[PATCH] D155245: AArch64: don't crash when .cfi_startproc/.cfi_endproc are improperly nested

[Jon Roelofs via Phabricator via llvm-commits]

jroelofs updated this revision to Diff 558108.
jroelofs added a comment.

Address review feedback from @iains and @MaskRay


CHANGES SINCE LAST ACTION
  https://reviews.llvm.org/D155245/new/

https://reviews.llvm.org/D155245

Files:
  llvm/lib/MC/MCParser/AsmParser.cpp
  llvm/test/MC/MachO/AArch64/cfi-bad-nesting.s


Index: llvm/test/MC/MachO/AArch64/cfi-bad-nesting.s
===================================================================
--- /dev/null
+++ llvm/test/MC/MachO/AArch64/cfi-bad-nesting.s
@@ -0,0 +1,21 @@
+; RUN: not llvm-mc -triple arm64-apple-darwin %s -filetype=obj -o /dev/null 2>&1 | FileCheck %s
+
+	.section	__TEXT,locomotive,regular,pure_instructions
+
+	.globl	_locomotive
+	.p2align	2
+_locomotive:
+	.cfi_startproc
+	ret
+
+    ; It is invalid to have a non-private label between .cfi_startproc / .cfi_endproc
+	.section	__TEXT,__text,regular,pure_instructions
+	.globl	_caboose
+	.p2align	2
+_caboose:
+; CHECK: [[#@LINE-1]]:1: error: non-private labels cannot appear between .cfi_startproc / .cfi_endproc pairs
+; CHECK: [[#@LINE-9]]:2: error: previous .cfi_startproc was here
+	ret
+	.cfi_endproc
+
+.subsections_via_symbols
Index: llvm/lib/MC/MCParser/AsmParser.cpp
===================================================================
--- llvm/lib/MC/MCParser/AsmParser.cpp
+++ llvm/lib/MC/MCParser/AsmParser.cpp
@@ -125,6 +125,7 @@
   void *SavedDiagContext;
   std::unique_ptr<MCAsmParserExtension> PlatformParser;
   SMLoc StartTokLoc;
+  std::optional<SMLoc> CFIStartProcLoc;
 
   /// This is the current buffer index we're lexing from as managed by the
   /// SourceMgr object.
@@ -1949,6 +1950,11 @@
       Lex();
     }
 
+    if (CFIStartProcLoc && (Sym->isExternal() || Sym->isWeakExternal()))
+      return Error(StartTokLoc, "non-private labels cannot appear between "
+                                ".cfi_startproc / .cfi_endproc pairs") &&
+             Error(*CFIStartProcLoc, "previous .cfi_startproc was here");
+
     if (discardLTOSymbol(IDVal))
       return false;
 
@@ -4193,6 +4199,8 @@
 /// parseDirectiveCFIStartProc
 /// ::= .cfi_startproc [simple]
 bool AsmParser::parseDirectiveCFIStartProc() {
+  CFIStartProcLoc = StartTokLoc;
+
   StringRef Simple;
   if (!parseOptionalToken(AsmToken::EndOfStatement)) {
     if (check(parseIdentifier(Simple) || Simple != "simple",
@@ -4213,8 +4221,11 @@
 /// parseDirectiveCFIEndProc
 /// ::= .cfi_endproc
 bool AsmParser::parseDirectiveCFIEndProc() {
+  CFIStartProcLoc = std::nullopt;
+
   if (parseEOL())
     return true;
+
   getStreamer().emitCFIEndProc();
   return false;
 }


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