Reland "[LiveDebugValues] Introduce entry values of unmodified params"

Relanding this after resolving the cause of the test failure.

3 files changed, 60 insertions, 16 deletions

diff --git a/lldb/packages/Python/lldbsuite/test/functionalities/param_entry_vals/basic_entry_values_x86_64/Makefile b/lldb/packages/Python/lldbsuite/test/functionalities/param_entry_vals/basic_entry_values_x86_64/Makefile
index 1adf3fc44a6..a49ffa84c54 100644
--- a/lldb/packages/Python/lldbsuite/test/functionalities/param_entry_vals/basic_entry_values_x86_64/Makefile
+++ b/lldb/packages/Python/lldbsuite/test/functionalities/param_entry_vals/basic_entry_values_x86_64/Makefile
@@ -1,5 +1,5 @@
 LEVEL = ../../../make
 CXX_SOURCES := main.cpp
 include $(LEVEL)/Makefile.rules
-CXXFLAGS_EXTRAS := -O1 -glldb -Xclang -femit-debug-entry-values
+CXXFLAGS_EXTRAS := -O2 -glldb -Xclang -femit-debug-entry-values
 include Makefile.rules
diff --git a/lldb/packages/Python/lldbsuite/test/functionalities/param_entry_vals/basic_entry_values_x86_64/TestBasicEntryValuesX86_64.py b/lldb/packages/Python/lldbsuite/test/functionalities/param_entry_vals/basic_entry_values_x86_64/TestBasicEntryValuesX86_64.py
index 1192c2b672f..e0285e6d626 100644
--- a/lldb/packages/Python/lldbsuite/test/functionalities/param_entry_vals/basic_entry_values_x86_64/TestBasicEntryValuesX86_64.py
+++ b/lldb/packages/Python/lldbsuite/test/functionalities/param_entry_vals/basic_entry_values_x86_64/TestBasicEntryValuesX86_64.py
@@ -6,8 +6,7 @@ supported_platforms = ["linux"]
 supported_platforms.extend(lldbplatformutil.getDarwinOSTriples())
 
 lldbinline.MakeInlineTest(__file__, globals(),
-        [decorators.skipIf(bugnumber="llvm.org/pr44059"),
-         decorators.skipUnlessPlatform(supported_platforms),
+        [decorators.skipUnlessPlatform(supported_platforms),
          decorators.skipIf(compiler="clang", compiler_version=['<', '10.0']),
          decorators.skipUnlessArch('x86_64'),
          decorators.skipUnlessHasCallSiteInfo,
diff --git a/lldb/packages/Python/lldbsuite/test/functionalities/param_entry_vals/basic_entry_values_x86_64/main.cpp b/lldb/packages/Python/lldbsuite/test/functionalities/param_entry_vals/basic_entry_values_x86_64/main.cpp
index ff72a81c6b2..9aac6e94783 100644
--- a/lldb/packages/Python/lldbsuite/test/functionalities/param_entry_vals/basic_entry_values_x86_64/main.cpp
+++ b/lldb/packages/Python/lldbsuite/test/functionalities/param_entry_vals/basic_entry_values_x86_64/main.cpp
@@ -18,6 +18,14 @@ template<typename T> __attribute__((noinline)) void use(T x) {
       /* Clobbers */ : "rsi" \
   );
 
+// Destroy %rbx in the current frame.
+#define DESTROY_RBX \
+  asm volatile ("xorq %%rbx, %%rbx" \
+      /* Outputs */  : \
+      /* Inputs */   : \
+      /* Clobbers */ : "rbx" \
+  );
+
 struct S1 {
   int field1 = 123;
   int *field2 = &field1;
@@ -30,10 +38,17 @@ void func1(int &sink, int x) {
   // Destroy 'x' in the current frame.
   DESTROY_RSI;
 
-  //% self.filecheck("image lookup -va $pc", "main.cpp", "-check-prefix=FUNC1-DESC")
-  // FUNC1-DESC: name = "x", type = "int", location = DW_OP_entry_value(DW_OP_reg4 RSI)
+  // NOTE: Currently, we do not generate DW_OP_entry_value for the 'x',
+  // since it gets copied into a register that is not callee saved,
+  // and we can not guarantee that its value has not changed.
 
