Add --target-spv option to set target SPIR-V version (google#750)

Adds shaderc_compile_options_set_targte_spirv and associated enums.
Defaults to SPIR-V 1.0.

Passes that down into Glslang so we generate a module with the
specified version of SPIR-V.

Refactor how we map to Glslang target and client, and test that
better.

Setting spirv version is just an override.

Plumb through to glslc

glslc/README.asciidoc

@@ -23,10 +23,12 @@ glslc [-c|-S|-E]
       [-fhlsl-functionality1]
       [-fentry-point=<name>]
       [-fauto-map-locations]
+      [-finvert-y]
       [-flimit=...]
       [-flimit-file <resource-limits-file>]
       [-fshader-stage=...]
       [--target-env=...]
+      [--target-spv=...]
       [-g]
       [-O0|-Os]
       [-Idirectory...]
@@ -134,6 +136,11 @@ multiple files generated. A filename of `-` represents standard output.
 
 === Language and Mode Selection Options
 
+[[option-finverty]]
+==== `-finverty`
+
+Inverts position.Y output in a vertex shader.
+
 [[option-flimit]]
 ==== `-flimit=`
 
@@ -233,6 +240,21 @@ Generated code uses SPIR-V 1.0, except that code compiled for Vulkan 1.1 uses SP
 
 If this option is not specified, a default of `vulkan1.0` is used.
 
+==== `--target-spv=`
+
+`--target-spv=<value>` lets you specify the SPIR-V version to be used by the generated
+module.  The default is to use the highest version of SPIR-V required to be supported
+by the target environment.  For example, the default is SPIR-V 1.0 for Vulkan 1.0, and
+and SPIR-V 1.3 for Vulkan 1.1.
+
+The ``<value>`` can be one of the following:
+
+* `spv1.0`
+* `spv1.1`
+* `spv1.2`
+* `spv1.3`
+* `spv1.4`
+
 ==== `-x`
 
 `-x` lets you specify the language of the input shader files. Valid languages

glslc/src/main.cc

@@ -32,6 +32,7 @@
 #include "libshaderc_util/string_piece.h"
 #include "resource_parse.h"
 #include "shader_stage.h"
+#include "shaderc/env.h"
 #include "shaderc/shaderc.h"
 #include "spirv-tools/libspirv.h"
 
@@ -155,6 +156,14 @@ An input file of - represents standard input.
                         vulkan          # Same as vulkan1.0
                         opengl4.5
                         opengl          # Same as opengl4.5
+  --target-spv=<spirv-version>
+                    Set the SPIR-V version to be used for the generated SPIR-V
+                    module.  The default is the highest version of SPIR-V
+                    required to be supported for the target environment.
+                    For example, default for vulkan1.0 is spv1.0, and
+                    the default for vulkan1.1 is spv1.3.
+                    Values are:
+                        spv1.0, spv1.1, spv1.2, spv1.3, spv1.4
   --version         Display compiler version information.
   -w                Suppresses all warning messages.
   -Werror           Treat all warnings as errors.
@@ -430,6 +439,25 @@ int main(int argc, char** argv) {
         return 1;
       }
       compiler.options().SetTargetEnvironment(target_env, version);
+    } else if (arg.starts_with("--target-spv=")) {
+      shaderc_spirv_version ver = shaderc_spirv_version_1_0;
+      const string_piece ver_str = arg.substr(std::strlen("--target-spv="));
+      if (ver_str == "spv1.0") {
+        ver = shaderc_spirv_version_1_0;
+      } else if (ver_str == "spv1.1") {
+        ver = shaderc_spirv_version_1_1;
+      } else if (ver_str == "spv1.2") {
+        ver = shaderc_spirv_version_1_2;
+      } else if (ver_str == "spv1.3") {
+        ver = shaderc_spirv_version_1_3;
+      } else if (ver_str == "spv1.4") {
+        ver = shaderc_spirv_version_1_4;
+      } else {
+        std::cerr << "glslc: error: invalid value '" << ver_str
+                  << "' in '--target-spv=" << ver_str << "'" << std::endl;
+        return 1;
+      }
+      compiler.options().SetTargetSpirv(ver);
     } else if (arg.starts_with("-mfmt=")) {
       const string_piece binary_output_format =
           arg.substr(std::strlen("-mfmt="));

