commit f85e3910636c6ef1424194a1d1317c87aa07f7e1
author Erik Pilkington <erik.pilkington@gmail.com> Thu Sep 06 17:19:33 2018 +0000
committer Erik Pilkington <erik.pilkington@gmail.com> Thu Sep 06 17:19:33 2018 +0000
tree efd890f1e6615d1dbe77b9e940b28519d770c902
parent 1b34b01a8ed5d2c67c9f4b9843d15ba9b85737e9

[Sema] Clean up some __builtin_*_chk diagnostics

Namely, print the likely macro name when it's used, and include the actual
computed sizes in the diagnostic message, which are sometimes not obvious.

rdar://43909200

Differential revision: https://reviews.llvm.org/D51697

llvm-svn: 341566

clang/lib/Sema/SemaChecking.cpp

diff --git a/clang/lib/Sema/SemaChecking.cpp b/clang/lib/Sema/SemaChecking.cpp
index ac7c046..0f6b6a6 100644
--- a/clang/lib/Sema/SemaChecking.cpp
+++ b/clang/lib/Sema/SemaChecking.cpp
@@ -238,7 +238,8 @@
 
 static void SemaBuiltinMemChkCall(Sema &S, FunctionDecl *FDecl,
                                   CallExpr *TheCall, unsigned SizeIdx,
-                                  unsigned DstSizeIdx) {
+                                  unsigned DstSizeIdx,
+                                  StringRef LikelyMacroName) {
   if (TheCall->getNumArgs() <= SizeIdx ||
       TheCall->getNumArgs() <= DstSizeIdx)
     return;
@@ -256,12 +257,21 @@
   if (Size.ule(DstSize))
     return;
 
-  // confirmed overflow so generate the diagnostic.
-  IdentifierInfo *FnName = FDecl->getIdentifier();
+  // Confirmed overflow, so generate the diagnostic.
+  StringRef FunctionName = FDecl->getName();
   SourceLocation SL = TheCall->getBeginLoc();
-  SourceRange SR = TheCall->getSourceRange();
+  SourceManager &SM = S.getSourceManager();
+  // If we're in an expansion of a macro whose name corresponds to this builtin,
+  // use the simple macro name and location.
+  if (SL.isMacroID() && Lexer::getImmediateMacroName(SL, SM, S.getLangOpts()) ==
+                            LikelyMacroName) {
+    FunctionName = LikelyMacroName;
+    SL = SM.getImmediateMacroCallerLoc(SL);
+  }
 
-  S.Diag(SL, diag::warn_memcpy_chk_overflow) << SR << FnName;
+  S.Diag(SL, diag::warn_memcpy_chk_overflow)
+      << FunctionName << DstSize.toString(/*Radix=*/10)
+      << Size.toString(/*Radix=*/10);
 }
 
 static bool SemaBuiltinCallWithStaticChain(Sema &S, CallExpr *BuiltinCall) {
@@ -1219,21 +1229,37 @@
   // check secure string manipulation functions where overflows
   // are detectable at compile time
   case Builtin::BI__builtin___memcpy_chk:
+    SemaBuiltinMemChkCall(*this, FDecl, TheCall, 2, 3, "memcpy");
+    break;
   case Builtin::BI__builtin___memmove_chk:
+    SemaBuiltinMemChkCall(*this, FDecl, TheCall, 2, 3, "memmove");
+    break;
   case Builtin::BI__builtin___memset_chk:
+    SemaBuiltinMemChkCall(*this, FDecl, TheCall, 2, 3, "memset");
+    break;
   case Builtin::BI__builtin___strlcat_chk:
+    SemaBuiltinMemChkCall(*this, FDecl, TheCall, 2, 3, "strlcat");
+    break;
   case Builtin::BI__builtin___strlcpy_chk:
+    SemaBuiltinMemChkCall(*this, FDecl, TheCall, 2, 3, "strlcpy");
+    break;
   case Builtin::BI__builtin___strncat_chk:
+    SemaBuiltinMemChkCall(*this, FDecl, TheCall, 2, 3, "strncat");
+    break;
   case Builtin::BI__builtin___strncpy_chk:
+    SemaBuiltinMemChkCall(*this, FDecl, TheCall, 2, 3, "strncpy");
+    break;
   case Builtin::BI__builtin___stpncpy_chk:
-    SemaBuiltinMemChkCall(*this, FDecl, TheCall, 2, 3);
+    SemaBuiltinMemChkCall(*this, FDecl, TheCall, 2, 3, "stpncpy");
     break;
   case Builtin::BI__builtin___memccpy_chk:
-    SemaBuiltinMemChkCall(*this, FDecl, TheCall, 3, 4);
+    SemaBuiltinMemChkCall(*this, FDecl, TheCall, 3, 4, "memccpy");
     break;
   case Builtin::BI__builtin___snprintf_chk:
+    SemaBuiltinMemChkCall(*this, FDecl, TheCall, 1, 3, "snprintf");
+    break;
   case Builtin::BI__builtin___vsnprintf_chk:
-    SemaBuiltinMemChkCall(*this, FDecl, TheCall, 1, 3);
+    SemaBuiltinMemChkCall(*this, FDecl, TheCall, 1, 3, "vsnprintf");
     break;
   case Builtin::BI__builtin_call_with_static_chain:
     if (SemaBuiltinCallWithStaticChain(*this, TheCall))