Fix char and string literals in reverse mode AD

vaithak · Feb 7, 2024 · 241f526 · 241f526
1 parent 19cc205
commit 241f526
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Showing 3 changed files with 47 additions and 7 deletions.
diff --git a/include/clad/Differentiator/ReverseModeVisitor.h b/include/clad/Differentiator/ReverseModeVisitor.h
@@ -347,6 +347,8 @@ namespace clad {
     virtual StmtDiff VisitCompoundStmt(const clang::CompoundStmt* CS);
     StmtDiff VisitConditionalOperator(const clang::ConditionalOperator* CO);
     StmtDiff VisitCXXBoolLiteralExpr(const clang::CXXBoolLiteralExpr* BL);
+    StmtDiff VisitCharacterLiteral(const clang::CharacterLiteral* CL);
+    StmtDiff VisitStringLiteral(const clang::StringLiteral* SL);
     StmtDiff VisitCXXDefaultArgExpr(const clang::CXXDefaultArgExpr* DE);
     virtual StmtDiff VisitDeclRefExpr(const clang::DeclRefExpr* DRE);
     StmtDiff VisitDeclStmt(const clang::DeclStmt* DS);

diff --git a/lib/Differentiator/ReverseModeVisitor.cpp b/lib/Differentiator/ReverseModeVisitor.cpp
@@ -1147,6 +1147,17 @@ Expr* getArraySizeExpr(const ArrayType* AT, ASTContext& context,
     return Clone(BL);
   }
 
+  StmtDiff
+  ReverseModeVisitor::VisitCharacterLiteral(const CharacterLiteral* CL) {
+    return Clone(CL);
+  }
+
+  StmtDiff ReverseModeVisitor::VisitStringLiteral(const StringLiteral* SL) {
+    return StmtDiff(Clone(SL), StringLiteral::Create(
+                                   m_Context, "", SL->getKind(), SL->isPascal(),
+                                   SL->getType(), utils::GetValidSLoc(m_Sema)));
+  }
+
   StmtDiff ReverseModeVisitor::VisitReturnStmt(const ReturnStmt* RS) {
     // Initially, df/df = 1.
     const Expr* value = RS->getRetValue();
@@ -1386,7 +1397,7 @@ Expr* getArraySizeExpr(const ArrayType* AT, ASTContext& context,
         // subexpression.
         if (const auto* MTE = dyn_cast<MaterializeTemporaryExpr>(arg))
           arg = clad_compat::GetSubExpr(MTE)->IgnoreImpCasts();
-        if (!isa<FloatingLiteral>(arg) && !isa<IntegerLiteral>(arg)) {
+        if (!arg->isEvaluatable(m_Context)) {
           allArgsAreConstantLiterals = false;
           break;
         }

diff --git a/test/Gradient/FunctionCalls.C b/test/Gradient/FunctionCalls.C
@@ -1,9 +1,9 @@
-// RUN: %cladnumdiffclang -std=c++17 %s  -I%S/../../include -oFunctionCalls.out 2>&1 | FileCheck %s
+// RUN: %cladnumdiffclang -std=c++17 -Wno-writable-strings %s  -I%S/../../include -oFunctionCalls.out 2>&1 | FileCheck %s
 // RUN: ./FunctionCalls.out | FileCheck -check-prefix=CHECK-EXEC %s
-// RUN: %cladnumdiffclang -Xclang -plugin-arg-clad -Xclang -enable-tbr -std=c++17 %s  -I%S/../../include -oFunctionCalls.out
+// RUN: %cladnumdiffclang -Xclang -plugin-arg-clad -Xclang -enable-tbr -std=c++17 -Wno-writable-strings %s  -I%S/../../include -oFunctionCalls.out
 // RUN: ./FunctionCalls.out | FileCheck -check-prefix=CHECK-EXEC %s
 
-//CHECK-NOT: {{.*error|warning|note:.*}}
+// CHECK-NOT: {{.*error|warning|note:.*}}
 
 #include "clad/Differentiator/Differentiator.h"
 
@@ -456,20 +456,47 @@ double fn7(double i, double j) {
 // CHECK-NEXT:     }
 // CHECK-NEXT: }
 
+double check_and_return(double x, char c, const char* s) {
+  if (c == 'a' && s[0] == 'a')
+    return x;
+  return 1;
+}
+// CHECK: void check_and_return_pullback(double x, char c, const char *s, double _d_y, clad::array_ref<double> _d_x, clad::array_ref<char> _d_c, clad::array_ref<char> _d_s) {
+// CHECK-NEXT:     bool _cond0;
+// CHECK-NEXT:     _cond0 = c == 'a' && s[0] == 'a';
+// CHECK-NEXT:     if (_cond0)
+// CHECK-NEXT:         goto _label0;
+// CHECK-NEXT:     goto _label1;
+// CHECK-NEXT:   _label1:
+// CHECK-NEXT:     ;
+// CHECK-NEXT:     if (_cond0)
+// CHECK-NEXT:       _label0:
+// CHECK-NEXT:         * _d_x += _d_y;
+// CHECK-NEXT: }
+
 double fn8(double x, double y) {
-  return x*y*std::tanh(1.0)*std::max(1.0, 2.0);
+  return check_and_return(x, 'a', "aa") * y * std::tanh(1.0) * std::max(1.0, 2.0); // expected-warning {{ISO C++11 does not allow conversion from string literal to 'char *' [-Wwritable-strings]}}
 }
 
 // CHECK: void fn8_grad(double x, double y, clad::array_ref<double> _d_x, clad::array_ref<double> _d_y) {
 // CHECK-NEXT:     double _t0;
 // CHECK-NEXT:     double _t1;
+// CHECK-NEXT:     double _t3;
+// CHECK-NEXT:     _t3 = check_and_return(x, 'a', "aa");
 // CHECK-NEXT:     _t1 = std::tanh(1.);
 // CHECK-NEXT:     _t0 = std::max(1., 2.);
 // CHECK-NEXT:     goto _label0;
 // CHECK-NEXT:   _label0:
 // CHECK-NEXT:     {
-// CHECK-NEXT:         * _d_x += 1 * _t0 * _t1 * y;
-// CHECK-NEXT:         * _d_y += x * 1 * _t0 * _t1;
+// CHECK-NEXT:         double _grad0 = 0.;
+// CHECK-NEXT:         char _grad1 = 0i8;
+// CHECK-NEXT:         clad::array_ref<char> _t2 = {"", 3UL};
+// CHECK-NEXT:         check_and_return_pullback(x, 'a', "aa", 1 * _t0 * _t1 * y, &_grad0, &_grad1, _t2);
+// CHECK-NEXT:         double _r0 = _grad0;
+// CHECK-NEXT:         * _d_x += _r0;
+// CHECK-NEXT:         char _r1 = _grad1;
+// CHECK-NEXT:         clad::array<char> _r2({"", 3UL});
+// CHECK-NEXT:         * _d_y += _t3 * 1 * _t0 * _t1;
 // CHECK-NEXT:     }
 // CHECK-NEXT: }