glslc/test/parameter_tests.py

@@ -160,6 +160,14 @@ class HelpParameters(
                         vulkan          # Same as vulkan1.0
                         opengl4.5
                         opengl          # Same as opengl4.5
+  --target-spv=<spirv-version>
+                    Set the SPIR-V version to be used for the generated SPIR-V
+                    module.  The default is the highest version of SPIR-V
+                    required to be supported for the target environment.
+                    For example, default for vulkan1.0 is spv1.0, and
+                    the default for vulkan1.1 is spv1.3.
+                    Values are:
+                        spv1.0, spv1.1, spv1.2, spv1.3, spv1.4
   --version         Display compiler version information.
   -w                Suppresses all warning messages.
   -Werror           Treat all warnings as errors.

libshaderc/include/shaderc/env.h

@@ -48,6 +48,20 @@ typedef enum {
   shaderc_env_version_webgpu,
 } shaderc_env_version;
 
+// The known versions of SPIR-V.
+typedef enum {
+  // Use the values used for word 1 of a SPIR-V binary:
+  // - bits 24 to 31: zero
+  // - bits 16 to 23: major version number
+  // - bits 8 to 15: minor version number
+  // - bits 0 to 7: zero
+  shaderc_spirv_version_1_0 = (((uint32_t)0x010000)),
+  shaderc_spirv_version_1_1 = (((uint32_t)0x010100)),
+  shaderc_spirv_version_1_2 = (((uint32_t)0x010200)),
+  shaderc_spirv_version_1_3 = (((uint32_t)0x010300)),
+  shaderc_spirv_version_1_4 = (((uint32_t)0x010400))
+} shaderc_spirv_version;
+
 #ifdef __cplusplus
 }
 #endif  // __cplusplus

libshaderc/include/shaderc/shaderc.h

@@ -385,6 +385,14 @@ SHADERC_EXPORT void shaderc_compile_options_set_target_env(
     shaderc_target_env target,
     uint32_t version);
 
+// Sets the target SPIR-V version. The generated module will use this version
+// of SPIR-V.  Each target environment determines what versions of SPIR-V
+// it can consume.  Defaults to the highest version of SPIR-V 1.0 which is
+// required to be supported by the target environment.  E.g. Default to SPIR-V
+// 1.0 for Vulkan 1.0 and SPIR-V 1.3 for Vulkan 1.1.
+SHADERC_EXPORT void shaderc_compile_options_set_target_spirv(
+    shaderc_compile_options_t options, shaderc_spirv_version version);
+
 // Sets the compiler mode to treat all warnings as errors. Note the
 // suppress-warnings mode overrides this option, i.e. if both
 // warning-as-errors and suppress-warnings modes are set, warnings will not

libshaderc/include/shaderc/shaderc.hpp

@@ -246,6 +246,15 @@ class CompileOptions {
     shaderc_compile_options_set_target_env(options_, target, version);
   }
 
+  // Sets the target SPIR-V version.  The generated module will use this version
+  // of SPIR-V.  Each target environment determines what versions of SPIR-V
+  // it can consume.  Defaults to the highest version of SPIR-V 1.0 which is
+  // required to be supported by the target environment.  E.g. Default to SPIR-V
+  // 1.0 for Vulkan 1.0 and SPIR-V 1.3 for Vulkan 1.1.
+  void SetTargetSpirv(shaderc_spirv_version version) {
+    shaderc_compile_options_set_target_spirv(options_, version);
+  }
+
   // Sets the compiler mode to make all warnings into errors. Note the
   // suppress-warnings mode overrides this option, i.e. if both
   // warning-as-errors and suppress-warnings modes are set on, warnings will not

libshaderc/src/shaderc.cc

@@ -477,6 +477,13 @@ void shaderc_compile_options_set_target_env(shaderc_compile_options_t options,
                                  GetCompilerTargetEnvVersion(version));
 }
 
