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[ELF] Reject error-prone meta characters in input section description #84130

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Merged
merged 5 commits into from
Mar 7, 2024
Merged

[ELF] Reject error-prone meta characters in input section description #84130

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0803329
[𝘀𝗽𝗿] initial version
MaskRay Mar 6, 2024
5aca4c0
improve comment and tests
MaskRay Mar 6, 2024
f31fc0b
add missing "add" in a comment.
MaskRay Mar 6, 2024
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update message
MaskRay Mar 7, 2024
ac23c0a
improve a test
MaskRay Mar 7, 2024
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14 changes: 12 additions & 2 deletions lld/ELF/ScriptParser.cpp
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Original file line number Diff line number Diff line change
Expand Up @@ -717,9 +717,19 @@ SmallVector<SectionPattern, 0> ScriptParser::readInputSectionsList() {

StringMatcher SectionMatcher;
// Break if the next token is ), EXCLUDE_FILE, or SORT*.
while (!errorCount() && peek() != ")" && peek() != "EXCLUDE_FILE" &&
peekSortKind() == SortSectionPolicy::Default)
while (!errorCount() && peekSortKind() == SortSectionPolicy::Default) {
StringRef s = peek();
if (s == ")" || s == "EXCLUDE_FILE")
break;
// Detect common mistakes when certain non-wildcard meta characters are
// used without a closing ')'.
if (!s.empty() && strchr("(){}", s[0])) {
skip();
setError("section pattern is expected");
break;
}
SectionMatcher.addPattern(unquote(next()));
}

if (!SectionMatcher.empty())
ret.push_back({std::move(excludeFilePat), std::move(SectionMatcher)});
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32 changes: 24 additions & 8 deletions lld/test/ELF/linkerscript/wildcards.s
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Expand Up @@ -91,26 +91,42 @@ SECTIONS {
.text : { *([.]abc .ab[v-y] ) }
}

## Test a few non-wildcard meta characters rejected by GNU ld.
## Test a few non-wildcard characters rejected by GNU ld.

#--- lbrace.lds
# RUN: ld.lld -T lbrace.lds a.o -o out
# RUN: not ld.lld -T lbrace.lds a.o 2>&1 | FileCheck %s --check-prefix=ERR-LBRACE --match-full-lines --strict-whitespace
# ERR-LBRACE:{{.*}}: section pattern is expected
# ERR-LBRACE-NEXT:>>> .text : { *(.a* { ) }
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Is it worth adding a case when there is no space between the disallowed character for example .text : { *(.a*{) as I understand it (,),{,} are lexed as a single token so the spaces shouldn't matter.

From reading the line and the tests all having the character separated by spaces, it made me double check that we could catch more than just a single isolated character.

if (s.size() == 1 && strchr("(){}", s[0]))

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Thanks for the suggestion. Updated. Changed s.size() == 1 to !s.empty() to be clearer that we just guard again "" special case.

# ERR-LBRACE-NEXT:>>> ^
SECTIONS {
.text : { *(.a* { ) }
}

#--- lbrace2.lds
# RUN: not ld.lld -T lbrace2.lds a.o 2>&1 | FileCheck %s --check-prefix=ERR-LBRACE2 --match-full-lines --strict-whitespace
# ERR-LBRACE2:{{.*}}: section pattern is expected
# ERR-LBRACE2-NEXT:>>> .text : { *(.a*{) }
# ERR-LBRACE2-NEXT:>>> ^
SECTIONS {
.text : { *(.a*{) }
}

#--- lparen.lds
## ( is recognized as a section name pattern. Note, ( is rejected by GNU ld.
# RUN: ld.lld -T lparen.lds a.o -o out
# RUN: llvm-objdump --section-headers out | FileCheck --check-prefix=SEC-NO %s
# RUN: not ld.lld -T lparen.lds a.o 2>&1 | FileCheck %s --check-prefix=ERR-LPAREN --match-full-lines --strict-whitespace
# ERR-LPAREN:{{.*}}: section pattern is expected
# ERR-LPAREN-NEXT:>>> .text : { *(.a* ( ) }
# ERR-LPAREN-NEXT:>>> ^
SECTIONS {
.text : { *(.a* ( ) }
.text : { *(.a* ( ) }
}

#--- rbrace.lds
# RUN: ld.lld -T rbrace.lds a.o -o out
# RUN: not ld.lld -T rbrace.lds a.o 2>&1 | FileCheck %s --check-prefix=ERR-RBRACE --match-full-lines --strict-whitespace
# ERR-RBRACE:{{.*}}: section pattern is expected
# ERR-RBRACE-NEXT:>>> .text : { *(.a* x = 3; } ) }
# ERR-RBRACE-NEXT:>>> ^
SECTIONS {
.text : { *(.a* } ) }
.text : { *(.a* x = 3; } ) }
}

#--- rparen.lds
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