Only allow equality comparisons for non-elementary types.

mesonbuild/interpreterbase.py

@@ -221,6 +221,10 @@ def evaluate_comparison(self, node):
             return val1 == val2
         elif node.ctype == '!=':
             return val1 != val2
+        elif not self.is_elementary_type(val1):
+            raise InterpreterException('{} can only be compared for equality.'.format(node.left.value))
+        elif not self.is_elementary_type(val2):
+            raise InterpreterException('{} can only be compared for equality.'.format(node.right.value))
         elif node.ctype == '<':
             return val1 < val2
         elif node.ctype == '<=':

test cases/common/19 comparison/meson.build

@@ -1,5 +1,7 @@
 project('comparison', 'c')
 
+# Compare equality of strings
+
 var1 = 'foo'
 var2 = 'bar'
 
@@ -31,3 +33,96 @@ test('equalfalse', exe1)
 test('equaltrue', exe2)
 test('nequaltrue', exe3)
 test('nequalfalse', exe4)
+
+# Non-equality comparisons
+
+var3 = 3
+var4 = 4
+
+if var3 < var4
+  exe5 = executable('prog5', 'prog.c')
+else
+  exe5 = executable('broken', 'broken.c')
+endif
+
+if var3 < var3
+  exe6 = executable('broken', 'broken.c')
+else
+  exe6 = executable('prog6', 'prog.c')
+endif
+
+if var4 > var3
+  exe7 = executable('prog7', 'prog.c')
+else
+  exe7 = executable('broken', 'broken.c')
+endif
+
+if var3 > var3
+  exe8 = executable('broken', 'broken.c')
+else
+  exe8 = executable('prog8', 'prog.c')
+endif
+
+if var4 <= var3
+  exe9 = executable('broken', 'broken.c')
+else
+  exe9 = executable('prog9', 'prog.c')
+endif
+
+if var3 <= var3
+  exe10 = executable('prog10', 'prog.c')
+else
+  exe10 = executable('broken', 'broken.c')
+endif
+
+if var3 >= var4
+  exe11 = executable('broken', 'broken.c')
+else
+  exe11 = executable('prog11', 'prog.c')
+endif
+
+if var3 >= var3
+  exe12 = executable('prog12', 'prog.c')
+else
+  exe12 = executable('broken', 'broken.c')
+endif
+
+test('lttrue', exe5)
+test('ltfalse', exe6)
+test('gttrue', exe7)
+test('gtfalse', exe8)
+test('lefalse', exe9)
+test('letrue', exe10)
+test('gefalse', exe11)
+test('getrue', exe12)
+
+# Non-elementary type comparisons
+
+if exe1 == exe2
+  exe13 = executable('broken', 'broken.c')
+else
+  exe13 = executable('prog13', 'prog.c')
+endif
+
+if exe1 == exe1
+  exe14 = executable('prog14', 'prog.c')
+else
+  exe14 = executable('broken', 'broken.c')
+endif
+
+if exe1 != exe2
+  exe15 = executable('prog15', 'prog.c')
+else
+  exe15 = executable('broken', 'broken.c')
+endif
+
+if exe1 != exe1
+  exe16 = executable('broken', 'broken.c')
+else
+  exe16 = executable('prog16', 'prog.c')
+endif
+
+test('equalfalse', exe13)
+test('equaltrue', exe14)
+test('nequaltrue', exe15)
+test('nequalfalse', exe16)

test cases/failing/51 executable comparison/meson.build

@@ -0,0 +1,6 @@
+project('executable comparison', 'c')
+
+exe1 = executable('prog1', sources : 'prog.c')
+exe2 = executable('prog2', sources : 'prog.c')
+
+assert(exe1 < exe2, 'should fail')

test cases/failing/51 executable comparison/prog.c

@@ -0,0 +1 @@
+int main(int argc, char **argv) { return 0; }