[PATCH] D123056: [clang][extract-api] Undefining macros should not result in a crash

[Daniel Grumberg via Phabricator via cfe-commits]

dang created this revision.
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This fixes the situation where a undefining a not previously defined
macro resulted in a crash. Before trying to remove a definition from
PendingMacros we first check to see if the macro did indeed have a
previous definition.


Repository:
  rG LLVM Github Monorepo

https://reviews.llvm.org/D123056

Files:
  clang/lib/ExtractAPI/ExtractAPIConsumer.cpp
  clang/test/ExtractAPI/macro_undefined.c


Index: clang/test/ExtractAPI/macro_undefined.c
===================================================================
--- clang/test/ExtractAPI/macro_undefined.c
+++ clang/test/ExtractAPI/macro_undefined.c
@@ -19,6 +19,8 @@
 FUNC_GEN(foo)
 FUNC_GEN(bar, const int *, unsigned);
 #undef FUNC_GEN
+// Undefining a not previously defined macro should not result in a crash.
+#undef FOO
 
 //--- reference.output.json.in
 {
Index: clang/lib/ExtractAPI/ExtractAPIConsumer.cpp
===================================================================
--- clang/lib/ExtractAPI/ExtractAPIConsumer.cpp
+++ clang/lib/ExtractAPI/ExtractAPIConsumer.cpp
@@ -534,6 +534,11 @@
   // macro definition for it.
   void MacroUndefined(const Token &MacroNameToken, const MacroDefinition &MD,
                       const MacroDirective *Undef) override {
+    // If this macro wasn't previously defined we don't need to do anything
+    // here.
+    if (!Undef)
+      return;
+
     llvm::erase_if(PendingMacros, [&MD](const PendingMacro &PM) {
       return MD.getMacroInfo()->getDefinitionLoc() ==
              PM.MD->getMacroInfo()->getDefinitionLoc();


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