Improve ResourceLimits interface to be more forward compatible

New interface allows users to generate ResourceLimits for interface so
that additions to TBuiltInResource do not break the ABI.

Users should use the glslang-default-resource-limits library and the
Public/ResourceLimits.h header. Similar changes have been made to the
C interface. Use Public/resource_limits_c.h.

Fixes #2822

BUILD.bazel

@@ -210,7 +210,7 @@ cc_library(
 cc_library(
     name = "glslang-default-resource-limits",
     srcs = ["StandAlone/ResourceLimits.cpp"],
-    hdrs = ["StandAlone/ResourceLimits.h"],
+    hdrs = ["glslang/Public/ResourceLimits.h"],
     copts = COMMON_COPTS,
     linkstatic = 1,
     deps = [":glslang"],

StandAlone/ResourceLimits.cpp

@@ -37,9 +37,9 @@
 #include <sstream>
 #include <cctype>
 
-#include "ResourceLimits.h"
+#include "glslang/Public/ResourceLimits.h"
 
-namespace glslang {
+TBuiltInResource Resources;
 
 const TBuiltInResource DefaultTBuiltInResource = {
     /* .MaxLights = */ 32,
@@ -529,4 +529,12 @@ void DecodeResourceLimits(TBuiltInResource* resources, char* config)
     }
 }
 
-}  // end namespace glslang
+TBuiltInResource* GetResources()
+{
+   return &Resources;
+}
+
+const TBuiltInResource* GetDefaultResources()
+{
+    return &DefaultTBuiltInResource;
+}

StandAlone/StandAlone.cpp

@@ -41,7 +41,7 @@
 #define _CRT_SECURE_NO_WARNINGS
 #endif
 
-#include "ResourceLimits.h"
+#include "glslang/Public/ResourceLimits.h"
 #include "Worklist.h"
 #include "DirStackFileIncluder.h"
 #include "./../glslang/Include/ShHandle.h"
@@ -149,7 +149,6 @@ bool LinkFailed = false;
 // array of unique places to leave the shader names and infologs for the asynchronous compiles
 std::vector<std::unique_ptr<glslang::TWorkItem>> WorkItems;
 
-TBuiltInResource Resources;
 std::string ConfigFile;
 
 //
@@ -158,11 +157,11 @@ std::string ConfigFile;
 void ProcessConfigFile()
 {
     if (ConfigFile.size() == 0)
-        Resources = glslang::DefaultTBuiltInResource;
+        *GetResources() = *GetDefaultResources();
 #ifndef GLSLANG_WEB
     else {
         char* configString = ReadFileData(ConfigFile.c_str());
-        glslang::DecodeResourceLimits(&Resources,  configString);
+        DecodeResourceLimits(GetResources(),  configString);
         FreeFileData(configString);
     }
 #endif
@@ -1417,7 +1416,7 @@ void CompileAndLinkShaderUnits(std::vector<ShaderCompUnit> compUnits)
 #ifndef GLSLANG_WEB
         if (Options & EOptionOutputPreprocessed) {
             std::string str;
-            if (shader->preprocess(&Resources, defaultVersion, ENoProfile, false, false, messages, &str, includer)) {
+            if (shader->preprocess(GetResources(), defaultVersion, ENoProfile, false, false, messages, &str, includer)) {
                 PutsIfNonEmpty(str.c_str());
             } else {
                 CompileFailed = true;
@@ -1428,7 +1427,7 @@ void CompileAndLinkShaderUnits(std::vector<ShaderCompUnit> compUnits)
         }
 #endif
 
-        if (! shader->parse(&Resources, defaultVersion, false, messages, includer))
+        if (! shader->parse(GetResources(), defaultVersion, false, messages, includer))
             CompileFailed = true;
 
         program.addShader(shader);
@@ -1612,7 +1611,7 @@ int singleMain()
 
