8 files changed, 127 insertions, 2 deletions
diff --git a/gnu-taler-error-codes/.gitignore b/gnu-taler-error-codes/.gitignore
index 9111c0f..4331786 100644
--- a/gnu-taler-error-codes/.gitignore
+++ b/gnu-taler-error-codes/.gitignore
@@ -1,8 +1,13 @@
 taler-error-codes.h
+taler-error-codes.c
 taler-error-codes.ts
 taler-error-codes.kt
 
 combined.tmp
+combined-escaped.tmp
+length.tmp
 taler-error-codes.h.tmp
+taler-error-codes.c.tmp
+taler-error-codes-length.c.tmp
 taler-error-codes.ts.tmp
 taler-error-codes.kt.tmp
diff --git a/gnu-taler-error-codes/Makefile b/gnu-taler-error-codes/Makefile
index c0bb208..2837753 100644
--- a/gnu-taler-error-codes/Makefile
+++ b/gnu-taler-error-codes/Makefile
@@ -1,4 +1,5 @@
 FILES=taler-error-codes.h \
+  taler-error-codes.c \
   taler-error-codes.ts \
   taler-error-codes.kt
 all: check $(FILES)
@@ -17,12 +18,27 @@ prep:
 combined.tmp: registry.rec prep
 	recsel -t TalerErrorCode -j HttpStatus -p Description,Name,Value,HttpStatus,HttpStatus.Value,HttpStatus.Identifier ../http-status-codes/registry.rec registry.rec > $@
 
+combined-escaped.tmp: combined.tmp
+	sed 's/"/\\"/g' $^ > $@
+
+length.tmp: combined.tmp
+	recsel -p "Count(Description):ECS_LENGTH" combined.tmp > $@
+
 taler-error-codes.h.tmp: combined.tmp h.template
 	../format.sh h.template < combined.tmp > $@
 
 taler-error-codes.h: h.header taler-error-codes.h.tmp h.footer
 	cat $^ > $@
 
+taler-error-codes.c.tmp: combined-escaped.tmp c.template
+	../format.sh c.template < combined-escaped.tmp > $@
+
+taler-error-codes-length.c.tmp: length.tmp c-length.template
+	../format.sh c-length.template < length.tmp > $@
+
+taler-error-codes.c: c.header taler-error-codes.c.tmp taler-error-codes-length.c.tmp c.footer
+	cat $^ > $@
+
 taler-error-codes.ts.tmp: combined.tmp ts.template
 	../format.sh ts.template < combined.tmp > $@
 
diff --git a/gnu-taler-error-codes/c-length.template b/gnu-taler-error-codes/c-length.template
new file mode 100644
index 0000000..24e3e41
--- /dev/null
+++ b/gnu-taler-error-codes/c-length.template
@@ -0,0 +1,9 @@
+
+
+};
+
+
+/**
+ * The length of @e code_hint_pairs.
+ */
+static const unsigned int code_hint_pairs_length = {{ECS_LENGTH}};
diff --git a/gnu-taler-error-codes/c.footer b/gnu-taler-error-codes/c.footer
new file mode 100644
index 0000000..c348200
--- /dev/null
+++ b/gnu-taler-error-codes/c.footer
@@ -0,0 +1,33 @@
+
+
+
+/**
+ * Returns a hint for a given error code.
+ *
+ * @param ec the error code.
+ * @return the hint if it could be found, otherwise NULL.
+ */
+const char *
+TALER_ErrorCode_get_hint (enum TALER_ErrorCode ec)
+{
+  unsigned int lower = 0;
+  unsigned int upper = code_hint_pairs_length - 1;
+  unsigned int mid = upper / 2;
+  while (lower <= upper)
+  {
+    mid = (upper + lower) / 2;
+    if (code_hint_pairs[mid].ec < ec)
+    {
+      lower = mid + 1;
+    }
+    else if (code_hint_pairs[mid].ec > ec)
+    {
+      upper = mid - 1;
+    }
+    else
+    {
+      return code_hint_pairs[mid].hint;
+    }
+  }
+  return NULL;
+}
diff --git a/gnu-taler-error-codes/c.header b/gnu-taler-error-codes/c.header
new file mode 100644
index 0000000..434bcee
--- /dev/null
+++ b/gnu-taler-error-codes/c.header
@@ -0,0 +1,47 @@
+/*
+     This file is part of GNU Taler
+     Copyright (C) 2012-2020 Taler Systems SA
+
+     GNU Taler is free software: you can redistribute it and/or modify it
+     under the terms of the GNU Lesser General Public License as published
+     by the Free Software Foundation, either version 3 of the License,
+     or (at your option) any later version.
+
+     GNU Taler is distributed in the hope that it will be useful, but
+     WITHOUT ANY WARRANTY; without even the implied warranty of
+     MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+     Lesser General Public License for more details.
+
+     You should have received a copy of the GNU Lesser General Public License
+     along with this program.  If not, see <http://www.gnu.org/licenses/>.
+
+     SPDX-License-Identifier: LGPL3.0-or-later
+
+     Note: the LGPL does not apply to all components of GNU Taler,
+     but it does apply to this file.
+ */
+#include "taler-error-codes.h"
+#include <stddef.h>
+
+
+/**
+ * A pair containing an error code and its hint.
+ */
+struct ErrorCodeAndHint
+{
+  /**
+   * The error code.
+   */
+  enum TALER_ErrorCode ec;
+
+  /**
+   * The hint.
+   */
+  const char *hint;
+};
+
+
+/**
+ * The list of all error codes with their hints.
+ */
+static const struct ErrorCodeAndHint code_hint_pairs[] = {
diff --git a/gnu-taler-error-codes/c.template b/gnu-taler-error-codes/c.template
new file mode 100644
index 0000000..02c39ed
--- /dev/null
+++ b/gnu-taler-error-codes/c.template
@@ -0,0 +1,5 @@
+
+  {
+    .ec = TALER_EC_{{Name}},
+    .hint = "{{Description}}"
+  },
diff --git a/gnu-taler-error-codes/h.footer b/gnu-taler-error-codes/h.footer
index 5d32ee9..1357a9e 100644
--- a/gnu-taler-error-codes/h.footer
+++ b/gnu-taler-error-codes/h.footer
@@ -3,6 +3,16 @@
 };
 
 
+/**
+ * Returns a hint for a given error code.
+ *
+ * @param ec the error code.
+ * @return the hint if it could be found, otherwise NULL.
+ */
+const char *
+TALER_ErrorCode_get_hint (enum TALER_ErrorCode ec);
+
+
 #if 0 /* keep Emacsens' auto-indent happy */
 {
 #endif
diff --git a/gnu-taler-error-codes/registry.rec b/gnu-taler-error-codes/registry.rec
index 5fb2954..e7ca9e1 100644
--- a/gnu-taler-error-codes/registry.rec
+++ b/gnu-taler-error-codes/registry.rec
@@ -74,7 +74,7 @@ HttpStatus: 0
 
 Value: 10
 Name: ENDPOINT_UNKNOWN
-Description: There is no endpoint defined for the URL provided by the client (
+Description: There is no endpoint defined for the URL provided by the client.
 HttpStatus: 404
 
 Value: 11
@@ -84,7 +84,7 @@ HttpStatus: 414
 
 Value: 12
 Name: WRONG_NUMBER_OF_SEGMENTS
-Description: The number of segments included in the URI does not match the number of segments expected by the endpoint. (
+Description: The number of segments included in the URI does not match the number of segments expected by the endpoint.
 HttpStatus: 404
 
 Value: 13