[lldb]Make list command work with headers when possible.

lldb/source/Commands/CommandObjectSource.cpp

@@ -1114,16 +1114,19 @@ class CommandObjectSourceList : public CommandObjectParsed {
             matching_modules.Clear();
             target.GetImages().FindModules(module_spec, matching_modules);
             num_matches += matching_modules.ResolveSymbolContextForFilePath(
-                filename, 0, check_inlines,
+                filename, 1, check_inlines,
                 SymbolContextItem(eSymbolContextModule |
-                                  eSymbolContextCompUnit),
+                                  eSymbolContextCompUnit |
+                                  eSymbolContextLineEntry),
                 sc_list);
           }
         }
       } else {
         num_matches = target.GetImages().ResolveSymbolContextForFilePath(
-            filename, 0, check_inlines,
-            eSymbolContextModule | eSymbolContextCompUnit, sc_list);
+            filename, 1, check_inlines,
+            eSymbolContextModule | eSymbolContextCompUnit |
+                eSymbolContextLineEntry,
+            sc_list);
       }
 
       if (num_matches == 0) {
@@ -1170,10 +1173,18 @@ class CommandObjectSourceList : public CommandObjectParsed {
           if (m_options.num_lines == 0)
             m_options.num_lines = 10;
           const uint32_t column = 0;
+
+          // Headers aren't always in the DWARF but if they have
+          // executable code (eg., inlined-functions) then the callsite's
+          // file(s) will be found and assigned to
+          // sc.comp_unit->GetPrimarySupportFile, which is NOT what we want to
+          // print. Instead, we want to print the one from the line entry.
+          lldb::SupportFileSP found_file_sp = sc.line_entry.file_sp;
+
           target.GetSourceManager().DisplaySourceLinesWithLineNumbers(
-              sc.comp_unit->GetPrimarySupportFile(),
-              m_options.start_line, column, 0, m_options.num_lines, "",
-              &result.GetOutputStream(), GetBreakpointLocations());
+              found_file_sp, m_options.start_line, column, 0,
+              m_options.num_lines, "", &result.GetOutputStream(),
+              GetBreakpointLocations());
 
           result.SetStatus(eReturnStatusSuccessFinishResult);
         } else {

lldb/source/Core/ModuleList.cpp

@@ -714,6 +714,8 @@ uint32_t ModuleList::ResolveSymbolContextsForFileSpec(
     const FileSpec &file_spec, uint32_t line, bool check_inlines,
     SymbolContextItem resolve_scope, SymbolContextList &sc_list) const {
   std::lock_guard<std::recursive_mutex> guard(m_modules_mutex);
+  // If we're looking for a header (not source), then need to check inline.
+  check_inlines = check_inlines || !file_spec.IsSourceImplementationFile();
   for (const ModuleSP &module_sp : m_modules) {
     module_sp->ResolveSymbolContextsForFileSpec(file_spec, line, check_inlines,
                                                 resolve_scope, sc_list);

lldb/test/Shell/Commands/list-header.test

@@ -0,0 +1,57 @@
+## Test that `list header.h:<line>` works correctly when header is available.
+## 
+# RUN: split-file %s %t
+
+# RUN: %clang_host -g %t/main_with_inlined.cc %t/foo.cc -o %t/main_with_inlined.out
+# RUN: %clang_host -g %t/main_no_inlined.cc %t/foo.cc -o %t/main_no_inlined.out
+
+# RUN: %lldb %t/main_with_inlined.out -o "list foo.h:2" -o "exit" 2>&1 \
+# RUN:   | FileCheck %s --check-prefix=CHECK-INLINED
+
+## Would be nice if this listed the header too - but probably not something
+## we want to support right now.
+# RUN: echo quit | %lldb %t/main_no_inlined.out -o "list foo.h:2" -o "exit" 2>&1 \
+# RUN:   | FileCheck %s --check-prefix=CHECK-NO-INLINED
+
+# CHECK-INLINED: 2      extern int* ptr;
+# CHECK-INLINED: 3   	void f(int x);
+# CHECK-INLINED: 4   	
+# CHECK-INLINED: 5   	inline void g(int x) {
+# CHECK-INLINED: 6   	  *ptr = x; // should crash here
+# CHECK-INLINED: 7   	}
+
+# CHECK-NO-INLINED: error: Could not find source file "foo.h".
+
+#--- foo.h
+// foo.h
+extern int* ptr;
+void f(int x);
+
+inline void g(int x) {
+  *ptr = x; // should crash here
+}
+
+#--- foo.cc
+#include "foo.h"
+
+int* ptr;
+
+void f(int x) {
+  *ptr = x;
+}
+
+#--- main_with_inlined.cc
+#include "foo.h"
+
+int main() {
+  g(123); // Call the inlined function
+  return 0;
+}
+
+#--- main_no_inlined.cc
+#include "foo.h"
+
+int main() {
+  f(234);
+  return 0;
+}