 #ifndef GLSLANG_WEB
     if (Options & EOptionDumpConfig) {
-        printf("%s", glslang::GetDefaultTBuiltInResourceString().c_str());
+        printf("%s", GetDefaultTBuiltInResourceString().c_str());
         if (workList.empty())
             return ESuccess;
     }
@@ -1838,7 +1837,7 @@ void CompileFile(const char* fileName, ShHandle compiler)
     for (int i = 0; i < ((Options & EOptionMemoryLeakMode) ? 100 : 1); ++i) {
         for (int j = 0; j < ((Options & EOptionMemoryLeakMode) ? 100 : 1); ++j) {
             // ret = ShCompile(compiler, shaderStrings, NumShaderStrings, lengths, EShOptNone, &Resources, Options, (Options & EOptionDefaultDesktop) ? 110 : 100, false, messages);
-            ret = ShCompile(compiler, &shaderString, 1, nullptr, EShOptNone, &Resources, Options, (Options & EOptionDefaultDesktop) ? 110 : 100, false, messages);
+            ret = ShCompile(compiler, &shaderString, 1, nullptr, EShOptNone, GetResources(), Options, (Options & EOptionDefaultDesktop) ? 110 : 100, false, messages);
             // const char* multi[12] = { "# ve", "rsion", " 300 e", "s", "\n#err",
             //                         "or should be l", "ine 1", "string 5\n", "float glo", "bal",
             //                         ";\n#error should be line 2\n void main() {", "global = 2.3;}" };

StandAlone/resource_limits_c.cpp

@@ -26,15 +26,20 @@ OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
 OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 **/
 
-#include "resource_limits_c.h"
-#include "ResourceLimits.h"
+#include "glslang/Public/resource_limits_c.h"
+#include "glslang/Public/ResourceLimits.h"
 #include <stdlib.h>
 #include <string.h>
 #include <string>
 
+glslang_resource_t* glslang_resource(void)
+{
+    return reinterpret_cast<glslang_resource_t*>(GetResources());
+}
+
 const glslang_resource_t* glslang_default_resource(void)
 {
-    return reinterpret_cast<const glslang_resource_t*>(&glslang::DefaultTBuiltInResource);
+    return reinterpret_cast<const glslang_resource_t*>(GetDefaultResources());
 }
 
 #if defined(__clang__) || defined(__GNUC__)
@@ -47,7 +52,7 @@ const glslang_resource_t* glslang_default_resource(void)
 
 const char* glslang_default_resource_string()
 {
-    std::string cpp_str = glslang::GetDefaultTBuiltInResourceString();
+    std::string cpp_str = GetDefaultTBuiltInResourceString();
     char* c_str = (char*)malloc(cpp_str.length() + 1);
     strcpy(c_str, cpp_str.c_str());
     return c_str;
@@ -61,5 +66,5 @@ const char* glslang_default_resource_string()
 
 void glslang_decode_resource_limits(glslang_resource_t* resources, char* config)
 {
-    glslang::DecodeResourceLimits(reinterpret_cast<TBuiltInResource*>(resources), config);
+    DecodeResourceLimits(reinterpret_cast<TBuiltInResource*>(resources), config);
 }

glslang/CInterface/glslang_c_interface.cpp

@@ -33,7 +33,7 @@ OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 #include "glslang/Include/glslang_c_interface.h"
 
 #include "StandAlone/DirStackFileIncluder.h"
-#include "StandAlone/ResourceLimits.h"
+#include "glslang/Public/ResourceLimits.h"
 #include "glslang/Include/ShHandle.h"
 
 #include "glslang/Include/ResourceLimits.h"

glslang/CMakeLists.txt

@@ -149,6 +149,8 @@ set(GLSLANG_SOURCES
 
 set(GLSLANG_HEADERS
     Public/ShaderLang.h
+    Public/ResourceLimits.h
+    Public/resource_limits_c.h
     Include/arrays.h
     Include/BaseTypes.h
     Include/Common.h

glslang/Public/ResourceLimits.h

@@ -37,14 +37,16 @@
 
 #include <string>
 
-#include "../glslang/Include/ResourceLimits.h"
+#include "../Include/ResourceLimits.h"
 
-namespace glslang {
+// Return pointer to user-writable Resource to pass through API in
+// future-proof way.
+extern TBuiltInResource* GetResources();
 
