Improve behavior of DebugInfoEntryMinimal::getSubprogramName() introduced in r159512.

To fetch a subprogram name we should not only inspect the DIE for this subprogram, but optionally inspect
its specification, or its abstract origin (even if there is no inlining), or even specification of an abstract origin.

Reviewed by Benjamin Kramer.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@160365 91177308-0d34-0410-b5e6-96231b3b80d8

lib/DebugInfo/DWARFContext.cpp

@@ -155,8 +155,10 @@ DILineInfo DWARFContext::getLineInfoForAddress(uint64_t address,
   if (specifier.needs(DILineInfoSpecifier::FunctionName)) {
     const DWARFDebugInfoEntryMinimal *function_die =
         cu->getFunctionDIEForAddress(address);
-    if (function_die)
-      functionName = function_die->getSubprogramName(cu);
+    if (function_die) {
+      if (const char *name = function_die->getSubprogramName(cu))
+        functionName = name;
+    }
   }
   if (specifier.needs(DILineInfoSpecifier::FileLineInfo)) {
     // Get the line table for this compile unit.

lib/DebugInfo/DWARFDebugInfoEntry.cpp

@@ -456,35 +456,38 @@ DWARFDebugInfoEntryMinimal::addressRangeContainsAddress(
   return false;
 }
 
-static inline const char*
-getSubprogramNameFromDie(const DWARFCompileUnit *cu,
-                         const DWARFDebugInfoEntryMinimal *die) {
-  const char *result = 0;
-  if (!die->isNULL() && die->getTag() == DW_TAG_subprogram) {
-    // Try to get mangled name if possible.
-    result = die->getAttributeValueAsString(cu, DW_AT_MIPS_linkage_name, 0);
-    if (result == 0)
-      result = die->getAttributeValueAsString(cu, DW_AT_linkage_name, 0);
-    if (result == 0)
-      result = die->getAttributeValueAsString(cu, DW_AT_name, 0);
-  }
-  return result;
-}
-
 const char*
 DWARFDebugInfoEntryMinimal::getSubprogramName(
     const DWARFCompileUnit *cu) const {
   if (isNULL() || getTag() != DW_TAG_subprogram)
     return 0;
-  const char *name = getSubprogramNameFromDie(cu, this);
-  if (name == 0) {
-    // Try to get name from specification DIE.
-    uint32_t ref = getAttributeValueAsReference(cu, DW_AT_specification, -1U);
-    if (ref != -1U) {
-      DWARFDebugInfoEntryMinimal spec_die;
-      if (spec_die.extract(cu, &ref))
-        name = getSubprogramNameFromDie(cu, &spec_die);
+  // Try to get mangled name if possible.
+  if (const char *name =
+      getAttributeValueAsString(cu, DW_AT_MIPS_linkage_name, 0))
+    return name;
+  if (const char *name = getAttributeValueAsString(cu, DW_AT_linkage_name, 0))
+    return name;
+  if (const char *name = getAttributeValueAsString(cu, DW_AT_name, 0))
+    return name;
+  // Try to get name from specification DIE.
+  uint32_t spec_ref =
+      getAttributeValueAsReference(cu, DW_AT_specification, -1U);
+  if (spec_ref != -1U) {
+    DWARFDebugInfoEntryMinimal spec_die;
+    if (spec_die.extract(cu, &spec_ref)) {
+      if (const char *name = spec_die.getSubprogramName(cu))
+        return name;
     }
   }
-  return name;
+  // Try to get name from abstract origin DIE.
+  uint32_t abs_origin_ref =
+      getAttributeValueAsReference(cu, DW_AT_abstract_origin, -1U);
+  if (abs_origin_ref != -1U) {
+    DWARFDebugInfoEntryMinimal abs_origin_die;
+    if (abs_origin_die.extract(cu, &abs_origin_ref)) {
+      if (const char *name = abs_origin_die.getSubprogramName(cu))
+        return name;
+    }
+  }
+  return 0;
 }

lib/DebugInfo/DWARFDebugInfoEntry.h

@@ -132,8 +132,10 @@ public:
   bool addressRangeContainsAddress(const DWARFCompileUnit *cu,
                                    const uint64_t address) const;
 
-  // If a DIE represents a subroutine, returns its mangled name
-  // (or short name, if mangled is missing). Otherwise returns null.
+  // If a DIE represents a subprogram, returns its mangled name
+  // (or short name, if mangled is missing). This name may be fetched
+  // from specification or abstract origin for this subprogram.
+  // Returns null if no name is found.
   const char* getSubprogramName(const DWARFCompileUnit *cu) const;
 };
 

test/DebugInfo/dwarfdump-test.test

@@ -8,6 +8,8 @@ RUN: llvm-dwarfdump %p/Inputs/dwarfdump-test2.elf-x86-64 \
 RUN:   --address=0x4004b8 --functions | FileCheck %s -check-prefix MANY_CU_1
 RUN: llvm-dwarfdump %p/Inputs/dwarfdump-test2.elf-x86-64 \
 RUN:   --address=0x4004c4 --functions | FileCheck %s -check-prefix MANY_CU_2
+RUN: llvm-dwarfdump %p/Inputs/dwarfdump-test3.elf-x86-64 \
+RUN:   --address=0x538 --functions | FileCheck %s -check-prefix ABS_ORIGIN_1
 
 MAIN: main
 MAIN-NEXT: dwarfdump-test.cc:16:10
@@ -23,3 +25,6 @@ MANY_CU_1-NEXT: a.cc:2:0
 
 MANY_CU_2: main
 MANY_CU_2-NEXT: main.cc:4:0
+
+ABS_ORIGIN_1: C
+ABS_ORIGIN_1-NEXT: def.cc:3:0

test/DebugInfo/lit.local.cfg

@@ -1 +1 @@
-config.suffixes = ['.ll', '.c', '.cpp']
+config.suffixes = ['.ll', '.c', '.cpp', '.test']