Enable clang warnings for uninitialized variables/structs (#2424)

* Enable clang warnings for uninitialized variables/fields

* Fix typo

tools/clang/lib/Sema/AnalysisBasedWarnings.cpp

@@ -2006,6 +2006,18 @@ AnalysisBasedWarnings::IssueWarnings(sema::AnalysisBasedWarnings::Policy P,
     Analyzer.run(AC);
   }
 
+  // HLSL changes begin
+  // Enable diagnostics related to uninitialized variables
+  if (S.getLangOpts().HLSL) {
+    Diags.setSeverity(diag::warn_uninit_var, diag::Severity::Warning,
+                      D->getLocStart());
+    Diags.setSeverity(diag::warn_sometimes_uninit_var, diag::Severity::Warning,
+                      D->getLocStart());
+    Diags.setSeverity(diag::warn_maybe_uninit_var, diag::Severity::Warning,
+                      D->getLocStart());
+  }
+  // HLSL changes end
+
   if (!Diags.isIgnored(diag::warn_uninit_var, D->getLocStart()) ||
       !Diags.isIgnored(diag::warn_sometimes_uninit_var, D->getLocStart()) ||
       !Diags.isIgnored(diag::warn_maybe_uninit_var, D->getLocStart())) {

tools/clang/test/HLSL/matrix-syntax-exact-precision.hlsl

@@ -7,17 +7,17 @@
 matrix m;
 
 void abs_without_using_result() {
-    matrix<float, 4, 4> mymatrix;
-    abs(mymatrix);            /* expected-warning {{ignoring return value of function declared with const attribute}} fxc-pass {{}} */
+    matrix<float, 4, 4> mymatrix; /* expected-note {{variable 'mymatrix' is declared here}} fxc-pass {{}} */
+    abs(mymatrix);            /* expected-warning {{ignoring return value of function declared with const attribute}} expected-warning {{variable 'mymatrix' is uninitialized when used here}} fxc-pass {{}} */
 
-    matrix<float, 1, 4> mymatrix2;
-    abs(mymatrix2);           /* expected-warning {{ignoring return value of function declared with const attribute}} fxc-pass {{}} */
+    matrix<float, 1, 4> mymatrix2;/* expected-note {{variable 'mymatrix2' is declared here}} fxc-pass {{}} */
+    abs(mymatrix2);           /* expected-warning {{ignoring return value of function declared with const attribute}} expected-warning{{variable 'mymatrix2' is uninitialized when used here}} fxc-pass {{}} */
 }
 
 void abs_with_assignment() {
-    matrix<float, 4, 4> mymatrix;
+    matrix<float, 4, 4> mymatrix;/* expected-note {{variable 'mymatrix' is declared here}} fxc-pass {{}} */
     matrix<float, 4, 4> absMatrix;
-    absMatrix = abs(mymatrix);
+    absMatrix = abs(mymatrix); /* expected-warning{{variable 'mymatrix' is uninitialized when used here}} fxc-pass{{}} */
 }
 
 matrix<float, 4, 4> abs_for_result(matrix<float, 4, 4> value) {
@@ -27,8 +27,8 @@ matrix<float, 4, 4> abs_for_result(matrix<float, 4, 4> value) {
 void fn_use_matrix(matrix<float, 4, 4> value) { }
 
 void abs_in_argument() {
-    matrix<float, 4, 4> mymatrix;
-    fn_use_matrix(abs(mymatrix));
+    matrix<float, 4, 4> mymatrix;/* expected-note {{variable 'mymatrix' is declared here}} fxc-pass {{}} */
+    fn_use_matrix(abs(mymatrix)); /* expected-warning{{variable 'mymatrix' is uninitialized when used here}} fxc-pass{{}} */
     /*verify-ast
       CallExpr <col:5, col:32> 'void'
       |-ImplicitCastExpr <col:5> 'void (*)(matrix<float, 4, 4>)' <FunctionToPointerDecay>
@@ -49,8 +49,8 @@ void matrix_on_demand() {
 }
 
 void abs_on_demand() {
-   float1x2 f12;
-   float1x2 result = abs(f12);
+   float1x2 f12;/* expected-note {{variable 'f12' is declared here}} fxc-pass {{}} */
+   float1x2 result = abs(f12); /* expected-warning{{variable 'f12' is uninitialized when used here}} fxc-pass{{}} */
 }
 
 void matrix_out_of_bounds() {

tools/clang/test/HLSL/matrix-syntax.hlsl

@@ -7,17 +7,17 @@
 matrix m;
 
 void abs_without_using_result() {
-    matrix<float, 4, 4> mymatrix;
-    abs(mymatrix);            /* expected-warning {{ignoring return value of function declared with const attribute}} fxc-pass {{}} */
+    matrix<float, 4, 4> mymatrix; /* expected-note {{variable 'mymatrix' is declared here}} */
+    abs(mymatrix);            /* expected-warning {{ignoring return value of function declared with const attribute}} expected-warning {{variable 'mymatrix' is uninitialized when used here}} fxc-pass {{}} */
 