+void shaderc_compile_options_set_target_spirv(shaderc_compile_options_t options,
+                                              shaderc_spirv_version ver) {
+  // We made the values match, so we can get away with a static cast.
+  options->compiler.SetTargetSpirv(
+      static_cast<shaderc_util::Compiler::SpirvVersion>(ver));
+}
+
 void shaderc_compile_options_set_warnings_as_errors(
     shaderc_compile_options_t options) {
   options->compiler.SetWarningsAsErrors();

libshaderc_util/include/libshaderc_util/compiler.h

@@ -121,6 +121,15 @@ class Compiler {
     OpenGL_4_5 = 450,
   };
 
+  // SPIR-V version.
+  enum class SpirvVersion : uint32_t {
+    v1_0 = 0x010000u,
+    v1_1 = 0x010100u,
+    v1_2 = 0x010200u,
+    v1_3 = 0x010300u,
+    v1_4 = 0x010400u,
+  };
+
   enum class OutputType {
     SpirvBinary,  // A binary module, as defined by the SPIR-V specification.
     SpirvAssemblyText,  // Assembly syntax defined by the SPIRV-Tools project.
@@ -222,6 +231,8 @@ class Compiler {
         enabled_opt_passes_(),
         target_env_(TargetEnv::Vulkan),
         target_env_version_(TargetEnvVersion::Default),
+        target_spirv_version_(SpirvVersion::v1_0),
+        target_spirv_version_is_forced_(false),
         source_language_(SourceLanguage::GLSL),
         limits_(kDefaultTBuiltInResource),
         auto_bind_uniforms_(false),
@@ -278,6 +289,12 @@ class Compiler {
   void SetTargetEnv(TargetEnv env,
                     TargetEnvVersion version = TargetEnvVersion::Default);
 
+  // Sets the target version of SPIR-V.  The module will use this version
+  // of SPIR-V.  Defaults to the highest version of SPIR-V required to be
+  // supported by the target environment.  E.g. default to SPIR-V 1.0 for
+  // Vulkan 1.0, and SPIR-V 1.3 for Vulkan 1.1.
+  void SetTargetSpirv(SpirvVersion version);
+
   // Sets the souce language.
   void SetSourceLanguage(SourceLanguage lang);
 
@@ -496,6 +513,11 @@ class Compiler {
   // for those defaults.
   TargetEnvVersion target_env_version_;
 
+  // The SPIR-V version to be used for the generated module.  Defaults to 1.0.
+  SpirvVersion target_spirv_version_;
+  // True if the user explicitly set the target SPIR-V version.
+  bool target_spirv_version_is_forced_;
+
   // The source language.  Defaults to GLSL.
   SourceLanguage source_language_;
 
@@ -589,5 +611,36 @@ inline Compiler::Stage ConvertToStage(EShLanguage stage) {
   return Compiler::Stage::Compute;
 }
 
+// A GlslangClientInfo captures target client version and desired SPIR-V
+// version.
+struct GlslangClientInfo {
+  GlslangClientInfo() {}
+  GlslangClientInfo(const std::string& e, glslang::EShClient c,
+                    glslang::EShTargetClientVersion cv,
+                    glslang::EShTargetLanguage l,
+                    glslang::EShTargetLanguageVersion lv)
+      : error(e),
+        client(c),
+        client_version(cv),
+        target_language(l),
+        target_language_version(lv) {}
+
+  std::string error;  // Empty if ok, otherwise contains the error message.
+  glslang::EShClient client = glslang::EShClientNone;
+  glslang::EShTargetClientVersion client_version;
+  glslang::EShTargetLanguage target_language = glslang::EShTargetSpv;
+  glslang::EShTargetLanguageVersion target_language_version =
+      glslang::EShTargetSpv_1_0;
+};
+
+// Returns the mappings to Glslang client, client version, and SPIR-V version.
+// Also indicates whether the input values were valid.
+GlslangClientInfo GetGlslangClientInfo(
+    const std::string& error_tag,  // Indicates source location, for errors.
+    shaderc_util::Compiler::TargetEnv env,
+    shaderc_util::Compiler::TargetEnvVersion env_version,
+    shaderc_util::Compiler::SpirvVersion spv_version,
+    bool spv_version_is_forced);
+
 }  // namespace shaderc_util
 #endif  // LIBSHADERC_UTIL_INC_COMPILER_H