[clang] aaae6b1 - Revert "PR44684: Look through parens and similar constructs when determining"

[Nico Weber via cfe-commits]

Author: Nico Weber
Date: 2020-01-28T09:03:27-05:00
New Revision: aaae6b1b617378362462c1685e754813ed82b394

URL: https://github.com/llvm/llvm-project/commit/aaae6b1b617378362462c1685e754813ed82b394
DIFF: https://github.com/llvm/llvm-project/commit/aaae6b1b617378362462c1685e754813ed82b394.diff

LOG: Revert "PR44684: Look through parens and similar constructs when determining"

This reverts commit af80b8ccc5772c14920d4554b7ca7e15f2fad1c4.
It broke clang-tidy/checkers/modernize-use-uncaught-exceptions.cpp in
check-clang-tools on macOS and Windows, see e.g.
http://lab.llvm.org:8011/builders/clang-x64-windows-msvc/builds/13976/steps/stage%201%20check/logs/stdio

Added: 
    

Modified: 
    clang/lib/AST/Expr.cpp
    clang/lib/AST/ExprConstant.cpp
    clang/test/Parser/builtin_classify_type.c
    clang/test/Sema/constant-builtins.c

Removed: 
    


################################################################################
diff  --git a/clang/lib/AST/Expr.cpp b/clang/lib/AST/Expr.cpp
index c2f73c2dc9d5..20505b21b15c 100644
--- a/clang/lib/AST/Expr.cpp
+++ b/clang/lib/AST/Expr.cpp
@@ -1443,28 +1443,19 @@ void CallExpr::updateDependenciesFromArg(Expr *Arg) {
 Decl *Expr::getReferencedDeclOfCallee() {
   Expr *CEE = IgnoreParenImpCasts();
 
-  while (SubstNonTypeTemplateParmExpr *NTTP =
-             dyn_cast<SubstNonTypeTemplateParmExpr>(CEE)) {
-    CEE = NTTP->getReplacement()->IgnoreParenImpCasts();
+  while (SubstNonTypeTemplateParmExpr *NTTP
+                                = dyn_cast<SubstNonTypeTemplateParmExpr>(CEE)) {
+    CEE = NTTP->getReplacement()->IgnoreParenCasts();
   }
 
   // If we're calling a dereference, look at the pointer instead.
-  while (true) {
-    if (BinaryOperator *BO = dyn_cast<BinaryOperator>(CEE)) {
-      if (BO->isPtrMemOp()) {
-        CEE = BO->getRHS()->IgnoreParenImpCasts();
-        continue;
-      }
-    } else if (UnaryOperator *UO = dyn_cast<UnaryOperator>(CEE)) {
-      if (UO->getOpcode() == UO_Deref || UO->getOpcode() == UO_AddrOf ||
-          UO->getOpcode() == UO_Plus) {
-        CEE = UO->getSubExpr()->IgnoreParenImpCasts();
-        continue;
-      }
-    }
-    break;
+  if (BinaryOperator *BO = dyn_cast<BinaryOperator>(CEE)) {
+    if (BO->isPtrMemOp())
+      CEE = BO->getRHS()->IgnoreParenCasts();
+  } else if (UnaryOperator *UO = dyn_cast<UnaryOperator>(CEE)) {
+    if (UO->getOpcode() == UO_Deref)
+      CEE = UO->getSubExpr()->IgnoreParenCasts();
   }
-
   if (DeclRefExpr *DRE = dyn_cast<DeclRefExpr>(CEE))
     return DRE->getDecl();
   if (MemberExpr *ME = dyn_cast<MemberExpr>(CEE))
@@ -1475,11 +1466,28 @@ Decl *Expr::getReferencedDeclOfCallee() {
   return nullptr;
 }
 
