llvm-project/clang/test/Modules/Inputs/diamond_bottom.h

@import diamond_left;
@import diamond_right;

char bottom(char *x);
Use @import rather than @__experimental_modules_import, since the latter is rather a mess to type. llvm-svn: 169919 2012-12-12 06:11:52 +08:00			`@import diamond_left;`
			`@import diamond_right;`
Introduce support for a simple module import declaration, which loads the named module. The syntax itself is intentionally hideous and will be replaced at some later point with something more palatable. For now, we're focusing on the semantics: - Module imports are handled first by the preprocessor (to get macro definitions) and then the same tokens are also handled by the parser (to get declarations). If both happen (as in normal compilation), the second one is redundant, because we currently have no way to hide macros or declarations when loading a module. Chris gets credit for this mad-but-workable scheme. - The Preprocessor now holds on to a reference to a module loader, which is responsible for loading named modules. CompilerInstance is the only important module loader: it now knows how to create and wire up an AST reader on demand to actually perform the module load. - We search for modules in the include path, using the module name with the suffix ".pcm" (precompiled module) for the file name. This is a temporary hack; we hope to improve the situation in the future. llvm-svn: 138679 2011-08-27 07:56:07 +08:00
Teach ModuleManager::addModule() to check whether a particular module has already been loaded before allocating a new Module structure. If the module has already been loaded (uniquing based on file name), then just return the existing module rather than trying to load it again. This allows us to load a DAG of modules. Introduce a simple test case that forms a diamond-shaped module graph, and illustrates that a source file importing the bottom of the diamond can see declarations in all four of the modules that make up the diamond. Note that this version moves the file-opening logic into the module manager, rather than splitting it between the module manager and the AST reader. More importantly, it properly handles the weird-but-possibly-useful case of loading an AST file from "-". llvm-svn: 138030 2011-08-19 10:29:29 +08:00			`char bottom(char *x);`