Refactor the way we handle diagnosing unused expression results.
Rather than sprinkle calls to DiagnoseUnusedExprResult() around in places where we want diagnostics, we now diagnose unused expression statements and full expressions in a more generic way when acting on the final expression statement. This results in more appropriate diagnostics for [[nodiscard]] where we were previously lacking them, such as when the body of a for loop is not a compound statement.
This patch fixes PR39837.
llvm-svn: 350404
diff --git a/clang/test/Parser/cxx1z-init-statement.cpp b/clang/test/Parser/cxx1z-init-statement.cpp
index 3d119ef..ade60dc 100644
--- a/clang/test/Parser/cxx1z-init-statement.cpp
+++ b/clang/test/Parser/cxx1z-init-statement.cpp
@@ -13,9 +13,9 @@
if (T(n) = 0; n) {}
// init-statement expressions
- if (T{f()}; f()) {}
- if (T{f()}, g, h; f()) {} // expected-warning 2{{unused}}
- if (T(f()), g, h + 1; f()) {} // expected-warning 2{{unused}}
+ if (T{f()}; f()) {} // expected-warning {{expression result unused}}
+ if (T{f()}, g, h; f()) {} // expected-warning 2{{unused}} expected-warning {{expression result unused}}
+ if (T(f()), g, h + 1; f()) {} // expected-warning 2{{unused}} expected-warning {{expression result unused}}
// condition declarations
if (T(n){g}) {}
@@ -35,7 +35,7 @@
// Likewise for 'switch'
switch (int n; n) {}
- switch (g; int g = 5) {}
+ switch (g; int g = 5) {} // expected-warning {{expression result unused}}
if (int a, b; int c = a) { // expected-note 6{{previous}}
int a; // expected-error {{redefinition}}