix=YES2 %s
# YES2: 66000011 22000011 22000011 22000011
## Confirming that address was correct:
# RUN: echo "SECTIONS { .mysec : { *(.mysec*) } =0x99887766 }" > %t.script
# RUN: ld.lld -o %t.out --script %t.script %t
# RUN: llvm-objdump -s %t.out | FileCheck -check-prefix=YES2 %s
# YES2: 66998877 66998877 66998877 66998877
# RUN: llvm-objdump -s %t.out | FileCheck -check-prefix=YES3 %s
# YES3: 66998877 66998877 66998877 66998877
## Default padding value is 0x00:
# RUN: echo "SECTIONS { .mysec : { *(.mysec*) } }" > %t.script
@ -51,7 +56,7 @@
# RUN: ld.lld -o %t.out --script %t.script %t
# RUN: llvm-objdump -s %t.out | FileCheck -check-prefix=YES %s
## Check we report an error if expression value is larger that 32-bits.
## Check we report an error if expression value is larger than 32-bits.
# RUN: echo "SECTIONS { .mysec : { *(.mysec*) } =(0x11 << 32) }" > %t.script
# RUN: not ld.lld -o %t.out --script %t.script %t 2>&1 | FileCheck --check-prefix=ERR3 %s
# ERR3: filler expression result does not fit 32-bit: 0x1100000000