Merge pull request #43 from bonachea/assert_always

Assert always

Author: rouson

README.md

@@ -35,8 +35,8 @@ preprocessor ASSERTIONS to non-zero, eg:
 ```
 fpm build --flag "-DASSERTIONS"
 ```
-The program [example/invoke-via-macro.F90] demonstrates the preferred way to invoke the `assert` subroutine via the three provided macros. 
-Invoking `assert` this way insures that `assert` invocations will be completely removed whenever the `ASSERTIONS` macro is undefined (or defined to zero) during compilation.
+The program [example/invoke-via-macro.F90] demonstrates the preferred way to invoke assertions via the three provided macros. 
+Invoking assertions this way ensures such calls will be completely removed whenever the `ASSERTIONS` macro is undefined (or defined to zero) during compilation.
 Due to a limitation of `fpm`, this approach works best if the project using Assert is also a `fpm` project.
 If instead `fpm install` is used, then either the user must copy `include/assert_macros.h` to the installation directory (default: `~/.local/include`) or 
 the user must invoke `assert` directly (via `call assert(...)`).

example/invoke-via-macro.F90

@@ -3,9 +3,10 @@
 program invoke_via_macro
   !! Demonstrate how to invoke the 'assert' subroutine using a preprocessor macro that facilitates
   !! the complete removal of the call in the absence of the compiler flag: -DASSERTIONS
-  use assert_m, only : assert, intrinsic_array_t, string
-    !! If an "only" clause is employed as above, it must include the "string" function that the
-    !! call_assert* macros reference when transforming the code below into "assert" subroutine calls.
+  use assert_m ! <--- this is the recommended use statement
+    !! If an "only" clause is employed above, the symbols required by the
+    !! macro expansion are subject to change without notice between versions.
+    !! You have been warned!
   implicit none
 
 #if !ASSERTIONS
@@ -15,7 +16,7 @@ program invoke_via_macro
   print *
 #endif
 
-  ! The C preprocessor will convert each call_assert* macro below into calls to the "assert" subroutine 
+  ! The C preprocessor will convert each call_assert* macro below into calls that enforce the assertion
   ! whenever the ASSERTIONS macro is defined to non-zero (e.g. via the -DASSERTIONS compiler flag).
   ! Whenever the ASSERTIONS macro is undefined or defined to zero (e.g. via the -DASSERTIONS=0 compiler flag),
   ! these calls will be entirely removed by the preprocessor.

include/assert_macros.h

@@ -22,9 +22,9 @@
 #endif
 
 #if ASSERTIONS
-# define call_assert(assertion) call assert(assertion, "call_assert(" // STRINGIFY(assertion) // ") in file " // __FILE__ // ", line " // string(__LINE__))
-# define call_assert_describe(assertion, description) call assert(assertion, description // " in file " // __FILE__ // ", line " // string(__LINE__))
-# define call_assert_diagnose(assertion, description, diagnostic_data) call assert(assertion, description // " in file " // __FILE__ // ", line " // string(__LINE__), diagnostic_data)
+# define call_assert(assertion) call assert_always(assertion, "call_assert(" // STRINGIFY(assertion) // ") in file " // __FILE__ // ", line " // string(__LINE__))
+# define call_assert_describe(assertion, description) call assert_always(assertion, description // " in file " // __FILE__ // ", line " // string(__LINE__))
+# define call_assert_diagnose(assertion, description, diagnostic_data) call assert_always(assertion, description // " in file " // __FILE__ // ", line " // string(__LINE__), diagnostic_data)
 #else
 # define call_assert(assertion)
 # define call_assert_describe(assertion, description)

src/assert/assert_subroutine_m.F90

@@ -33,7 +33,7 @@ module assert_subroutine_m
   !!
   implicit none
   private
-  public :: assert
+  public :: assert, assert_always
 
 #ifndef USE_ASSERTIONS
 #  if ASSERTIONS
@@ -47,7 +47,8 @@ module assert_subroutine_m
   interface
 
     pure module subroutine assert(assertion, description, diagnostic_data)
-      !! If assertion is .false., error-terminate with a character stop code that contains diagnostic_data if present
+      !! If assertion is .false. and enforcement is enabled (e.g. via -DASSERTIONS=1), 
+      !! then error-terminate with a character stop code that contains diagnostic_data if present
       implicit none
       logical, intent(in) :: assertion
         !! Most assertions will be expressions such as i>0
@@ -57,6 +58,14 @@ pure module subroutine assert(assertion, description, diagnostic_data)
         !! Data to include in an error ouptput: may be of an intrinsic type or a type that extends characterizable_t
     end subroutine
 
+    pure module subroutine assert_always(assertion, description, diagnostic_data)
+      !! Same as above but always enforces the assertion (regardless of ASSERTIONS)
+      implicit none
+      logical, intent(in) :: assertion
+      character(len=*), intent(in) :: description
+      class(*), intent(in), optional :: diagnostic_data
+    end subroutine
+
   end interface
 
 end module assert_subroutine_m

src/assert/assert_subroutine_s.F90

@@ -10,12 +10,18 @@
 contains
 
   module procedure assert
-    use characterizable_m, only : characterizable_t
-
-    character(len=:), allocatable :: header, trailer
 
     toggle_assertions: &
     if (enforce_assertions) then
+        call assert_always(assertion, description, diagnostic_data)
+    end if toggle_assertions
+    
+  end procedure
+
+  module procedure assert_always
+    use characterizable_m, only : characterizable_t
+
+    character(len=:), allocatable :: header, trailer
 
       check_assertion: &
       if (.not. assertion) then
@@ -59,8 +65,6 @@
 
       end if check_assertion
 
-    end if toggle_assertions
-    
   contains
 
     pure function string(numeric) result(number_as_string)

test/test-assert-macro.F90

@@ -71,7 +71,32 @@ program test_assert_macros
 
 #undef ASSERTIONS
 #include "assert_macros.h"
-  call_assert_describe(.false., "")
-  print *,"  passes on being removed by the preprocessor when ASSERTIONS is undefined"
+  call_assert_diagnose(.false., "", "")
+  print *,"  passes on being removed by the preprocessor when ASSERTIONS is undefined" // new_line('')
+
+  !------------------------------------------
+
+#undef ASSERTIONS
+#define ASSERTIONS 1
+#include "assert_macros.h"
+  print *,"The call_assert_* macros"
+  block
+    logical :: foo
+    foo = check_assert(.true.)
+    print *,"  pass on invocation from a pure function"
+  end block
+
+contains 
+
+  pure function check_assert(cond) result(ok)
+    logical, intent(in) :: cond
+    logical ok
+
+    call_assert(cond)
+    call_assert_describe(cond, "check_assert")
+    call_assert_diagnose(cond, "check_assert", "")
+
+    ok = .true.
+  end function
 
 end program