Fix oslc crash with invalid field selection. (#835)

Author: marsupial

CMakeLists.txt

@@ -265,7 +265,7 @@ TESTSUITE ( and-or-not-synonyms aastep arithmetic array array-derivs array-range
             pnoise pnoise-cell pnoise-gabor pnoise-perlin pnoise-uperlin
             operator-overloading
             oslc-comma oslc-D
-            oslc-err-arrayindex oslc-err-closuremul
+            oslc-err-arrayindex oslc-err-closuremul oslc-err-field
             oslc-err-format oslc-err-intoverflow
             oslc-err-noreturn oslc-err-notfunc
             oslc-err-outputparamvararray oslc-err-paramdefault

src/liboslcomp/ast.cpp

@@ -628,6 +628,8 @@ ASTstructselect::find_fieldsym (int &structid, int &fieldid)
 {
     if (! lvalue()->typespec().is_structure() &&
         ! lvalue()->typespec().is_structure_array()) {
+        error ("type '%s' does not have a member '%s'",
+               type_c_str(lvalue()->typespec()), m_field);
         return NULL;
     }
 

src/liboslcomp/codegen.cpp

@@ -1873,10 +1873,13 @@ ASTfunction_call::codegen_arg (SymbolPtrVec &argdest, SymbolPtrVec &index1,
                    form->typespec().c_str());
         }
     }
-    argdest.push_back (thisarg);
-    index1.push_back (ind1);
-    index2.push_back (ind2);
-    index3.push_back (ind3);
+    if (thisarg) {
+        argdest.push_back (thisarg);
+        index1.push_back (ind1);
+        index2.push_back (ind2);
+        index3.push_back (ind3);
+    } else
+        arg->error("Invalid argument to function");
 }
 
 

testsuite/oslc-err-field/ref/out.txt

@@ -0,0 +1,3 @@
+test.osl:8: error: type 'color' does not have a member 'nope'
+test.osl:11: error: struct type 'custom' does not have a member 'bad'
+FAILED test.osl

testsuite/oslc-err-field/run.py

@@ -0,0 +1,5 @@
+#!/usr/bin/env python
+
+# command = oslc("test.osl")
+# don't even need that -- it's automatic
+failureok = 1     # this test is expected to have oslc errors

testsuite/oslc-err-field/test.osl

@@ -0,0 +1,12 @@
+// Test invalid field selections in function calls
+
+struct custom { float field; };
+
+shader test ()
+{
+    color c = color(4,3,2);
+    printf("c.nope: %g\n", c.nope);
+
+    custom cc = { 1 };
+    printf("cc.bad: %g\n", cc.bad);
+}