From 7f928dbda88bf0309dec4999a9f3ca9f184e10d5 Mon Sep 17 00:00:00 2001
From: martin <martin@michael>
Date: Fri, 16 Jul 2021 17:40:49 +0100
Subject: [PATCH] Avoid diagnostic code crashing when external front-ends use
 "C" mode

At the time of writing both the rust and the Ada external front-ends
generate .json_symtab files that use the "C" mode.  If the ansi-c
front-end is not loaded then these will crash when reporting some linking
errors.
---
 src/symtab2gb/CMakeLists.txt              | 1 +
 src/symtab2gb/Makefile                    | 1 +
 src/symtab2gb/module_dependencies.txt     | 1 +
 src/symtab2gb/symtab2gb_parse_options.cpp | 4 ++++
 4 files changed, 7 insertions(+)

diff --git a/src/symtab2gb/CMakeLists.txt b/src/symtab2gb/CMakeLists.txt
index bfbc03a78f8..7aada9212ae 100644
--- a/src/symtab2gb/CMakeLists.txt
+++ b/src/symtab2gb/CMakeLists.txt
@@ -7,6 +7,7 @@ generic_includes(symtab2gb)
 
 target_link_libraries(symtab2gb
         util
+        ansi-c
         goto-programs
         json-symtab-language)
 
diff --git a/src/symtab2gb/Makefile b/src/symtab2gb/Makefile
index dd18aaa51c0..1f18f880430 100644
--- a/src/symtab2gb/Makefile
+++ b/src/symtab2gb/Makefile
@@ -4,6 +4,7 @@ SRC = \
   # Empty last line
 
 OBJ += \
+  ../ansi-c/ansi-c$(LIBEXT) \
   ../util/util$(LIBEXT) \
   ../goto-programs/goto-programs$(LIBEXT) \
   ../big-int/big-int$(LIBEXT) \
diff --git a/src/symtab2gb/module_dependencies.txt b/src/symtab2gb/module_dependencies.txt
index f1ce5725fbb..0e2983204cd 100644
--- a/src/symtab2gb/module_dependencies.txt
+++ b/src/symtab2gb/module_dependencies.txt
@@ -2,3 +2,4 @@ util
 json-symtab-language
 langapi
 goto-programs
+ansi-c
diff --git a/src/symtab2gb/symtab2gb_parse_options.cpp b/src/symtab2gb/symtab2gb_parse_options.cpp
index 21767c5ab83..d8d9f3568e6 100644
--- a/src/symtab2gb/symtab2gb_parse_options.cpp
+++ b/src/symtab2gb/symtab2gb_parse_options.cpp
@@ -12,6 +12,8 @@ Author: Diffblue Ltd.
 #include <iostream>
 #include <string>
 
+#include <ansi-c/ansi_c_language.h>
+
 #include <goto-programs/goto_convert_functions.h>
 #include <goto-programs/goto_model.h>
 #include <goto-programs/link_goto_model.h>
@@ -113,6 +115,8 @@ int symtab2gb_parse_optionst::doit()
     gb_filename = cmdline.get_value(SYMTAB2GB_OUT_FILE_OPT);
   }
   register_language(new_json_symtab_language);
+  // Workaround to allow external front-ends to use "C" mode
+  register_language(new_ansi_c_language);
   config.set(cmdline);
   run_symtab2gb(symtab_filenames, gb_filename);
   return CPROVER_EXIT_SUCCESS;