Get function start line number from DWARF info
DWARF info contains info about the line number at which a function starts (DW_AT_decl_line).
This patch creates a function to look up the start line number for a function, and returns it in
DILineInfo when looking up debug info for a particular address.
Patch by Simon Que!
Reviewed By: dblaikie
Differential Revision: https://reviews.llvm.org/D27962
llvm-svn: 294231
diff --git a/llvm/lib/DebugInfo/DWARF/DWARFContext.cpp b/llvm/lib/DebugInfo/DWARF/DWARFContext.cpp
index ab9f76a..4d62091 100644
--- a/llvm/lib/DebugInfo/DWARF/DWARFContext.cpp
+++ b/llvm/lib/DebugInfo/DWARF/DWARFContext.cpp
@@ -439,23 +439,32 @@
return getCompileUnitForOffset(CUOffset);
}
-static bool getFunctionNameForAddress(DWARFCompileUnit *CU, uint64_t Address,
- FunctionNameKind Kind,
- std::string &FunctionName) {
- if (Kind == FunctionNameKind::None)
- return false;
+static bool getFunctionNameAndStartLineForAddress(DWARFCompileUnit *CU,
+ uint64_t Address,
+ FunctionNameKind Kind,
+ std::string &FunctionName,
+ uint32_t &StartLine) {
// The address may correspond to instruction in some inlined function,
// so we have to build the chain of inlined functions and take the
- // name of the topmost function in it.SmallVectorImpl<DWARFDie> &InlinedChain
+ // name of the topmost function in it.
SmallVector<DWARFDie, 4> InlinedChain;
CU->getInlinedChainForAddress(Address, InlinedChain);
- if (InlinedChain.size() == 0)
+ if (InlinedChain.empty())
return false;
- if (const char *Name = InlinedChain[0].getSubroutineName(Kind)) {
+
+ const DWARFDie &DIE = InlinedChain[0];
+ bool FoundResult = false;
+ const char *Name = nullptr;
+ if (Kind != FunctionNameKind::None && (Name = DIE.getSubroutineName(Kind))) {
FunctionName = Name;
- return true;
+ FoundResult = true;
}
- return false;
+ if (auto DeclLineResult = DIE.getDeclLine()) {
+ StartLine = DeclLineResult;
+ FoundResult = true;
+ }
+
+ return FoundResult;
}
DILineInfo DWARFContext::getLineInfoForAddress(uint64_t Address,
@@ -465,7 +474,9 @@
DWARFCompileUnit *CU = getCompileUnitForAddress(Address);
if (!CU)
return Result;
- getFunctionNameForAddress(CU, Address, Spec.FNKind, Result.FunctionName);
+ getFunctionNameAndStartLineForAddress(CU, Address, Spec.FNKind,
+ Result.FunctionName,
+ Result.StartLine);
if (Spec.FLIKind != FileLineInfoKind::None) {
if (const DWARFLineTable *LineTable = getLineTableForUnit(CU))
LineTable->getFileLineInfoForAddress(Address, CU->getCompilationDir(),
@@ -483,13 +494,16 @@
return Lines;
std::string FunctionName = "<invalid>";
- getFunctionNameForAddress(CU, Address, Spec.FNKind, FunctionName);
+ uint32_t StartLine = 0;
+ getFunctionNameAndStartLineForAddress(CU, Address, Spec.FNKind, FunctionName,
+ StartLine);
// If the Specifier says we don't need FileLineInfo, just
// return the top-most function at the starting address.
if (Spec.FLIKind == FileLineInfoKind::None) {
DILineInfo Result;
Result.FunctionName = FunctionName;
+ Result.StartLine = StartLine;
Lines.push_back(std::make_pair(Address, Result));
return Lines;
}
@@ -510,6 +524,7 @@
Result.FunctionName = FunctionName;
Result.Line = Row.Line;
Result.Column = Row.Column;
+ Result.StartLine = StartLine;
Lines.push_back(std::make_pair(Row.Address, Result));
}
@@ -549,6 +564,8 @@
// Get function name if necessary.
if (const char *Name = FunctionDIE.getSubroutineName(Spec.FNKind))
Frame.FunctionName = Name;
+ if (auto DeclLineResult = FunctionDIE.getDeclLine())
+ Frame.StartLine = DeclLineResult;
if (Spec.FLIKind != FileLineInfoKind::None) {
if (i == 0) {
// For the topmost frame, initialize the line table of this
diff --git a/llvm/lib/DebugInfo/DWARF/DWARFDie.cpp b/llvm/lib/DebugInfo/DWARF/DWARFDie.cpp
index 9a05ae8..6949366 100644
--- a/llvm/lib/DebugInfo/DWARF/DWARFDie.cpp
+++ b/llvm/lib/DebugInfo/DWARF/DWARFDie.cpp
@@ -291,6 +291,10 @@
return nullptr;
}
+uint64_t DWARFDie::getDeclLine() const {
+ return toUnsigned(findRecursively(DW_AT_decl_line), 0);
+}
+
void DWARFDie::getCallerFrame(uint32_t &CallFile, uint32_t &CallLine,
uint32_t &CallColumn) const {
CallFile = toUnsigned(find(DW_AT_call_file), 0);
diff --git a/llvm/lib/DebugInfo/Symbolize/DIPrinter.cpp b/llvm/lib/DebugInfo/Symbolize/DIPrinter.cpp
index aae009e..c1e2536 100644
--- a/llvm/lib/DebugInfo/Symbolize/DIPrinter.cpp
+++ b/llvm/lib/DebugInfo/Symbolize/DIPrinter.cpp
@@ -84,6 +84,8 @@
return;
}
OS << " Filename: " << Filename << "\n";
+ if (Info.StartLine)
+ OS << "Function start line: " << Info.StartLine << "\n";
OS << " Line: " << Info.Line << "\n";
OS << " Column: " << Info.Column << "\n";
if (Info.Discriminator)