vpr: Re-work error suppression to use VPR_ERROR() instead of VPR_THROW()

Historically VPR_THROW() has been used to unconditionally throw an
exception (to signal an error). Since some parts of the code rely on
this unconditional behaviour, VPR_THROWs should not be suppress-able.
(If VPR_THROW is allowed to be suppressible a number of new compiler
warnings are generated since calls to it can now return.)

Instead, this commit adds VPR_ERROR() which signals an error which (by
default) throws an exception, but which may be converted/supressed to
a warning (i.e. to signal a non-fatal error).

* VPR_THROW() should now be used for unconditional fatal errors.
* VPR_ERROR() should now be used for suppressible (non-fatal) errors.

Since the code-base did not previously make the distinction between
fatal/non-fatal errors, there are likely a number of legacy VPR_THROWs
(but not all) which can be converted to VPR_ERRORs in the future.

Author: kmurray

vpr/src/util/vpr_error.cpp

@@ -34,7 +34,7 @@ void vpr_throw(enum e_vpr_error type,
     // Reset variable argument list
     va_end(va_args);
 
-    throw VprError(type, msg, psz_file_name, line_num);
+    vpr_throw_msg(type, psz_file_name, line_num, msg);
 }
 
 void vvpr_throw(enum e_vpr_error type,
@@ -45,7 +45,7 @@ void vvpr_throw(enum e_vpr_error type,
     //Format the message
     std::string msg = vtr::vstring_fmt(psz_message, va_args);
 
-    throw VprError(type, msg, psz_file_name, line_num);
+    vpr_throw_msg(type, psz_file_name, line_num, msg);
 }
 
 void vpr_throw_msg(enum e_vpr_error type,
@@ -72,13 +72,13 @@ void vpr_throw_opt(enum e_vpr_error type,
     //Format the message
     std::string msg = vtr::vstring_fmt(psz_message, va_args);
 
+    // Reset variable argument list
+    va_end(va_args);
+
     auto result = functions_to_demote.find(func_name);
     if (result != functions_to_demote.end()) {
         VTR_LOGFF_WARN(psz_file_name, line_num, psz_func_name, msg.data());
     } else {
         vpr_throw_msg(type, psz_file_name, line_num, msg);
     }
-
-    // Reset variable argument list
-    va_end(va_args);
 }

vpr/src/util/vpr_error.h

@@ -68,13 +68,45 @@ void map_error_activation_status(std::string function_name);
 
 void vpr_throw_opt(enum e_vpr_error type, const char* psz_func_name, const char* psz_file_name, unsigned int line_num, const char* psz_message, ...);
 
+//Figure out what macro to use to get the name of the current function
+// We default to __func__ which is defined in C99
+//
+// g++ > 2.6 define __PRETTY_FUNC__ which includes class/namespace/overload
+// information, so we prefer to use it if possible
+#define VPR_THROW_FUNCTION __func__
+#ifdef __GNUC__
+#    ifdef __GNUC_MINOR__
+#        if __GNUC__ >= 2 && __GNUC_MINOR__ > 6
+#            undef VPR_THROW_FUNCTION
+#            define VPR_THROW_FUNCTION __PRETTY_FUNCTION__
+#        endif
+#    endif
+#endif
+
+
 /*
  * Macro wrapper around vpr_throw() which automatically
  * specifies file and line number of call site.
+ *
+ * VPR_THROW() is used to signal an *unconditional* fatal error which should
+ * stop the program.
  */
 #define VPR_THROW(type, ...)                                            \
     do {                                                                \
-        vpr_throw_opt(type, __func__, __FILE__, __LINE__, __VA_ARGS__); \
+        vpr_throw(type, __FILE__, __LINE__, __VA_ARGS__); \
+    } while (false)
+
+/*
+ * Macro wrapper around vpr_throw_opt() which automatically
+ * specifies file and line number of call site.
+ *
+ * VPR_ERROR() is used to signal an error (potentially non-fatal) which by
+ * default stops the program, but may be suppressed (i.e. converted to a
+ * warning).
+ */
+#define VPR_ERROR(type, ...)                                            \
+    do {                                                                \
+        vpr_throw_opt(type, VPR_THROW_FUNCTION, __FILE__, __LINE__, __VA_ARGS__); \
     } while (false)
 
 #endif