[dsymutil] Fix handling of inlined_subprogram low_pcs

The value of an inlined subprogram low_pc attribute should not
get relocated, but it can happen that it matches the enclosing
function's start address and thus gets the generic treatment.
Special case it to avoid applying the PC offset twice.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@246406 91177308-0d34-0410-b5e6-96231b3b80d8

diff --git a/test/tools/dsymutil/ARM/dummy-debug-map-amr64.map b/test/tools/dsymutil/ARM/dummy-debug-map-amr64.map
new file mode 100644 (file)
index 0000000..a23e0c3
--- /dev/null
+++ b/test/tools/dsymutil/ARM/dummy-debug-map-amr64.map
@@ -0,0 +1,15 @@
+# This is a dummy debug map used for some tests where the contents of the
+# map are just an implementation detail. The tests wanting to use that file
+# should put all there object files in an explicitely named sub-directory
+# of Inputs, and they should be named 1.o, 2.o, ...
+# As not finding an object file or symbols isn't a fatal error for dsymutil,
+# you can extend this file with as much object files and symbols as needed.
+
+---
+triple:          'arm64-apple-darwin'
+objects:
+  - filename: 1.o
+    symbols:
+      - { sym: _bar, objAddr: 0x0, binAddr: 0x10000, size: 0x10 }
+...
+

diff --git a/test/tools/dsymutil/ARM/inlined-low_pc.c b/test/tools/dsymutil/ARM/inlined-low_pc.c
new file mode 100644 (file)
index 0000000..7ade33e
--- /dev/null
+++ b/test/tools/dsymutil/ARM/inlined-low_pc.c
@@ -0,0 +1,15 @@
+/* Compiled with: clang -arch=arm64 -O2 -g -c inlined_low_pc.c */
+
+static int foo(int i) { return 42 + i; }
+int bar(int a) { return foo(a); }
+
+// RUN: llvm-dsymutil -f -y %p/dummy-debug-map-amr64.map -oso-prepend-path %p/../Inputs/inlined-low_pc -o - | llvm-dwarfdump - | FileCheck %s
+
+// CHECK: DW_TAG_subprogram
+// CHECK: DW_AT_low_pc{{.*}}0x0000000000010000
+// CHECK: DW_AT_name{{.*}}"bar"
+// CHECK-NOT: NULL
+// CHECK: DW_TAG_inlined_subroutine
+// CHECK-NEXT: DW_AT_abstract_origin{{.*}}"foo"
+// CHECK-NEXT: DW_AT_low_pc{{.*}}0x0000000000010000
+

diff --git a/test/tools/dsymutil/ARM/lit.local.cfg b/test/tools/dsymutil/ARM/lit.local.cfg
index b704ac4031fe781c576eff4417ec6131e6f083ac..442cd554bfed963a404edd0034fac54077a63f19 100644 (file)
--- a/test/tools/dsymutil/ARM/lit.local.cfg
+++ b/test/tools/dsymutil/ARM/lit.local.cfg
@@ -2,3 +2,6 @@ if not 'ARM' in config.root.targets:
     config.unsupported = True
 if not 'AArch64' in config.root.targets:
     config.unsupported = True
+
+config.suffixes = ['.test', '.cpp', '.c']
+

diff --git a/test/tools/dsymutil/Inputs/inlined-low_pc/1.o b/test/tools/dsymutil/Inputs/inlined-low_pc/1.o
new file mode 100644 (file)
index 0000000..7ab4e92
Binary files /dev/null and b/test/tools/dsymutil/Inputs/inlined-low_pc/1.o differ

diff --git a/tools/dsymutil/DwarfLinker.cpp b/tools/dsymutil/DwarfLinker.cpp
index 0be12375b2658ba3a5ac58e7f4722b412a36e495..1e171db44c4e4fc36942ac223d08ebfbc6bca85a 100644 (file)
--- a/tools/dsymutil/DwarfLinker.cpp
+++ b/tools/dsymutil/DwarfLinker.cpp
@@ -1206,6 +1206,7 @@ private:
     const char *Name, *MangledName;         ///< Names.
     uint32_t NameOffset, MangledNameOffset; ///< Offsets in the string pool.
 
+    uint64_t OrigLowPc;  ///< Value of AT_low_pc in the input DIE
     uint64_t OrigHighPc; ///< Value of AT_high_pc in the input DIE
     int64_t PCOffset;    ///< Offset to apply to PC addresses inside a function.
 
@@ -1214,8 +1215,8 @@ private:
 
     AttributesInfo()
         : Name(nullptr), MangledName(nullptr), NameOffset(0),
-          MangledNameOffset(0), OrigHighPc(0), PCOffset(0), HasLowPc(false),
-          IsDeclaration(false) {}
+          MangledNameOffset(0), OrigLowPc(UINT64_MAX), OrigHighPc(0),
+          PCOffset(0), HasLowPc(false), IsDeclaration(false) {}
   };
 
   /// \brief Helper for cloneDIE.
@@ -2274,7 +2275,12 @@ unsigned DwarfLinker::cloneAddressAttribute(DIE &Die, AttributeSpec AttrSpec,
   if (AttrSpec.Attr == dwarf::DW_AT_low_pc) {
     if (Die.getTag() == dwarf::DW_TAG_inlined_subroutine ||
         Die.getTag() == dwarf::DW_TAG_lexical_block)
-      Addr += Info.PCOffset;
+      // The low_pc of a block or inline subroutine might get
+      // relocated because it happens to match the low_pc of the
+      // enclosing subprogram. To prevent issues with that, always use
+      // the low_pc from the input DIE if relocations have been applied.
+      Addr = (Info.OrigLowPc != UINT64_MAX ? Info.OrigLowPc : Addr) +
+             Info.PCOffset;
     else if (Die.getTag() == dwarf::DW_TAG_compile_unit) {
       Addr = Unit.getLowPc();
       if (Addr == UINT64_MAX)
@@ -2522,6 +2528,11 @@ DIE *DwarfLinker::cloneDIE(const DWARFDebugInfoEntryMinimal &InputDIE,
     // high_pc value is done in cloneAddressAttribute().
     AttrInfo.OrigHighPc =
         InputDIE.getAttributeValueAsAddress(&U, dwarf::DW_AT_high_pc, 0);
+    // Also store the low_pc. It might get relocated in an
+    // inline_subprogram that happens at the beginning of its
+    // inlining function.
+    AttrInfo.OrigLowPc =
+        InputDIE.getAttributeValueAsAddress(&U, dwarf::DW_AT_low_pc, UINT64_MAX);
   }
 
   // Reset the Offset to 0 as we will be working on the local copy of