Config->ZCopyreloc = getZFlag(Args, "copyreloc", "nocopyreloc", true);
Config->ZExecstack = getZFlag(Args, "execstack", "noexecstack", false);
Config->ZHazardplt = hasZOption(Args, "hazardplt");
+ Config->ZKeepTextSectionPrefix = getZFlag(
+ Args, "keep-text-section-prefix", "nokeep-text-section-prefix", false);
Config->ZNodelete = hasZOption(Args, "nodelete");
Config->ZNodlopen = hasZOption(Args, "nodlopen");
Config->ZNow = getZFlag(Args, "now", "lazy", false);
};
} // anonymous namespace
+static bool isSectionPrefix(StringRef Prefix, StringRef Name) {
+ return Name.startswith(Prefix) || Name == Prefix.drop_back();
+}
+
StringRef elf::getOutputSectionName(InputSectionBase *S) {
if (Config->Relocatable)
return S->Name;
}
}
+ // This check is for -z keep-text-section-prefix. This option separates text
+ // sections with prefix ".text.hot", ".text.unlikely", ".text.startup" or
+ // ".text.exit".
+ // When enabled, this allows identifying the hot code region (.text.hot) in
+ // the final binary which can be selectively mapped to huge pages or mlocked,
+ // for instance.
+ if (Config->ZKeepTextSectionPrefix)
+ for (StringRef V :
+ {".text.hot.", ".text.unlikely.", ".text.startup.", ".text.exit."}) {
+ if (isSectionPrefix(V, S->Name))
+ return V.drop_back();
+ }
+
for (StringRef V :
{".text.", ".rodata.", ".data.rel.ro.", ".data.", ".bss.rel.ro.",
".bss.", ".init_array.", ".fini_array.", ".ctors.", ".dtors.", ".tbss.",
".gcc_except_table.", ".tdata.", ".ARM.exidx.", ".ARM.extab."}) {
- StringRef Prefix = V.drop_back();
- if (S->Name.startswith(V) || S->Name == Prefix)
- return Prefix;
+ if (isSectionPrefix(V, S->Name))
+ return V.drop_back();
}
// CommonSection is identified as "COMMON" in linker scripts.
--- /dev/null
+# RUN: llvm-mc -filetype=obj %s -o %t
+# RUN: ld.lld -z keep-text-section-prefix %t -o %t2
+# RUN: llvm-readelf -l %t2 | FileCheck %s
+# RUN: ld.lld %t -o %t3
+# RUN: llvm-readelf -l %t3 | FileCheck --check-prefix=CHECKNO %s
+# RUN: ld.lld -z nokeep-text-section-prefix %t -o %t4
+# RUN: llvm-readelf -l %t4 | FileCheck --check-prefix=CHECKNO %s
+
+# CHECK: .text
+# CHECK: .text.hot
+# CHECK: .text.startup
+# CHECK: .text.exit
+# CHECK: .text.unlikely
+# CHECKNO: .text
+# CHECKNO-NOT: .text.hot
+
+_start:
+ ret
+
+.section .text.f,"ax"
+f:
+ nop
+
+.section .text.hot.f_hot,"ax"
+f_hot:
+ nop
+
+.section .text.startup.f_startup,"ax"
+f_startup:
+ nop
+
+.section .text.exit.f_exit,"ax"
+f_exit:
+ nop
+
+.section .text.unlikely.f_unlikely,"ax"
+f_unlikely:
+ nop