[llvm] r343884 - dwarfdump: Avoid parsing units unnecessarily

[David Blaikie via llvm-commits]

Author: dblaikie
Date: Fri Oct  5 13:55:20 2018
New Revision: 343884

URL: http://llvm.org/viewvc/llvm-project?rev=343884&view=rev
Log:
dwarfdump: Avoid parsing units unnecessarily

NFC-ish (the parsing of the units is not a functional change - no
errors/warnings are emitted during the shallow parsing - though without
parsing them here, the "max version" would be wrong (still zero) later
on, so in those cases the units do need to be parsed)

Modified:
    llvm/trunk/include/llvm/DebugInfo/DWARF/DWARFContext.h
    llvm/trunk/lib/DebugInfo/DWARF/DWARFContext.cpp

Modified: llvm/trunk/include/llvm/DebugInfo/DWARF/DWARFContext.h
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/include/llvm/DebugInfo/DWARF/DWARFContext.h?rev=343884&r1=343883&r2=343884&view=diff
==============================================================================
--- llvm/trunk/include/llvm/DebugInfo/DWARF/DWARFContext.h (original)
+++ llvm/trunk/include/llvm/DebugInfo/DWARF/DWARFContext.h Fri Oct  5 13:55:20 2018
@@ -231,7 +231,17 @@ public:
   /// Get a DIE given an exact offset.
   DWARFDie getDIEForOffset(uint32_t Offset);
 
-  unsigned getMaxVersion() const { return MaxVersion; }
+  unsigned getMaxVersion() {
+    // Ensure info units have been parsed to discover MaxVersion
+    info_section_units();
+    return MaxVersion;
+  }
+
+  unsigned getMaxDWOVersion() {
+    // Ensure DWO info units have been parsed to discover MaxVersion
+    dwo_info_section_units();
+    return MaxVersion;
+  }
 
   void setMaxVersionIfGreater(unsigned Version) {
     if (Version > MaxVersion)

Modified: llvm/trunk/lib/DebugInfo/DWARF/DWARFContext.cpp
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/DebugInfo/DWARF/DWARFContext.cpp?rev=343884&r1=343883&r2=343884&view=diff
==============================================================================
--- llvm/trunk/lib/DebugInfo/DWARF/DWARFContext.cpp (original)
+++ llvm/trunk/lib/DebugInfo/DWARF/DWARFContext.cpp Fri Oct  5 13:55:20 2018
@@ -328,21 +328,20 @@ void DWARFContext::dump(
                  DObj->getAbbrevDWOSection()))
     getDebugAbbrevDWO()->dump(OS);
 
-  auto dumpDebugInfo = [&](bool IsExplicit, const char *Name,
-                           DWARFSection Section, unit_iterator_range Units) {
-    if (shouldDump(IsExplicit, Name, DIDT_ID_DebugInfo, Section.Data)) {
-      if (DumpOffset)
-        getDIEForOffset(DumpOffset.getValue())
-            .dump(OS, 0, DumpOpts.noImplicitRecursion());
-      else
-        for (const auto &U : Units)
-          U->dump(OS, DumpOpts);
-    }
+  auto dumpDebugInfo = [&](unit_iterator_range Units) {
+    if (DumpOffset)
+      getDIEForOffset(DumpOffset.getValue())
+          .dump(OS, 0, DumpOpts.noImplicitRecursion());
+    else
+      for (const auto &U : Units)
+        U->dump(OS, DumpOpts);
   };
-  dumpDebugInfo(Explicit, ".debug_info", DObj->getInfoSection(),
-                info_section_units());
-  dumpDebugInfo(ExplicitDWO, ".debug_info.dwo", DObj->getInfoDWOSection(),
-                dwo_info_section_units());
+  if (shouldDump(Explicit, ".debug_info", DIDT_ID_DebugInfo,
+                 DObj->getInfoSection().Data))
+    dumpDebugInfo(info_section_units());
+  if (shouldDump(ExplicitDWO, ".debug_info.dwo", DIDT_ID_DebugInfo,
+                 DObj->getInfoDWOSection().Data))
+    dumpDebugInfo(dwo_info_section_units());
 
   auto dumpDebugType = [&](const char *Name, unit_iterator_range Units) {
     OS << '\n' << Name << " contents:\n";
@@ -543,7 +542,7 @@ void DWARFContext::dump(
     dumpStringOffsetsSection(OS, "debug_str_offsets.dwo", *DObj,
                              DObj->getStringOffsetDWOSection(),
                              DObj->getStringDWOSection(), dwo_units(),
-                             isLittleEndian(), getMaxVersion());
+                             isLittleEndian(), getMaxDWOVersion());
 
   if (shouldDump(Explicit, ".gnu_index", DIDT_ID_GdbIndex,
                  DObj->getGdbIndexSection())) {