[lld-macho] Add support for category names in ConcatInputSection's #90850
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✅ With the latest revision this PR passed the C/C++ code formatter. |
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@llvm/pr-subscribers-lld Author: None (alx32) ChangesIn some cases we see strings from categories being part of "data" sections (Ex: Adding a test that previously would result in an assert. Full diff: https://github.com/llvm/llvm-project/pull/90850.diff 2 Files Affected:
diff --git a/lld/MachO/ObjC.cpp b/lld/MachO/ObjC.cpp
index 95fe0c9374f150..68a8645532dff6 100644
--- a/lld/MachO/ObjC.cpp
+++ b/lld/MachO/ObjC.cpp
@@ -186,13 +186,24 @@ ObjcCategoryChecker::ObjcCategoryChecker()
roClassLayout(target->wordSize), listHeaderLayout(target->wordSize),
methodLayout(target->wordSize) {}
-// \p r must point to an offset within a cstring section.
+// \p r must point to an offset within a CStringInputSection or a
+// ConcatInputSection
static StringRef getReferentString(const Reloc &r) {
if (auto *isec = r.referent.dyn_cast<InputSection *>())
return cast<CStringInputSection>(isec)->getStringRefAtOffset(r.addend);
auto *sym = cast<Defined>(r.referent.get<Symbol *>());
- return cast<CStringInputSection>(sym->isec())
- ->getStringRefAtOffset(sym->value + r.addend);
+ if (isa<CStringInputSection>(sym->isec()))
+ return cast<CStringInputSection>(sym->isec())
+ ->getStringRefAtOffset(sym->value + r.addend);
+
+ if (isa<ConcatInputSection>(sym->isec())) {
+ auto &data = sym->isec()->data;
+ const char *pDataStart = reinterpret_cast<const char *>(data.data());
+ uint32_t len = strnlen(pDataStart + sym->value, data.size() - sym->value);
+ return StringRef(pDataStart + sym->value, len);
+ }
+
+ llvm_unreachable("unknown reference section in getReferentString");
}
void ObjcCategoryChecker::parseMethods(const ConcatInputSection *methodsIsec,
diff --git a/lld/test/MachO/objc-category-merging-extern-class-minimal.s b/lld/test/MachO/objc-category-merging-extern-class-minimal.s
index ede7ef5d9c32d4..3e220ef372ca0d 100644
--- a/lld/test/MachO/objc-category-merging-extern-class-minimal.s
+++ b/lld/test/MachO/objc-category-merging-extern-class-minimal.s
@@ -118,7 +118,7 @@ __OBJC_$_CATEGORY_MyBaseClass_$_Category01:
.quad 0
.long 64 ; 0x40
.space 4
- .section __TEXT,__objc_classname,cstring_literals
+ .section __DATA,__objc_const
l_OBJC_CLASS_NAME_.1: ; @OBJC_CLASS_NAME_.1
.asciz "Category02"
.section __TEXT,__objc_methname,cstring_literals
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@llvm/pr-subscribers-lld-macho Author: None (alx32) ChangesIn some cases we see strings from categories being part of "data" sections (Ex: Adding a test that previously would result in an assert. Full diff: https://github.com/llvm/llvm-project/pull/90850.diff 2 Files Affected:
diff --git a/lld/MachO/ObjC.cpp b/lld/MachO/ObjC.cpp
index 95fe0c9374f150..68a8645532dff6 100644
--- a/lld/MachO/ObjC.cpp
+++ b/lld/MachO/ObjC.cpp
@@ -186,13 +186,24 @@ ObjcCategoryChecker::ObjcCategoryChecker()
roClassLayout(target->wordSize), listHeaderLayout(target->wordSize),
methodLayout(target->wordSize) {}
-// \p r must point to an offset within a cstring section.
+// \p r must point to an offset within a CStringInputSection or a
+// ConcatInputSection
static StringRef getReferentString(const Reloc &r) {
if (auto *isec = r.referent.dyn_cast<InputSection *>())
return cast<CStringInputSection>(isec)->getStringRefAtOffset(r.addend);
auto *sym = cast<Defined>(r.referent.get<Symbol *>());
- return cast<CStringInputSection>(sym->isec())
- ->getStringRefAtOffset(sym->value + r.addend);
+ if (isa<CStringInputSection>(sym->isec()))
+ return cast<CStringInputSection>(sym->isec())
+ ->getStringRefAtOffset(sym->value + r.addend);
+
+ if (isa<ConcatInputSection>(sym->isec())) {
+ auto &data = sym->isec()->data;
+ const char *pDataStart = reinterpret_cast<const char *>(data.data());
+ uint32_t len = strnlen(pDataStart + sym->value, data.size() - sym->value);
+ return StringRef(pDataStart + sym->value, len);
+ }
+
+ llvm_unreachable("unknown reference section in getReferentString");
}
void ObjcCategoryChecker::parseMethods(const ConcatInputSection *methodsIsec,
diff --git a/lld/test/MachO/objc-category-merging-extern-class-minimal.s b/lld/test/MachO/objc-category-merging-extern-class-minimal.s
index ede7ef5d9c32d4..3e220ef372ca0d 100644
--- a/lld/test/MachO/objc-category-merging-extern-class-minimal.s
+++ b/lld/test/MachO/objc-category-merging-extern-class-minimal.s
@@ -118,7 +118,7 @@ __OBJC_$_CATEGORY_MyBaseClass_$_Category01:
.quad 0
.long 64 ; 0x40
.space 4
- .section __TEXT,__objc_classname,cstring_literals
+ .section __DATA,__objc_const
l_OBJC_CLASS_NAME_.1: ; @OBJC_CLASS_NAME_.1
.asciz "Category02"
.section __TEXT,__objc_methname,cstring_literals
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ellishg
reviewed
May 2, 2024
Address Feedback nr.1 Co-authored-by: Ellis Hoag <ellis.sparky.hoag@gmail.com>
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In some cases we see strings from categories being part of "data" sections (Ex:
__objc_const), not part of of sections marked ascstring_literals. Since lld treats these sections differently we need to explicitly implement support for reading strings from the non-cstring_literalssections.Adding a test that previously would result in an assert.