b572f64212
LowerDbgDeclare inserts a dbg.value before each use of an address described by a dbg.declare. When inserting a dbg.value before a CallInst use, however, it fails to append DW_OP_deref to the DIExpression. The DW_OP_deref is needed to reflect the fact that a dbg.value describes a source variable directly (as opposed to a dbg.declare, which relies on pointer indirection). This patch adds in the DW_OP_deref where needed. This results in the correct values being shown during a debug session for a program compiled with ASan and optimizations (see https://reviews.llvm.org/D49520). Note that ConvertDebugDeclareToDebugValue is already correct -- no changes there were needed. One complication is that SelectionDAG is unable to distinguish between direct and indirect frame-index (FRAMEIX) SDDbgValues. This patch also fixes this long-standing issue in order to not regress integration tests relying on the incorrect assumption that all frame-index SDDbgValues are indirect. This is a necessary fix: the newly-added DW_OP_derefs cannot be lowered properly otherwise. Basically the fix prevents a direct SDDbgValue with DIExpression(DW_OP_deref) from being dereferenced twice by a debugger. There were a handful of tests relying on this incorrect "FRAMEIX => indirect" assumption which actually had incorrect DW_AT_locations: these are all fixed up in this patch. Testing: - check-llvm, and an end-to-end test using lldb to debug an optimized program. - Existing unit tests for DIExpression::appendToStack fully cover the new DIExpression::append utility. - check-debuginfo (the debug info integration tests) Differential Revision: https://reviews.llvm.org/D49454 llvm-svn: 338069 |
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|---|---|---|
| .. | ||
| .arcconfig | ||
| CMakeLists.txt | ||
| README.txt | ||
| aggregate-indirect-arg.cpp | ||
| apple-accel.cpp | ||
| asan-blocks.c | ||
| asan-deque.cpp | ||
| asan.c | ||
| block_var.m | ||
| blocks.m | ||
| ctor.cpp | ||
| dbg-arg.c | ||
| foreach.m | ||
| forward-declare-class.cpp | ||
| lit.cfg.py | ||
| lit.local.cfg | ||
| lit.site.cfg.py.in | ||
| llgdb.py | ||
| nested-struct.cpp | ||
| nrvo-string.cpp | ||
| safestack.c | ||
| sret.cpp | ||
| stack-var.c | ||
| static-member-2.cpp | ||
| static-member.cpp | ||
| test_debuginfo.pl | ||
| vla.c | ||
README.txt
-*- rst -*-
This is a collection of tests to check debugging information generated by
compiler. This test suite can be checked out inside clang/test folder. This
will enable 'make test' for clang to pick up these tests. Typically, test
cases included here includes debugger commands and intended debugger output
as comments in source file using DEBUGGER: and CHECK: as prefixes respectively.
For example::
define i32 @f1(i32 %i) nounwind ssp {
; DEBUGGER: break f1
; DEBUGGER: r
; DEBUGGER: p i
; CHECK: $1 = 42
entry:
}
is a testcase where the debugger is asked to break at function 'f1' and
print value of argument 'i'. The expected value of 'i' is 42 in this case.