[DWARF] Emit reasonable debug info for empty .s files.

pogo59 · pogo59 · commit 4ca29477d9d6 · 2019-01-29T20:53:51.000Z
llvm-svn: 352541
diff --git a/llvm/lib/MC/MCParser/AsmParser.cpp b/llvm/lib/MC/MCParser/AsmParser.cpp
@@ -900,6 +900,9 @@ bool AsmParser::Run(bool NoInitialTextSection, bool NoFinalize) {
       eatToEndOfStatement();
   }
 
+  // Make sure we get proper DWARF even for empty files.
+  (void)enabledGenDwarfForAssembly();
+
   getTargetParser().onEndOfFile();
   printPendingErrors();
 
diff --git a/llvm/test/MC/AsmParser/debug-only-comments.s b/llvm/test/MC/AsmParser/debug-only-comments.s
@@ -0,0 +1,6 @@
+        # RUN: llvm-mc -triple i386-linux-gnu -g -dwarf-version 4 < %s | FileCheck %s
+        # RUN: llvm-mc -triple i386-linux-gnu -g -dwarf-version 5 < %s | FileCheck %s
+        # CHECK: .section .debug_info
+        # CHECK: .section .debug_info
+        # CHECK-NOT: .section
+        # CHECK: .ascii "<stdin>"

Original file line number	Diff line number	Diff line change
`@@ -900,6 +900,9 @@ bool AsmParser::Run(bool NoInitialTextSection, bool NoFinalize) {`
`900`	`900`	`eatToEndOfStatement();`
`901`	`901`	`}`
`902`	`902`
	`903`	`+ // Make sure we get proper DWARF even for empty files.`
	`904`	`+ (void)enabledGenDwarfForAssembly();`
	`905`	`+`
`903`	`906`	`getTargetParser().onEndOfFile();`
`904`	`907`	`printPendingErrors();`
`905`	`908`