[Lldb-commits] [lldb] Reapply "[lldb] Convert file address to load address when reading memory for DW_OP_piece" (PR #117168)

[Ilia Kuklin via lldb-commits]

https://github.com/kuilpd created https://github.com/llvm/llvm-project/pull/117168

This commit fixes the test in so that the breakpoint is triggered correctly after `array` usage on Aarch64.

Reapplies #116411 with a fix.


>From b59a2114542999fa233e802cbc36500678132cb2 Mon Sep 17 00:00:00 2001
From: Ilia Kuklin <ikuklin at accesssoftek.com>
Date: Thu, 14 Nov 2024 20:15:19 +0500
Subject: [PATCH 1/3] Convert file address to load address when reading memory
 for DW_OP_piece

---
 lldb/source/Expression/DWARFExpression.cpp | 19 ++++++++++++++++---
 1 file changed, 16 insertions(+), 3 deletions(-)

diff --git a/lldb/source/Expression/DWARFExpression.cpp b/lldb/source/Expression/DWARFExpression.cpp
index f92f25ed342a9c..a7126b25c1cc38 100644
--- a/lldb/source/Expression/DWARFExpression.cpp
+++ b/lldb/source/Expression/DWARFExpression.cpp
@@ -1853,12 +1853,25 @@ llvm::Expected<Value> DWARFExpression::Evaluate(
           const Value::ValueType curr_piece_source_value_type =
               curr_piece_source_value.GetValueType();
           Scalar &scalar = curr_piece_source_value.GetScalar();
-          const lldb::addr_t addr = scalar.ULongLong(LLDB_INVALID_ADDRESS);
+          lldb::addr_t addr = scalar.ULongLong(LLDB_INVALID_ADDRESS);
           switch (curr_piece_source_value_type) {
           case Value::ValueType::Invalid:
             return llvm::createStringError("invalid value type");
-          case Value::ValueType::LoadAddress:
-          case Value::ValueType::FileAddress: {
+          case Value::ValueType::FileAddress:
+            if (target) {
+              curr_piece_source_value.ConvertToLoadAddress(module_sp.get(),
+                                                           target);
+              addr = scalar.ULongLong(LLDB_INVALID_ADDRESS);
+            } else {
+              return llvm::createStringError(
+                  "unable to convert file address 0x%" PRIx64
+                  " to load address "
+                  "for DW_OP_piece(%" PRIu64 "): "
+                  "no target available",
+                  addr, piece_byte_size);
+            }
+            [[fallthrough]];
+          case Value::ValueType::LoadAddress: {
             if (target) {
               if (curr_piece.ResizeData(piece_byte_size) == piece_byte_size) {
                 if (target->ReadMemory(addr, curr_piece.GetBuffer().GetBytes(),

>From 930bac5a6b36c29fcbf3b602e5fc619b6469dfb5 Mon Sep 17 00:00:00 2001
From: Ilia Kuklin <ikuklin at accesssoftek.com>
Date: Fri, 15 Nov 2024 20:42:58 +0500
Subject: [PATCH 2/3] Add a test

---
 .../Shell/SymbolFile/DWARF/DW_OP_piece-O3.c   | 23 +++++++++++++++++++
 1 file changed, 23 insertions(+)
 create mode 100644 lldb/test/Shell/SymbolFile/DWARF/DW_OP_piece-O3.c

diff --git a/lldb/test/Shell/SymbolFile/DWARF/DW_OP_piece-O3.c b/lldb/test/Shell/SymbolFile/DWARF/DW_OP_piece-O3.c
new file mode 100644
index 00000000000000..d31250426dc112
--- /dev/null
+++ b/lldb/test/Shell/SymbolFile/DWARF/DW_OP_piece-O3.c
@@ -0,0 +1,23 @@
+// Check that optimized with -O3 values that have a file address can be read
+// DWARF info:
+// 0x00000023:   DW_TAG_variable
+//                 DW_AT_name      ("array")
+//                 DW_AT_type      (0x00000032 "char[5]")
+//                 DW_AT_location  (DW_OP_piece 0x2, DW_OP_addrx 0x0, DW_OP_piece 0x1)
+
+// RUN: %clang_host -O3 -gdwarf %s -o %t
+// RUN: %lldb %t \
+// RUN:   -o "b 22" \
+// RUN:   -o "r" \
+// RUN:   -o "p/x array[2]" \
+// RUN:   -b | FileCheck %s
+//
+// CHECK: (lldb) p/x array[2]
+// CHECK: (char) 0x03
+
+static char array[5] = {0, 1, 2, 3, 4};
+
+int main(void) {
+  array[2]++;
+  return 0;
+}
\ No newline at end of file

>From ff7cd83f1d99215803bbc3279f93dd8cb7dd1a77 Mon Sep 17 00:00:00 2001
From: Ilia Kuklin <ikuklin at accesssoftek.com>
Date: Wed, 20 Nov 2024 21:50:35 +0500
Subject: [PATCH 3/3] Move array usage to a separate function to ensure there
 is a breakpoint afterwards

---
 lldb/test/Shell/SymbolFile/DWARF/DW_OP_piece-O3.c | 9 ++++++---
 1 file changed, 6 insertions(+), 3 deletions(-)

diff --git a/lldb/test/Shell/SymbolFile/DWARF/DW_OP_piece-O3.c b/lldb/test/Shell/SymbolFile/DWARF/DW_OP_piece-O3.c
index d31250426dc112..77ea81f30395f0 100644
--- a/lldb/test/Shell/SymbolFile/DWARF/DW_OP_piece-O3.c
+++ b/lldb/test/Shell/SymbolFile/DWARF/DW_OP_piece-O3.c
@@ -7,7 +7,7 @@
 
 // RUN: %clang_host -O3 -gdwarf %s -o %t
 // RUN: %lldb %t \
-// RUN:   -o "b 22" \
+// RUN:   -o "b 25" \
 // RUN:   -o "r" \
 // RUN:   -o "p/x array[2]" \
 // RUN:   -b | FileCheck %s
@@ -17,7 +17,10 @@
 
 static char array[5] = {0, 1, 2, 3, 4};
 
+void func() __attribute__((noinline));
+void func() { ++array[2]; };
+
 int main(void) {
-  array[2]++;
+  func();
   return 0;
-}
\ No newline at end of file
+}