[PATCH] RedfishPkg/JsonLib: Fix build errors

["Abner Chang" <abner.chang@hpe.com>]

This patch fixes the build errors when build JsonLib with EDK2
Redfish feature driver.

- Add JsonLoadString function to load a NULL terminated-string JSON
- json_string_value() in JsonValueGetAsciiString () is removed
by accident.

Signed-off-by: Abner Chang <abner.chang@hpe.com>

Cc: Leif Lindholm <leif@nuviainc.com>
Cc: Nickle Wang <nickle.wang@hpe.com>
Cc: Michael D Kinney <michael.d.kinney@intel.com>
---
 RedfishPkg/Library/JsonLib/JsonLib.inf |  5 +++--
 RedfishPkg/Include/Library/JsonLib.h   | 21 ++++++++++++++++++
 RedfishPkg/Library/JsonLib/JsonLib.c   | 30 ++++++++++++++++++++++++--
 3 files changed, 52 insertions(+), 4 deletions(-)

diff --git a/RedfishPkg/Library/JsonLib/JsonLib.inf b/RedfishPkg/Library/JsonLib/JsonLib.inf
index 48b094a78a..9d52a622e1 100644
--- a/RedfishPkg/Library/JsonLib/JsonLib.inf
+++ b/RedfishPkg/Library/JsonLib/JsonLib.inf
@@ -75,12 +75,13 @@
   #   C4244: conversion from type1 to type2, possible loss of data
   #   C4334: 32-bit shift implicitly converted to 64-bit
   #   C4204: nonstandard extension used: non-constant aggregate initializer
+  #   C4706: assignment within conditional expression
   #
   # Define macro HAVE_CONFIG_H to include jansson_private_config.h to build.
   # Undefined _WIN32, WIN64, _MSC_VER macros
   # On GCC, no error on the unused-function and unused-but-set-variable.
   #
-  MSFT:*_*_X64_CC_FLAGS = /wd4204 /wd4244 /wd4090 /wd4334 /DHAVE_CONFIG_H=1 /U_WIN32 /UWIN64 /U_MSC_VER
-  MSFT:*_*_IA32_CC_FLAGS = /wd4204 /wd4244 /wd4090 /DHAVE_CONFIG_H=1 /U_WIN32 /UWIN64 /U_MSC_VER
+  MSFT:*_*_X64_CC_FLAGS = /wd4204 /wd4244 /wd4090 /wd4334 /wd4706 /DHAVE_CONFIG_H=1 /U_WIN32 /UWIN64 /U_MSC_VER
+  MSFT:*_*_IA32_CC_FLAGS = /wd4204 /wd4244 /wd4090 /wd4706 /DHAVE_CONFIG_H=1 /U_WIN32 /UWIN64 /U_MSC_VER
   GCC:*_*_*_CC_FLAGS = -Wno-unused-function -Wno-unused-but-set-variable
 
diff --git a/RedfishPkg/Include/Library/JsonLib.h b/RedfishPkg/Include/Library/JsonLib.h
index 3c10f67d27..82ca4bad60 100644
--- a/RedfishPkg/Include/Library/JsonLib.h
+++ b/RedfishPkg/Include/Library/JsonLib.h
@@ -664,6 +664,27 @@ JsonDumpString (
   IN    UINTN               Flags
   );
 
+/**
+  Convert a string to JSON object.
+  The function is used to convert a NULL terminated UTF8 encoded string to a JSON
+  value. Only object and array represented strings can be converted successfully,
+  since they are the only valid root values of a JSON text for UEFI usage.
+
+  Real number and number with exponent part are not supportted by UEFI.
+
+  Caller needs to cleanup the root value by calling JsonValueFree().
+
+  @param[in]   String        The NULL terminated UTF8 encoded string to convert
+
+  @retval      Array JSON value or object JSON value, or NULL when any error occurs.
+
+**/
+EDKII_JSON_VALUE
+EFIAPI
+JsonLoadString (
+  IN   CONST CHAR8*    String
+  );
+
 /**
   Load JSON from a buffer.
 
diff --git a/RedfishPkg/Library/JsonLib/JsonLib.c b/RedfishPkg/Library/JsonLib/JsonLib.c
index 34ff381aee..1762c6f5af 100644
--- a/RedfishPkg/Library/JsonLib/JsonLib.c
+++ b/RedfishPkg/Library/JsonLib/JsonLib.c
@@ -430,10 +430,10 @@ JsonValueGetAsciiString (
   IN    EDKII_JSON_VALUE    Json
   )
 {
-  CHAR8          *AsciiStr;
+  CONST CHAR8    *AsciiStr;
   UINTN          Index;
 
-  AsciiStr = (CHAR8 *)  ((json_t *) Json);
+  AsciiStr = json_string_value ((json_t *) Json);
   if (AsciiStr == NULL) {
     return NULL;
   }
@@ -819,6 +819,32 @@ JsonDumpString (
     return json_dumps((json_t *)JsonValue, Flags);
 }
 
+/**
+  Convert a string to JSON object.
+  The function is used to convert a NULL terminated UTF8 encoded string to a JSON
+  value. Only object and array represented strings can be converted successfully,
+  since they are the only valid root values of a JSON text for UEFI usage.
+
+  Real number and number with exponent part are not supportted by UEFI.
+
+  Caller needs to cleanup the root value by calling JsonValueFree().
+
+  @param[in]   String        The NULL terminated UTF8 encoded string to convert
+
+  @retval      Array JSON value or object JSON value, or NULL when any error occurs.
+
+**/
+EDKII_JSON_VALUE
+EFIAPI
+JsonLoadString (
+  IN    CONST CHAR8*    String
+  )
+{
+  json_error_t    JsonError;
+
+  return (EDKII_JSON_VALUE) json_loads ((const char *)String, 0, &JsonError);
+}
+
 /**
   Load JSON from a buffer.
 
-- 
2.17.1