 // These are the default resources for TBuiltInResources, used for both
 //  - parsing this string for the case where the user didn't supply one,
 //  - dumping out a template for user construction of a config file.
-extern const TBuiltInResource DefaultTBuiltInResource;
+extern const TBuiltInResource* GetDefaultResources();
 
 // Returns the DefaultTBuiltInResource as a human-readable string.
 std::string GetDefaultTBuiltInResourceString();
@@ -52,6 +54,4 @@ std::string GetDefaultTBuiltInResourceString();
 // Decodes the resource limits from |config| to |resources|.
 void DecodeResourceLimits(TBuiltInResource* resources, char* config);
 
-}  // end namespace glslang
-
 #endif  // _STAND_ALONE_RESOURCE_LIMITS_INCLUDED_

glslang/Public/resource_limits_c.h

@@ -35,6 +35,9 @@ OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 extern "C" {
 #endif
 
+// Returns a struct that can be use to create custom resource values.
+glslang_resource_t* glslang_resource(void);
+
 // These are the default resources for TBuiltInResources, used for both
 //  - parsing this string for the case where the user didn't supply one,
 //  - dumping out a template for user construction of a config file.

gtests/BuiltInResource.FromFile.cpp

@@ -36,7 +36,7 @@
 
 #include <gtest/gtest.h>
 
-#include "StandAlone/ResourceLimits.h"
+#include "glslang/Public/ResourceLimits.h"
 #include "TestFixture.h"
 
 namespace glslangtest {
@@ -49,7 +49,7 @@ TEST_F(DefaultResourceTest, FromFile)
     const std::string path = GlobalTestSettings.testRoot + "/baseResults/test.conf";
     std::string expectedConfig;
     tryLoadFile(path, "expected resource limit", &expectedConfig);
-    const std::string realConfig = glslang::GetDefaultTBuiltInResourceString();
+    const std::string realConfig = GetDefaultTBuiltInResourceString();
     ASSERT_EQ(expectedConfig, realConfig);
 }
 

gtests/Config.FromFile.cpp

@@ -32,7 +32,7 @@
 // ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
 // POSSIBILITY OF SUCH DAMAGE.
 
-#include "StandAlone/ResourceLimits.h"
+#include "glslang/Public/ResourceLimits.h"
 #include "TestFixture.h"
 
 namespace glslangtest {
@@ -65,7 +65,7 @@ TEST_P(ConfigTest, FromFile)
         char* configChars = new char[len + 1];
         memcpy(configChars, configContents.data(), len);
         configChars[len] = 0;
-        glslang::DecodeResourceLimits(&resources, configChars);
+        DecodeResourceLimits(&resources, configChars);
         delete[] configChars;
     }
 

gtests/TestFixture.h

@@ -48,7 +48,7 @@
 #include "SPIRV/disassemble.h"
 #include "SPIRV/doc.h"
 #include "SPIRV/SPVRemapper.h"
-#include "StandAlone/ResourceLimits.h"
+#include "glslang/Public/ResourceLimits.h"
 #include "glslang/Public/ShaderLang.h"
 
 #include "Initializer.h"
@@ -199,7 +199,7 @@ public:
             shader->setStringsWithLengths(&shaderStrings, &shaderLengths, 1);
         if (!entryPointName.empty()) shader->setEntryPoint(entryPointName.c_str());
         return shader->parse(
-                (resources ? resources : &glslang::DefaultTBuiltInResource),
+                (resources ? resources : GetDefaultResources()),
                 defaultVersion, isForwardCompatible, controls);
     }
 
@@ -640,7 +640,7 @@ public:
         std::string ppShader;
         glslang::TShader::ForbidIncluder includer;
         const bool success = shader.preprocess(
-            &glslang::DefaultTBuiltInResource, defaultVersion, defaultProfile,
+            GetDefaultResources(), defaultVersion, defaultProfile,
             forceVersionProfile, isForwardCompatible, (EShMessages)(EShMsgOnlyPreprocessor | EShMsgCascadingErrors),
             &ppShader, includer);