   ++sink;
+
+  // Destroy 'sink' in the current frame.
+  DESTROY_RBX;
+
+  //% self.filecheck("image lookup -va $pc", "main.cpp", "-check-prefix=FUNC1-DESC")
+  // FUNC1-DESC: name = "sink", type = "int &", location = DW_OP_entry_value(DW_OP_reg5 RDI)
 }
 
 __attribute__((noinline))
@@ -43,10 +58,16 @@ void func2(int &sink, int x) {
   // Destroy 'x' in the current frame.
   DESTROY_RSI;
 
-  //% self.filecheck("expr x", "main.cpp", "-check-prefix=FUNC2-EXPR")
-  // FUNC2-EXPR: (int) ${{.*}} = 123
+  //% self.filecheck("expr x", "main.cpp", "-check-prefix=FUNC2-EXPR-FAIL", expect_cmd_failure=True)
+  // FUNC2-EXPR-FAIL: couldn't get the value of variable x: variable not available
 
   ++sink;
+
+  // Destroy 'sink' in the current frame.
+  DESTROY_RBX;
+
+  //% self.filecheck("expr sink", "main.cpp", "-check-prefix=FUNC2-EXPR")
+  // FUNC2-EXPR: ${{.*}} = 2
 }
 
 __attribute__((noinline))
@@ -69,10 +90,16 @@ void func4_amb(int &sink, int x) {
   // Destroy 'x' in the current frame.
   DESTROY_RSI;
 
-  //% self.filecheck("expr x", "main.cpp", "-check-prefix=FUNC4-EXPR", expect_cmd_failure=True)
-  // FUNC4-EXPR: couldn't get the value of variable x: Could not evaluate DW_OP_entry_value.
+  //% self.filecheck("expr x", "main.cpp", "-check-prefix=FUNC4-EXPR-FAIL", expect_cmd_failure=True)
+  // FUNC4-EXPR-FAIL: couldn't get the value of variable x: variable not available
 
   ++sink;
+
+  // Destroy 'sink' in the current frame.
+  DESTROY_RBX;
+
+  //% self.filecheck("expr sink", "main.cpp", "-check-prefix=FUNC4-EXPR", expect_cmd_failure=True)
+  // FUNC4-EXPR: couldn't get the value of variable sink: Could not evaluate DW_OP_entry_value.
 }
 
 __attribute__((noinline))
@@ -98,10 +125,16 @@ void func7(int &sink, int x) {
   // Destroy 'x' in the current frame.
   DESTROY_RSI;
 
-  //% self.filecheck("expr x", "main.cpp", "-check-prefix=FUNC7-EXPR")
-  // FUNC7-EXPR: (int) ${{.*}} = 123
+  //% self.filecheck("expr x", "main.cpp", "-check-prefix=FUNC7-EXPR-FAIL", expect_cmd_failure=True)
+  // FUNC7-EXPR-FAIL: couldn't get the value of variable x: variable not available
 
   ++sink;
+
+  // Destroy 'sink' in the current frame.
+  DESTROY_RBX;
+
+  //% self.filecheck("expr sink", "main.cpp", "-check-prefix=FUNC7-EXPR")
+  // FUNC7-EXPR: ${{.*}} = 4
 }
 
 __attribute__((always_inline))
@@ -129,10 +162,16 @@ void func11_tailcalled(int &sink, int x) {
   // Destroy 'x' in the current frame.
   DESTROY_RSI;
 
-  //% self.filecheck("expr x", "main.cpp", "-check-prefix=FUNC11-EXPR")
-  // FUNC11-EXPR: (int) ${{.*}} = 123
+  //% self.filecheck("expr x", "main.cpp", "-check-prefix=FUNC11-EXPR-FAIL", expect_cmd_failure=True)
+  // FUNC11-EXPR-FAIL: couldn't get the value of variable x: variable not available
 
   ++sink;
+
+  // Destroy 'sink' in the current frame.
+  DESTROY_RBX;
+
+  //% self.filecheck("expr sink", "main.cpp", "-check-prefix=FUNC11-EXPR")
+  // FUNC11-EXPR: ${{.*}} = 5
 }
 
 __attribute__((noinline))
@@ -150,10 +189,16 @@ void func13(int &sink, int x) {
   // Destroy 'x' in the current frame.
   DESTROY_RSI;
 
-  //% self.filecheck("expr x", "main.cpp", "-check-prefix=FUNC13-EXPR")
-  // FUNC13-EXPR: (int) ${{.*}} = 123
+  //% self.filecheck("expr x", "main.cpp", "-check-prefix=FUNC13-EXPR-FAIL", expect_cmd_failure=True)
+  // FUNC13-EXPR-FAIL: couldn't get the value of variable x: variable not available
 
-  ++sink;
+  use(sink);
+
+  // Destroy 'sink' in the current frame.
+  DESTROY_RBX;
+
+  //% self.filecheck("expr sink", "main.cpp", "-check-prefix=FUNC13-EXPR")
+  // FUNC13-EXPR: ${{.*}} = 5
 }
 
 __attribute__((noinline, disable_tail_calls))