[PDB] Support PDB-backed expressions evaluation (+ fix stuck test)

Summary:
This patch contains several small fixes, which makes it possible to evaluate
expressions on Windows using information from PDB. The changes are:
- several sanitize checks;
- make IRExecutionUnit::MemoryManager::getSymbolAddress to not return a magic
  value on a failure, because callers wait 0 in this case;
- entry point required to be a file address, not RVA, in the ObjectFilePECOFF;
- do not crash on a debuggee second chance exception - it may be an expression
  evaluation crash. Also fix detection of "crushed" threads in tests;
- create parameter declarations for functions in AST to make it possible to call
  debugee functions from expressions;
- relax name searching rules for variables, functions, namespaces and types. Now
  it works just like in the DWARF plugin;
- fix endless recursion in SymbolFilePDB::ParseCompileUnitFunctionForPDBFunc.

Reviewers: zturner, asmith, stella.stamenova

Reviewed By: stella.stamenova, asmith

Tags: #lldb

Differential Revision: https://reviews.llvm.org/D53759

llvm-svn: 348136

4 files changed, 30 insertions, 0 deletions

diff --git a/lldb/lit/SymbolFile/PDB/Inputs/ExpressionsTest.cpp b/lldb/lit/SymbolFile/PDB/Inputs/ExpressionsTest.cpp
new file mode 100644
index 00000000000..3785cd3c64c
--- /dev/null
+++ b/lldb/lit/SymbolFile/PDB/Inputs/ExpressionsTest.cpp
@@ -0,0 +1,20 @@
+namespace N0 {
+namespace N1 {
+
+char *buf0 = nullptr;
+char buf1[] = {0, 1, 2, 3, 4, 5, 6, 7};
+
+char sum(char *buf, int size) {
+  char result = 0;
+  for (int i = 0; i < size; i++)
+    result += buf[i];
+  return result;
+}
+
+} // namespace N1
+} // namespace N0
+
+int main() {
+  char result = N0::N1::sum(N0::N1::buf1, sizeof(N0::N1::buf1));
+  return 0;
+}
diff --git a/lldb/lit/SymbolFile/PDB/Inputs/ExpressionsTest0.script b/lldb/lit/SymbolFile/PDB/Inputs/ExpressionsTest0.script
new file mode 100644
index 00000000000..d31a2abb68a
--- /dev/null
+++ b/lldb/lit/SymbolFile/PDB/Inputs/ExpressionsTest0.script
@@ -0,0 +1,7 @@
+breakpoint set --file ExpressionsTest.cpp --line 19
+run
+print result
+print N0::N1::sum(N0::N1::buf1, sizeof(N0::N1::buf1))
+print N1::sum(N1::buf1, sizeof(N1::buf1))
+print sum(buf1, sizeof(buf1))
+print sum(buf1, 1000000000)
diff --git a/lldb/lit/SymbolFile/PDB/Inputs/ExpressionsTest1.script b/lldb/lit/SymbolFile/PDB/Inputs/ExpressionsTest1.script
new file mode 100644
index 00000000000..dac887faa5b
--- /dev/null
+++ b/lldb/lit/SymbolFile/PDB/Inputs/ExpressionsTest1.script
@@ -0,0 +1 @@
+print sum(buf0, 1)
diff --git a/lldb/lit/SymbolFile/PDB/Inputs/ExpressionsTest2.script b/lldb/lit/SymbolFile/PDB/Inputs/ExpressionsTest2.script
new file mode 100644
index 00000000000..b19240baf99
--- /dev/null
+++ b/lldb/lit/SymbolFile/PDB/Inputs/ExpressionsTest2.script
@@ -0,0 +1,2 @@
+print sum(buf0, result - 28)
+print sum(buf1 + 3, 3)