-/// If this is a call to a builtin, return the builtin ID. If not, return 0.
+/// getBuiltinCallee - If this is a call to a builtin, return the builtin ID. If
+/// not, return 0.
 unsigned CallExpr::getBuiltinCallee() const {
-  auto *FDecl =
-      dyn_cast_or_null<FunctionDecl>(getCallee()->getReferencedDeclOfCallee());
-  return FDecl ? FDecl->getBuiltinID() : 0;
+  // All simple function calls (e.g. func()) are implicitly cast to pointer to
+  // function. As a result, we try and obtain the DeclRefExpr from the
+  // ImplicitCastExpr.
+  const ImplicitCastExpr *ICE = dyn_cast<ImplicitCastExpr>(getCallee());
+  if (!ICE) // FIXME: deal with more complex calls (e.g. (func)(), (*func)()).
+    return 0;
+
+  const DeclRefExpr *DRE = dyn_cast<DeclRefExpr>(ICE->getSubExpr());
+  if (!DRE)
+    return 0;
+
+  const FunctionDecl *FDecl = dyn_cast<FunctionDecl>(DRE->getDecl());
+  if (!FDecl)
+    return 0;
+
+  if (!FDecl->getIdentifier())
+    return 0;
+
+  return FDecl->getBuiltinID();
 }
 
 bool CallExpr::isUnevaluatedBuiltinCall(const ASTContext &Ctx) const {

diff  --git a/clang/lib/AST/ExprConstant.cpp b/clang/lib/AST/ExprConstant.cpp
index 75554c4692e9..c79973507323 100644
--- a/clang/lib/AST/ExprConstant.cpp
+++ b/clang/lib/AST/ExprConstant.cpp
@@ -10660,7 +10660,7 @@ static bool getBuiltinAlignArguments(const CallExpr *E, EvalInfo &Info,
 
 bool IntExprEvaluator::VisitBuiltinCallExpr(const CallExpr *E,
                                             unsigned BuiltinOp) {
-  switch (BuiltinOp) {
+  switch (unsigned BuiltinOp = E->getBuiltinCallee()) {
   default:
     return ExprEvaluatorBaseTy::VisitCallExpr(E);
 

diff  --git a/clang/test/Parser/builtin_classify_type.c b/clang/test/Parser/builtin_classify_type.c
index 94434e9f2ee4..63fd8e28045a 100644
--- a/clang/test/Parser/builtin_classify_type.c
+++ b/clang/test/Parser/builtin_classify_type.c
@@ -9,7 +9,7 @@ int main() {
   struct foo s;
 
   static int ary[__builtin_classify_type(a)];
-  static int ary2[(__builtin_classify_type)(a)];
+  static int ary2[(__builtin_classify_type)(a)]; // expected-error{{variable length array declaration cannot have 'static' storage duration}}
   static int ary3[(*__builtin_classify_type)(a)]; // expected-error{{builtin functions must be directly called}}
 
   int result;

diff  --git a/clang/test/Sema/constant-builtins.c b/clang/test/Sema/constant-builtins.c
index ae3b9135c965..c98f62dfc5a2 100644
--- a/clang/test/Sema/constant-builtins.c
+++ b/clang/test/Sema/constant-builtins.c
@@ -25,13 +25,4 @@ short somefunc();
 
 short t = __builtin_constant_p(5353) ? 42 : somefunc();
 
-// PR44684
-_Static_assert((__builtin_clz)(1u) >= 15, "");
-_Static_assert((__builtin_popcount)(1u) == 1, "");
-_Static_assert((__builtin_ctz)(2u) == 1, "");
-_Static_assert(_Generic(1u,unsigned:__builtin_clz)(1u) >= 15, "");
-_Static_assert(_Generic(1u,unsigned:__builtin_popcount)(1u) == 1, "");
-_Static_assert(_Generic(1u,unsigned:__builtin_ctz)(2u) == 1, "");
-
-__SIZE_TYPE__ strlen(const char*);
-_Static_assert((__builtin_constant_p(1) ? (***&strlen)("foo") : 0) == 3, "");
+