[LLDB][MIPS] microMIPS breakpoints, disassembly and compressed addresses
SUMMARY:
This patch detects microMIPS symbols, sets breakpoints using un-compressed address and
display disassembly in mixed mode for microMIPS applications (running on bare-iron targets).
Reviewers: clayborg
Subscribers: nitesh.jain, mohit.bhakkad, sagar, bhushan and lldb-commits
Differential Revision: http://reviews.llvm.org/D12079
llvm-svn: 248248
diff --git a/lldb/source/Plugins/ObjectFile/ELF/ObjectFileELF.cpp b/lldb/source/Plugins/ObjectFile/ELF/ObjectFileELF.cpp
index 4c6782d..cb8bd64 100644
--- a/lldb/source/Plugins/ObjectFile/ELF/ObjectFileELF.cpp
+++ b/lldb/source/Plugins/ObjectFile/ELF/ObjectFileELF.cpp
@@ -1894,6 +1894,10 @@
return '\0';
}
+#define STO_MIPS_ISA (3 << 6)
+#define STO_MICROMIPS (2 << 6)
+#define IS_MICROMIPS(ST_OTHER) (((ST_OTHER) & STO_MIPS_ISA) == STO_MICROMIPS)
+
// private
unsigned
ObjectFileELF::ParseSymbols (Symtab *symtab,
@@ -2113,6 +2117,37 @@
}
}
}
+
+ /*
+ * MIPS:
+ * The bit #0 of an address is used for ISA mode (1 for microMIPS, 0 for MIPS).
+ * This allows processer to switch between microMIPS and MIPS without any need
+ * for special mode-control register. However, apart from .debug_line, none of
+ * the ELF/DWARF sections set the ISA bit (for symbol or section). Use st_other
+ * flag to check whether the symbol is microMIPS and then set the address class
+ * accordingly.
+ */
+ const llvm::Triple::ArchType llvm_arch = arch.GetMachine();
+ if (llvm_arch == llvm::Triple::mips || llvm_arch == llvm::Triple::mipsel
+ || llvm_arch == llvm::Triple::mips64 || llvm_arch == llvm::Triple::mips64el)
+ {
+ if (IS_MICROMIPS(symbol.st_other))
+ m_address_class_map[symbol.st_value] = eAddressClassCodeAlternateISA;
+ else if ((symbol.st_value & 1) && (symbol_type == eSymbolTypeCode))
+ {
+ symbol.st_value = symbol.st_value & (~1ull);
+ m_address_class_map[symbol.st_value] = eAddressClassCodeAlternateISA;
+ }
+ else
+ {
+ if (symbol_type == eSymbolTypeCode)
+ m_address_class_map[symbol.st_value] = eAddressClassCode;
+ else if (symbol_type == eSymbolTypeData)
+ m_address_class_map[symbol.st_value] = eAddressClassData;
+ else
+ m_address_class_map[symbol.st_value] = eAddressClassUnknown;
+ }
+ }
}
// symbol_value_offset may contain 0 for ARM symbols or -1 for