-    matrix<float, 1, 4> mymatrix2;
-    abs(mymatrix2);           /* expected-warning {{ignoring return value of function declared with const attribute}} fxc-pass {{}} */
+    matrix<float, 1, 4> mymatrix2; /* expected-note {{variable 'mymatrix2' is declared here}} */
+    abs(mymatrix2);           /* expected-warning {{ignoring return value of function declared with const attribute}} expected-warning {{variable 'mymatrix2' is uninitialized when used here}} fxc-pass {{}} */
 }
 
 void abs_with_assignment() {
-    matrix<float, 4, 4> mymatrix;
+    matrix<float, 4, 4> mymatrix; /* expected-note {{variable 'mymatrix' is declared here}} */
     matrix<float, 4, 4> absMatrix;
-    absMatrix = abs(mymatrix);
+    absMatrix = abs(mymatrix); /* expected-warning {{variable 'mymatrix' is uninitialized when used here}} fxc-pass {{}} */
 }
 
 matrix<float, 4, 4> abs_for_result(matrix<float, 4, 4> value) {
@@ -27,8 +27,8 @@ matrix<float, 4, 4> abs_for_result(matrix<float, 4, 4> value) {
 void fn_use_matrix(matrix<float, 4, 4> value) { }
 
 void abs_in_argument() {
-    matrix<float, 4, 4> mymatrix;
-    fn_use_matrix(abs(mymatrix));
+    matrix<float, 4, 4> mymatrix; /* expected-note {{variable 'mymatrix' is declared here}} */
+    fn_use_matrix(abs(mymatrix)); /* expected-warning {{variable 'mymatrix' is uninitialized when used here}} fxc-pass {{}}*/
     /*verify-ast
       CallExpr <col:5, col:32> 'void'
       |-ImplicitCastExpr <col:5> 'void (*)(matrix<float, 4, 4>)' <FunctionToPointerDecay>
@@ -49,8 +49,8 @@ void matrix_on_demand() {
 }
 
 void abs_on_demand() {
-   float1x2 f12;
-   float1x2 result = abs(f12);
+   float1x2 f12; /* expected-note {{variable 'f12' is declared here}} */
+   float1x2 result = abs(f12); /* expected-warning {{variable 'f12' is uninitialized when used here}} fxc-pass {{}}*/
 }
 
 void matrix_out_of_bounds() {

tools/clang/test/HLSL/uninitialized-warnings.hlsl

@@ -0,0 +1,55 @@
+// RUN: %clang_cc1 -verify %s
+
+// This file contains scenarios to test warnings are generated when uninitialized
+// variables or structs are used.
+
+struct MyStruct
+{
+ float a;
+ int b;
+};
+
+cbuffer MyCBuf
+{
+	float c;
+}
+
+uint uninitvar()
+{
+	uint sum; /* expected-note {{initialize the variable 'sum' to silence this warning}} */
+    sum++; /* expected-warning {{variable 'sum' is uninitialized when used here}} */
+	return sum;
+}
+
+uint uninitvarself()
+{
+	uint sum = sum; /* expected-warning {{variable 'sum' is uninitialized when used within its own initialization}} */
+	return sum;
+}
+
+uint mayuninit(uint i)
+{
+	uint s; /* expected-note {{initialize the variable 's' to silence this warning}} */
+	if(i > 10) /* expected-warning {{variable 's' is used uninitialized whenever 'if' condition is false}} expected-note {{remove the 'if' if its condition is always true}} */
+	{
+		s = 10;
+	}
+	return s; /* expected-note {{uninitialized use occurs here}} */
+}
+
+uint uninit2(uint s)
+{
+	s = s << 4;
+	return s;
+}
+
+void main(uint i : IN){
+	uint s; /* expected-note {{initialize the variable 's' to silence this warning}} */
+	(void) uninit2(s); /* expected-warning {{variable 's' is uninitialized when used here}} */
+	(void) uninitvar();
+	(void) uninitvarself();
+	MyStruct val1,val2; /* expected-note {{initialize the variable 'val1' to silence this warning}} */
+	val2 = val1; /* expected-warning {{variable 'val1' is uninitialized when used here}} */
+	mayuninit(i);
+	float d = c;
+}

tools/clang/unittests/HLSL/VerifierTest.cpp

@@ -87,6 +87,7 @@ public:
   TEST_METHOD(RunBadInclude)
   TEST_METHOD(RunWave)
   TEST_METHOD(RunBinopDims)
+  TEST_METHOD(RunUninitWarnings)
 
   void CheckVerifies(const wchar_t* path) {
     WEX::TestExecution::SetVerifyOutput verifySettings(WEX::TestExecution::VerifyOutputSettings::LogOnlyFailures);
@@ -353,3 +354,7 @@ TEST_F(VerifierTest, RunWave) {
 TEST_F(VerifierTest, RunBinopDims) {
   CheckVerifiesHLSL(L"binop-dims.hlsl");
 }
+
+TEST_F(VerifierTest, RunUninitWarnings) {
+    CheckVerifiesHLSL(L"uninitialized-warnings.hlsl");
+}