aprantl created this revision.
aprantl added a reviewer: clayborg.
aprantl added a subscriber: lldb-commits.
aprantl set the repository for this revision to rL LLVM.
The System-V x86_64 ABI requires floating point values to be passed in 128-but
SSE vector registers (xmm0, ...).
When printing such a variable this currently yields an <invalid load address>.
This patch makes LLDB's DWARF expression evaluator accept 128-bit registers as
scalars. It also relaxes the check that the size of the result of the DWARF
expression be equal to the size of the variable to a greater-than. DWARF defers
to the ABI how smaller values are being placed in a larger register.
Implementation note: I found the code in Value::SetContext() that changes the
m_value_type after the fact to be questionable. I added a sanity check that the
Value's memory buffer has indeed been written to (this is necessary, because we
may have a scalar value in a vector register), but really I feel like this is
the wrong place to be setting it.
<rdar://problem/24944340>
Repository:
rL LLVM
http://reviews.llvm.org/D17897
Files:
include/lldb/Core/Value.h
packages/Python/lldbsuite/test/lang/c/register_variables/TestRegisterVariables.py
packages/Python/lldbsuite/test/lang/c/register_variables/test.c
source/Core/RegisterValue.cpp
source/Expression/Materializer.cpp
Index: source/Expression/Materializer.cpp
===================================================================
--- source/Expression/Materializer.cpp
+++ source/Expression/Materializer.cpp
@@ -531,15 +531,15 @@
return;
}
- if (data.GetByteSize() != m_variable_sp->GetType()->GetByteSize())
+ if (data.GetByteSize() < m_variable_sp->GetType()->GetByteSize())
{
if (data.GetByteSize() == 0 && m_variable_sp->LocationExpression().IsValid() == false)
{
err.SetErrorStringWithFormat("the variable '%s' has no location, it may have been optimized out", m_variable_sp->GetName().AsCString());
}
else
{
- err.SetErrorStringWithFormat("size of variable %s (%" PRIu64 ") disagrees with the ValueObject's size (%" PRIu64 ")",
+ err.SetErrorStringWithFormat("size of variable %s (%" PRIu64 ") is larger than the ValueObject's size (%" PRIu64 ")",
m_variable_sp->GetName().AsCString(),
m_variable_sp->GetType()->GetByteSize(),
data.GetByteSize());
Index: source/Core/RegisterValue.cpp
===================================================================
--- source/Core/RegisterValue.cpp
+++ source/Core/RegisterValue.cpp
@@ -247,6 +247,9 @@
case 2: scalar = *(const uint16_t *)buffer.bytes; return true;
case 4: scalar = *(const uint32_t *)buffer.bytes; return true;
case 8: scalar = *(const uint64_t *)buffer.bytes; return true;
+ case 16:
+ scalar = llvm::APInt(128, llvm::ArrayRef<uint64_t>((const uint64_t *)buffer.bytes, 2));
+ return true;
}
}
break;
@@ -374,6 +377,7 @@
case eTypeLongDouble: SetFloat (src.GetLongDouble (&src_offset)); break;
case eTypeBytes:
{
+ m_type = eTypeBytes;
buffer.length = reg_info->byte_size;
buffer.byte_order = src.GetByteOrder();
assert (buffer.length <= kMaxRegisterByteSize);
Index: packages/Python/lldbsuite/test/lang/c/register_variables/test.c
===================================================================
--- packages/Python/lldbsuite/test/lang/c/register_variables/test.c
+++ packages/Python/lldbsuite/test/lang/c/register_variables/test.c
@@ -18,10 +18,18 @@
printf("%d\n", c); // set breakpoint here
}
+float f3() __attribute__ ((noinline));
+float f3() {
+ return 3.14f;
+}
+
int main()
{
struct bar myBar = { 3, 4 };
f1(2, &myBar);
f2(&myBar);
+
+ float f = f3();
+ printf("%f\n", f); // set breakpoint here
return 0;
}
Index: packages/Python/lldbsuite/test/lang/c/register_variables/TestRegisterVariables.py
===================================================================
--- packages/Python/lldbsuite/test/lang/c/register_variables/TestRegisterVariables.py
+++ packages/Python/lldbsuite/test/lang/c/register_variables/TestRegisterVariables.py
@@ -24,7 +24,7 @@
self.runCmd("file " + exe, CURRENT_EXECUTABLE_SET)
# Break inside the main.
- lldbutil.run_break_set_by_source_regexp(self, "break", num_expected_locations=2)
+ lldbutil.run_break_set_by_source_regexp(self, "break", num_expected_locations=3)
####################
# First breakpoint
@@ -68,4 +68,22 @@
self.expect("expr c", VARIABLES_DISPLAYED_CORRECTLY,
substrs = ['(int) $3 = 5'])
+ #####################
+ # Third breakpoint
+
+ self.runCmd("continue")
+
+ # The stop reason of the thread should be breakpoint.
+ self.expect("thread list", STOPPED_DUE_TO_BREAKPOINT,
+ substrs = ['stopped',
+ 'stop reason = breakpoint'])
+
+ # The breakpoint should have a hit count of 1.
+ self.expect("breakpoint list -f", BREAKPOINT_HIT_ONCE,
+ substrs = [' resolved, hit count = 1'])
+
+ # Try some variables that should be visible
+ self.expect("expr f", VARIABLES_DISPLAYED_CORRECTLY,
+ substrs = ['(float) $4 = 3.1'])
+
self.runCmd("kill")
Index: include/lldb/Core/Value.h
===================================================================
--- include/lldb/Core/Value.h
+++ include/lldb/Core/Value.h
@@ -169,9 +169,8 @@
m_context = p;
if (m_context_type == eContextTypeRegisterInfo) {
RegisterInfo *reg_info = GetRegisterInfo();
- if (reg_info->encoding == lldb::eEncodingVector)
- SetValueType(eValueTypeVector);
- else
+ if (reg_info->encoding == lldb::eEncodingVector &&
+ m_vector.byte_order != lldb::eByteOrderInvalid)
SetValueType(eValueTypeScalar);
}
}
_______________________________________________
lldb-commits mailing list
lldb-commits@lists.llvm.org
http://lists.llvm.org/cgi-bin/mailman/listinfo/lldb-commits
